Spaceflight without electricity?
Allen Thomson
In the absence of sci.space.what-if, I'll ask this question here, as it
vexes me every now and then:
Is there anything about manned spaceflight that requires even
electricity, let alone electronics?
Could a no-electricity analog of Soyuz or Gemini work? How about
Apollo? Not just the orbital vehicles, but the launchers, stuff on the
ground, the works.
I keep thinking there should be *something* that at least requires a
battery, an electric motor, maybe a lightbulb. But I haven't
identified it as yet. Note that I don't dispute for a minute that
electricity, electronics, radios are really nice things to have and
make life a lot easier for rocket scientists; but are they absolutely
necessary for getting to orbit, maybe the moon, and coming back?
Sent via Deja.com http://www.deja.com/
Before you buy.
John Schilling
I can't think of anything that absolutely requires electricity either.
The obvious place to look is in the flight controls and instrumentation.
I rather suspect mechanical flight computers would be too heavy, so
you'd be limited to manual control with hydraulic boosting. The pilot
would have to fly a boost trajectory using a vacuum gyro, mechanical
accelerometer, stopwatch, and the like. Might be doable, but I wouldn't
bet on an optimal trajectory, much less any sort of robust failure recovery.
The less-obvious place to look is in staging. Electricity to fire the
pyros and light the engines is *really* useful, and the only substitutes
I can see are major kludges. I have a mental image of Duck Dodgers
holding a match to a length of cannon fuse labeled "Stage 2" protruding
from his control panel...
--
*John Schilling * "Anything worth doing, *
*Member:AIAA,NRA,ACLU,SAS,LP * is worth doing for money" *
*Chief Scientist & General Partner * -13th Rule of Acquisition *
*White Elephant Research, LLC * "There is no substitute *
*schi...@spock.usc.edu * for success" *
*661-951-9107 or 661-275-6795 * -58th Rule of Acquisition *
MA Lloyd
>In the absence of sci.space.what-if, I'll ask this question here, as it
>vexes me every now and then:
>Is there anything about manned spaceflight that requires even
>electricity, let alone electronics?
Probably not. There are lot of things that are a lot easier with
electronics, but the basic technology (rockets) predates electricity
by quite a bit. I suspect the hardest problems to work around without
electricity are going to be obtaining affordable light metals (which
means your structural weights are going to be high) and doing navigation
without radio.
--
-- MA Lloyd (mall...@io.com)
cra...@hotmail.com
Allen Thomson <thom...@flash.net> wrote:
>
>
> In the absence of sci.space.what-if, I'll ask this question
> here, as it vexes me every now and then:
>
> Is there anything about manned spaceflight that requires even
> electricity, let alone electronics?
Hmm.
"The isolated colony on, um, Vesta was one of the surviving
bastions of humanity after the terrible WWIII, or the First
Interplanetary War. While many necessities for human life
could be found there, Vesta was desperately short of some
critical metals and the ability to produce electronics. It
was not for lack of talent that Vesta could not build significant
electronics, but rather for lack of knowledge. EMP from Rooskies
and ChiCom attacks had destroyed computers. Blowouts had stolen
the skilled workers and scientists who might've replaced the
destroyed databases. Thus, while able to build intricate
mechanical gizmos and machinery, Vesta could not so much as
make a simple vacuum tube.
"Desperately needing resources on other asteroids, the
inhabitants of Vesta set about building spacecraft to reach
USSt-1978e (US Steel Asteroid, the fifth nickel-iron asteroid
discovered and claimed by that long-gone corporation in 1978)."
>
> Could a no-electricity analog of Soyuz or Gemini work? How about
> Apollo? Not just the orbital vehicles, but the launchers, stuff on
the
> ground, the works.
Aw, darn. The launchers? Orbital vehicles I could justify.
Steam and hydraulic systems for power, hydroponics and
chemical scrubbers for lifesupport...no problem. Heavy, but
no problem. Programmable Babbage Engines for navigation and
control.
But the launchers...sure, why not? How many electronic
gizmos does a solid rocket booster actually need? :)
--
Mike Miller, Materials Engineer
Henry Spencer
Allen Thomson <thom...@flash.net> wrote:
>Is there anything about manned spaceflight that requires even
>electricity, let alone electronics?
Mmmm... Interesting problem. You'd have to accept some mass increases,
of course.
Launching into orbit without electronics in the guidance systems would be
tricky. Not impossible, but it would be a considerable challenge to get
something accurate enough to be workable for manned flight. The accuracy
requirements are fairly tight, to reliably reach orbit and yet stay below
the inner Van Allen belt.
Once launched, you could do without electronics in LEO (and for descent)
if the designers were careful and clever. You could probably even do
fairly sophisticated work; non-computer/radar methods of navigation etc.
have been tested and do work. Rendezvous would be pretty challenging but
could probably be done, especially if you had plenty of fuel and weren't
in a big hurry.
>...How about Apollo?
I have doubts about navigation and trajectory calculation, which are a lot
harder for lunar trips than for LEO. Maybe. Given large performance
margins, you could be less fussy about trajectory. Apollo's navigation
optics were not themselves electrical, although the inertial system and
computer behind them were; limited substitutes might be feasible.
--
Microsoft shouldn't be broken up. | Henry Spencer he...@spsystems.net
It should be shut down. -- Phil Agre | (aka he...@zoo.toronto.edu)
Steve Schaper
Allen Thomson wrote:
>
> In the absence of sci.space.what-if, I'll ask this question here, as it
> vexes me every now and then:
>
> Is there anything about manned spaceflight that requires even
> electricity, let alone electronics?
>
Advanced clockwork, including a Babbage engine?
whiten...@my-deja.com
> Is there anything about manned spaceflight that requires even
> electricity, let alone electronics?
Navigation alone absolutely requires electronics (and thus electricity).
Without them you might get into SOME orbit, but not to any specific
point in orbit, let alone Moon. Life-support system MIGHT be doable
without electricity (steam powered?), but would be enormously heavier
and with far more moving parts prone to breaking. Likewise for firing
retro-rockets to return home - can be done in a purely mechanical
manner, but far heavier and less reliable.
> Could a no-electricity analog of Soyuz or Gemini work? How about
> Apollo? Not just the orbital vehicles, but the launchers, stuff on
the
> ground, the works.
No. The best you could do without electricity is a suborbital shot to no
place in particular.
Michel Morton
Allen Thomson wrote:
>
> In the absence of sci.space.what-if, I'll ask this question here, as it
> vexes me every now and then:
>
> Is there anything about manned spaceflight that requires even
> electricity, let alone electronics?
>
> Could a no-electricity analog of Soyuz or Gemini work? How about
> Apollo? Not just the orbital vehicles, but the launchers, stuff on the
> ground, the works.
>
I'd say it's doable but not easy, if we imagine a simple orbital
capsule..
Life Support
Use an open system similar to SCUBA equipment, using pressurized
or liquid O2 with waste atmosphere simply vented overboard.
Control
Cold gas thrusters with valves mechanically linked to the flight
controls. Something like the Vostock Vizor device could be used
to line up the spacecraft for the de-orbit burn.
Engines
For de-orbit, probably some sort of pressure fed liquid system
similar to the LM ascent engine. Just turn the valve to start it.
Re-Entry
Use a stable shape, like the Vostock sphere. You could probably get
away with conventional parachutes, with a mortar deployed drogue
to deploy the main. The astronaut would fire the mortar manually
at the appropriate altitude.
The trouble is, everything would have to be self-contained. It's
hard to imagine how you could have mechanical controls going through
a pressure hull to operate systems in a separate service module or
how to reliably severe those links when you wanted to discard the
thing before re-entry.
End result. A big, heavy capsule that couldn't do much more then
keep a person alive in orbit for 24 hours then bring them back. Imagine
something Apollo CM sized with space only for one and that would
probably
be quite a risky thing to fly. The launcher would be the significant
problem however. How you'd built one of those that could work without
electricity I'll leave for somebody else.
--
Michael Morton
>==========================================================<
School of Information Systems | Everything is linear if
University of East Anglia | plotted on log-log with
Norwich | a fat magic marker.
>==========================================================<
Herman Rubin
Allen Thomson <thom...@flash.net> wrote:
>In the absence of sci.space.what-if, I'll ask this question here, as it
>vexes me every now and then:
>Is there anything about manned spaceflight that requires even
>electricity, let alone electronics?
>Could a no-electricity analog of Soyuz or Gemini work? How about
>Apollo? Not just the orbital vehicles, but the launchers, stuff on the
>ground, the works.
>I keep thinking there should be *something* that at least requires a
>battery, an electric motor, maybe a lightbulb. But I haven't
>identified it as yet. Note that I don't dispute for a minute that
>electricity, electronics, radios are really nice things to have and
>make life a lot easier for rocket scientists; but are they absolutely
>necessary for getting to orbit, maybe the moon, and coming back?
I doubt that they are absolutely necessary. However, controls
would be much more difficult, and other sources of lighting
would be very hard to handle on a spacecraft. One place where
there might be major problems is in handling distances; are the
mechanical methods of calculating light paths adequate for
the necessary adjustments of height, and especially so for
something as precise as a lunar landing? Triangulation at
orbital speeds might not be easy.
There was considerable discussion at one time of the possibility
of computers operating through air pressure, and "hydraulic"
controls using air pressure as well as other fluids could be
used. Computation itself is not a problem.
--
This address is for information only. I do not claim that these views
are those of the Statistics Department or of Purdue University.
Herman Rubin, Dept. of Statistics, Purdue Univ., West Lafayette IN47907-1399
hru...@stat.purdue.edu Phone: (765)494-6054 FAX: (765)494-0558
Christopher M. Jones
"Allen Thomson" <thom...@flash.net> wrote:
> In the absence of sci.space.what-if, I'll ask this question here, as it
> vexes me every now and then:
>
> Is there anything about manned spaceflight that requires even
> electricity, let alone electronics?
>
> Could a no-electricity analog of Soyuz or Gemini work? How about
> Apollo? Not just the orbital vehicles, but the launchers, stuff on the
> ground, the works.
>
> I keep thinking there should be *something* that at least requires a
> battery, an electric motor, maybe a lightbulb. But I haven't
> identified it as yet. Note that I don't dispute for a minute that
> electricity, electronics, radios are really nice things to have and
> make life a lot easier for rocket scientists; but are they absolutely
> necessary for getting to orbit, maybe the moon, and coming back?
I suppose you could get away with not using electricity, but
it wouldn't be easy. I'd imagine the hardest part would actually
be launching the rocket! Big rockets require active control
systems and computers, since they are usually inherently not
stable. It might be possible to launch a rocket with no active
control but it would be a _severe_ pain in the ass, and very
dangerous besides. After that things are a bit easier but still
difficult.
Electronics and rocketry go together _really_ well. They are
almost like brother and sister. All modern rocket engines are
electronically started. I suppose you could create a non-
electronic system for running attitutde control jets, etc.
Maybe some sort of collection of valves and rods and hydraulics
and wires and fuses and caps etc. For example, you could use
a fuse to light a solid rocket motor for your descent engine
to re-enter the atmosphere. Maybe you could have a battery
of little one-shot solid rocket motors on the outside of your
spacecraft that were each set off by a percussion cap for
attitude control (each cap would be set off by a hammer that
could be activated by an individual switch inside the craft).
I'd imagine you might want to use momentum wheels or something
like that for attitude control instead. It would certainly
make things interesting. One thing though is that it would
be a lot like flying a small plane, only a lot more demanding.
The biggest problem I see is simply navigation. It takes a
lot of precision to navigate in space, especially if you want
to land on the Earth and not die. You might be able to do
some of that navigation by the seat of your pants. You
certainly could not get away with not knowing advanced
mathematics though. In fact, it would be much more important
then than with electronics.
So, I guess I'd have to say "it's possible, but it won't be
easy, and it will be a _lot_ more dangerous".
Christopher M. Jones
a sci.space.what-if of sorts (as well as other things)).
"Allen Thomson" <thom...@flash.net> wrote in message
news:8sig7g$cb0$1...@nnrp1.deja.com...
>
>
>
> In the absence of sci.space.what-if, I'll ask this question here, as it
> vexes me every now and then:
>
> Is there anything about manned spaceflight that requires even
> electricity, let alone electronics?
>
> Could a no-electricity analog of Soyuz or Gemini work? How about
> Apollo? Not just the orbital vehicles, but the launchers, stuff on the
> ground, the works.
>
> I keep thinking there should be *something* that at least requires a
> battery, an electric motor, maybe a lightbulb. But I haven't
> identified it as yet. Note that I don't dispute for a minute that
> electricity, electronics, radios are really nice things to have and
> make life a lot easier for rocket scientists; but are they absolutely
> necessary for getting to orbit, maybe the moon, and coming back?
>
>
Christopher M. Jones
"John Schilling" <schi...@spock.usc.edu> wrote:
> I can't think of anything that absolutely requires electricity either.
>
> The obvious place to look is in the flight controls and instrumentation.
> I rather suspect mechanical flight computers would be too heavy, so
> you'd be limited to manual control with hydraulic boosting. The pilot
> would have to fly a boost trajectory using a vacuum gyro, mechanical
> accelerometer, stopwatch, and the like. Might be doable, but I wouldn't
> bet on an optimal trajectory, much less any sort of robust failure
recovery.
Mechanical computers, excellent, I wonder why I didn't think of
that? Now, weight is definitely going to be a problem, however,
if you assume some sort of nth generation mechanical computer,
it would probably be quite a bit smaller and faster and probably
require less power. Also, if we suppose that all this is taking
place not on an Earth like planet, but perhaps a moon of a gas
giant or something of that sort, then the decreased gravity might
give you more leeway in terms of launching heavy stuff.
> The less-obvious place to look is in staging. Electricity to fire the
> pyros and light the engines is *really* useful, and the only substitutes
> I can see are major kludges. I have a mental image of Duck Dodgers
> holding a match to a length of cannon fuse labeled "Stage 2" protruding
> from his control panel...
Heh. Although I would imagine that you wouldn't have to physically
light the fuse from inside the cabin, you can setup mechanical
whosawhatsits to do that.
Michael J Wise
> The obvious place to look is in the flight controls and instrumentation.
BioComputers? "ShadowTech"?
> The less-obvious place to look is in staging. Electricity to fire the
> pyros and light the engines is *really* useful, and the only substitutes
> I can see are major kludges.
Find out how an "Electric Eel" does it?
> I have a mental image of Duck Dodgers holding a match to a length of
> cannon fuse labeled "Stage 2" protruding from his control panel...
Cute!
Aloha mai Nai`a!
--
"Please have your Internet License http://kapu.net/~mjwise/
and Usenet Registration handy..."
jakem...@my-deja.com
schi...@spock.usc.edu (John Schilling) wrote:
> The less-obvious place to look is in staging. Electricity to fire the
> pyros and light the engines is *really* useful, and the only
> substitutes I can see are major kludges
Lighting engines is easy - just use hypergolic propellants.
Stage sep is a bit tougher, but again hydraulics could save the day.
Hold your stages together with a couple of bolts for static loads and
some hefty hydraulically activated latches for dynamic loads. After
engine cutoff, undo the latches, then use hydraulic rams to push the
stages apart, breaking the bolts. All the heavy stuff goes on the
lower stage, of course.
--
Jake McGuire
cfr...@my-deja.com
At least two crewed US missions suffered near-total power failure, and
a couple of Soviet missions. Reentry was performed without power to
most systems.
An interesting case was Mercury Faith-7 piloted by Gordon Cooper.
Re-entry was performed with no electrical power to any of the control
systems. Even life support was out, and CO2 levels above limits. The
only electrical system functioning was communications, but even this
was not essential. Comm was only important to get an accurate
countdown to start the re-entry burn in order to hit the target area.
Otherwise, he could have re-entered safely in the blind but nobody
would know where he landed, making recovery very difficult.
The re-entry manouvers, orientation, burn, attitude control and
parachute deployment were all performed manually with no electrical
power.
jtingle
Christopher M. Jones <christ...@uswest.net> wrote in message
news:I4rH5.902$7V6.2...@news.uswest.net...
>
> "John Schilling" <schi...@spock.usc.edu> wrote:
> > I can't think of anything that absolutely requires electricity either.
> >
> > you'd be limited to manual control with hydraulic boosting. The pilot
> > would have to fly a boost trajectory using a vacuum gyro, mechanical
> > accelerometer, stopwatch, and the like. Might be doable, but I wouldn't
> > bet on an optimal trajectory, much less any sort of robust failure
> recovery.
>
> Mechanical computers, excellent, I wonder why I didn't think of
> that? Now, weight is definitely going to be a problem, however,
> if you assume some sort of nth generation mechanical computer,
> it would probably be quite a bit smaller and faster and probably
> require less power. Also, if we suppose that all this is taking
> place not on an Earth like planet, but perhaps a moon of a gas
> giant or something of that sort, then the decreased gravity might
> give you more leeway in terms of launching heavy stuff.
>
> > pyros and light the engines is *really* useful, and the only substitutes
> > holding a match to a length of cannon fuse labeled "Stage 2" protruding
> > from his control panel...
>
> light the fuse from inside the cabin, you can setup mechanical
> whosawhatsits to do that.
In the context of SF (since the item was cross posted), I recall a story by
Christopher Anvil (Harry C. Crosby) which considered just this idea. The
protagonist was a very frustrated W. VonBraun analog. It wasn't that the
job was impossible, just so frustratingly difficult that progress was
weepingly slow. When some troublemaker came up with the silly idea that a
'fluid' could flow through solid metal, he was at first kicked out, but as
the story ends, the protagonist is softening and deciding that he might as
well take a look.
I believe the story is called 'Troublemaker', but I could be wrong. It's
been a long time.
Regards,
Jack Tingle
Henry Spencer
Michel Morton <m...@sys.uea.ac.uk> wrote:
>The trouble is, everything would have to be self-contained. It's
>hard to imagine how you could have mechanical controls going through
>a pressure hull to operate systems in a separate service module
Vacuum researchers routinely couple mechanical devices through pressure
hulls; it's no big deal. Simple mechanical seals work well enough, for
rotary joints in particular. Note also that in this case, you can use air
pressure lines for control, like the brakes on trains.
>or how to reliably severe those links when you wanted to discard the
>thing before re-entry.
Mechanical break-away couplings, although a bit heavy, can be made to work
quite adequately.
Henry Spencer
Despite some over-optimistic fiction, Babbage engines were heavy and very
slow. (Indeed, they were too slow to compete with hand calculation in
Babbage's time, given their extremely high development and production cost.)
They might be useful for development, if you had modern labor costs and no
other computing, but wouldn't be flown.
Jonathan Cresswell
jtingle <jti...@shore.net> wrote in message
news:04LH5.481$Mf4....@news.shore.net...
>
> Christopher M. Jones <christ...@uswest.net> wrote in message
> news:I4rH5.902$7V6.2...@news.uswest.net...
> >
> > "John Schilling" <schi...@spock.usc.edu> wrote:
> In the context of SF (since the item was cross posted), I recall a story
by
> Christopher Anvil (Harry C. Crosby) which considered just this idea. The
> protagonist was a very frustrated W. VonBraun analog. It wasn't that the
> job was impossible, just so frustratingly difficult that progress was
> weepingly slow. When some troublemaker came up with the silly idea that a
> 'fluid' could flow through solid metal, he was at first kicked out, but as
> the story ends, the protagonist is softening and deciding that he might as
> well take a look.
>
> I believe the story is called 'Troublemaker', but I could be wrong. It's
> been a long time.
Also, Pournelle's "King David's Spaceship" features low-tech spaceflight.
The only electrical item on the craft was a spark-gap transmitter.
--
Jonathan Cresswell
Kevin Strietzel
>
> > Is there anything about manned spaceflight that requires even
> > electricity, let alone electronics?
>
> Without them you might get into SOME orbit, but not to any specific
> point in orbit, let alone Moon. Life-support system MIGHT be doable
> without electricity (steam powered?), but would be enormously heavier
> and with far more moving parts prone to breaking. Likewise for firing
> retro-rockets to return home - can be done in a purely mechanical
> manner, but far heavier and less reliable.
What part of navigation requires electronics? Computation can
be done mechanically, hydraulically, pneumatically -- or by the
pilot. Remember automobile gizmos like automatic
transmissions. Reasonably good mechanical and optical
navigational instruments (compasses, sextants, telescopes) have
existed since the 19th century; surely we could make more
precise instruments now. (They also used beacons, i.e. bouies,
light houses, and horns,
You can build mechanical, hydraulic, and pneumatic analog or
digital computers. The most interesting method for pneumatic
computation I know of used gas jets through channels as logic.
They constructed intersecting channels so the presence or
absence of one jet at a junction would affect the flow of
another jet at the junction. It was based on both pressure and
the dynamic effects of the high-velocity flows.
A man-rated vessel sans electricity would almost certainly be
large, imprecise, and unwieldy by current standards, but it
should still be possible. It would probably have to maneuver
slowly and with many fuel-consuming course corrections, since
the control mechanism (including pilot) would would be slow and
imprecise. And it would probably need significant safety
margins for things like fuel capacity.
You'd have to do without radio though; maybe a mechanical
semaphore system and telescopes would work.
Do we count the human nervous system? It's more or less
electrochemical....
--Kevin Strietzel
Speaking from Stratus, not for Stratus.
PS - Besides, how much does navigating require real-time
advanced mathematics? An awful lot of terrestrial navigational
computation can be done with table-lookups, arithmetic, various
forms of slide rule, and an experienced human.
Herman Rubin
>> Is there anything about manned spaceflight that requires even
>> electricity, let alone electronics?
>Navigation alone absolutely requires electronics (and thus electricity).
Most navigation could be done with slide rules and small books
of tables. Hohmann orbits are particularly easy, and the tools
are far more accurate than the controls of the motors.
Duke Skylurker
In the near future all computers will go OPTICAL.
They can work without electricity source,
if you pump enough light from the outside.
Duke S
se...@mac.com
Jones" <christ...@uswest.net> wrote:
> "John Schilling" <schi...@spock.usc.edu> wrote:
> > I can't think of anything that absolutely requires electricity either.
> >
> > The obvious place to look is in the flight controls and instrumentation.
> > I rather suspect mechanical flight computers would be too heavy, so
> > you'd be limited to manual control with hydraulic boosting. The pilot
> > would have to fly a boost trajectory using a vacuum gyro, mechanical
> > accelerometer, stopwatch, and the like. Might be doable, but I wouldn't
> > bet on an optimal trajectory, much less any sort of robust failure recovery.
>
> Mechanical computers, excellent, I wonder why I didn't think of
> that? Now, weight is definitely going to be a problem, however,
> if you assume some sort of nth generation mechanical computer,
> it would probably be quite a bit smaller and faster and probably
> require less power.
Forget gears, go with fluidic controls. They can use air as the
working fluid.
> > The less-obvious place to look is in staging. Electricity to fire the
> > pyros and light the engines is *really* useful, and the only substitutes
> > I can see are major kludges. I have a mental image of Duck Dodgers
> > holding a match to a length of cannon fuse labeled "Stage 2" protruding
> > from his control panel...
Mechanical igniters actuated by pushrod or bellcrank?
--
To get random signatures put text files into a folder called ³Random Signatures² into your Preferences folder.
Steve VanSickle
> In article <39EDB898...@uswest.net>,
> Steve Schaper <ssch...@uswest.net> wrote:
>>Advanced clockwork, including a Babbage engine?
>
> Despite some over-optimistic fiction, Babbage engines were heavy and very
> slow. (Indeed, they were too slow to compete with hand calculation in
> Babbage's time, given their extremely high development and production cost.)
> They might be useful for development, if you had modern labor costs and no
> other computing, but wouldn't be flown.
How about a special purpose analog mechanical computer. Change cams to
change trajectories.
Don Stokes
Michael J Wise <mjw...@kapu.net> wrote:
>> I have a mental image of Duck Dodgers holding a match to a length of
>> cannon fuse labeled "Stage 2" protruding from his control panel...
>
And not as stupid as it might sound. PETN fuses are often used instead
of electrical wiring to get precise timings for blasting -- the stuff
burns incredibly fast, and very reliably.
'course you have to make sure it doesn't blow the side off the capsule
and upper stages in the process...
-- don
Derek Lyons
> Stage sep is a bit tougher, but again hydraulics could save the day.
>Hold your stages together with a couple of bolts for static loads and
>some hefty hydraulically activated latches for dynamic loads. After
>engine cutoff, undo the latches, then use hydraulic rams to push the
>stages apart, breaking the bolts. All the heavy stuff goes on the
>lower stage, of course.
Hmmm... Or use hydraulically activated 'bolt cutter' to snap the
bolts.
D.
------------------------------
Proprietor, Interim Books http://www.interimbooks.com
USS Henry L. Stimson homepage http://www.interimbooks.com/655/
Derek on Books http://www.interimbooks.com/derek/books/
------------------------------
Derek Lyons
It's easy.. Use CDF (Confined Detonation Fuse), basically a very
small core of PETN surrounded by many, many layers of braid to break
up the outgassing.
Henry Spencer
Steve VanSickle <sj...@alpha2.csd.uwm.edu> wrote:
>How about a special purpose analog mechanical computer. Change cams to
>change trajectories.
You'd need such a thing only when actually under power. Rather than
building a mechanical analog of the Apollo guidance algorithms, it would
be simpler to just plan all maneuvers with a fixed pointing direction, and
accept a need for greater margins and more correction burns.
Christopher M. Jones
Not just electronics but electricity. Optical computers
run on electric power, unless you know some other way
to create low power continuous operation lasers?
It is _really_ hard to get along without electricity.
Moreover, I wholeheartedly dispute your notion that
computers are "going optical". Optical computation is
in not even in its infancy yet. Electronics has a huge
head start and it keeps leaping forward. And there are
other alternatives to modern electronic computers that
will compete with optical computers as possible
successors. Not the least of which are Rapid Single
Flux Quantum devices which can operate in near terahertz
clock frequencies. They also use very little power.
And, RSFQ technology is arguably in a much more advanced
state of development than optical computers.
Mark Miller
<97200267...@shelley.paradise.net.nz>:
The use of fuses for timing rocket motor firings is not a hypothetical
thing. When I was dabbling in rockets in the mid '80s, I know I saw a lot
of 'ETA' called out on the drawings; I believe it was in the context of
igniting Star-48s and Star-60s we were using for upper stages. 'ETA' was
'explosive transfer assembly' and it consisted of a thin-walled aluminum (I
think?) tube with some easily-controlled explosive. I remember when the
light slowly dawned on me - "You mean the tube is filled with, like,
gunpowder?" "Well, of course, it's not actually gunpowder, but the
principle is the same." "So, we start the rocket by lighting a FUSE?"
"Well, we don't actually *call* it a fuse . . ."
Keith Harwood
>
> The obvious place to look is in the flight controls and instrumentation.
> I rather suspect mechanical flight computers would be too heavy, so
> you'd be limited to manual control with hydraulic boosting. The pilot
> would have to fly a boost trajectory using a vacuum gyro, mechanical
> accelerometer, stopwatch, and the like. Might be doable, but I wouldn't
> bet on an optimal trajectory, much less any sort of robust failure recovery.
>
My uncle, circa 1966, was refurbishing missile guidance systems which
included a ball and disk integrator. The name Pershing comes to mind.
Keith Harwood.
Tom Clarke
Tom Clarke
cra...@hotmail.com
Did you read the original post?
Someone was curious if an entirely non-electrical
launch vehicle and spacecraft was possible. That this
is ludicrous by modern standards is irrelevant. It is
an interesting thought experiment.
The term you might be more familar with is "We were
playing a game of pretend" and pretending that we
could not use electrical systems.
> In the near future all computers will go OPTICAL.
> They can work without electricity source,
> if you pump enough light from the outside.
Right. I believe you, too.
--
Mike Miller, Materials Engineer
"You're a psychopath!" -- Debbie
"Nonono! A psycho kills for no reason. I kill for money. That
didn't sound right." -- Martin Blank
Henry Spencer
Keith Harwood <ke...@betor.dialix.com.au> wrote:
>My uncle, circa 1966, was refurbishing missile guidance systems which
>included a ball and disk integrator. The name Pershing comes to mind.
While a lot of mechanical gear was used in early guidance systems, the
overall systems were *electro*mechanical -- getting all the electrical
stuff out of them would have been difficult.
Michael R. Irwin
John Schilling wrote:
>
> The less-obvious place to look is in staging. Electricity to fire the
> pyros and light the engines is *really* useful, and the only substitutes
> I can see are major kludges. I have a mental image of Duck Dodgers
> holding a match to a length of cannon fuse labeled "Stage 2" protruding
> from his control panel...
>
If
Duck Dodgers inadvertently hit 2 or 3 fuses at the same time
Then
MIRV would become Multiple Independent Rocket Vehicles.
I can see several crews of ducklings wandering around looking
for Captain Dodgers :-)
Any chance at all of getting home without a midair collision? LOL
Regards,
Mike Irwin
Michael R. Irwin
Derek Lyons wrote:
> It's easy.. Use CDF (Confined Detonation Fuse), basically a very
> small core of PETN surrounded by many, many layers of braid to break
> up the outgassing.
>
For the chemically and explosively challenged amonst us:
Does this detonation cord work in a vacuum, in the atmospheres
of Jovian satellites, etc.
Have we finally found a generic technology that transfers
well around the solar system?
Regards,
Mike Irwin
Michael J Wise
> Navigation alone absolutely requires electronics (and thus electricity).
I seem to recall that one of the Gemini crews had a CPU failure, and used
a sextant and their watches to dock....
Andrew Gray
> The trouble is, everything would have to be self-contained. It's
> hard to imagine how you could have mechanical controls going through
> a pressure hull to operate systems in a separate service module or
> how to reliably severe those links when you wanted to discard the
> thing before re-entry.
This is a real bugger, actually. I'd never thought of that. Very heavily
built hydraulics to actually cross the pressure hull?
> End result. A big, heavy capsule that couldn't do much more then
> keep a person alive in orbit for 24 hours then bring them back. Imagine
> something Apollo CM sized with space only for one and that would
> probably
> be quite a risky thing to fly. The launcher would be the significant
> problem however. How you'd built one of those that could work without
> electricity I'll leave for somebody else.
Am I the only one envisaging a Saturn V with a little tag saying "Light
blue touchpaper and retire" here? Manned spaceflight shouldn't be
unnatainable, but *reliable* manned flight might be optomistic...
certainly you'd be leaving a lot to not-quite-but-pretty-much-chance,
especially in terms of trajectories & landing sites. It's a nice choice
- you can have a good bet on which hemisphere you'd hit, but after
that...
<g>
Andrew Gray
>
> Allen Thomson <thom...@flash.net> writes:
>
> >In the absence of sci.space.what-if, I'll ask this question here, as it
> >vexes me every now and then:
>
> >Is there anything about manned spaceflight that requires even
> >electricity, let alone electronics?
>
> electronics, but the basic technology (rockets) predates electricity
> by quite a bit. I suspect the hardest problems to work around without
> electricity are going to be obtaining affordable light metals (which
> means your structural weights are going to be high) and doing navigation
> without radio.
Radio nav could be annulled by simply designing a trajectory in advance,
plotting it out as well as possible (and then rediscovering
religion...), but the metals would be a problem.
Especially given the fact that welding would be out of the question,
most probably...
Allen Thomson
mall...@fnord.io.com (MA Lloyd) wrote:
> I suspect the hardest problems to work around without
> electricity are going to be obtaining affordable light metals
Good point about metals. Are there ways of obtaining aluminum or
magnesium without electrolysis? What about stainless steel (Atlas?)?
Venturing a bit further out, what about composites?
> (which means your structural weights are going to be high)
But is that a show-stopper, vs something that could be designed around?
(The BDB comes to mind.)
> and doing navigation without radio.
I don't think that would be much of a problem. Once in space, optical
techniques would do well enough if the spacecraft were manned. Guidance
during the 15-minute launch phase could be done with a no-electricity
inertial system.
BTW, I'm surprised that the possibility of solar-dynamic pressurized
hydraulics and pneumatics hasn't come up.
Jason Goodman
MA Lloyd wrote:
> I suspect the hardest problems to work around without
> means your structural weights are going to be high) and doing navigation
> without radio.
True, aluminum, magnesium, and perhaps titanium are impractical
to produce without electricity.
But what about fiberglass, carbon fiber, and other composite technologies?
I've been looking at how these substances are made, and there doesn't seem
to be any obvious mandatory use of electricity, although there might be
electricity buried in the production of the plastic resin binder.
The validity of this idea boils down to who's building the spaceship. Are
they historically-accurate 19th century people, or some speculative
society which just didn't get around to figuring out electricity? If the
latter, they may more experience with composite materials well before we did.
--
Jason Goodman, climatology grad student, MIT. Remove a.s. to email me.
-----
"Everyone talks about plate tectonics, but nobody ever *does* anything
about it."
Henry Spencer
Michael R. Irwin <mir...@harborside.com> wrote:
>> It's easy.. Use CDF (Confined Detonation Fuse), basically a very
>> small core of PETN surrounded by many, many layers of braid to break
>> up the outgassing.
>
>For the chemically and explosively challenged amonst us:
>Does this detonation cord work in a vacuum, in the atmospheres
>of Jovian satellites, etc.
Yes. Explosives are self-contained, they don't rely on outside oxidizer.
The only issue that comes up is that they sometimes have temperature
restrictions.
Don Stokes
Michael R. Irwin <mir...@harborside.com> wrote:
>For the chemically and explosively challenged amonst us:
>
>Does this detonation cord work in a vacuum, in the atmospheres
>of Jovian satellites, etc.
Yep. Most explosives (and rocket fuels) function by reaction with their
components (eg gunpowder, rocket fuels) or by breakdown of a single
component (all? high explosives).
High explosives such as PETN (and TNT, nitroglycerine etc) by definition
have the additional property that the reaction proceeds through the
material faster than the speed of sound through the same material. That
means that the reaction goes faster than the shock wave from the
reacting material behind it. This means that the explosive can't be
blown apart before it reacts, which in turn means none of the explosive
escapes intact, giving a more efficient explosion, and more importantly
for this discussion, the reaction is *very* reliable.
Detonate a PETN fuse, the the reaction *will* get to the other end,
regardless of the environment it's in. Of course some extreme
environments might let the stuff off early...
-- don
Paul F. Dietz
> True, aluminum, magnesium, and perhaps titanium are impractical
> to produce without electricity.
Actually, no, one of the industrial processes for producing
magnesium is purely thermochemical.
Paul
John Schilling
>In article <CHoH5.62675$bI6.2...@news1.giganews.com>,
> mall...@fnord.io.com (MA Lloyd) wrote:
>> I suspect the hardest problems to work around without
>> electricity are going to be obtaining affordable light metals
>Good point about metals. Are there ways of obtaining aluminum or
>magnesium without electrolysis? What about stainless steel (Atlas?)?
>Venturing a bit further out, what about composites?
Aluminum, not economically. Magnesium is *usually* produced by way
of electrolysis, but the direct-reduction process is still used with
some ores. So you'd have magnesium for your structure, and I don't
see any show-stoppers for stainless or some composites. Should be
fine on materials.
>> and doing navigation without radio.
>I don't think that would be much of a problem. Once in space, optical
>techniques would do well enough if the spacecraft were manned. Guidance
>during the 15-minute launch phase could be done with a no-electricity
>inertial system.
Agreed. You wouldn't try for direct insertion into your final orbit,
due to the difficulty of navigating during boost. Shoot for a 100-km
perigee and 1000-km apogee, with insertion at perigee. Then you have
fourty-five quiet minutes to break out sextant and slide rule and plan
the perigee raising burn, and fourty-five minutes after that to set up
the apogee reduction.
And unless you screw up the boost *really* bad, you get a default
abort-once-around to a landing a few thousand kilometers west of
the launch site.
--
*John Schilling * "Anything worth doing, *
*Member:AIAA,NRA,ACLU,SAS,LP * is worth doing for money" *
*Chief Scientist & General Partner * -13th Rule of Acquisition *
*White Elephant Research, LLC * "There is no substitute *
*schi...@spock.usc.edu * for success" *
*661-951-9107 or 661-275-6795 * -58th Rule of Acquisition *
Ian Stirling
>MA Lloyd wrote:
>> I suspect the hardest problems to work around without
>> electricity are going to be obtaining affordable light metals (which
>> means your structural weights are going to be high) and doing navigation
>> without radio.
>True, aluminum, magnesium, and perhaps titanium are impractical
>to produce without electricity.
>But what about fiberglass, carbon fiber, and other composite technologies?
None require it, though carbon fibre, and carbon-carbon composites,
may be harder, as they need heating under vacuum to temperatures
where not much has any strength.
Fibreglass isn't made much harder to make, nor is epoxy.
>The validity of this idea boils down to who's building the spaceship. Are
>they historically-accurate 19th century people, or some speculative
>society which just didn't get around to figuring out electricity? If the
>latter, they may more experience with composite materials well before we did.
Or are we talking present day earth, with a "suppressor field", put up by
those that like to listen to the music of the spheres, without all the crap
those noisy terrans spew all over the spectrum.
--
http://inquisitor.i.am/ | mailto:inqui...@i.am | Ian Stirling.
---------------------------+-------------------------+--------------------------
Two fish in a tank: one says to the other, "you know how to drive this thing??"
Allen Thomson
Jason Goodman <good...@ASmit.edu> wrote:
>
> The validity of this idea boils down to who's building the
> spaceship. Are they historically-accurate 19th century people, or
> some speculative society which just didn't get around to figuring
> out electricity? If the latter, they may more experience with
> composite materials well before we did.
What I had in mind was more the latter. Fairly sophisticated people at
roughly the late Twentieth Century level, in possession of the
scientific method and good engineering, but no electricity. Or maybe
us, trying to win the Bill Gates Electricityless Spaceflight
Sweepstakes. (Using electronic computers to design the no-electricity
spaceship would be cheating, of course.)
But putting the question in the context of the historical 1880 might
also be interesting, maybe even allowing them the electric technology
of the time.
tom
Allen Thomson wrote:
> In article <CHoH5.62675$bI6.2...@news1.giganews.com>,
>
> mall...@fnord.io.com (MA Lloyd) wrote:
>
> > I suspect the hardest problems to work around without
> > electricity are going to be obtaining affordable light metals
>
> Good point about metals. Are there ways of obtaining aluminum or
> magnesium without electrolysis?
Yes. The original process for Aluminum used Sodium to reduce aluminum
chloride. It was quite expensive compared to the Hall process, but it could
be done, given Sodium metal.
> What about stainless steel (Atlas?)?
That has been produced in open hearth furnaces with a special non-oxidizing
gas layer maintained, IIRC. Electrical has been most used, however. In
Space, the carbonyl chemistry of the ferrous metals can help here, since
Iron, Nickel, and Chromium all have carbonyl complexes. You could refine
the metals coarsely using Hydrogen reduction, then grind the result fine,
and separate the gange from the metal by generating gaseous carbonyls.
Condense these, and then bring them into a lower pressure/higher
temperature environment in a mold you desire to fill. The carbonyls break
down into carbon monoxide and their metallic constituents. That last step
is done today on a small scale here on Earth. A good bonus is that
temperatures needn't go above 200 Celsius, IIRC. Don't overlook the good
properties of pure Nickel, either.
>
> Venturing a bit further out, what about composites?
Several processes, including carbonyls, may help here if you want
metal/carbon composites. Carbon/plastic composites would require some of
the goop that is believed to make up some NEOs that send us carbonaceous
chondrites.
Regards,
Tom Billings
Meir Pann
and chemical reactions would be perfectly feasible.
Chemical reactions are the base of an excellent computer, i.e., our
brain. Yes, there are also electronics involved but I think that optics
might replace them.
--
Meir Pann
"You can't learn one damn thing from people who agree with you."
Jonathan Cresswell wrote:
>
> jtingle <jti...@shore.net> wrote in message
> news:04LH5.481$Mf4....@news.shore.net...
> >
> > Christopher M. Jones <christ...@uswest.net> wrote in message
> > news:I4rH5.902$7V6.2...@news.uswest.net...
> > >
> > > "John Schilling" <schi...@spock.usc.edu> wrote:
> >snip<
> > In the context of SF (since the item was cross posted), I recall a story
> by
> > Christopher Anvil (Harry C. Crosby) which considered just this idea. The
> > protagonist was a very frustrated W. VonBraun analog. It wasn't that the
> > job was impossible, just so frustratingly difficult that progress was
> > weepingly slow. When some troublemaker came up with the silly idea that a
> > 'fluid' could flow through solid metal, he was at first kicked out, but as
> > the story ends, the protagonist is softening and deciding that he might as
> > well take a look.
> >
> > I believe the story is called 'Troublemaker', but I could be wrong. It's
> > been a long time.
>
> Also, Pournelle's "King David's Spaceship" features low-tech spaceflight.
> The only electrical item on the craft was a spark-gap transmitter.
>
> --
> Jonathan Cresswell
Rob Shimmin
On Mon, 23 Oct 2000, tom wrote:
> > Good point about metals. Are there ways of obtaining aluminum or
> > magnesium without electrolysis?
>
> Yes. The original process for Aluminum used Sodium to reduce aluminum
> chloride. It was quite expensive compared to the Hall process, but it could
> be done, given Sodium metal.
But the sodium was produced via electrolysis of molten salt, if I recall
correctly. It's just hard to climb the elctrochemical ladder that high
without electrons.
--RS
Paul F. Dietz
> > Good point about metals. Are there ways of obtaining aluminum or
> > magnesium without electrolysis?
>
> Yes. The original process for Aluminum used Sodium to reduce aluminum
> chloride. It was quite expensive compared to the Hall process, but it could
> be done, given Sodium metal.
Tom, how do you think sodium is made?
Paul
John Powell
<thom...@flash.net> wrote:
>
> But putting the question in the context of the historical 1880 might
> also be interesting, maybe even allowing them the electric technology
> of the time.
I think someone mentioned "King David's Spaceship" by Jerry Pournelle.
Great fictional account of a 1880's level society getting a manned
capsule into space.
As far as real life? I have no doubts that the Victorians could have
built a spacecraft that could have kept a person alive in orbit and
re-entered safely. I have serious doubts that they could have launched
such a spacecraft into orbit in the first place. Everything would have
been just too heavy. Suborbital hops would be much easier - especially
from a guidance+control point of view.
But if I were a Werner Von Braun in Queen Victoria's Court, I'd
probably decide my best bet would be 4-7 stage solid rocket launched
from the mother of all hydrogen balloons, or rather a collection of
hydrogen balloons.
John
Wayne Throop
: Mechanical controls are fine, but I think that a ship based on optics
: and chemical reactions would be perfectly feasible.
:
: Chemical reactions are the base of an excellent computer, i.e., our
: brain. Yes, there are also electronics involved but I think that optics
: might replace them.
Well, if you've got a "chemical reaction", you've got electromagnetic
activity going on, no matter how you cut it. I think the electrical
activity of the human nervous system is pretty much secondary to
its correct functioning; enough so to form a proof-of-concept of
a "chemical computer without electronics". No particular need for
augmenting optics.
But anytime you've got rapidly switching chemical reactions in
a water solution full of membranes'n'stuff, you are *going* to get
voltages generated here and there. Further, applying voltages here
and there will drive the raction. But IMO that doesn't make what's
going on "electronic". The causation is still all in the chemical
reaction, not in switching of electric current.
Or so it seems to me.
Anyways, I've thought that a water-dwelling intelligent species might
well never stumble on static electricity and spark gaps and thus radio
waves and so on and so on. At least, not early. But even there,
biology would lead towards discovery of electricity, what with the
usefulness of EM sensors of various sorts underwater, and the probable
existance of some analogue to the electric eel, or even natural
formation of batteries. But per above, it might not lead to
*electronics* as such, and might remain an interesing offshoot of
biological and chemical sciences for quite a long time.
But I dunno. By the time such critters knew enough physics to propose
putting a squid in orbit, might they not have discovered lodestones, and have
the squidly equivalent of a Franklin and a Maxwell? Which would lead
to experiments trying to generate and detect radio waves, etc.
I guess the question I wonder about is, is it reasonable to suppose
they'd field a space program before they discovered that electronic
analogue and digital components (at the primitive level, eg, a switch
or a bit of information) are an order of magnitude faster than
biochemical components?
Hmmmmm. Seems plausible enough so far... after all, even WE had
hundreds of years between Newton and Maxwell. Plenty of time to mine
out the study of ballistics before turning to the study of minor
anomalies like action-of-eels-at-a-distance, and magic north-pointing
stones (which are probably just coral reef legend and old-squids-tales
anyways; I would sooner think a Yankee scientist would lie than suppose
a stone would fall from the ... er, could pick one direction from another.
Ahem.
Wayne Throop thr...@sheol.org http://sheol.org/throopw
"He's not just a Galaxy Ranger... he's a Super-Trooper!"
Henry Spencer
Allen Thomson <thom...@flash.net> wrote:
>Good point about metals. Are there ways of obtaining aluminum or
>magnesium without electrolysis?
Magnesium I *think* you can get with purely chemical processes, although
it's not easy. Aluminum is essentially impossible.
>What about stainless steel (Atlas?)?
Not a serious problem, although it's harder to work with, and heavy.
>Venturing a bit further out, what about composites?
In principle, very promising, although high-strength fibers are not easy
to make.
>...Guidance
>during the 15-minute launch phase could be done with a no-electricity
>inertial system.
Not as easy as it sounds. All practical inertial systems have had some
electrical components, as far as I know. The basic sensors are
non-electrical, but there are assorted secondary problems, like reading
their values without disturbing them, which would be hard to solve. Even
something as simple as using gyros to stabilize an inertial platform is
*not* done purely mechanically, but by electronic feedback loops.
Derek Lyons
>Good point about metals. Are there ways of obtaining aluminum or
>magnesium without electrolysis?
Dunno about Magnesium, but certaintainly for Aluminum. (But it's
complicated, messy, and expensive. Prior to the discovery of the
electrolytic process Aluminum was considered a precious metal. That's
why the Washington Monument capstone is Aluminum.)
D.
------------------------------
Proprietor, Interim Books http://www.interimbooks.com
USS Henry L. Stimson homepage http://www.interimbooks.com/655/
Derek on Books http://www.interimbooks.com/derek/books/
------------------------------
Derek Lyons
>Agreed. You wouldn't try for direct insertion into your final orbit,
>due to the difficulty of navigating during boost. Shoot for a 100-km
>perigee and 1000-km apogee, with insertion at perigee. Then you have
>fourty-five quiet minutes to break out sextant and slide rule and plan
>the perigee raising burn, and fourty-five minutes after that to set up
>the apogee reduction.
The big problem will be reliably determining velocity.
Michael R. Irwin
Allen Thomson wrote:
>
?snip>
> Or maybe
> us, trying to win the Bill Gates Electricityless Spaceflight
> Sweepstakes. (Using electronic computers to design the no-electricity
> spaceship would be cheating, of course.)
You could always setup a handicap class based on the
percentage of design computers running Windows.
Mike Irwin
Derek Lyons
>> It's easy.. Use CDF (Confined Detonation Fuse), basically a very
>> small core of PETN surrounded by many, many layers of braid to break
>> up the outgassing.
>>
>
>
>Does this detonation cord work in a vacuum, in the atmospheres
>of Jovian satellites, etc.
>
>well around the solar system?
Yes to both.
Henry Spencer
John Powell <jo...@jetcity.com> wrote:
>But if I were a Werner Von Braun in Queen Victoria's Court, I'd
>probably decide my best bet would be 4-7 stage solid rocket launched
>from the mother of all hydrogen balloons, or rather a collection of
>hydrogen balloons.
I'd go for pressure-fed liquid rockets launched from the ground.
Making *reliable* big solids is not at all easy -- it tends to require
large X-ray machines, ultrasonic bond testing, etc. Inspecting welds in
tanks is simple by comparison.
Air launch doesn't gain you all that much, it severely limits the mass of
your rocket (which is particularly bad when the simplest answer to various
technological limitations is to just make the thing bigger), and it makes
well-controlled launches quite difficult. Just adding another rocket
stage works better.
John Schilling
>schi...@spock.usc.edu (John Schilling) wrote:
>>Agreed. You wouldn't try for direct insertion into your final orbit,
>>due to the difficulty of navigating during boost. Shoot for a 100-km
>>perigee and 1000-km apogee, with insertion at perigee. Then you have
>>fourty-five quiet minutes to break out sextant and slide rule and plan
>>the perigee raising burn, and fourty-five minutes after that to set up
>>the apogee reduction.
>The big problem will be reliably determining velocity.
Timing the ascent of stars along your orbit track would seem to do fairly
well. If you are in a circular orbit at radius R kilometers, and a star
dead ahead climbs above the horizon at W radians/second, your velocity
is R/W km/sec.
Granted, your orbit may not be circular, and your altitude may not be
known, which makes it a three-variable problem. I suspect that with
careful choice of guide stars you can seperate the variables ahead of
time, and if not I am confident that we can find astronauts capable of
solving a system of three equations in three unknowns in rather less
than fourty-five minutes.
Guidance during the ascent is the hard part; once you are in orbit things
get a lot less hectic.
Gord Deinstadt
> Hold your stages together with a couple of bolts for static loads and
> some hefty hydraulically activated latches for dynamic loads. After
> engine cutoff, undo the latches, then use hydraulic rams to push the
> stages apart, breaking the bolts. All the heavy stuff goes on the
> lower stage, of course.
Something I've wondered about - why use bolts at all? Why not just
have posts in the lower stage mating with greased holes in a flange on
the upper stage? The stages could be stacked right on the launch pad
with a crane. Gravity would hold the stages together on
the launch pad and the thrust of the lower stage would hold them
together in flight. When the lower stage burned out, while the stack
was coasting, a simple spring would separate them. For a two-stager
you shouldn't need anything more. Am I missing something?
--
Gord Deinstadt gdei...@home.com
Michael R. Irwin
Gord Deinstadt wrote:
When you gimbal the lower stage thrust to maintain
the rocket stack on the proper trajectory approximately
half your greased studs are fine initially, as they are
in compression. The other half are in tension, except
your proposed joint will not support tension as a bolt
is designed to support it.
First there is a crack and then as the top stages
fall further away from the center thrust line of your
gimbaling lower stage, the rocket stack comes
completely apart.
You might propose longer greased
studs but once your top stages begin moving you move
into dynamic load multipliers and impact loading. Consider
hammering lightly sideways on a firmly set nail (tap tap and
it bends a bit with each tap) instead of pushing on it lightly
(firmer, firmer, firmer finally it bends) with the hammer.
Your top stage even with long enough studs will encounter
this hammering (impact or dynamic loading) problem.
Also the delay in response of the upper stage rattling (instead
staying in firm line with the bottom in known designed
orientation used in designing control system) quickly leads to
oscillation in the gimbaling as the top stage rattles around and the flight
control system tries to adjust for the cycling dynamic loads
and resulting orientation it senses.
Consider that the torque/tension applied to the joining
bolts (to rotate the upper stages to the proper trajectory)
have a lever arm the length of the upper stages
and you quickly come to realize why they use such
large bolts. Picture a 40 foot crowbar with its pivot
on your toe. It is not obvious unless you have done
the calculations a few times for an engineering class
in statics or dynamics and drawn the force diagrams
a few times.
The actual calcuations can be more complicated
if you wish to consider that the actual rotation is related
to the center of mass, moment of inertia and line of
the gimbaled rocket thrust at the end of the stack.
Just keep in mind nobody ever got fired for oversizing
the bolts ... unless weight was really critical! LOL
If you wish to investigate this empirically (no fuzzy math LOL)
stack a couple of tall glasses, tape a ring of tooth picks around the
bottom one to simulate the greased studs, and swoop the stack
through the living room in 30% arcs 30% degrees off of vertical,
or vice versa by applying simulated thrust to the bottom
glass. Your offspring will find this more amusing
than your wife, but you will gain an intuitive appreciation of
the problem. Do not forget to add expensive whiskey,
(water may be easier on the rug but not as much fun) to
simulate the baffled propellant tanks. I guess you could
put sponges in the glass to simulate baffles, in this case
drink the whiskey first, no sense wasting it, and use water
for the preliminary testing phase.
I hope that made some sense, I enjoyed writing it
anyway. Easily bored people should stay away
from small towns! LOL
Regards,
Mike Irwin
tom_d_...@my-deja.com
Allen Thomson <thom...@flash.net> wrote:
>
>
> In the absence of sci.space.what-if, I'll ask this question here, as
it
> vexes me every now and then:
>
> Is there anything about manned spaceflight that requires even
> electricity, let alone electronics?
>
> Apollo? Not just the orbital vehicles, but the launchers, stuff on
the
> ground, the works.
>
> I keep thinking there should be *something* that at least requires a
> battery, an electric motor, maybe a lightbulb. But I haven't
> identified it as yet. Note that I don't dispute for a minute that
> electricity, electronics, radios are really nice things to have and
> make life a lot easier for rocket scientists; but are they absolutely
> necessary for getting to orbit, maybe the moon, and coming back?Give 'King David's Spaceship' a read. You'll get a kick out of it.
Tom Perkins
motani semper liberi
Ian Stirling
>jakem...@my-deja.com wrote:
>> Hold your stages together with a couple of bolts for static loads and
>> some hefty hydraulically activated latches for dynamic loads. After
>> engine cutoff, undo the latches, then use hydraulic rams to push the
>> stages apart, breaking the bolts. All the heavy stuff goes on the
>> lower stage, of course.
>Something I've wondered about - why use bolts at all? Why not just
>have posts in the lower stage mating with greased holes in a flange on
>the upper stage?
This way vibration/lower stage roughness/aero loading can instead of
just adding a bit of buffetting, totally destroy the vehicle.
(A bad thing)
It'll also probably limit maximum AOA, to some lower value, but that
may not be an issue.
--
http://inquisitor.i.am/ | mailto:inqui...@i.am | Ian Stirling.
---------------------------+-------------------------+--------------------------
"Melchett : Unhappily Blackadder, the Lord High Executioner is dead
Blackadder : Oh woe! Murdered of course.
Melchett : No, oddly enough no. They usually are but this one just got
careless one night and signed his name on the wrong dotted line.
They came for him while he slept." - Blackadder II
Henry Spencer
Gord Deinstadt <gdei...@home.com> wrote:
>> Hold your stages together with a couple of bolts for static loads...
>
>Something I've wondered about - why use bolts at all? Why not just
>have posts in the lower stage mating with greased holes in a flange on
>the upper stage? The stages could be stacked right on the launch pad
>with a crane. Gravity would hold the stages together on
>the launch pad and the thrust of the lower stage would hold them
In practice, particularly for big launchers, the stack needs considerable
rigidity to survive things like wind gusts and engine gimbaling. This is
usually felt to require rigid joints.
A contributing issue is that loose joints are very difficult to analyze;
their behavior is nonlinear and very hard to predict.
Anthony Q. Bachler
digital electronics that cant be done with pneumatics.
Allen Thomson wrote in message <8sig7g$cb0$1...@nnrp1.deja.com>...
Jason Goodman
>
> Well, aside from the obvious weight increase, there is
> nothing special about digital electronics that cant be
> done with pneumatics.
Maybe, but it would be BIG and SLOOOOOW.
A more-or-less fundamental limit(*) on electronic chip clock
rates is that lightspeed signals must be able to cross the
chip in one clock pulse. For a 1-cm chip, this is 30 gigahertz.
For pneumatic circuitry, this same fundamental limit is given
by the time needed for a *sound* wave to cross from one side
of the machine to the other. For a machine 1 meter across which
uses air as the working fluid(**), the max clock speed is 330
hertz.
The fundamental limit for a pneumatic system is 100 million times
slower than the limit for an electronic system, and 2 million times
slower than modern computers. Just as it has taken us 50 years to
get anywhere near the fundamental limit for electronic systems, we
should expect a similar amount of effort to get a pneumatic computer
as fast as 1 hertz.
(*) I can conceive of a chip with a clock rate too fast to allow
all parts of the chip to communicate with each other. But there
are severe complexities involved, and the term "clock rate" doesn't
really mean the same thing in such a system.
(**) You can do better by using water or another substance with a
faster speed of sound as your working fluid, but that only gains
you a factor of 10 or so. In any case, the density and viscosity
of water may destroy any gains caused by greater sound speed.
--
Jason Goodman, climatology grad student, MIT. Remove a.s. to email me.
-----
"Everyone talks about plate tectonics, but nobody ever *does* anything
about it."
DMeriman
no appreciation/use for electricity (akin to Wells' Martians not
using/understanding the wheel or fixed pivot).
David D. Merriman, Jr.
r/c submarines, 'the only way to fly!'
"Barns! Cargrave!... Come back here!!!"
Anthony Q. Bachler
brains functioning that the neurons have special structures whose only
purpose is to speed the propogation of the pulse trains. If you doubt this,
look at what happens to people with progressive de-myalinization (sp?). If
anything the chemical processes are secondary, there merely to support the
electrical ptocesses.
Wayne Throop wrote in message <9723...@sheol.org>...
Anthony Q. Bachler
possible to do. It is possible to do with pneumatics. It would also have
several advantages such as immunity to EMP, increased stealth from passive
radar, and better maintainability over long periods. I ts far easier to
replace a single pneumatic realy than it is to replace a blown transistor in
a microchip. Dont take me wrong Im not in any way shape or form advocating
pneumatics as the better solution, i was merely stating in reply to the
original posters question that it is possible to do anything with pneumatics
that you can do with electronics. Granted teh overall system woud be slower
than teh same system implemented with electronics, but with parallel
processing, it is certainly possible to build a system that could handle the
computational requirements of the space shuttle in real time.
Jason Goodman wrote in message <3A04C1E3...@ASmit.edu>...
Anthony Q. Bachler
was not exactly available in victorian times...
Henry Spencer wrote in message ...
>In article <231020001919589615%jo...@jetcity.com>,
>John Powell <jo...@jetcity.com> wrote:
>>But if I were a Werner Von Braun in Queen Victoria's Court, I'd
>>probably decide my best bet would be 4-7 stage solid rocket launched
>>from the mother of all hydrogen balloons, or rather a collection of
>>hydrogen balloons.
>
>I'd go for pressure-fed liquid rockets launched from the ground.
>
>Making *reliable* big solids is not at all easy -- it tends to require
>large X-ray machines, ultrasonic bond testing, etc. Inspecting welds in
>tanks is simple by comparison.
>
>Air launch doesn't gain you all that much, it severely limits the mass of
>your rocket (which is particularly bad when the simplest answer to various
>technological limitations is to just make the thing bigger), and it makes
>well-controlled launches quite difficult. Just adding another rocket
>stage works better.
Bob the younger
On Sat, 25 Nov 2000, Anthony Q. Bachler wrote:
> The problem with liquid rockets, is that I believe they require LOX, which
> was not exactly available in victorian times...
Think again. Louis Cailletet first produced liquid oxygen in the
laboratory in the 1870's, and in 1894 Heile Kammerling Onnes had set up a
plant to produce it on the industrial scale.
--RS
Tom McWilliams
Photosynthesis uses electron transport, as mitochondria uses a
proton-gradient.
Are they electric or chemical? Since all chemical-interaction is
charge-mediated, it's a moot question.
-Tm
--
* . * '^
,.. " . *
,
' Tommy Mac
Henry Spencer
Anthony Q. Bachler <cwhi...@no.spam.mail.socket.net> wrote:
>The problem with liquid rockets, is that I believe they require LOX, which
>was not exactly available in victorian times...
No, there are several other suitable oxidizers, notably nitric acid. As I
recall, somebody once looked into this and concluded that a pressure-fed
liquid-fuel rocket burning nitric acid and petroleum distillates could
probably have been built at about the time of the US Civil War... had
anybody known how.
--
When failure is not an option, success | Henry Spencer he...@spsystems.net
can get expensive. -- Peter Stibrany | (aka he...@zoo.toronto.edu)
George William Herbert
>Anthony Q. Bachler <cwhi...@no.spam.mail.socket.net> wrote:
>>The problem with liquid rockets, is that I believe they require LOX, which
>>was not exactly available in victorian times...
>
>No, there are several other suitable oxidizers, notably nitric acid. As I
>recall, somebody once looked into this and concluded that a pressure-fed
>liquid-fuel rocket burning nitric acid and petroleum distillates could
>probably have been built at about the time of the US Civil War... had
>anybody known how.
The problem with nitric acid, of course, is going to be materials
compatability... you can't assume that you'd know to inhibit it with
~1% HF, if HF was even available at the time (I don't know).
Turpentine would be easier than petroleum in that timeframe and is
hypergolic with nitric acid. Given how much of a pain combustion
stability and ignition are to develop right even today, one would
assume that using hypergols would be a major priority in a 1800s
tech rocket program (either intentionally, or that's the only thing
which they'd be able to make work...).
The key problem is that the state of the art of materials technology
of the time precludes efficient pressure vessels for propellant
storage and limits what you can do with the rocket motor itself.
Regenerative cooling would be difficult, but ablative cooling
with say oak ablator would work.
The materials most likely in that time frame are wrought iron or
(by modern standards) low grade steel. By the 1890s "30-ton steel"
was coming into common use in boilers but its manufacture and use
was still highly problematic: there were numerous problems reported
in the shipbuilding community, failure analysies, etc. I have some
vintage editions of the various naval architecture societies transactions
and they clearly showed that there were serious problems manufacturing
and using the more advanced steels. Importantly, riveting was still
the only method of joining sections, which leads to major structural
inefficiencies at joints compared to welding or composite structures.
The following is a rough parametric analysis; I haven't done a complete
design through on a tank, or rocket stage, with these technologies.
It would be hard to end up with tankage fractions much less than about
20% assuming 250 PSI chamber pressures, blowdown pressurization (which
is about all the technology would support then, or MTI which is still
tricky for us today...) those propellants, materials, and fabrication.
That's about twice as much as modern "low end" BDB tanks like I've been
researching. Assuming rocket engines are equivalently heavier, a T/W
ratio of say 40:1 is about as high as you could go, so a zero-payload
rocket stage lifting off the ground would be about 3% engine, 81%
propellants, and 16% tanks. Delta-V assuming moderate combustion
efficiency wouldn't practically be higher than about 1,500 m/s.
You could make a short range ballistic missile, but staging to
orbit would be on the far side of impractical.
-george william herbert
gher...@retro.com
Henry Spencer
George William Herbert <gher...@gw.retro.com> wrote:
>>recall, somebody once looked into this and concluded that a pressure-fed
>>liquid-fuel rocket burning nitric acid and petroleum distillates could
>>probably have been built at about the time of the US Civil War...
>
>compatability... you can't assume that you'd know to inhibit it with
>~1% HF, if HF was even available at the time (I don't know).
I'm not sure either. But you can line your ground storage tanks with
glass, and simply accept that once you fuel the rocket, you've got to
launch promptly. People were building operational acid/aniline missiles
well before the inhibition trick was discovered; the reason for the great
interest in inhibition was not that you just couldn't build the rockets
without it, but that having to fuel the things in the field before launch
was a tremendous pain for operational tactical missiles.
>Turpentine would be easier than petroleum in that timeframe and is
>hypergolic with nitric acid.
Good point, I'd forgotten about that possibility.
>Given how much of a pain combustion
>stability and ignition are to develop right even today, one would
>assume that using hypergols would be a major priority in a 1800s
>tech rocket program (either intentionally, or that's the only thing
>which they'd be able to make work...).
It certainly would simplify ignition, but you can always do brute-force
pyrotechnic ignition with an expendable igniter.
The effect on stability is not simple. Hypergols are often *less* stable
than non-hypergols, because the instant reaction when the propellants
touch tends to blow them apart, delaying proper mixing and making the
process more sensitive to disturbances.
>The key problem is that the state of the art of materials technology
>of the time precludes efficient pressure vessels for propellant
>storage and limits what you can do with the rocket motor itself.
Agreed. Much before the Civil War and you're in real trouble in that
department, but even then it would limit you.
>Regenerative cooling would be difficult, but ablative cooling
>with say oak ablator would work.
Or just aggressive curtain cooling. (Goddard did not use regenerative
cooling.)
>It would be hard to end up with tankage fractions much less than about
>20% assuming 250 PSI chamber pressures, blowdown pressurization (which
>is about all the technology would support then, or MTI which is still
>tricky for us today...) those propellants, materials, and fabrication.
Hmm. I wonder whether you could improve the situation by winding the
tanks and chamber with steel wire. (Don't know what the start of the art
in wire was then, but wire is generally stronger than plate.)
>...Delta-V assuming moderate combustion
>efficiency wouldn't practically be higher than about 1,500 m/s.
>You could make a short range ballistic missile, but staging to
>orbit would be on the far side of impractical.
Yeah, you've really got to get the per-stage delta-V up a bit higher
before orbit becomes realistic.
Derek Lyons
>In article <t1ulfrl...@corp.supernews.com>,
>Anthony Q. Bachler <cwhi...@no.spam.mail.socket.net> wrote:
>>The problem with liquid rockets, is that I believe they require LOX, which
>>was not exactly available in victorian times...
>
>No, there are several other suitable oxidizers, notably nitric acid. As I
>recall, somebody once looked into this and concluded that a pressure-fed
>liquid-fuel rocket burning nitric acid and petroleum distillates could
>probably have been built at about the time of the US Civil War... had
>anybody known how.
Yah. Steel for the engine bells would have been a bit of a bear to
produce in suitable quantities for starters....
IIRC there was an SF writer who did a pretty good look at this and
other 'Conneticut Yankee at King Arthur's Court' types of stories.
His conclusion was that too much tech requires background processes
that may or may not be available. (Sure, that there amatuer
astronomer can make lenses and mirrors. Can he make optical glass?)
'You can't railroad until it's time to railroad'.
James A Davis
> As I
> recall, somebody once looked into this and concluded that a pressure-fed
> liquid-fuel rocket burning nitric acid and petroleum distillates could
> probably have been built at about the time of the US Civil War... had
> anybody known how.
High on the list of things not known at the time of the Civil War was
how to accelerate a flow to supersonic velocities in a nozzle. The
convergent-divergent nozzle was only discovered empirically about 1890
and was used in the reaction turbine. The theoretical foundations were
not understood until well into the 20th century.
Jim Davis
George William Herbert
>Henry Spencer wrote:
>> As I
>> recall, somebody once looked into this and concluded that a pressure-fed
>> liquid-fuel rocket burning nitric acid and petroleum distillates could
>> probably have been built at about the time of the US Civil War... had
>> anybody known how.
>
>how to accelerate a flow to supersonic velocities in a nozzle. The
>convergent-divergent nozzle was only discovered empirically about 1890
>and was used in the reaction turbine. The theoretical foundations were
>not understood until well into the 20th century.
Really? I could swear I saw bombardment rocket designs from
the late 1700s and early 1800s which had venturis...
Unfortunately, that specific area of history is not one
I stock reference books for at home, so someone else
will have to look it up and confirm or deny.
They may not have understood the theory, but the basic idea
of a supersonic nozzle can't have been completely unknown
if that's true.
-george william herbert
gher...@retro.com
Gordon D. Pusch
> IIRC there was an SF writer who did a pretty good look at this and
> other 'Conneticut Yankee at King Arthur's Court' types of stories.
> His conclusion was that too much tech requires background processes
> that may or may not be available. (Sure, that there amatuer
> astronomer can make lenses and mirrors. Can he make optical glass?)
Peradventure are you thinking of Leo Frankowski's character
``Conrad Stargard'' in his ``Crosstime Engineer'' series ???
Or possibly even H. Beam Piper's ``Lord Kalvan'' ???
-- Gordon D. Pusch
perl -e '$_ = "gdpusch\@NO.xnet.SPAM.com\n"; s/NO\.//; s/SPAM\.//; print;'
Tom Billings
> James A Davis <jimd...@primary.net> wrote:
> >Henry Spencer wrote:
> >> As I
> >> recall, somebody once looked into this and concluded that a pressure-fed
> >> liquid-fuel rocket burning nitric acid and petroleum distillates could
> >> probably have been built at about the time of the US Civil War... had
> >> anybody known how.
> >
> >High on the list of things not known at the time of the Civil War was
> >how to accelerate a flow to supersonic velocities in a nozzle. The
> >convergent-divergent nozzle was only discovered empirically about 1890
> >and was used in the reaction turbine. The theoretical foundations were
> >not understood until well into the 20th century.
>
> Really? I could swear I saw bombardment rocket designs from
> the late 1700s and early 1800s which had venturis...
> Unfortunately, that specific area of history is not one
> I stock reference books for at home, so someone else
> will have to look it up and confirm or deny.
>
The holes at the backs of some rockets did indeed look
like venturis to some extent.
However, they had more to do with packing the powder tightly
in a tube, and getting a good burning surface at the same time,
than with getting the gases out the rear faster.
>
> They may not have understood the theory, but the basic idea
> of a supersonic nozzle can't have been completely unknown
> if that's true.
Pierre DeLaval invented the nozzle named after him in 1876, IIRC,
to allow him to run a centrifugal cream seperator by steam power.
>From that point onwards, Parsons developed it from before 1884
for today's sort of steam turbines, with many rows of blades forming
temporary nozzles at lower rotation speeds, instead of one row of
nozzles running t higher speeds.
The DeLaval nozzle was first consciously applied to rockets in an 1898
science journal article, in theory, by Tsiolkovsky. There was an attempt
to use them by a swedish inventor soon after. The Definitive first use in
a continuing line of development over decades seems to have been that
of Robert Goddard, starting with his demonstrations in 1910-12 of its
use in a vacuum chamber, with the enhanced thrust that allowed.
Regards,
Tom Billings
James A Davis
> Really? I could swear I saw bombardment rocket designs from
> the late 1700s and early 1800s which had venturis...
> Unfortunately, that specific area of history is not one
> I stock reference books for at home, so someone else
> will have to look it up and confirm or deny.
Willy Ley's standard reference "Rockets, Missiles, and Space Travel"
describes the standard rocket manufacturing process (still in use today
for fireworks) in his chapter "The Rocket's Red Glare". There was a
constriction about two thirds the diameter of the rocket but it had
nothing to do with fluid dynamics - it was to provide mechanical support
to the powder as it was hammered into the cardboard tube.
In any event the cardboard tube would have been completely inadequate to
contain a combustion pressure sufficient to choke the constriction to
generate supersonic flow.
> They may not have understood the theory, but the basic idea
> of a supersonic nozzle can't have been completely unknown
> if that's true.
One of the things that Goddard discovered while experimenting with state
of the art rockets of the 1910s was that the very best of them had
efficiencies of about 1% - a specific impulse of about 25 seconds. One
of the reasons was that the "nozzles" used weren't very efficient.
Jim Davis
Henry Spencer
Derek Lyons <el...@hurricane.net> wrote:
>>recall, somebody once looked into this and concluded that a pressure-fed
>>liquid-fuel rocket burning nitric acid and petroleum distillates could
>>probably have been built at about the time of the US Civil War... had
>>anybody known how.
>
>produce in suitable quantities for starters....
They were building steam locomotives, remember. If you're willing to
settle for a relatively low-performance rocket, the materials don't have
to be all that great. As George has already pointed out, lightweight
pressurized tanks are a bigger challenge.
Jonathan Stone
Henry Spencer <he...@spsystems.net> wrote:
>In article <3a256692...@news.seanet.com>,
>Derek Lyons <el...@hurricane.net> wrote:
>>>recall, somebody once looked into this and concluded that a pressure-fed
>>>liquid-fuel rocket burning nitric acid and petroleum distillates could
>>>probably have been built at about the time of the US Civil War... had
>>>anybody known how.
>>
>>Yah. Steel for the engine bells would have been a bit of a bear to
>>produce in suitable quantities for starters....
>
>They were building steam locomotives, remember. If you're willing to
>settle for a relatively low-performance rocket, the materials don't have
>to be all that great. As George has already pointed out, lightweight
>pressurized tanks are a bigger challenge.
To be fair, steam locomotives at the time were comparatively low
performance devices, without superheating (thus, saturated steam? I
dont know the US term) at low pressures and low cut-off ratios.
Superheating, and thus high cut-off ratios, didnt come until
around the turn of the century.
High-pressure hoses (for compounding) was a signficant challenge
until the 20th century. I guess steering vanes sound more sensible?
Magnus Redin
> They were building steam locomotives, remember. If you're willing to
> settle for a relatively low-performance rocket, the materials don't
> have to be all that great. As George has already pointed out,
> lightweight pressurized tanks are a bigger challenge.
Perhaps a thin riveted tank reinforced with lots of wire in tension?
Regards,
--
--
Magnus Redin Lysator Academic Computer Society re...@lysator.liu.se
Mail: Magnus Redin, Klockaregården 6, 586 44 LINKöPING, SWEDEN
Phone: Sweden (0)70 5160046 and (0)13 214600
Henry Spencer
Jonathan Stone <jona...@DSG.Stanford.EDU> wrote:
>High-pressure hoses (for compounding) was a signficant challenge
>until the 20th century. I guess steering vanes sound more sensible?
Vanes, fluid injection, or possibly multiple engines and differential
throttling for thrust vectoring, I'd say.
Although you can do gimbaling without flexible plumbing if you build a
four-engine cluster and do things the way the British did their
peroxide/kerosene engines, with each engine gimbaling only on a single
axis and the propellants coming in along the axis. That does involve
rotating seals, though, which you might prefer to avoid.
Bob the younger
On 26 Nov 2000, George William Herbert wrote:
> The problem with nitric acid, of course, is going to be materials
> compatability... you can't assume that you'd know to inhibit it with
> ~1% HF, if HF was even available at the time (I don't know).
Hydrofluoric aid production is older than chemistry. One of the
borderline chemists/alchemists, Schwanlund, described a glass-etching
solution made by distilling flourspar in acid, which is pretty much how we
still make it over 300 years later. Many of the great chemists of the
late 18th / early 19th century, including Scheele, Lavoisier, and
Gay-Lussac worked extensively with, and were occasionally injured by, the
substance.
--RS
John R. Campbell
>In article <8vrrp7$nrp$1...@gw.retro.com>,
>George William Herbert <gher...@gw.retro.com> wrote:
>
>>It would be hard to end up with tankage fractions much less than about
>>20% assuming 250 PSI chamber pressures, blowdown pressurization (which
>>is about all the technology would support then, or MTI which is still
>>tricky for us today...) those propellants, materials, and fabrication.
>
>Hmm. I wonder whether you could improve the situation by winding the
>tanks and chamber with steel wire. (Don't know what the start of the art
>in wire was then, but wire is generally stronger than plate.)
Hmmmm...
Anybody remember the wire problems of the Queensboro Bridge?
And the Brooklyn Bridge?
Granted, some of this was caused by folks who didn't understand
how to avoid corrosives...
--
John R. Campbell Speaker to Machines so...@jtan.com
- As a SysAdmin, yes, I CAN read your e-mail, but I DON'T get that bored!
Disclaimer: All opinions expressed are those of John Campbell alone and
do not reflect the opinions of his employer(s) or lackeys
thereof. Anyone who says differently is itching for a fight!
Derek Lyons
>el...@hurricane.net (Derek Lyons) writes:
>
>> IIRC there was an SF writer who did a pretty good look at this and
>> other 'Conneticut Yankee at King Arthur's Court' types of stories.
>> His conclusion was that too much tech requires background processes
>> that may or may not be available. (Sure, that there amatuer
>> astronomer can make lenses and mirrors. Can he make optical glass?)
>
>Peradventure are you thinking of Leo Frankowski's character
>``Conrad Stargard'' in his ``Crosstime Engineer'' series ???
>
>Or possibly even H. Beam Piper's ``Lord Kalvan'' ???
>
Nah, it was an essay, not a story.
Derek Lyons
>In article <3a256692...@news.seanet.com>,
>Derek Lyons <el...@hurricane.net> wrote:
>>>recall, somebody once looked into this and concluded that a pressure-fed
>>>liquid-fuel rocket burning nitric acid and petroleum distillates could
>>>probably have been built at about the time of the US Civil War... had
>>>anybody known how.
>>
>>Yah. Steel for the engine bells would have been a bit of a bear to
>>produce in suitable quantities for starters....
>
>They were building steam locomotives, remember. If you're willing to
>settle for a relatively low-performance rocket, the materials don't have
>to be all that great. As George has already pointed out, lightweight
>pressurized tanks are a bigger challenge.
Henry; The steam locomotive ca the Civil War were iron, not steel.
The boilers were pretty low pressure.
Derek Lyons
>he...@spsystems.net (Henry Spencer) writes:
>
>> They were building steam locomotives, remember. If you're willing to
>> settle for a relatively low-performance rocket, the materials don't
>> have to be all that great. As George has already pointed out,
>> lightweight pressurized tanks are a bigger challenge.
>
>Perhaps a thin riveted tank reinforced with lots of wire in tension?
>
Historically speaking, wire-wounds guns come 50-70 years later.
Derek Lyons
>In article <8vrrp7$nrp$1...@gw.retro.com>,
>George William Herbert <gher...@gw.retro.com> wrote:
>>>recall, somebody once looked into this and concluded that a pressure-fed
>>>liquid-fuel rocket burning nitric acid and petroleum distillates could
>>>probably have been built at about the time of the US Civil War...
>>
>>The problem with nitric acid, of course, is going to be materials
>>compatability... you can't assume that you'd know to inhibit it with
>>~1% HF, if HF was even available at the time (I don't know).
>
>I'm not sure either. But you can line your ground storage tanks with
>glass, and simply accept that once you fuel the rocket, you've got to
>launch promptly.
When was float glass invented?
George William Herbert
>re...@lysator.liu.se (Magnus Redin) wrote:
>>he...@spsystems.net (Henry Spencer) writes:
>>> settle for a relatively low-performance rocket, the materials don't
>>> have to be all that great. As George has already pointed out,
>>> lightweight pressurized tanks are a bigger challenge.
>>
>
>Historically speaking, wire-wounds guns come 50-70 years later.
I'm not familiar with that, when exactly was that?
Btw, in email today, Russell Cook suggested to me using Silk wrapping...
-george
George William Herbert
>he...@spsystems.net (Henry Spencer) wrote:
>>Derek Lyons <el...@hurricane.net> wrote:
>>>>recall, somebody once looked into this and concluded that a pressure-fed
>>>>liquid-fuel rocket burning nitric acid and petroleum distillates could
>>>>probably have been built at about the time of the US Civil War... had
>>>>anybody known how.
>>>
>>>Yah. Steel for the engine bells would have been a bit of a bear to
>>>produce in suitable quantities for starters....
>>
>>They were building steam locomotives, remember. If you're willing to
>>settle for a relatively low-performance rocket, the materials don't have
>>to be all that great. As George has already pointed out, lightweight
>>pressurized tanks are a bigger challenge.
>
>The boilers were pretty low pressure.
Wrought Iron was the dominant material then, and it's properties are
roughly like today's cheap steel: 27,000 PSI or so yield, 35-37,000 PSI
ultimate tensile strength. It's very forgiving and ductile compared
to steel but not terribly strong. In rough terms, you'd be looking
at tankage fractions upwards of 35%, possibly 45% for mid-1800s 300 PSI
blowdown pressurized tanks and nitric acid/turpentine propellant density.
I'm becoming convinced that a liquid gas generator is really a good
idea with this, rather than blowdown, as it saves a lot of tank volume.
It's not harder to make a gas generator than it is to make a rocket engine.
-george william herbert
gher...@retro.com
Paul F. Dietz
> When was float glass invented?
Post WW2, I think.
Paul
Russell Crook
>
> Henry Spencer <he...@spsystems.net> wrote:
> >Anthony Q. Bachler <cwhi...@no.spam.mail.socket.net> wrote:
> >>The problem with liquid rockets, is that I believe they require LOX, which
> >>was not exactly available in victorian times...
> >
> >No, there are several other suitable oxidizers, notably nitric acid.
<snip oxidizer discussion - H2O2 another possibility via
sulfuric acid and electrolysis?>
> The key problem is that the state of the art of materials technology
> of the time precludes efficient pressure vessels for propellant
> storage and limits what you can do with the rocket motor itself.
> Regenerative cooling would be difficult, but ablative cooling
> with say oak ablator would work.
>
> The materials most likely in that time frame are wrought iron or
> (by modern standards) low grade steel. By the 1890s "30-ton steel"
> was coming into common use in boilers but its manufacture and use
> was still highly problematic: there were numerous problems reported
> in the shipbuilding community, failure analysies, etc. I have some
> vintage editions of the various naval architecture societies transactions
> and they clearly showed that there were serious problems manufacturing
> and using the more advanced steels. Importantly, riveting was still
> the only method of joining sections, which leads to major structural
> inefficiencies at joints compared to welding or composite structures.
Hmm... you seem to have missed a possibility; wrapping a relatively
thin tank with a high strength fiber.
No, not nylon, kevlar etc. but ye olde silkworm silk, which
was definitely available in quantity in that era, though pricey :-)
>From what I can find on the web, tensile strength of silk
would be about the same as good quality wrought iron per
unit area, but at one sixth or so of the weight due to lower density.
(reference http://www.lexfa.org/text/joht10b.htm - ya
gotta love Google :-))
A five to six fold weight reduction on the tankage (or corresponding
increase in pressure should be significant in your analysis)
>
> The following is a rough parametric analysis; I haven't done a complete
> design through on a tank, or rocket stage, with these technologies.
>
<cogent analysis snipped>
--
Russell Crook, Technology Specialist, Computer Systems
Sun Microsystems of Canada Inc. 15 Allstate Parkway, Suite 300
Markham, Ontario, Canada L3R 5B4 rmc...@Canada.Sun.com
Tel: +1-905-943-4625 (x56625) Fax: +1-905-943-4601
Not speaking officially for Sun (or anyone else, for that matter).
The experiments of Skinner and other operant researchers did far
more than teach us how to pull habits out of a rat.
-- Gideon Glass (ggla...@calvin.edu)
Russell Crook
> >>The problem with liquid rockets, is that I believe they require LOX, which
> >>was not exactly available in victorian times...
> >
> >No, there are several other suitable oxidizers, notably nitric acid.
<snip oxidizer discussion - H2O2 another possibility via
Russell Crook
> >>The problem with liquid rockets, is that I believe they require LOX, which
> >>was not exactly available in victorian times...
> >
> >No, there are several other suitable oxidizers, notably nitric acid.
<snip oxidizer discussion - H2O2 another possibility via
Joe Fischer
: I know of at least one SF story that described a space fairing culture that
: had no appreciation/use for electricity (akin to Wells' Martians not
: using/understanding the wheel or fixed pivot).
I think there are still some Amish farmers who will
not use electricity, but use windmills and air pumps with
storage tanks to run large barn operations.
Joe Fischer
--
3
Derek Lyons
>>>> settle for a relatively low-performance rocket, the materials don't
>>>> have to be all that great. As George has already pointed out,
>>>> lightweight pressurized tanks are a bigger challenge.
>>>
>>
>>Historically speaking, wire-wounds guns come 50-70 years later.
>
>I'm not familiar with that, when exactly was that?
The earliest ship I can identify with certainty as having wire wrapped
guns seems to the HMS Vengance (1898). Can't be too much earlier
because no MLR was wire wrapped AFAIK. The kind of construction that
lends itself to wire wrapping was used for BLRs in the main.
>Btw, in email today, Russell Cook suggested to me using Silk wrapping...
Hmmm........
D.