Cherryh's Chanur station docking geeky question
Rimrunner
[How does it work?]
I don't know; the only sketches I've ever seen were of the carriers from
"Downbelow Station". I'm guessing that the Chanur ships are similar in
design, but that's only a guess.
You could try e-mailing her at web...@cherryh.com and asking. She hasn't
updated her website lately, though, so she's probably really busy.
Rimrunner
http://www.cherryh.com, pretty neat
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RobLane
I'm reading the Chanur series for the nth time and as usual I'm sketching the
ships and stations. It doesn't work.
They dock nose in.
The access ramps, cargo and personnel, go up from the "promenade".
The docking gantries are opposite a row of shops.
The stations are spinning toruses.
Cargo goes "belowdecks".
Docked, they take the lift down to the access ramp.
The _Pride_ has a frame and a spine with access tube and airlock.
If the ships latch onto the side of the torus (Q) about midships, it might
work. The main corridor becomes a deep pit.
Has anyone seen a sketch of what CJ thinks it should look like? The story is
fine, I just skip over the physical inconsistencies. Let's not mention Urtur,
which brings images of a raft on the Mississipi, not the high vacuum of even a
dusty star system. "Clunk?" No, nasty hole in the ship...
David Given
In article <6mf4iu$bfj$1...@halcyon.com>, Rimrunner <rim...@halcyon.com> wrote:
>[How does it work?]
>
>I don't know; the only sketches I've ever seen were of the carriers from
>"Downbelow Station". I'm guessing that the Chanur ships are similar in
>design, but that's only a guess.
I've thought about this, too; it basicly doesn't work.
I rationalise it as follows: there are basically two kinds of ships in the
Cherryh universe. High-tech, small constant-acceleration ships (like the
_Pride_), and lower tech, muich larger carriers, with rotating rings (like
the _Norway_). CA ships dock on the rim of a station, carriers at the
centre, in free fall.
When docked, CA ships are arranged vertically, hanging from their noses.
Several gantries then extend from the station to the side of the ship: the
personnel access, the much larger cargo access, and several feeder lines.
Of course, the fact that the books disagree with this is entirely
irrelevant...
C.J. Cherryh persistently has her ships docking at station rims, even when
they're huge carriers with rotating rings. This just doesn't work! You
have to lock down your ring for docking, which means you lose access to
75% of it, and most of the other 25% is uncomfortably tilted. The station
itself will be rendered dangerously off-balance by the huge mass of a
carrier, and the grapples to hold such a ship to the station will be
*phenomenal*.
The other factor is time. My impression is that CA ships like the _Pride_
spend about two weeks in station, unloading and loading again, then a week
in space (ship time). It makes no sense whatsoever to have most of the
ship unusable most of the time due to locking the ring. It only makes
sense if the time spent in space far outweighs the time in station.
And I'm not even going to *start* on the strange fact that everyone's
docking adaptors appear to be compatible, regardless of faction or even
species (*humans* can dock at Compact stations...)
</RANT>
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aRJay
In an article using recycled electrons wrote :-
>In article <6mf4iu$bfj$1...@halcyon.com>, Rimrunner <rim...@halcyon.com> wrote:
>>[How does it work?]
>>
>>I don't know; the only sketches I've ever seen were of the carriers from
>>"Downbelow Station". I'm guessing that the Chanur ships are similar in
>>design, but that's only a guess.
>
>I've thought about this, too; it basicly doesn't work.
>
>I rationalise it as follows: there are basically two kinds of ships in the
>Cherryh universe. High-tech, small constant-acceleration ships (like the
>_Pride_), and lower tech, muich larger carriers, with rotating rings (like
>the _Norway_). CA ships dock on the rim of a station, carriers at the
>centre, in free fall.
>
Pride might well be higher tech (and probably is) but I don't remember
any indications that they were using ships acceleration to produce
gravity, all the descriptions of the interior match a rotational layout.
>When docked, CA ships are arranged vertically, hanging from their noses.
>Several gantries then extend from the station to the side of the ship: the
>personnel access, the much larger cargo access, and several feeder lines.
>
>Of course, the fact that the books disagree with this is entirely
>irrelevant...
>
Not entirely.
>C.J. Cherryh persistently has her ships docking at station rims, even when
>they're huge carriers with rotating rings. This just doesn't work! You
>have to lock down your ring for docking, which means you lose access to
>75% of it, and most of the other 25% is uncomfortably tilted. The station
>itself will be rendered dangerously off-balance by the huge mass of a
>carrier, and the grapples to hold such a ship to the station will be
>*phenomenal*.
>
The load on the station isn't much less no matter what you do to the
orientation of the ship, in fact hanging it vertically from the rim is
going to make things worse isn't it?
>The other factor is time. My impression is that CA ships like the _Pride_
>spend about two weeks in station, unloading and loading again, then a week
>in space (ship time). It makes no sense whatsoever to have most of the
>ship unusable most of the time due to locking the ring. It only makes
>sense if the time spent in space far outweighs the time in station.
>
>And I'm not even going to *start* on the strange fact that everyone's
>docking adaptors appear to be compatible, regardless of faction or even
>species (*humans* can dock at Compact stations...)
>
></RANT>
>
>
I'm blanking on this when do Human built ships actually dock at Compact
stations.
--
aRJay
Del Cotter
On Sat, 20 Jun 1998, in rec.arts.sf.written
dg@?.? wrote
>C.J. Cherryh persistently has her ships docking at station rims, even when
>they're huge carriers with rotating rings. This just doesn't work! You
>have to lock down your ring for docking, which means you lose access to
>75% of it, and most of the other 25% is uncomfortably tilted. The station
>itself will be rendered dangerously off-balance by the huge mass of a
>carrier, and the grapples to hold such a ship to the station will be
>*phenomenal*.
*All* of which points are explicitly made in the books. I recommend
them.
--
Del Cotter d...@branta.demon.co.uk
The Alien Design Bibliography
http://www.branta.demon.co.uk/alien-design/
Graydon
In article <898355886.28968.0...@news.demon.co.uk>,
David Given <dg@> wrote:
>In article <6mf4iu$bfj$1...@halcyon.com>, Rimrunner <rim...@halcyon.com> wrote:
>>[How does it work?]
>>
>>I don't know; the only sketches I've ever seen were of the carriers from
>>"Downbelow Station". I'm guessing that the Chanur ships are similar in
>>design, but that's only a guess.
>
>I've thought about this, too; it basicly doesn't work.
>
>I rationalise it as follows: there are basically two kinds of ships in the
>Cherryh universe. High-tech, small constant-acceleration ships (like the
>_Pride_), and lower tech, muich larger carriers, with rotating rings (like
>the _Norway_). CA ships dock on the rim of a station, carriers at the
>centre, in free fall.
The carriers are _higher_ tech than what the hani have general access to;
they can do things like jump short that come as big surprises to the hani,
although the mahendosat (damn if I can remember where the apostrophe
goes!) can do that and know about it. Plus the rider ship drives.
A carrier is, like everything else, an engine unit with vanes and a spine;
in the case of the carriers, with their huge crews, the usual habitation
ring with centrifugal gravity becomes a cylinder the whole length of the
spine; over that cylinder goes the non-rotating frame the riders dock to.
Something like :Pride: is the same, only a small habitation ring and a big
set of cargo holds down the spine. (inside the cylinder on the carriers
is presuambly weapons, supplies, and fabrication facilities.)
Everything docks nose-first.
>C.J. Cherryh persistently has her ships docking at station rims, even when
>they're huge carriers with rotating rings. This just doesn't work! You
>have to lock down your ring for docking, which means you lose access to
>75% of it, and most of the other 25% is uncomfortably tilted. The station
>itself will be rendered dangerously off-balance by the huge mass of a
>carrier, and the grapples to hold such a ship to the station will be
>*phenomenal*.
Grapples are pretty easy, really; you only need hard contact between
structural members at equivalent strength. Unbalance gets mentioned in
:Downbelow Station:; docking a carrier is a big deal.
>The other factor is time. My impression is that CA ships like the _Pride_
>spend about two weeks in station, unloading and loading again, then a week
>in space (ship time). It makes no sense whatsoever to have most of the
>ship unusable most of the time due to locking the ring. It only makes
>sense if the time spent in space far outweighs the time in station.
We only seem to see PRIDE OF CHANUR when they're in a tearing hurry.
There isn't any other solution; if you want spin gravity, you can't use it
when docked without twisting yourself off the dock. You probably need it
in general while under weigh, and they certainly needed it in the old
sublight ships.
docking adaptors can be clever 'smart' technology, you relaize, or there
is the theory that the compact is a (human descended) proto-Qhal artifact.
--
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--> mail to Graydon | is certain that there are vastly more ways of being
dead." - Richard Dawkins, :The Blind Watchmaker:
J.
gra...@gooroos.com (Graydon) wrote:
>docking adaptors can be clever 'smart' technology, you relaize, or there
>is the theory that the compact is a (human descended) proto-Qhal artifact.
Okay, you hooked me. What does this theory state, beyond what you've
already posted?
I don't recall seeing this discussed on the cherryhlist, but then, I
miss a lot of things...
J.
(my sig was so clever that it actually escaped)
Graydon
Compact Spoilers - meaning don't read this if you haven't read CJ
Cherryh's Chanur books - :The Pride of Chanur:, :Chanur's Venture:, :The
Kif Strike Back:, :Chanur's Homecoming:, and :Chanur's Legacy:.
If you don't know what Qhal are I might be inadvertently spoiling some
Morgaine novels, same author.
If you haven't read :Tripoint: there are some spoilers for that, too.
In article <358d953c...@news.ptd.net>,
J. <ja...@postoffice.ptd.net> wrote:
>gra...@gooroos.com (Graydon) wrote:
>
>>docking adaptors can be clever 'smart' technology, you relaize, or there
>>is the theory that the compact is a (human descended) proto-Qhal artifact.
>
>Okay, you hooked me. What does this theory state, beyond what you've
>already posted?
Well, Compact Space is ... peculiar. It's right near Earth; there are
five oxygen breathing intelligent species right close to each other, all
of whom have very similar biochemistries - mahendo'sat medical machinery
works on hani, and there is cross-species trade in luxury foodstuffs - and
which apparently all have analogous species in Terran fauna - the hani are
lions, the mahendo'sat are some sort of primate, probably chimps, the ssto
are (argueably) octopi, and the kif are African Wild Dogs. (or, to take
the other favourite theory, weasels forced to be social.)
It looks kinda like someone went and +put+ them there; the candidate for
that being the Fleet colony that they were headed off to in Corinthian at
the end of :Tripoint:, since the awake-in-jump Fleet Navigators seem to be
obvious candidates for the ancestors of the Qhal, who might have had odd
senses of humour once they started mucking about with time travel.
How one explains the t'ca and the knnn I have no idea; I suspect that the
knnn may have wandered by on their own.
Mark A Mandel
Graydon (gra...@gooroos.com) wrote:
: The carriers are _higher_ tech than what the hani have general access to;
: they can do things like jump short that come as big surprises to the hani,
: although the mahendosat (damn if I can remember where the apostrophe
: goes!) can do that and know about it. Plus the rider ship drives.
After the "o": mahendo'sat.
: docking adaptors can be clever 'smart' technology, you relaize, or there
: is the theory that the compact is a (human descended) proto-Qhal artifact.
Proto-WHO?! What in Cherryh's universe is that? (I haven't read it all;
this is a question, not a challenge.)
-- Mark A. Mandel
--
If you're reading this in a newsgroup: to reply by mail,
remove the obvious spam-blocker from my edress.
Dan Goodman
In article <Euxn3...@world.std.com>,
Mark A Mandel <mam-DIE-S...@world.std.com> wrote:
>Graydon (gra...@gooroos.com) wrote:
>
>: The carriers are _higher_ tech than what the hani have general access to;
>: they can do things like jump short that come as big surprises to the hani,
>: although the mahendosat (damn if I can remember where the apostrophe
>: goes!) can do that and know about it. Plus the rider ship drives.
>
>After the "o": mahendo'sat.
>
>: docking adaptors can be clever 'smart' technology, you relaize, or there
>: is the theory that the compact is a (human descended) proto-Qhal artifact.
>
>Proto-WHO?! What in Cherryh's universe is that? (I haven't read it all;
>this is a question, not a challenge.)
A _different_ universe, as far as I know.
The Qhal were (are? will be?) the second known species to use time gates
(which may also transport through space). Their safeguards against
improper use were inadequate; their civilization, and most of the Qhal,
died of time paradoxes. The species who left a time gate on a world in
the original Qhal solar system presumably suffered the same fate.
Humans, displaying a certain amount of intelligence for once, have sent
people out to close down the time gates. And that's where the Morgaine
books begin.... There's also a short story in the collection _Visible
Light_, which has some information I don't think is in the books.
--
Dan Goodman
dsg...@visi.com
http://www.visi.com/~dsgood/index.html
Whatever you wish for me, may you have twice as much.
Graydon
In article <Euxn3...@world.std.com>,
Mark A Mandel <mam-DIE-S...@world.std.com> wrote:
>Graydon (gra...@gooroos.com) wrote:
>: The carriers are _higher_ tech than what the hani have general access to;
>: they can do things like jump short that come as big surprises to the hani,
>: although the mahendosat (damn if I can remember where the apostrophe
>: goes!) can do that and know about it. Plus the rider ship drives.
>
>After the "o": mahendo'sat.
Thanks. I keep wanting to put it between the ma and the hen.
>: docking adaptors can be clever 'smart' technology, you relaize, or there
>: is the theory that the compact is a (human descended) proto-Qhal artifact.
>
>Proto-WHO?! What in Cherryh's universe is that? (I haven't read it all;
>this is a question, not a challenge.)
The ghoulies and ghosties and things as go bump in the night from the
Morgaine books, the titles of which I am blanking on utterly.
Georyn
>If you don't know what Qhal are I might be inadvertently spoiling some
>Morgaine novels, same author.
How so? The "qhal" are mentioned right at the beginning of "Gate Of
Ivrel". I could think of other ways you could spoil it for others, but I'm too
much of a gentleman to post spoilers to a newsgroup. ;-{)>
MIKE (a.k.a. "Progbear")
NOTE: The above screen name is for newsgroup postings only. For E-mail, send
to: Prog...@aol.com. Do NOT hit reply!
"Parece cosa de maligno. Los pianos no estallan por casualidad." --Gabriel
Garcia Marquez
N.P.:"Trash Man"- T h i r s t y M o o n /
Y o u ' l l N e v e r C o m e B a c k
Georyn
>The ghoulies and ghosties and things as go bump in the night from the
>Morgaine books, the titles of which I am blanking on utterly.
"Gate Of Ivrel", "Well Of Shiuan" and "Fires of Azeroth". Can you tell I'm
reading this series now, so have the book titles handy in my mental rolodex?
;-{)> The first one is kind of slow moving, but rewarding in the end, if only
because you get to read the other two, which are excellent (still a couple of
chapters from the end of "Fires of Azeroth", which I think may be the best of
the three).
Oh, there's a fourth book in the series, "Exile's Gate", but I'm always
wary of sequels written fifteen years after the original trilogy.
David Given
In article <KstEnDAW...@escore.demon.co.uk>,
aRJay <aR...@escore.demon.co.uk> wrote:
[...]
>The load on the station isn't much less no matter what you do to the
>orientation of the ship, in fact hanging it vertically from the rim is
>going to make things worse isn't it?
Except CA ships are much smaller than carriers. (BTW, I forgot to mention
that my CA ships don't have rings --- they don't need them, they use their
engines instead).
[...]
>>And I'm not even going to *start* on the strange fact that everyone's
>>docking adaptors appear to be compatible, regardless of faction or even
>>species (*humans* can dock at Compact stations...)
>>
>I'm blanking on this when do Human built ships actually dock at Compact
>stations.
[fx: stares abstractedly off into the distance, whistling]
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David Given
In article <6mjgek$5...@excalibur.gooroos.com>,
Graydon <goo...@interlog.com> wrote:
[...]
>The carriers are _higher_ tech than what the hani have general access to;
>they can do things like jump short that come as big surprises to the hani,
>although the mahendosat (damn if I can remember where the apostrophe
>goes!) can do that and know about it. Plus the rider ship drives.
If the carriers are higher tech than Compact CA ships, how come they have
to spend months coasting from jump point to jump point? Compact ships just
rev the drive up to 1g and accelerate all the way.
Humans can short-jump, yes, but that's not so much as better hyperspace
technology as a different point of view. *Noone* really understands
hyperspace tech.
And I don't recall hearing anywhere about any kind of special drive the
riders have. My impression was that they had very limited dV capability
--- the carriers fire the riders in a particular direction, and then go
and pick them up again later. The riders don't have nearly enough dV to
kill .3c of velocity.
[...]
>Grapples are pretty easy, really; you only need hard contact between
>structural members at equivalent strength. Unbalance gets mentioned in
>:Downbelow Station:; docking a carrier is a big deal.
Been a while since I read that one. (Cherryh has a habit of sneaking in
correct details and numbers when you aren't looking. It's just this
business about docking ships that irritates me.)
[...]
>We only seem to see PRIDE OF CHANUR when they're in a tearing hurry.
The _Pride_ is a trader. Time == money. They're *always* in a tearing
hurry.
[...]
Jerry Cullingford
>>C.J. Cherryh persistently has her ships docking at station rims, even when
>>they're huge carriers with rotating rings. This just doesn't work! You
>>have to lock down your ring for docking, which means you lose access to
>>75% of it, and most of the other 25% is uncomfortably tilted. The station
>>itself will be rendered dangerously off-balance by the huge mass of a
>>carrier, and the grapples to hold such a ship to the station will be
>>*phenomenal*.
The bit I could never figure out is the fuel economy - not being able to get
at parts of the ship is inconvenient, but how do the ships ever manage to
dock? docking on-axis would use virtually no propellant, but docking at the
rim requires incoming ships to accelerate at 1g (or whatever the rim
pseudogravity is - or more, if you want to avoid funky station-relative
spirals. And that's 1g at right angles to the ships spin axis....
--
_|_ Jerry Cullingford jerry.cu...@ffei.co.uk (Work)
/ | Fujifilm Electronic Imaging j...@selune.demon.co.uk (Home)
\_|_ Hemel Hempstead, UK PGP key at www.selune.demon.co.uk
\__/ (Speaking only for myself and not the company unless otherwise stated)
Michael S. Schiffer
In article <6mltdk$b...@suneng2.hh.ffei.co.uk>,
Jerry Cullingford <j...@hh.ffei.co.uk> wrote:
>In article <KstEnDAW...@escore.demon.co.uk>,
>aRJay <aR...@escore.demon.co.uk> wrote:
>>>In article <6mf4iu$bfj$1...@halcyon.com>, Rimrunner <rim...@halcyon.com> wrote:
>>>C.J. Cherryh persistently has her ships docking at station rims, even when
>>>they're huge carriers with rotating rings. This just doesn't work! You
>>>have to lock down your ring for docking, which means you lose access to
>>>75% of it, and most of the other 25% is uncomfortably tilted. The station
>>>itself will be rendered dangerously off-balance by the huge mass of a
>>>carrier, and the grapples to hold such a ship to the station will be
>>>*phenomenal*.
>The bit I could never figure out is the fuel economy - not being able to get
>at parts of the ship is inconvenient, but how do the ships ever manage to
>dock? docking on-axis would use virtually no propellant, but docking at the
>rim requires incoming ships to accelerate at 1g (or whatever the rim
>pseudogravity is - or more, if you want to avoid funky station-relative
>spirals. And that's 1g at right angles to the ships spin axis....
Can't you just plot a course that has you going at the
speed of the station's rim and at a tangent to it (within the plane of
rotation, of course)? Admittedly, the docking clamps need to be
pretty fast, but I'd think you could set them up to be automatic. (Of
course, I don't remember the diameter of the stations, which means I
don't know how fast the clamps would have to work.)
I'd strap down during that maneuver, though, since it
effectively means instantaneously accelerating from zero-g to 1 g (you
stop spinning first, or you'll get something that won't be at all
fun for the people _or_ the bearings).
Mike
--
Michael S. Schiffer, LHN,FCS GURPS Alternate Earths is being reprinted!
Co-author: GURPS Alt. Earths Check out Steve Jackson Games' page at
ms...@tezcat.com <http://www.sjgames.com/gurps/books/AltEarths/>
ms...@midway.uchicago.edu for details.
Jo Walton
In article <6mk865$a...@excalibur.gooroos.com>
goo...@interlog.com "Graydon" writes:
This post is boring if you haven't read the Chanur books and possibly
confusing if you don't know what Qhal are, but doesn't contain any
actual plot spoilers for Chanur books or Morgaine books. However
WARE SPOILERS FOR :TRIPOINT:.
This post will mostly be of interest to Cherryh universe nuts.
Theories in this post are supported by the evidence but are only
theories without other support.
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> In article <358d953c...@news.ptd.net>,
> J. <ja...@postoffice.ptd.net> wrote:
> >gra...@gooroos.com (Graydon) wrote:
> >
> >>docking adaptors can be clever 'smart' technology, you relaize, or there
> >>is the theory that the compact is a (human descended) proto-Qhal artifact.
> >
> >Okay, you hooked me. What does this theory state, beyond what you've
> >already posted?
>
> Well, Compact Space is ... peculiar. It's right near Earth; there are
> five oxygen breathing intelligent species right close to each other, all
> of whom have very similar biochemistries - mahendo'sat medical machinery
> works on hani, and there is cross-species trade in luxury foodstuffs - and
> which apparently all have analogous species in Terran fauna - the hani are
> lions, the mahendo'sat are some sort of primate, probably chimps, the ssto
> are (argueably) octopi, and the kif are African Wild Dogs. (or, to take
> the other favourite theory, weasels forced to be social.)
>
> It looks kinda like someone went and +put+ them there; the candidate for
> that being the Fleet colony that they were headed off to in Corinthian at
> the end of :Tripoint:, since the awake-in-jump Fleet Navigators seem to be
> obvious candidates for the ancestors of the Qhal, who might have had odd
> senses of humour once they started mucking about with time travel.
To expand on that slightly, this is the "get U/A space out of the corner
Cherryh may have painted herself into" theory.
The Qhal have gates that go from one world to another. The Morgaine
books are set in the far future of the same universe as the U/A books.
They _look_ very much like Capella in :Tripoint:. They also act a lot
like her. She's also older than she looks, and she has that _weird_
Jump skill. She's going off to a Fleet colony where people like her
are valuable, rare, and likely to both inbreed and concentrate on
developing the tech around that weird skill.
We don't know what happens to that Fleet colony post-:Tripoint:, but
there isn't anything about them in the written-earlier set-later
books (Mri books, :Serpent's Reach:, :Angel With The Sword: etc.) so
the assumption is that they are so far off they don't interact with
the rest of humanity once they get going. There's not all that many
of them, they're colonising a planet - hence inbreeding and speciation
and possibly becoming Qhal.
We _know_ the Qhal used the gates for something not unlike time travel.
We know they took humans and flora and fauna from Earth at different
periods and scattered them about. (:Gate of Ivriel: implies this
strongly, and the Cherryh-authored comic book version states this
explicitly on the first page.)
Therefore they could have taken those animals and uplifted them to
some degree and cheerfully put them all down on hospitable planets
very close together and not too far from Earth, and not too far from
the knnn to see what would happen.
> How one explains the t'ca and the knnn I have no idea; I suspect that the
> knnn may have wandered by on their own.
The chi, too. I think they were there, or maybe the t'ca were there
and that's what they got put near, the t'ca uplifted the chi and the
knnn could have come from _anywhere_.
--
Jo - - I kissed a kif at Kefk - - J...@bluejo.demon.co.uk
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
http://www.bluejo.demon.co.uk - Blood of Kings Poetry; rasfw FAQ;
Reviews; Interstichia; Momentum - a paying market for real poetry.
Graydon
In article <898514766.15631.0...@news.demon.co.uk>,
David Given <dg@> wrote:
>In article <6mjgek$5...@excalibur.gooroos.com>,
>Graydon <goo...@interlog.com> wrote:
>[...]
>>The carriers are _higher_ tech than what the hani have general access to;
>>they can do things like jump short that come as big surprises to the hani,
>>although the mahendosat (damn if I can remember where the apostrophe
>>goes!) can do that and know about it. Plus the rider ship drives.
>
>If the carriers are higher tech than Compact CA ships, how come they have
>to spend months coasting from jump point to jump point? Compact ships just
>rev the drive up to 1g and accelerate all the way.
Carriers can (and do) pull ten or eleven G, and are quite capable of
sustaining 1 G. But they're _warships_, not merchants, and they use a lot
of lurk-and-wait tactics, which is mostly when we see them, we don't see
them in plain transit. So they don't _have_ to spend months coasting in a
gravity well to jump out of it, they just do, the better to snaffle other
people using that gravity well as a way station.
>Humans can short-jump, yes, but that's not so much as better hyperspace
>technology as a different point of view. *Noone* really understands
>hyperspace tech.
Knn. Bok probably did; there are probably some human physicists who do.
>And I don't recall hearing anywhere about any kind of special drive the
>riders have. My impression was that they had very limited dV capability
Have you read :Hellburner:?
Riders launched from (near) rest accelerating to major fractions of C.
Rider plus missiles had the missiles going past the moon at .8 C from near
rest relative; that's a _lot_ of deltaV.
>--- the carriers fire the riders in a particular direction, and then go
>and pick them up again later. The riders don't have nearly enough dV to
>kill .3c of velocity.
Source, please?
>[...]
>>Grapples are pretty easy, really; you only need hard contact between
>>structural members at equivalent strength. Unbalance gets mentioned in
>>:Downbelow Station:; docking a carrier is a big deal.
>
>Been a while since I read that one. (Cherryh has a habit of sneaking in
>correct details and numbers when you aren't looking. It's just this
>business about docking ships that irritates me.)
There isn't any other way to do it, not really. And it can work just
fine, complex though it seems.
>[...]
>>We only seem to see PRIDE OF CHANUR when they're in a tearing hurry.
>
>The _Pride_ is a trader. Time == money. They're *always* in a tearing
>hurry.
They're not always in _that much_ of a hurry that they're ignorning wear
and tear provided that they get to where they're going in time.
Kristopher/EOS
Michael S. Schiffer wrote:
<bit o' snip>
> >The bit I could never figure out is the fuel economy - not being able to get
> >at parts of the ship is inconvenient, but how do the ships ever manage to
> >dock? docking on-axis would use virtually no propellant, but docking at the
> >rim requires incoming ships to accelerate at 1g (or whatever the rim
> >pseudogravity is - or more, if you want to avoid funky station-relative
> >spirals. And that's 1g at right angles to the ships spin axis....
>
> Can't you just plot a course that has you going at the
> speed of the station's rim and at a tangent to it (within the plane of
> rotation, of course)? Admittedly, the docking clamps need to be
> pretty fast, but I'd think you could set them up to be automatic. (Of
> course, I don't remember the diameter of the stations, which means I
> don't know how fast the clamps would have to work.)
>
> I'd strap down during that maneuver, though, since it
> effectively means instantaneously accelerating from zero-g to 1 g (you
> stop spinning first, or you'll get something that won't be at all
> fun for the people _or_ the bearings).
The station had better have some massive stabilization thrusters...remember that
the rim of the station is travelling in a circle, while the momentum of the ship is
linear. This means that the docking maneuver, with no counteraction, will impart a
linear velocity onto the station. Actually, I'm sure that catching latching a
moving object onto a spinning object in orbit would do something a lot stranger
than that, but you get the idea.
Kristopher/EOS
Michael S. Schiffer
In article <358E96C2...@net-link.net>,
><bit o' snip>
>> >The bit I could never figure out is the fuel economy - not being able to get
>> >at parts of the ship is inconvenient, but how do the ships ever manage to
>> >dock? docking on-axis would use virtually no propellant, but docking at the
>> >rim requires incoming ships to accelerate at 1g (or whatever the rim
>> >pseudogravity is - or more, if you want to avoid funky station-relative
>> >spirals. And that's 1g at right angles to the ships spin axis....
>> Can't you just plot a course that has you going at the
>> speed of the station's rim and at a tangent to it (within the plane of
>> rotation, of course)? Admittedly, the docking clamps need to be
>> pretty fast, but I'd think you could set them up to be automatic. (Of
>> course, I don't remember the diameter of the stations, which means I
>> don't know how fast the clamps would have to work.)
>...
> The station had better have some massive stabilization
> thrusters...remember that the rim of the station is travelling in a
> circle, while the momentum of the ship is linear. This means that
> the docking maneuver, with no counteraction, will impart a linear
> velocity onto the station.
Doesn't that happen regardless? At any given time while it's
latched on the rim, the ship's inertia will tend to carry it in a
straight line tangent to the spin. The station needs either
stabilization thrusters or some mass to balance the ship, or it's not
going to spin smoothly. Match spin by thrusting around in a circle,
and you still add the exact same jolt the moment you turn off the
engines, don't you?
Actually, I'm sure that catching
> latching a moving object onto a spinning object in orbit would do
> something a lot stranger than that, but you get the idea.
Mike
David G. Bell
In article <m1kj1.858$P8.20...@ptah.visi.com>
dsg...@visi.com "Dan Goodman" writes:
> In article <Euxn3...@world.std.com>,
> Mark A Mandel <mam-DIE-S...@world.std.com> wrote:
> >Graydon (gra...@gooroos.com) wrote:
> >
> >: The carriers are _higher_ tech than what the hani have general access to;
> >: they can do things like jump short that come as big surprises to the hani,
> >: although the mahendosat (damn if I can remember where the apostrophe
> >: goes!) can do that and know about it. Plus the rider ship drives.
> >
> >After the "o": mahendo'sat.
> >
> >: docking adaptors can be clever 'smart' technology, you relaize, or there
> >: is the theory that the compact is a (human descended) proto-Qhal artifact.
> >
> >Proto-WHO?! What in Cherryh's universe is that? (I haven't read it all;
> >this is a question, not a challenge.)
>
> A _different_ universe, as far as I know.
>
> The Qhal were (are? will be?) the second known species to use time gates
> (which may also transport through space). Their safeguards against
> improper use were inadequate; their civilization, and most of the Qhal,
> died of time paradoxes. The species who left a time gate on a world in
> the original Qhal solar system presumably suffered the same fate.
>
> Humans, displaying a certain amount of intelligence for once, have sent
> people out to close down the time gates. And that's where the Morgaine
> books begin.... There's also a short story in the collection _Visible
> Light_, which has some information I don't think is in the books.
I've not seen anything definite, either way, about a connection, but her
other SF is connected, with the Chanur books at roughly the same time as
Downbelow Station (_very_ roughly), and some of her other books and
short series in the far future.
The compatible docking adaptors aren't quite enough to justify a Qual
influence, I'd want other clues, but it seems less of a strain than the
efforts other authors have made to drag all their work into a coherent
Future History.
--
David G. Bell -- Farmer, SF Fan, Filker, and Punslinger.
Graydon
In article <358E96C2...@net-link.net>,
Kristopher/EOS <eosl...@net-link.net> wrote:
>The station had better have some massive stabilization thrusters...remember that
>the rim of the station is travelling in a circle, while the momentum of the ship is
>linear. This means that the docking maneuver, with no counteraction, will impart a
Nothing at all says that the ship can't match speeds with the angular
velocity of the station rim, and indeed we get told that's exactly what
they're doing at various times.
>linear velocity onto the station. Actually, I'm sure that catching latching a
>moving object onto a spinning object in orbit would do something a lot stranger
>than that, but you get the idea.
Why? It's all frames of references; from the POV of the point on the rim,
the ship can and will come in at a teeny teeny 3 cm/s speed as the docking
probe/grapples catch. What it looks like from a POV 10 km arbitrary up
from the arbitary north pole of the station doesn't matter, it's the
relative velocity of the points of contact.
Damien Neil
On 21 Jun 1998 13:38:28 -0400, Graydon <gra...@gooroos.com> wrote:
>docking adaptors can be clever 'smart' technology, you relaize, or there
>is the theory that the compact is a (human descended) proto-Qhal artifact.
Wasn't the point made in _Finity's End_ (WRT human space) that docking
adaptors were built specifically to be able to dock to any even vaguely
probable connection? The problem is that the adaptors on a station need
to deal with ships built over a century's span of development -- you get
very good at hooking up to different designs.
Things get even more entertaining in Compact space -- they have not just
different versions of the same species' tech, but different versions of
different species.
I suspect you could dock a cow to a Compact station, if you could find
a way to attach the vanes.
- Damien
Kristopher/EOS
Graydon wrote:
> In article <358E96C2...@net-link.net>,
> Kristopher/EOS <eosl...@net-link.net> wrote:
> >The station had better have some massive stabilization thrusters...remember that
> >the rim of the station is travelling in a circle, while the momentum of the ship is
> >linear. This means that the docking maneuver, with no counteraction, will impart a
>
> Nothing at all says that the ship can't match speeds with the angular
> velocity of the station rim, and indeed we get told that's exactly what
> they're doing at various times.
>
> >linear velocity onto the station. Actually, I'm sure that catching latching a
> >moving object onto a spinning object in orbit would do something a lot stranger
> >than that, but you get the idea.
>
> Why? It's all frames of references; from the POV of the point on the rim,
> the ship can and will come in at a teeny teeny 3 cm/s speed as the docking
> probe/grapples catch. What it looks like from a POV 10 km arbitrary up
> from the arbitary north pole of the station doesn't matter, it's the
> relative velocity of the points of contact.
So the docking ships approach in a spiral pattern? If the ship comes in on a straight
line, it WILL matter, AFAIK. The ship has linear velocity relative to the station's
center, equal to the angular velocity of the rim it's docking with, if the station in
spinning.
Graydon
In article <358EE261...@net-link.net>,
Kristopher/EOS <eosl...@net-link.net> wrote:
>Graydon wrote:
>> Why? It's all frames of references; from the POV of the point on the rim,
>> the ship can and will come in at a teeny teeny 3 cm/s speed as the docking
>> probe/grapples catch. What it looks like from a POV 10 km arbitrary up
>> from the arbitary north pole of the station doesn't matter, it's the
>> relative velocity of the points of contact.
>
>So the docking ships approach in a spiral pattern?
Yup. This is a Merchanter/Compact stock scenery bit.
[Your lines are too long; ~70 character max and a fixed pitch font would
be an improvement in legibility]
>If the ship comes in on a straight
>line, it WILL matter, AFAIK. The ship has linear velocity relative to the station's
>center, equal to the angular velocity of the rim it's docking with, if the station in
>spinning.
Coming in on a straight line would be very stressful, yes, which is why
they don't do it.
Georgiana Gates
I think this is really stretching. Gate of Ivrel was CJC's first
book - did she really have all this planned? When I first read
Cherryh, I didn't see any connection between Compact space, or the
mri trilogy (no one ever discusses them, and that's the first Cherryh
I read), or the qhal, or the iduve, or whatever. And I sort of like
it that way.
Bill Miller
Kristopher/EOS wrote:
> So the docking ships approach in a spiral pattern? If the ship comes in on a straight
> line, it WILL matter, AFAIK. The ship has linear velocity relative to the station's
> center, equal to the angular velocity of the rim it's docking with, if the station in
> spinning.
I know little about the Cherryh books (although this thread is making me want to read
them) but the real world docking mechanism for the shuttle Orbiter to Mir is a very
complicated beast. It has to damp out the relative motion of two fairly heavy and fairly
fragile objects and then pull them together to make an airtight connection. And the
allowable approach rates are very low indeed (in the watching paint dry regime....)
Bill
--
==================================================================
"Remember Thor Five!"
Work: william....@jsc.nasa.gov
Play: wbmi...@ghgcorp.com
Homepage: http://www.ghg.net/wbmiller3
Kristopher/EOS
Graydon wrote:
> [Your lines are too long; ~70 character max and a fixed pitch font would
> be an improvement in legibility]
I'm using Netscape Collabra. I've set the line length to 70 characters, and it hasn't
changed anything. I can't get my fixed-width font to be the default for my postings. It
stinks, I know...
Kristopher/EOS
Phil Fraering
gra...@gooroos.com (Graydon) writes:
> There isn't any other way to do it, not really. And it can work just
> fine, complex though it seems.
Can the material science of the era probably take it?
--
Phil Fraering "You will cooperate with Microsoft, for the
p...@globalreach.net good of Microsoft and for your own survival."
/Will work for *tape*/ - Navindra Umanee
Phil Fraering
db...@zhochaka.demon.co.uk ("David G. Bell") writes:
> I've not seen anything definite, either way, about a connection, but her
> other SF is connected, with the Chanur books at roughly the same time as
> Downbelow Station (_very_ roughly), and some of her other books and
> short series in the far future.
Yes, but somewhat afterwards.
I suspect they wouldn't happen until well after Mazian's two attempts
to take over Sol system.
Rimrunner
In article <199806220702...@ladder03.news.aol.com>,
Georyn <geo...@aol.com> wrote:
>>The ghoulies and ghosties and things as go bump in the night from the
>>Morgaine books, the titles of which I am blanking on utterly.
>
> "Gate Of Ivrel", "Well Of Shiuan" and "Fires of Azeroth". Can you tell I'm
>reading this series now, so have the book titles handy in my mental rolodex?
>;-{)> The first one is kind of slow moving, but rewarding in the end, if only
>because you get to read the other two, which are excellent (still a couple of
>chapters from the end of "Fires of Azeroth", which I think may be the best of
>the three).
> Oh, there's a fourth book in the series, "Exile's Gate", but I'm always
>wary of sequels written fifteen years after the original trilogy.
"Exile's Gate" is actually very good, though I may be biased on this point
because it was the first Cherryh I read. Liked it enough to pick up the
first three books and read the whole thing in order.
It's not seamless. Cherryh's writing style changed from the 70s to the
late 80s when "Exile" was published, and you'll definitely be aware of the
stylistic differences.
And it ends on a cliffhanger, too.
Rimrunner
i still want to know what happened to chei/gault
--
Murder of Crows official web site: http://www.nwlink.com/~noah/
Force This!: http://www.shavenwookie.com/rimrun
Pop-Culture Corn: http://www.pccmag.com
--
"Look, I don't know how they do things on your home planet, spaceman...but
here in Mayberry, we just don't talk to gun-toting, redneck, amphetamine
freaks that way." -- Milkman Dan, "Red Meat"
--
TimothyBil
>So the docking ships approach in a spiral pattern? If the ship comes in on a
>straight
>line, it WILL matter, AFAIK. The ship has linear velocity relative to the
>station's
>center, equal to the angular velocity of the rim it's docking with, if the
>station in
>spinning.
>
>
Visualize a station like the ones shown in all the 50s illustrations - a
central hub with ring. Visualize ships docking nose in to locations on the
rim. Now picture a ship located above the plane of rotation of the hub. It
should be possible to plot a path from the current ship location to the rim
such that the ship will reach the rim, missing all the already docked ships,
with minimal velocity just as the docking probe on the ship is latched by the
docking collar on the station. Explains why the station flips out when the
ship does it on its own rather than letting the station control the process.
Stephen Harker
Georgiana Gates <ram...@hal-pc.org> writes:
> Jo Walton wrote:
> > To expand on that slightly, this is the "get U/A space out of the corner
> > Cherryh may have painted herself into" theory.
> >
> > The Qhal have gates that go from one world to another. The Morgaine
> > books are set in the far future of the same universe as the U/A books.
> > [....]
> >
> > The chi, too. I think they were there, or maybe the t'ca were there
> > and that's what they got put near, the t'ca uplifted the chi and the
> > knnn could have come from _anywhere_.
> >
>
> I think this is really stretching. Gate of Ivrel was CJC's first
> book - did she really have all this planned? When I first read
> Cherryh, I didn't see any connection between Compact space, or the
> mri trilogy (no one ever discusses them, and that's the first Cherryh
> I read), or the qhal, or the iduve, or whatever. And I sort of like
> it that way.
I don't know how far it was planned, but _Gate of Ivrel_ had a
prologue which referred to the `Union Science Bureau' (as best I
remember) making the decision to send the team to destroy the Gates.
When _Downbelow Station_ came out I remember suddenly realising the
references to Union in it and in _Gate of Ivrel_ were clearly to the
same place and hence the books were in the same `universe'. So to a
fair extent the connections were planned.
You should find references to Union and Alliance in the mri books,
particularly in the final book when they return to human space to find
Alsec has had its power cut back post war.
--
Stephen Harker s-ha...@adfa.edu.au
School of Physics Baloney Baffles brains: Eric Frank Russell
University College
UNSW, ADFA
David G. Bell
> I think this is really stretching. Gate of Ivrel was CJC's first
> book - did she really have all this planned? When I first read
> Cherryh, I didn't see any connection between Compact space, or the
> mri trilogy (no one ever discusses them, and that's the first Cherryh
> I read), or the qhal, or the iduve, or whatever. And I sort of like
> it that way.
I remember C.J. saying that some features of the human culture in the
mri trilogy are recognisable, but warped, descendants of the human
culture in the U/A books. Organisations keep their names, but
objectives, and methods, drift.
Jerry Cullingford
In article <6mmajg$m...@excalibur.gooroos.com>,
Graydon <goo...@interlog.com> wrote:
>Nothing at all says that the ship can't match speeds with the angular
>velocity of the station rim, and indeed we get told that's exactly what
>they're doing at various times.
Which was my original objection - ships *could* do this, but they'd have to
accelerate at around the rim pseudogravity to do so - which is likely to be
very expensive in terms of propellant compared to docking on axis, and
requires thrust at right angles to the ships spin axis - while I've always had
the impression that normal thrust is along the spin axis.
Maybe the ships have enough deltaV that this isn't a problem - but it still
seems horribly inefficient - especially for insystem ships.
David Given
In article <898500...@zhochaka.demon.co.uk>,
David G. Bell <db...@zhochaka.demon.co.uk> wrote:
[...]
>I've not seen anything definite, either way, about a connection, but her
>other SF is connected, with the Chanur books at roughly the same time as
>Downbelow Station (_very_ roughly), and some of her other books and
>short series in the far future.
There's a throwaway line in _Cyteen_ about a group of xenophobic aliens on
the far side of Earth; that's the Compact. And Tully makes a big play of
the two major human factions (they aren't actually named as Union and
Alliance in the book, but it's plain what they are), and the fact that he
comes from neither and is an Earth man.
--
+- David Given ----------------+
| Work: d...@tao.co.uk | Organize for anarchy!
| Play: dgi...@iname.com |
+- http://wiredsoc.ml.org/~dg -+
David Given
In article <6mm0ri$k...@excalibur.gooroos.com>,
Graydon <goo...@interlog.com> wrote:
[...]
>>Humans can short-jump, yes, but that's not so much as better hyperspace
>>technology as a different point of view. *Noone* really understands
>>hyperspace tech.
>
>Knn. Bok probably did; there are probably some human physicists who do.
But nobody understands *them*. The knnn, Bok and the physicists all.
>>And I don't recall hearing anywhere about any kind of special drive the
>>riders have. My impression was that they had very limited dV capability
>
>Have you read :Hellburner:?
Uh, yes, that's my source...
>Riders launched from (near) rest accelerating to major fractions of C.
>
>Rider plus missiles had the missiles going past the moon at .8 C from near
>rest relative; that's a _lot_ of deltaV.
My impression was that the crew got into the rider, the carrier boosted
them up to speed and then they were launched. After combat was over, the
carrier would rendezvous and pick them up. There's a lot of talk about
intersecting trajectory cones; the riders can move a small amount
(relatively; ten gee for a few minutes isn't much compared to c, but
rather a lot compared to Apollo).
Diversion: the Compact may not be able to short jump, but they appear to
be able to use they hyperdrives to push up their velocity very quickly.
_Pride_ appeared to pulse up to translight speeds in several bursts, and
then, on entry to the target system, do the same thing in reverse to dump
speed. I've never seen a human ship do that.
>>--- the carriers fire the riders in a particular direction, and then go
>>and pick them up again later. The riders don't have nearly enough dV to
>>kill .3c of velocity.
>
>Source, please?
_Hellburner_, again. Remember that Cherryh doesn't have inertial dampers:
it takes time, a lot of it, to accelerate that fast. .8c = 2.4E8 m/s. 10g
= 1000 m/s^2. 2.4E8/1000 = 24000 seconds, or about 66 hours (just under
three days). That's a lot of time to spend in a liquid acceleration couch.
In _Frontier: First Encounters_, the longest distance I've ever spent in
real space is jumping into Alpha Centauri. You arrive just under 1000AU
from the station (6 light-days! Ye gods!). I can get back in about two
weeks, of continuous acceleration at 20g. (A bit less if I exploit a bug.)
In order for events to progress at a reasonable speed, all the ships in
the game are equipped with equally stupendous (and unlikely) drives
(except, possibly, the interplanetary shuttle, which is frankly
laughable).
[...]
>>The _Pride_ is a trader. Time == money. They're *always* in a tearing
>>hurry.
>
>They're not always in _that much_ of a hurry that they're ignorning wear
>and tear provided that they get to where they're going in time.
Well, okay. There's a difference between
if-we-don't-hurry-we're-going-to-go-broke and
if-we-don't-hurry-Compact-civilisation-will-end.
David Given
In article <EuyoA...@midway.uchicago.edu>,
Michael S. Schiffer <ms...@midway.uchicago.edu> wrote:
[...]
> Can't you just plot a course that has you going at the
>speed of the station's rim and at a tangent to it (within the plane of
>rotation, of course)? Admittedly, the docking clamps need to be
>pretty fast, but I'd think you could set them up to be automatic. (Of
>course, I don't remember the diameter of the stations, which means I
>don't know how fast the clamps would have to work.)
IIRC, _Legacy_ does just this, entirely against regulations, in order to
freak out the (possibly stsho) station managers. It succeeded. Both
meanings.
David Given
In article <6mnsmq$g...@suneng2.hh.ffei.co.uk>,
Jerry Cullingford <j...@hh.ffei.co.uk> wrote:
>In article <6mmajg$m...@excalibur.gooroos.com>,
>Graydon <goo...@interlog.com> wrote:
>>Nothing at all says that the ship can't match speeds with the angular
>>velocity of the station rim, and indeed we get told that's exactly what
>>they're doing at various times.
>
>Which was my original objection - ships *could* do this, but they'd have to
>accelerate at around the rim pseudogravity to do so - which is likely to be
>very expensive in terms of propellant compared to docking on axis, and
>requires thrust at right angles to the ships spin axis - while I've always had
>the impression that normal thrust is along the spin axis.
This is one reason why I like to think of the ships docking vertically
relative to station down rather than horizontally. Much less wear-and-tear
on the ship; it's not designed for lateral gees.
Of course, this only works on CA ships that don't have a gee ring.
>Maybe the ships have enough deltaV that this isn't a problem - but it still
>seems horribly inefficient - especially for insystem ships.
The cheapest way of docking is to approach the station at an angle, start
your ship tumbling end-over-end at the same speed as the station, turn off
your engines, and if you get the numbers right, your nose will touch the
station's docking adaptors at a low enough speed that you just close the
grapples and you're there. No sustained one gee burns, no spiral approach
path.
Get it wrong, though...
Graydon
In article <6mnsmq$g...@suneng2.hh.ffei.co.uk>,
Jerry Cullingford <j...@hh.ffei.co.uk> wrote:
>In article <6mmajg$m...@excalibur.gooroos.com>,
>Graydon <goo...@interlog.com> wrote:
>>Nothing at all says that the ship can't match speeds with the angular
>>velocity of the station rim, and indeed we get told that's exactly what
>>they're doing at various times.
>
>Which was my original objection - ships *could* do this, but they'd have to
>accelerate at around the rim pseudogravity to do so - which is likely to be
>very expensive in terms of propellant compared to docking on axis, and
>requires thrust at right angles to the ships spin axis - while I've always had
>the impression that normal thrust is along the spin axis.
Propellant is cheap, and the amount of side vector isn't much; they can
presumably produce that with some sort of thrust vectoring, since they
_aren't_ using a reaction drive.
>Maybe the ships have enough deltaV that this isn't a problem - but it still
>seems horribly inefficient - especially for insystem ships.
These things have delta-v in multiples of C!
What's a little maneuvering cost, compared to a large fixed cost and all
the manifold and comprehensive pain of not having enough docking adapters
and losing money to the next station over? (if you dock on axis, there
are only really _two_ docking slots that let you avoid solving the problem
of docking with the same velocity as the angular velocity of the station
rim, and if you can solve it at all, taking longer lets you solve it for
the edge of the spin hub.)
Graydon
In article <8790moy...@globalreach.net>,
Phil Fraering <p...@globalreach.net> wrote:
>gra...@gooroos.com (Graydon) writes:
>> There isn't any other way to do it, not really. And it can work just
>> fine, complex though it seems.
>
>Can the material science of the era probably take it?
Sure. The ships can take 10G worth of accelerative force transmitted up
from the vanes at the back; hanging them at 1G accleration from the nose
doesn't seem like any sort of stretch. The grapples probably got really
careful design reviews, but there's nothing too horribly implausible about
any of this.
Jo Walton
In article <358F0C...@hal-pc.org> ram...@hal-pc.org "Georgiana Gates" writes:
> I think this is really stretching. Gate of Ivrel was CJC's first
> book - did she really have all this planned? When I first read
> Cherryh, I didn't see any connection between Compact space, or the
> mri trilogy (no one ever discusses them, and that's the first Cherryh
> I read), or the qhal, or the iduve, or whatever. And I sort of like
> it that way.
You're entitled to.
But Cherryh has linked those books together - references to Alliance
and Union in the Morgaine books, even more references to Alliance
and Union in the Mri books, Pell is even mentioned. Then the Compact
books are specifically linked in - two mentions in :Cyteen:, and
the situation Tully describes is clearly the political situation
of "three human Compacts" Earth/Alliance/Union. The end note to
:The Kif Strikes Back: also specifically explains how they are
linked, as does the chronology in the end of :Angel With the Sword:.
My Capella theory and Graydon's "then that explains the biological
oddnesses in the Compact" theory are indeed stretching, but given
that those things are, by textual reference or by authorial plain
statement, in the same universe, it's not all that bad.
I don't, for the record, think Cherryh had that in mind when she
wrote :Gate:, I think she was just using the same universe and
then she put a lot of cool stuff in and it didn't all quite work
together. As I said originally, that's a paint-self-out-of-corner
solution she could use if she wanted to to justify that sort of
thing. As she doesn't seem even slightly bothered by inconsistencies
and she also seems to have moved on to writing in different universes,
this will probably never be illuminated unless some light is shone
by :Cyteen 2: when she writes it.
Tom Carman
dg@ (David Given) wrote:
>Diversion: the Compact may not be able to short jump, but they appear to
>be able to use they hyperdrives to push up their velocity very quickly.
>_Pride_ appeared to pulse up to translight speeds in several bursts, and
>then, on entry to the target system, do the same thing in reverse to dump
>speed. I've never seen a human ship do that.
Oh, I expect that human ships are physically capable of it... but the
crews are not. Remember that most of the Compact species have no
trouble tolerating jump space. Humans, like the shto, need to drug
down during jumps. Caveat: there are suggestions in _Tripoint_ and
maybe _Rimrunners_ that some carrier crews have much less of a problem
with slipping in and out of jump.
Jerry Cullingford
In article <6mo3s5$9...@excalibur.gooroos.com>,
Graydon <goo...@interlog.com> wrote:
>Propellant is cheap, and the amount of side vector isn't much; they can
>presumably produce that with some sort of thrust vectoring, since they
>_aren't_ using a reaction drive.
*blink!* they aren't? That must have slipped by me somwhere - I'd
assumed they *were* using reaction drives when they weren't using
jump-related stuff.
I have a vague memory of one of the books mentioning in-system propellant
transport/gas mining, which would fit with reaction drives; and a mention
of a misaligned docking thruster (which probably doesn't prove anything
either way, unless the description helps).
>These things have delta-v in multiples of C!
Are you sure? (I'm blanking on details of runs out to jump, which would
probably give a fairly good idea) I thought they popped out of jump at
a high velocity (presumably a side effect of the way the jump engines
work) and then dumped down (again via jump tech) to a relatively low
velocity. That would probably still need enough deltaV to make docking
relatively painless, though, unless dumping lets you change your vector -
arriving on the wrong side of the stations orbit, or out of plane, is
going to either take ages (not supported by books) or require major sustained
acceleration otherwise.
>What's a little maneuvering cost, compared to a large fixed cost and all
>the manifold and comprehensive pain of not having enough docking adapters
>and losing money to the next station over? (if you dock on axis, there
>are only really _two_ docking slots that let you avoid solving the problem
>of docking with the same velocity as the angular velocity of the station
>rim, and if you can solve it at all, taking longer lets you solve it for
>the edge of the spin hub.)
Ah - but you could solve it by either having an axial spine, and maybe counter
rotating docking collars - which reduces the problem drastically, by reducing
your effective "rim" radius to something much more manageable - or by having
movable docking adapters - grapple at the axis, then move the ships out to
the rim for final hookup - which would limit simultaneous dockings, but not
total capacity.
Guy_Under_...@my-dejanews.com
In article <6mm0ri$k...@excalibur.gooroos.com>,
goo...@interlog.com wrote:
> Rider plus missiles had the missiles going past the moon at .8 C from near
> rest relative; that's a _lot_ of deltaV.
If you recall, the major debate in Hellburner was weather or not the riders
should be piloted by AIs rather than humans, exactly because of the awesome
performance capabilities of the riders. There was concerns about weather a
human being can handle the beast in combat situations without killing himself
or breaking down.
-----== Posted via Deja News, The Leader in Internet Discussion ==-----
http://www.dejanews.com/ Now offering spam-free web-based newsreading
Jerry Cullingford
In article <898602011.20165.0...@news.demon.co.uk>,
David Given <dg@> wrote:
>The cheapest way of docking is to approach the station at an angle, start
>your ship tumbling end-over-end at the same speed as the station, turn off
>your engines, and if you get the numbers right, your nose will touch the
>station's docking adaptors at a low enough speed that you just close the
>grapples and you're there. No sustained one gee burns, no spiral approach
>path.
>
>Get it wrong, though...
Yes - I'd thought about this way of doing things, but then I thought that
only a motie would try it :-). At least the spiral version gives you time
to tweak things, and a fairly safe abort mode (just cut thrust).
.
.
.
.
.
Kristopher/EOS
TimothyBil wrote:
>
>>So the docking ships approach in a spiral pattern? If the ship >>comes in on a straight line, it WILL matter, AFAIK. The ship has >>linear velocity relative to the station's center, equal to the >>angular velocity of the rim it's docking with, if the station in
>>spinning.
>Visualize a station like the ones shown in all the 50s illustrations >- a central hub with ring. Visualize ships docking nose in to >locations on the rim. Now picture a ship located above the plane of >rotation of the hub. It should be possible to plot a path from the >current ship location to the rim such that the ship will reach the >rim, missing all the already docked ships, with minimal velocity just >as the docking probe on the ship is latched by the docking collar on >the station. Explains why the station flips out when the ship does it >on its own rather than letting the station control the process.
But if the station is spinning, the ship has to match the velocity of
rim of the ring section of the station, or there will be a massive
lurch, assuming that the docking equipment (clamps, whatever) isn't
simply ripped off by the attempted docking. The only way to dock to
the rim of a spinning station is to approach in a spiral, matching the
velocity of the staion rim, and moving a a circle around the station,
then slowly closing the distance. That's in insanely complex
maneuver, when you consider that the staion and the ship are also both
in orbit (I presume)and must take the orbital mechanics into account
as well.
Never mind the fact that the back end of the docked ship will be
moving at a horrendous velocity, and probably experience several gees
of gravity!
A much better method would be to have a long "rod" shaped extension
from both sides of the "hub" The ships could dock to these nonspining
sections, take advantage of microgravity for moving cargo, and so
on...
Kristopher/EOS
Graydon
In article <6modqh$6...@suneng2.hh.ffei.co.uk>,
Jerry Cullingford <j...@hh.ffei.co.uk> wrote:
>In article <6mo3s5$9...@excalibur.gooroos.com>,
>Graydon <goo...@interlog.com> wrote:
>>Propellant is cheap, and the amount of side vector isn't much; they can
>>presumably produce that with some sort of thrust vectoring, since they
>>_aren't_ using a reaction drive.
>
>*blink!* they aren't? That must have slipped by me somwhere - I'd
>assumed they *were* using reaction drives when they weren't using
>jump-related stuff.
Vanes is vanes. There is no way to accelerate to .9 C with anything like
a reaction drive; whatever vanes do, it doesn't have to get all its power
from the ship.
>I have a vague memory of one of the books mentioning in-system propellant
>transport/gas mining, which would fit with reaction drives; and a mention
>of a misaligned docking thruster (which probably doesn't prove anything
>either way, unless the description helps).
They probably use reaction thrusters for very fine docking maneuvers,
yeah. And in :Heavy Time:, the mining ships use reaction thrusters, and
perhaps the insystemers and miners in most systems use the cheaper
reaction thrusters, but the starships use vanes and go _fast_.
Note, frex, in :Merchanter's Luck:, when NORWAY is leaving Pell at ~10+G,
there is no concern for the exhaust; there's a clear lane for NORWAY that
messes up the traffic pattern, but the enourmous cloud of charged
particles that would result from a reaction drive able to do that isn't
there.
Also note mentions in :Rimrunner: of acceleration on little or no warning;
that points to a field effect drive, rather than a reaction drive. (It's
hard to come up with a high thrust nuclear design that would have that
fast a response.)
Plus all the mentions of ships being hard to spot, despite being under
drive; if the ships used reaction drives, they'd light up like stars.
>>These things have delta-v in multiples of C!
>
>Are you sure? (I'm blanking on details of runs out to jump, which would
>probably give a fairly good idea) I thought they popped out of jump at
>a high velocity (presumably a side effect of the way the jump engines
>work) and then dumped down (again via jump tech) to a relatively low
>velocity. That would probably still need enough deltaV to make docking
>relatively painless, though, unless dumping lets you change your vector -
>arriving on the wrong side of the stations orbit, or out of plane, is
>going to either take ages (not supported by books) or require major sustained
>acceleration otherwise.
So you jump short and come back in with your starting v near C.
Most ships can jump repeatedly on internal fuel.
They have to get out to the edge of the system in order to jump safely,
remember, and they have to be going ungodly fast to do that in the time
given from a near-rest start. No indication that the process has any
limits other than fuel and the v we already know the vane systems can
handle.
>>What's a little maneuvering cost, compared to a large fixed cost and all
>>the manifold and comprehensive pain of not having enough docking adapters
>>and losing money to the next station over? (if you dock on axis, there
>>are only really _two_ docking slots that let you avoid solving the problem
>>of docking with the same velocity as the angular velocity of the station
>>rim, and if you can solve it at all, taking longer lets you solve it for
>>the edge of the spin hub.)
>
>Ah - but you could solve it by either having an axial spine, and maybe counter
>rotating docking collars - which reduces the problem drastically, by reducing
>your effective "rim" radius to something much more manageable - or by having
>movable docking adapters - grapple at the axis, then move the ships out to
>the rim for final hookup - which would limit simultaneous dockings, but not
>total capacity.
Why add mechnical complexity?
And even the axial spine inolves the docking-with-matched-angular-velocity
unless you dock at the axial end of it. Less angular velocity, yes, but
still some and the advantages of debarking into steady acceleration
environments aren't small.
Tom Carman
Kristopher/EOS <eosl...@net-link.net> wrote:
>But if the station is spinning, the ship has to match the velocity of
>rim of the ring section of the station, or there will be a massive
>lurch, assuming that the docking equipment (clamps, whatever) isn't
>simply ripped off by the attempted docking. The only way to dock to
>the rim of a spinning station is to approach in a spiral, matching the
>velocity of the staion rim, and moving a a circle around the station,
>then slowly closing the distance. That's in insanely complex
>maneuver, when you consider that the staion and the ship are also both
>in orbit (I presume)and must take the orbital mechanics into account
>as well.
No, that is NOT the only way to dock! In fact, I can't readily think
of a more awkward approach to the problem. Try this:
The ship's trajectory is tangent to the rim. The approach is
carefully timed so that the ship will pass the station rim at its
assigned docking port, moving at the same velocity as the rim's
rotation. At this point, the extended grapples snag the ship's frame
and pull it in to the dock.
view this in fixed-width font:
| | | | | | | | | | |
| | | | | | | | | | |
| | /|--|--|---|--|---|--|---|--|---
| | / | | | | | | | | | |
| |/ | | | | | | | | | |
| |\ | | | | | | | | | |
| | \ | | | | | | | | | |
| | \|--|--|---|--|---|--|---|--|---
|_______________|___| |__| |__| |__| |__|
Habitat ring Ship in non-pressurized area
shops this side wall
David G. Bell
In article <3591a6e3...@news.newsguy.com>
7177...@compuserve.com "Tom Carman" writes:
> with slipping in and out of jump.
Which is not inconsistent with the speculated Tripoint -> Qhal ->
Compact chain.
Kristopher/EOS
Tom Carman wrote:
>
> Kristopher/EOS <eosl...@net-link.net> wrote:
>
> >But if the station is spinning, the ship has to match the velocity of
> >rim of the ring section of the station, or there will be a massive
> >lurch, assuming that the docking equipment (clamps, whatever) isn't
> >simply ripped off by the attempted docking. The only way to dock to
> >the rim of a spinning station is to approach in a spiral, matching the
> >velocity of the staion rim, and moving a a circle around the station,
> >then slowly closing the distance. That's in insanely complex
> >maneuver, when you consider that the staion and the ship are also both
> >in orbit (I presume)and must take the orbital mechanics into account
> >as well.
>
> No, that is NOT the only way to dock! In fact, I can't readily think
> of a more awkward approach to the problem. Try this:
>
> The ship's trajectory is tangent to the rim. The approach is
> carefully timed so that the ship will pass the station rim at its
> assigned docking port, moving at the same velocity as the rim's
> rotation. At this point, the extended grapples snag the ship's frame
> and pull it in to the dock.
We've already covered why that doesn't work. A ship on a linear
trajaectory imparts quite a jolt to the station...it's moving at the
velecity of the station rim with respect to the station as a whole,
just as you said. This would not be good for the station, the ship,
or any of the people involved.
It has to approach in a spiral, in order to match the angular velocity
of the rim while minimizing its linear velocity WRT to station as a
whole.
Kristopher/EOS
Georgiana Gates
Jo Walton wrote:
>
> But Cherryh has linked those books together - references to Alliance
> and Union in the Morgaine books, even more references to Alliance
> and Union in the Mri books, Pell is even mentioned. Then the Compact
> books are specifically linked in - two mentions in :Cyteen:, and
> the situation Tully describes is clearly the political situation
> of "three human Compacts" Earth/Alliance/Union. The end note to
> :The Kif Strikes Back: also specifically explains how they are
> linked, as does the chronology in the end of :Angel With the Sword:.
>
> My Capella theory and Graydon's "then that explains the biological
> oddnesses in the Compact" theory are indeed stretching, but given
> that those things are, by textual reference or by authorial plain
> statement, in the same universe, it's not all that bad.
>
> I don't, for the record, think Cherryh had that in mind when she
> wrote :Gate:, I think she was just using the same universe and
> then she put a lot of cool stuff in and it didn't all quite work
> together. As I said originally, that's a paint-self-out-of-corner
> solution she could use if she wanted to to justify that sort of
> thing. As she doesn't seem even slightly bothered by inconsistencies
> and she also seems to have moved on to writing in different universes,
> this will probably never be illuminated unless some light is shone
> by :Cyteen 2: when she writes it.
>
references.
Robert A. Woodward
In article <898601521.9717.0...@news.demon.co.uk>, dg@
(David Given) wrote:
> In article <6mm0ri$k...@excalibur.gooroos.com>,
> Graydon <goo...@interlog.com> wrote:
<snip>
>
> >Riders launched from (near) rest accelerating to major fractions of C.
> >
> >Rider plus missiles had the missiles going past the moon at .8 C from near
> >rest relative; that's a _lot_ of deltaV.
>
> My impression was that the crew got into the rider, the carrier boosted
> them up to speed and then they were launched. After combat was over, the
> carrier would rendezvous and pick them up. There's a lot of talk about
> intersecting trajectory cones; the riders can move a small amount
> (relatively; ten gee for a few minutes isn't much compared to c, but
> rather a lot compared to Apollo).
>
> Diversion: the Compact may not be able to short jump, but they appear to
> be able to use they hyperdrives to push up their velocity very quickly.
> _Pride_ appeared to pulse up to translight speeds in several bursts, and
> then, on entry to the target system, do the same thing in reverse to dump
> speed. I've never seen a human ship do that.
>
I thought that several ships were doing that in _Merchanter's Luck_ (near
the end when they were mouse-trapping a Mazani ship IIRC).
<snip>
Anna F. Dal Dan
Georyn <geo...@aol.com> wrote:
> Oh, there's a fourth book in the series, "Exile's Gate", but I'm always
> wary of sequels written fifteen years after the original trilogy.
It's not really a "trilogy". More like an open-ended series. Exile's is
to me one of the best if not *the* best of the bunch. Trouble is, it
begs a sequel that doesn't seem to be forthcoming.
--
Anna Feruglio Dal Dan: substitute "tin" to "nit" to mail me
http://www.fantascienza.com/sfpeople/elethiomel
Andrew Plotkin
Kristopher/EOS (eosl...@net-link.net) wrote:
> > The ship's trajectory is tangent to the rim. The approach is
> > carefully timed so that the ship will pass the station rim at its
> > assigned docking port, moving at the same velocity as the rim's
> > rotation. At this point, the extended grapples snag the ship's frame
> > and pull it in to the dock.
> We've already covered why that doesn't work. A ship on a linear
> trajaectory imparts quite a jolt to the station...it's moving at the
> velecity of the station rim with respect to the station as a whole,
> just as you said. This would not be good for the station, the ship,
> or any of the people involved.
>
> It has to approach in a spiral, in order to match the angular velocity
> of the rim while minimizing its linear velocity WRT to station as a
> whole.
I've just been dipping in and out of the thread, but it seems to me that
this is completely and totally wrong. Er, sorry. :)
The approach is irrelevant -- momentum doesn't have a memory.
The only thing that's relevant is the moment of grab-on. At that moment, if
the ships velocity is tangent to the rim and has the same linear velocity,
the docking is smooth. The station is not "jolted" with an instant
application of delta-vee.
The station *is* "jolted" with an instant application of *force* --
centrifugal force, directed radially outward. (Yes, or centripetal force,
same result no matter which way you work it out.) That's a different kind
of jolt.
It's analogous to catching a cannonball tossed vertically upward, just at
the top of the trajectory. At the moment of grab, your hands are not
knocked upward or downward. But at that moment, they start feeling a
strong downward force, and your feet may start sinking slowly into the
mud.
To put it differently: yes, the ship has linear velocity compared to the
station's COG. And just after the join, the whole system still has that
momentum. But it's still distributed as it was before, because the
centripetal force pulling on the docking clamps hasn't had time to
transfer it yet. Over time, the docking clamp force transfers momentum
back and forth -- exactly in the manner of two rigidly-connected objects
spinning around a common COG. Which is what we have. (The station is
heavier, so the common COG is near the station's center. This is a
detail.)
Note: there is a second-order jolt problem, which is caused by the fact
that the ship comes in with no spin, and has to gain some when it clamps
on. This puts twisting force on the docking clamps. Very bad. But it's
easy to fix -- have the ship spinning slowly as it approaches (on its
straight-line tangent course.) Same rpm as the station, same direction.
The timing is a little trickier, because you have to make sure the ship's
nose is pointed stationwards at the moment of contact.
--Z
--
"And Aholibamah bare Jeush, and Jaalam, and Korah: these were the
borogoves..."
Damien Neil
On Tue, 23 Jun 1998 20:17:30 -0400, Kristopher/EOS <eosl...@net-link.net>
wrote:
>We've already covered why that doesn't work. A ship on a linear
>trajaectory imparts quite a jolt to the station...it's moving at the
>velecity of the station rim with respect to the station as a whole,
>just as you said. This would not be good for the station, the ship,
>or any of the people involved.
Hrm.
There isn't anything in life OTHER than a linear trajectory. At least,
absent forces acting on the object. You can't send a ship on a spiral
trajectory without keeping the engines on all the time. And if you do
that...well, why? You get the same effect by approaching on a straight
path, and flipping the engines on at the last second.
- Damien
Michael S. Schiffer
In article <3590459A...@net-link.net>,
>> Kristopher/EOS <eosl...@net-link.net> wrote:
>> No, that is NOT the only way to dock! In fact, I can't readily think
>> of a more awkward approach to the problem. Try this:
>> The ship's trajectory is tangent to the rim. The approach is
>> carefully timed so that the ship will pass the station rim at its
>> assigned docking port, moving at the same velocity as the rim's
>> rotation. At this point, the extended grapples snag the ship's frame
>> and pull it in to the dock.
>We've already covered why that doesn't work. A ship on a linear
>trajaectory imparts quite a jolt to the station...it's moving at the
>velecity of the station rim with respect to the station as a whole,
>just as you said. This would not be good for the station, the ship,
>or any of the people involved.
My brain may be atrophied, so bear with me. Isn't anything on
the station rim moving at the velocity of the rim with respect to the
station as a whole? Isn't that why staying with the station requires
a change in velocity (in this case direction rather than speed), so
that the object's natural tendency to keep going in a straight line
pushes it against the station wall, to be felt as "centrifugal force"?
If we immediately release the docking clamps, won't the ship
immediately be moving at the velocity of the station rim along a
tangent line-- the exact opposite of the maneuver described above?
What am I missing here?
Mike
--
Michael S. Schiffer, LHN,FCS GURPS Alternate Earths is being reprinted!
Co-author: GURPS Alt. Earths Check out Steve Jackson Games' page at
ms...@tezcat.com <http://www.sjgames.com/gurps/books/AltEarths/>
ms...@midway.uchicago.edu for details.
Mark A Mandel
Andrew Plotkin (erky...@netcom.com) wrote:
: It's analogous to catching a cannonball tossed vertically upward, just at
: the top of the trajectory. At the moment of grab, your hands are not
: knocked upward or downward. But at that moment, they start feeling a
: strong downward force, and your feet may start sinking slowly into the
: mud.
No different from what you would feel if someone (very strong ;-)\ ) put
the cannonball into your hands and let go. At the top of its arc the ball
has zero vertical velocity. This may be what you meant, but I can't be
sure.
: Note: there is a second-order jolt problem, which is caused by the fact
: that the ship comes in with no spin, and has to gain some when it clamps
: on. This puts twisting force on the docking clamps. Very bad. But it's
: easy to fix -- have the ship spinning slowly as it approaches (on its
: straight-line tangent course.) Same rpm as the station, same direction.
: The timing is a little trickier, because you have to make sure the ship's
: nose is pointed stationwards at the moment of contact.
Yah, you do it by using attitude {jets or equivalent}. And as someone said
earlier, it is tricky, which is why the station wants it under their
comp's control.
-- Mark A. Mandel
--
If you're reading this in a newsgroup: to reply by mail,
remove the obvious spam-blocker from my edress.
Justin Fang
In article <Euysz...@midway.uchicago.edu>,> Doesn't that happen regardless? At any given time while it's
>latched on the rim, the ship's inertia will tend to carry it in a
>straight line tangent to the spin. The station needs either
>stabilization thrusters or some mass to balance the ship, or it's not
>going to spin smoothly.
Isn't there a bit in _Downbelow Station_ where the the controls keeping the
rotation of the station steady get temporarily disrupted?
--
Justin Fang (jus...@ugcs.caltech.edu)
This space intentionally left blank.
Justin Fang
In article <898601521.9717.0...@news.demon.co.uk>,
David Given <dg@> wrote:
>Diversion: the Compact may not be able to short jump, but they appear to
>be able to use they hyperdrives to push up their velocity very quickly.
>_Pride_ appeared to pulse up to translight speeds in several bursts, and
>then, on entry to the target system, do the same thing in reverse to dump
>speed. I've never seen a human ship do that.
Um, I got the impression human ships did that all the time. How else do the
carriers manage to get up to fractional-c speeds insystem (besides when
they're coming in from a jump, that is)? I also thought that the rider
drives were basically baby versions of the FTL drive.
Of course, I may be misremembering...
Andrew Plotkin
> : It's analogous to catching a cannonball tossed vertically upward, just at
> : the top of the trajectory. At the moment of grab, your hands are not
> : knocked upward or downward. But at that moment, they start feeling a
> : strong downward force, and your feet may start sinking slowly into the
> : mud.
> No different from what you would feel if someone (very strong ;-)\ ) put
> the cannonball into your hands and let go. At the top of its arc the ball
> has zero vertical velocity. This may be what you meant, but I can't be
> sure.
Yes, this is what I meant. Good analogy extension.
> : Note: there is a second-order jolt problem, which is caused by the fact
> : that the ship comes in with no spin, and has to gain some when it clamps
> : on. This puts twisting force on the docking clamps. Very bad. But it's
> : easy to fix -- have the ship spinning slowly as it approaches (on its
> : straight-line tangent course.) Same rpm as the station, same direction.
> : The timing is a little trickier, because you have to make sure the ship's
> : nose is pointed stationwards at the moment of contact.
> Yah, you do it by using attitude {jets or equivalent}. And as someone said
> earlier, it is tricky, which is why the station wants it under their
> comp's control.
Agreed.
Kristopher/EOS
Andrew Plotkin wrote:
>
> Kristopher/EOS (eosl...@net-link.net) wrote:
> > > The ship's trajectory is tangent to the rim. The approach is
> > > carefully timed so that the ship will pass the station rim at its
> > > assigned docking port, moving at the same velocity as the rim's
> > > rotation. At this point, the extended grapples snag the ship's frame
> > > and pull it in to the dock.
>
> > We've already covered why that doesn't work. A ship on a linear
> > trajaectory imparts quite a jolt to the station...it's moving at the
> > velecity of the station rim with respect to the station as a whole,
> > just as you said. This would not be good for the station, the ship,
> > or any of the people involved.
> >
> > of the rim while minimizing its linear velocity WRT to station as a
> > whole.
>
> I've just been dipping in and out of the thread, but it seems to me that
> this is completely and totally wrong. Er, sorry. :)
>
> The approach is irrelevant -- momentum doesn't have a memory.
>
> The only thing that's relevant is the moment of grab-on. At that moment, if
> the ships velocity is tangent to the rim and has the same linear velocity,
> the docking is smooth. The station is not "jolted" with an instant
> application of delta-vee.
>
> The station *is* "jolted" with an instant application of *force* --
> centrifugal force, directed radially outward. (Yes, or centripetal force,
> same result no matter which way you work it out.) That's a different kind
> of jolt.
>
> the top of the trajectory. At the moment of grab, your hands are not
> knocked upward or downward. But at that moment, they start feeling a
> strong downward force, and your feet may start sinking slowly into the
> mud.
>
> station's COG. And just after the join, the whole system still has that
> momentum. But it's still distributed as it was before, because the
> centripetal force pulling on the docking clamps hasn't had time to
> transfer it yet. Over time, the docking clamp force transfers momentum
> back and forth -- exactly in the manner of two rigidly-connected objects
> spinning around a common COG. Which is what we have. (The station is
> heavier, so the common COG is near the station's center. This is a
> detail.)
>
> that the ship comes in with no spin, and has to gain some when it clamps
> on. This puts twisting force on the docking clamps. Very bad. But it's
> easy to fix -- have the ship spinning slowly as it approaches (on its
> straight-line tangent course.) Same rpm as the station, same direction.
> The timing is a little trickier, because you have to make sure the ship's
> nose is pointed stationwards at the moment of contact.
So where does the ship's inertia go? It has inertia, because it has
mass, and whatever velocity the rim of the staion has. The station
has to "jerk" the ship into a circular path around the new center of
gravity...it has to overcome the inertia of the ship. The ship is
moving in a straight line, with a velocity equal to the rim of the
station, and then it is NOT moving in a straight line. So, some force
had to act on the ship...simple newtonian stuff...an object in motion
and all that.
Kristopher/EOS
Andrew Plotkin
Kristopher/EOS (eosl...@net-link.net) wrote:
> > The approach is irrelevant -- momentum doesn't have a memory.
> >
> > The only thing that's relevant is the moment of grab-on. At that moment, if
> > the ships velocity is tangent to the rim and has the same linear velocity,
> > the docking is smooth. The station is not "jolted" with an instant
> > application of delta-vee.
> >
> > The station *is* "jolted" with an instant application of *force* --
> > centrifugal force, directed radially outward. (Yes, or centripetal force,
> > same result no matter which way you work it out.) That's a different kind
> > of jolt.
> > To put it differently: yes, the ship has linear velocity compared to the
> > station's COG. And just after the join, the whole system still has that
> > momentum. But it's still distributed as it was before, because the
> > centripetal force pulling on the docking clamps hasn't had time to
> > transfer it yet. Over time, the docking clamp force transfers momentum
> > back and forth -- exactly in the manner of two rigidly-connected objects
> > spinning around a common COG. Which is what we have. (The station is
> > heavier, so the common COG is near the station's center. This is a
> > detail.)
> So where does the ship's inertia go? It has inertia, because it has
> mass, and whatever velocity the rim of the staion has. The station
> has to "jerk" the ship into a circular path around the new center of
> gravity...it has to overcome the inertia of the ship. The ship is
> moving in a straight line, with a velocity equal to the rim of the
> station, and then it is NOT moving in a straight line.
This is exactly what I was addressing with the paragraphs quoted above.
You don't have to jerk something from a tangent path into a circular path
-- it's not an instantaneous change of velocity. So overcoming inertia is
not a problem. (Except, as I said in a snipped paragraph, the
second-order problem of the ship's spin.)
It *is* an instantaneous change of *force*. That force is the inward pull
of the clamps, which goes from zero to a one-gee pull at the moment of
grab. The ship's course begins changing at that moment; the velocity
graph has a corner but not a discontinuity.
A circular path is, moment-to-moment, a bunch of short straight paths.
(Or can be approximated so -- calculus is fun.) Centripetal force applies
the changes.
I could start drawing graphs... :-)
David G. Bell
In article <slrn6p0jsa...@grace.acm.rpi.edu>
ne...@acm.rpi.edu "Damien Neil" writes:
> On Tue, 23 Jun 1998 20:17:30 -0400, Kristopher/EOS <eosl...@net-link.net>
> wrote:
> >We've already covered why that doesn't work. A ship on a linear
> >trajaectory imparts quite a jolt to the station...it's moving at the
> >velecity of the station rim with respect to the station as a whole,
> >just as you said. This would not be good for the station, the ship,
> >or any of the people involved.
>
> Hrm.
>
> There isn't anything in life OTHER than a linear trajectory. At least,
> absent forces acting on the object. You can't send a ship on a spiral
> trajectory without keeping the engines on all the time. And if you do
> that...well, why? You get the same effect by approaching on a straight
> path, and flipping the engines on at the last second.
Good point, but the practical engineering and safety problems would
probably be better served by a longer final burn. If there is any error
in the timing of the approach, for instance, it would be better if the
straight-line vector was clear of the station by the length of a docked
ship. Also, a burn that is sustained after the initial docking contact,
and which can be throttled down in a controlled manner, allows time for
the pumping of ballast between the tanks around the rim, and the
maintenance of balance when the engines are off. Similarly for the
undocking.
A safe miss distance if the thrusters don't fire for any reason, coupled
with enough time for thruster operating conditions to stabilise, appears
to have several advantages over tring to suddenly bang it in.
Craig West
David G. Bell (db...@zhochaka.demon.co.uk) wrote:
+>Good point, but the practical engineering and safety problems would
+>probably be better served by a longer final burn. If there is any error
+>in the timing of the approach, for instance, it would be better if the
+>straight-line vector was clear of the station by the length of a docked
+>ship. Also, a burn that is sustained after the initial docking contact,
+>and which can be throttled down in a controlled manner, allows time for
+>the pumping of ballast between the tanks around the rim, and the
+>maintenance of balance when the engines are off. Similarly for the
+>undocking.
+>A safe miss distance if the thrusters don't fire for any reason, coupled
+>with enough time for thruster operating conditions to stabilise, appears
+>to have several advantages over tring to suddenly bang it in.
Hmm. This trick of keeping the thrust going after the initial contact would be
very helpful in getting the ship's spin up to the same rate as the station.
It would remove the tensile loading on the docking clamps, at least until
the spin was matched, and the tensile loading would be a steady 1G, which
would be much easier to deal with.
--
Craig West Ph: (905) 821-8300 | It's not a bug,
Pulse Microsystems Fx: (905) 821-7331 | It's a feature...
2660 Meadowvale Blvd, Unit #10 | acw...@echo-on.net
Mississauga, Ont., Canada L5N-6M6 | cr...@pulsemicro.com
Graydon
In article <6mptgn$3...@gap.cco.caltech.edu>,
Justin Fang <jus...@ugcs.caltech.edu> wrote:
>In article <Euysz...@midway.uchicago.edu>,
>Michael S. Schiffer <ms...@midway.uchicago.edu> wrote:
>> Doesn't that happen regardless? At any given time while it's
>>latched on the rim, the ship's inertia will tend to carry it in a
>>straight line tangent to the spin. The station needs either
>>stabilization thrusters or some mass to balance the ship, or it's not
>>going to spin smoothly.
>
>Isn't there a bit in _Downbelow Station_ where the the controls keeping the
>rotation of the station steady get temporarily disrupted?
There is; carriers leaving with great abruptness, and the damping system
(which works by pumping fluids around rim holding tanks to maintain
balance) can't cope in the short term.
Michael S. Schiffer
In article <1db4kng.1xh...@baboon-filt-24.rmplc.co.uk>,>Extreme trimming:
>
>> instantaneously accelerating from zero-g to 1 g
>Accelerating from no acceleration to 9.8 m/s/s, that's some acceleration
Not necessarily. You can do the same thing by jumping off
your porch, after all.
Tom Carman
On Wed, 24 Jun 1998 20:19:51 GMT, j...@freeyellow.com (Johnny TwoBit)
wrote:
>The sketch of the station also clearly shows that ships are supposed
>to dock on the _side_ of the station rim rather than hanging straight
>out from it, the axis of the ship is paralell to the axis of the station.
>This will stress the grapples _considerably_ , it's like holding a
>baseball bat straight out from your hip holding it just on the knob
>with one hand. This requires a good grip, a strong hand and a handle
>that cannot be to thin or it will snap. Since the walls are used as
>floors during burn anyway it would make more sense to let the ship
>just hang from the nose, something that would give a lot less stress
>and would yield more floor space than that slim ship-long strip of
>cylinder used as floor this way. Now the forces try to bend the ship
>away from the rotation all the time instead of just initially if it
>hangs from the nose.
>
>I wonder why she chose this method?
You appear to be assuming that the grapples holding a ship are just
around the docking guide cone. Assuming that the cover painting is
gospel (I don't; for one thing, there aren't _near_ enough docking
ports shown), there would probably be grapples retracted into the ring
wall "above" the docking ports that hold on to the ship's frame.
I am picturing something that would be left off the cover painting for
aesthetics, and off the diagram for clarity. The habitat ring is
probably half or less of the width (thickness?) of the wheel. The
rest of the wheel would be unpressurized (maybe open gridwork, maybe
enclosed). The frames above and beside the docking ports would
provide attachment points for the grapples, and access to cargo holds
in the ship's frame, fuel tanks, engine systems, etc. I can't recall
anything in the text on this subject.
aRJay
In an article using recycled electrons Johnny TwoBit wrote :-
>The sketch of the station also clearly shows that ships are supposed
>to dock on the _side_ of the station rim rather than hanging straight
>out from it, the axis of the ship is paralell to the axis of the station.
>This will stress the grapples _considerably_ , it's like holding a
>baseball bat straight out from your hip holding it just on the knob
>with one hand. This requires a good grip, a strong hand and a handle
>that cannot be to thin or it will snap. Since the walls are used as
>floors during burn anyway it would make more sense to let the ship
>just hang from the nose, something that would give a lot less stress
>and would yield more floor space than that slim ship-long strip of
>cylinder used as floor this way. Now the forces try to bend the ship
>away from the rotation all the time instead of just initially if it
>hangs from the nose.
>
>I wonder why she chose this method?
Possibly because in your method the nose of the ship is at 1g but the
vanes etc are at a higher level and maybe she doesn't like holes in the
floor of her station.
--
aRJay
David G. Bell
In article <jpl-250698...@dialup184-2-46.swipnet.se>
j...@freeyellow.com "Johnny TwoBit" writes:
> In article <+SnpIJAg...@escore.demon.co.uk>, aRJay
> <aR...@escore.demon.co.uk> wrote:
>
> Possibly Cherryh had the idea of pumping balast water not only to the
> opposite ring half to balance the weight, but also to the opposite wall
> to counteract the tilting. This would require a lot of water though, but
> before I or anyone else gets too critical I's like to say that she does
> a great job on the technical stuff considering that she doesn't have any
> real technical education, her studies where as far as I know more academical.
Classics. But I suspect you're underestimating the educational
standards of the past. The mechanics of all this is very simple, and,
while you might need calculus to prove the equations that give the force
exerted to move a body along a circular arc, the figures are simple
arithmetic.
J.
J...@bluejo.demon.co.uk (Jo Walton) wrote:
>My Capella theory and Graydon's "then that explains the biological
>oddnesses in the Compact" theory are indeed stretching, but given
>that those things are, by textual reference or by authorial plain
>statement, in the same universe, it's not all that bad.
Hmm. First, thanks to all of you for answering my original query.
Second, I gotta agree with you, Jo: the theory is *stretching* indeed.
If the abilities of the Qhal are what they appear to be, why on Earth
would they *go* to Earth for their biological playthings? Granted
that the Fleet colony has imported trees and various other specimens,
but wouldn't it make so much more sense to use what they've found at
the sites for uplift purposes? Takes away a lot of the work (hauling
and much of the bioengineering), and explains some of the *vast*
differences found between Compact races and those of Earth (the Kif's
double jaws, the common ability of Compact species' [other than Stsho]
to handle jump without drugs, etc., etc.). I can see the Qhal
creating races in the old neighborhood, but I seriously doubt they
used Terran animal stock to do so. I think Cherryh just found some
interesting behaviors in various species and decided to explore them
using aliens as examples.
And somebody explain how Stsho were made from octopuses. That one has
me flummoxed.
>I don't, for the record, think Cherryh had that in mind when she
>wrote :Gate:, I think she was just using the same universe and
>then she put a lot of cool stuff in and it didn't all quite work
>together. As I said originally, that's a paint-self-out-of-corner
>solution she could use if she wanted to to justify that sort of
>thing. As she doesn't seem even slightly bothered by inconsistencies
>and she also seems to have moved on to writing in different universes,
>this will probably never be illuminated unless some light is shone
>by :Cyteen 2: when she writes it.
>
>--
>Jo - - I kissed a kif at Kefk - - J...@bluejo.demon.co.uk
>xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>http://www.bluejo.demon.co.uk - Blood of Kings Poetry; rasfw FAQ;
>Reviews; Interstichia; Momentum - a paying market for real poetry.
>
David Given
In article <robertaw-230...@blv-lx105-ip12.nwnexus.net>,
Robert A. Woodward <robe...@halcyon.com> wrote:
[...]
>> Diversion: the Compact may not be able to short jump, but they appear to
>> be able to use they hyperdrives to push up their velocity very quickly.
>> _Pride_ appeared to pulse up to translight speeds in several bursts, and
>> then, on entry to the target system, do the same thing in reverse to dump
>> speed. I've never seen a human ship do that.
>>
>
>the end when they were mouse-trapping a Mazani ship IIRC).
I haven't read that one. I'll have to look out for it.
Strange, isn't it, that you get this perfectly clear, detailed and
consistent image of what's happening in a book inside your head... and
it's completely inconsistent with anyone else's. Part of the magic of
reading...
--
+- David Given ----------------+
| Work: d...@tao.co.uk | Truth is stranger than fiction, because
| Play: dgi...@iname.com | fiction has to make sense.
+- http://wiredsoc.ml.org/~dg -+
David Zink
In article <898809...@zhochaka.demon.co.uk>
But where her lack of education may hobble her is that she may not
understand the energy requirements for moving that much ballast water,
nor have a good grasp of the reasonable limits of how fast it could be
done. For instance, assuming the transfer is done at less than the
speed of sound (in the water), how much bobble will the station
develop before the water has all been moved? One assumes undocking a
ship is effectively (by those time standards) instantaneous, or there
is at least some miniscule passage of time when ship goes from full
contact to almost none.
David G. Bell
The time factor is why I suggested that docking/undocking would involve
a sustained thruster burn, normally controlled by the station, with the
thrust changing to compensate for the movement of the ballast.
In normal operation, the ship would be in a powered orbit around the
station at the point when the docking latches operate.
Now, if you want to suggest that C.J. hasn't worked out how long it
would take to move the ballast, and how much reaction mass the ship
would expend, I wouldn't argue. But even an SF novel is a _novel_. We
may expect a better appreciation of science and engineering, and laugh
at writers who have a short-sighted boy use his spectacle lenses to
light a fire with sunlight, but we don't expect the author to have run a
detailed mathematical simulation of the events.
Andrew Plotkin
> may expect a better appreciation of science and engineering, and laugh
> at writers who have a short-sighted boy use his spectacle lenses to
> light a fire with sunlight, but we don't expect the author to have run a
> detailed mathematical simulation of the events.
Of course not -- that's what fans are for. :)
Rimrunner
In article <1998062310...@a-pd12-35.tin.it>,
Anna F. Dal Dan <ada...@nit.it> wrote:
>Georyn <geo...@aol.com> wrote:
>
>> Oh, there's a fourth book in the series, "Exile's Gate", but I'm always
>> wary of sequels written fifteen years after the original trilogy.
>
>It's not really a "trilogy". More like an open-ended series. Exile's is
>to me one of the best if not *the* best of the bunch. Trouble is, it
>begs a sequel that doesn't seem to be forthcoming.
I think she's said that she would do it if a publisher bought it. None
seem to have picked it up yet, which is a shame because I'm *dying* to
know what happened on the other side of that gate...
Rimrunner
let's go world-hopping!
--
Murder of Crows: http://www.nwlink.com/~noah/ EP NOW AVAILABLE
Force This!: http://www.shavenwookie.com/rimrun
"Son of god or son of man, you can't fuck your sister and expect
much good to come of it." -- Starr, "Preacher"
--
Del Cotter
On Mon, 22 Jun 1998, in rec.arts.sf.written
Damien Neil <ne...@acm.rpi.edu> wrote
>Things get even more entertaining in Compact space -- they have not just
>different versions of the same species' tech, but different versions of
>different species.
And at the end of _The Pride of Chanur_, a human ship docks at Meetpoint
and a group of humans walk out onto the station. No-one in Compact
space has ever seen a human ship before.
>I suspect you could dock a cow to a Compact station, if you could find
>a way to attach the vanes.
--
Del Cotter d...@branta.demon.co.uk
The Alien Design Bibliography
http://www.branta.demon.co.uk/alien-design/
Jyrki Valkama
Distribution:
In rec.arts.sf.written Del Cotter <d...@branta.demon.co.uk> wrote:
: On Mon, 22 Jun 1998, in rec.arts.sf.written
: Damien Neil <ne...@acm.rpi.edu> wrote
: >Things get even more entertaining in Compact space -- they have not just
: >different versions of the same species' tech, but different versions of
: >different species.
: And at the end of _The Pride of Chanur_, a human ship docks at Meetpoint
: and a group of humans walk out onto the station. No-one in Compact
: space has ever seen a human ship before.
If I remember correctly there was some mention about emergency couplings
and improvisations to said coupling.
: >I suspect you could dock a cow to a Compact station, if you could find
: >a way to attach the vanes.
Emergency couplings might do the trick as they would be equipped to couple
any part of ship damaged or undamaged.
--
Jyrki Valkama
Tharsia
><HTML><PRE>On Mon, 22 Jun 1998, in rec.arts.sf.written
>Damien Neil <ne...@acm.rpi.edu> wrote
>
>>Things get even more entertaining in Compact space -- they have not just
>>different versions of the same species' tech, but different versions of
>>different species.
>
>And at the end of _The Pride of Chanur_, a human ship docks at Meetpoint
>and a group of humans walk out onto the station. No-one in Compact
>space has ever seen a human ship before.
>
>>a way to attach the vanes.
>
Rubber cement.
Seriously -- some similar fluid sealant, quick-hardening but
still-flexible-when-solid. You pump whacking great gobs of it around your
coupling to fill in all the gaps, and you peel it off when you're done and
ready to go. If it's like hot-glue, you can reuse it . . .
Tharsia/aol.com (aka joan barger; standardize address to reply)
--Whoever does not study history is doomed to repeat it
"But when I came at last to wive
(With a hey, ho, the wind and the rain)
With swaggering I never could thrive --"