Remember the Ranger probes? 6 failures in a row....
Ron Noteborn
you've almost got nothing in this case. What could an investigation be
based on? Anything could have happened... malfunctioning thrusters,
chutes that don't open, backshells that don't separate, even a windgust
which turns the thing upside down.
Ron
Robert Casey wrote:
> Remember back in the good old days? It took 7 tries before they got
> the Ranger lunar probes to work.
>
> So lets figure out what probably went wrong with teh MPL and get on
> with exploring Mars.
Robert Casey
Henry Spencer
Robert Casey <wa2...@netcom.com> wrote:
>Remember back in the good old days? It took 7 tries before they got
>the Ranger lunar probes to work.
Well, there was a price for that too. By the time of Ranger 7, JPL's very
existence was at stake, despite the space program being a major national
priority then. Congress has gotten less tolerant since...
(Actually, the really spectacular example was Discoverer -- the supposed
technology program which was really a front for spysat development --
which finally had a full mission success on the *fourteenth* try. But
that was very nearly a "black" program, and a major strategic priority.)
--
The space program reminds me | Henry Spencer he...@spsystems.net
of a government agency. -Jim Baen | (aka he...@zoo.toronto.edu)
Henry Spencer
>Well, I always find it remarkable how they find out what happened...
>you've almost got nothing in this case. What could an investigation be
>based on?
Evidence of exactly what happened is a bit thin. What they'll do is to go
over all the hardware design for the slightest hint of problems, and then
try to assess whether each questionable item could produce the known
result. The final report will necessarily waffle a bit because of the
evidence problem, but they can usually make a reasonable guess.
>Anything could have happened... malfunctioning thrusters,
>chutes that don't open, backshells that don't separate, even a windgust
>which turns the thing upside down.
Actually, none of these is likely to even make the short list, unless a
significant design flaw can also be found in the DS2 probes. A single
problem must explain *all three* failures, not just one.
David Lesher
>>Remember back in the good old days? It took 7 tries before they got
>>the Ranger lunar probes to work.
>Well, there was a price for that too. By the time of Ranger 7, JPL's very
>existence was at stake, despite the space program being a major national
>priority then. Congress has gotten less tolerant since...
After that, the relief at the first Surveyer working was visible.
BTW, I was told that one strong suspect in early Ranger failures
was poor soldering; that prompted the ?2-3 day? "Space Age Soldering"
course the techs all had to attend....
--
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433
Darren C. Bly
don't think it's out of the question to expect better than that now.
I think the real problem is " Faster, Better, Cheaper" ! As a old race driver
I learned you can do it faster, you can do it better and you can do it cheaper.
You can even do any two of them, but you can't do all three at the same time.
How about "Slower, Better Cheaper.
Darren in Bakersfield
John Beaderstadt
> A single
> problem must explain *all three* failures, not just one.
Not necessarily. The probes were entirely different craft, and it's reasonable to
suppose that they simply weren't up to withstanding a 400-mph impact. IIRC,
tornados clock internal windspeeds of 400+ MPH, and any objects that survive do so
entirely by chance (I know the analogy probably won't hold, but the coincidence of
the two velocities is striking... um, I mean...oh, forget it). At any rate, I
remember seeing one of the designers expressing a degree of doubt whether the
probes could survive.
The lander, itself? I'd say a simple communications glitch is the least likely
possibility; we're just too good at building durable systems. I would bet on
something more physical, such as half-landing on a boulder and tumbling, or
perhaps a parachute failure, or some such.
--
"I tried to imagine the easiest way God could have done it."
--Albert Einstein
George Herbert
>Henry Spencer wrote:
>> A single
>> problem must explain *all three* failures, not just one.
>
>Not necessarily. The probes were entirely different craft, and it's
>reasonable to suppose that they simply weren't up to withstanding a
>400-mph impact. IIRC, tornados clock internal windspeeds of 400+ MPH,
>and any objects that survive do so entirely by chance (I know the analogy
>probably won't hold, but the coincidence of the two velocities is striking...
>um, I mean...oh, forget it). At any rate, I remember seeing one of the
>designers expressing a degree of doubt whether the probes could survive.
The impact forces were expected to be no more than 60,000 Gs for the
afterbody and 30,000 Gs for the forebody. Artillery shells, some of
which contain complex electronics including radio and radar systems,
are routinely accellerated at 100,000 Gs on launch. Engineering for
this has been standard procedure since WW 2. That's not to say
that it's impossible for there to have been a design or manufacturing
flaw in them... but they were pretty clearly not past the known
edge of state of the art in terms of rugged electronics or mechanical
manufacturing.
If they hit a particularly hard rock, they probably would have failed,
but the odds that one would hit a hard enough rock are low: for most
of Mars' surface, it's about 17% covered in inch-sized and up rocks...
smaller ones won't kill a DS2 type probe. The odds that both would
have hit large rocks at that coverage percentage are about 3%.
-george william herbert
gher...@crl.com
David Shaw
> he...@spsystems.net (Henry Spencer) writes:
>
> >>Remember back in the good old days? It took 7 tries before they got
> >>the Ranger lunar probes to work.
>
> >Well, there was a price for that too. By the time of Ranger 7, JPL's very
> >existence was at stake, despite the space program being a major national
> >priority then. Congress has gotten less tolerant since...
>
> After that, the relief at the first Surveyer working was visible.
>
> BTW, I was told that one strong suspect in early Ranger failures
> was poor soldering; that prompted the ?2-3 day? "Space Age Soldering"
> course the techs all had to attend....
Okay, I'll bite.. what makes "Space Age Soldering" different from
regular soldering?
David
--
David Shaw | dshaw at jabberwocky dot com | WWW http://www.jabberwocky.com/
+---------------------------------------------------------------------------+
"There are two major products that come out of Berkeley: LSD and UNIX.
We don't believe this to be a coincidence." - Jeremy S. Anderson
Eric Smith
>Ranger and Discovery were in the "Wild West" days of the space program. I
>don't think it's out of the question to expect better than that now.
Of course we expect better. MPL arrived at the exact spot on Mars for
which it was targeted, after a journey of eleven months. That's a heck
of a lot better. But we can also still expect problems sometimes landing
an intricate spacecraft on the surface of another planet.
(BTW, it was Discoverer, not Discovery.)
>I think the real problem is " Faster, Better, Cheaper" ! As a old race driver
>I learned you can do it faster, you can do it better and you can do it cheaper.
> You can even do any two of them, but you can't do all three at the same time.
Well, Mars Pathfinder, Cassini, Deep Space 1, Lunar Prospector,
to name a few, argue that it can be done. And we don't even know that
the failure is attributable to "faster, better, cheaper." Remember
that the last major Mars mission before "faster, better, cheaper,"
the $1 billion Mars Observer, was also lost without a trace. Sometimes
things are just going to go wrong. After all, this *is* rocket science.
-----
Eric Smith | "They were like travellers unwillingly
eric @ catsdogs . com | returned from brilliant realms, not yet
http://www.catsdogs.com | adjusted to their return." - Olivia Manning
This was posted with an altered address to thwart bulk email programs.
To respond by email, take out the ".remove.this" part.
Henry Spencer
John Beaderstadt <be...@together.net> wrote:
>> A single problem must explain *all three* failures, not just one.
>
>Not necessarily. The probes were entirely different craft, and it's reasonable
>to suppose that they simply weren't up to withstanding a 400-mph impact.
Possible... but penetrators are not new technology, so I'd be surprised to
see something gross like that, unless the surface is unexpectedly hard.
The plausibility of an explanation goes down considerably if it requires
that a *separate* fatal design mistake be made in the probes.
Henry Spencer
Darren C. Bly <dc...@aol.comnospam> wrote:
> You can even do any two of them, but you can't do all three at the same time.
Actually, Slower almost invariably means More Expensive. Stretching out
the work usually makes it more costly, because people don't subdivide well
and neither do facilities. Also, it means that Congress starts to dial
your budget up and down at random, whereas a fast project can usually get
the thing done and launched before they get much chance.
OM
wrote:
>In article <384EF69F...@together.net>,
>John Beaderstadt <be...@together.net> wrote:
>>> A single problem must explain *all three* failures, not just one.
>>
>>Not necessarily. The probes were entirely different craft, and it's reasonable
>>to suppose that they simply weren't up to withstanding a 400-mph impact.
>
>Possible... but penetrators are not new technology, so I'd be surprised to
>see something gross like that, unless the surface is unexpectedly hard.
>The plausibility of an explanation goes down considerably if it requires
>that a *separate* fatal design mistake be made in the probes.
...The more I look at what's been released so far, I'm beginning to
suspect this may be a simple case of the reentry shroud not detaching,
and the entire package of all three probes impacted hard. Possible
failure of the pyros due to some reentry heat-related problem,
perhaps?
OM
Derek Lyons
>The impact forces were expected to be no more than 60,000 Gs for the
>afterbody and 30,000 Gs for the forebody. Artillery shells, some of
>which contain complex electronics including radio and radar systems,
>are routinely accellerated at 100,000 Gs on launch. Engineering for
>this has been standard procedure since WW 2. That's not to say
>that it's impossible for there to have been a design or manufacturing
>flaw in them... but they were pretty clearly not past the known
>edge of state of the art in terms of rugged electronics or mechanical
>manufacturing.
Was it SPARTAN that did not use any recovery systems because the shock
of impact was actually less than that off the launch? One of the ABM
interceptors anyhow....
Derek L.
------------------------------
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Used & Rare Books of all sorts
http://www.hurricane.net/~fairwater/
------------------------------
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http://www.hurricane.net/~elde/655.html
------------------------------
Matthew F Funke
>regular soldering?
Speaking as one who has worked on the CATSAT satellite program, I can
tell you that we had to have *licensed* people come in for our soldering
jobs. They certainly turn out nice work. Not too much oxidation in the
solder, excellent amounts of coverage and contact... I don't know how they
pick up all their techniques, but it's certainly a lot better than *my*
work (even though the PI said I was getting better <grin>). From what I
was told, NASA has *very* specific guidelines, written out by virtue of
experience, as to what makes a good "solder joint" and what does not.
Sorry that I was only able to give half an answer... but I hope it
helps.
--
-- Lurking in the Shadows,
"Nikolai" (m...@hopper.unh.edu)
Goth.Code 4.0 zUibba3baWabaaaaLbaa75KxARUSvacnmeiybZan3FmaH17T1aGbZueaqiq
5eedO#di1hbjrpk6!RpsEbacRZUFaaaicaeusnh
Henry Spencer
David Shaw <Use-Author-Address-Header@[127.1]> wrote:
>> BTW, I was told that one strong suspect in early Ranger failures
>> was poor soldering; that prompted the ?2-3 day? "Space Age Soldering"
>> course the techs all had to attend....
>
>regular soldering?
Basically, a lot more care to get all the details reproducibly right, and
careful attention to side issues like post-soldering cleanup.
Henry Spencer
OM <om@RE_MOVE_THIS.ccsi.com> wrote:
>>The plausibility of an explanation goes down considerably if it requires
>>that a *separate* fatal design mistake be made in the probes.
>
>...The more I look at what's been released so far, I'm beginning to
>suspect this may be a simple case of the reentry shroud not detaching,
>and the entire package of all three probes impacted hard. Possible
>failure of the pyros due to some reentry heat-related problem,
>perhaps?
That exact explanation won't work, because the probes separated before
reentry. However, pyro problems in separation are definitely a hot
suspect...
Jens Lerch
>he...@spsystems.net (Henry Spencer) wrote:
>>Possible... but penetrators are not new technology, so I'd be surprised to
>>see something gross like that, unless the surface is unexpectedly hard.
>>The plausibility of an explanation goes down considerably if it requires
>>that a *separate* fatal design mistake be made in the probes.
>...The more I look at what's been released so far, I'm beginning to
>suspect this may be a simple case of the reentry shroud not detaching,
>and the entire package of all three probes impacted hard. Possible
>failure of the pyros due to some reentry heat-related problem,
>perhaps?
The DS2 probes were (supposed to be) jettisoned before atmospheric
reentry. More likely it was a cold-related problem.
--
"Space travel is utter bilge." | Jens Lerch
Richard van der Riet Wooley, | jle...@geocities.com
British Astronomer Royal, 1956 | http://jens.lerch.home.pages.de/
George Herbert
>David Shaw <Use-Author-Address-Header@[127.1]> wrote:
>>Okay, I'll bite.. what makes "Space Age Soldering" different from
>>regular soldering?
>
>Basically, a lot more care to get all the details reproducibly right, and
>careful attention to side issues like post-soldering cleanup.
A bit more than that, as I understand it. Also the understanding
that to a much larger degree in spacecraft than in normal electronics,
the solder is structural, so the bond has to be reliably full pad rather
than just enough that it won't pop off during shipping and will conduct.
But reproducability and cleanup are very important.
Frank, didn't you do that class? Or did you just work closely with
someone who had taken it?
-george william herbert
gher...@crl.com
Julian
> The DS2 probes were (supposed to be) jettisoned before atmospheric
> reentry. More likely it was a cold-related problem.
This is not supposed to be a troll or being picky, but is a genuine
question.
Is it still really called re-entry when it is arriving for the first time?
I thought re-entry was to earth's atmosphere.
--
Regards
Julian
Melbourne, Australia
Dave Michelson
>
> >
> > The DS2 probes were (supposed to be) jettisoned before atmospheric
> > reentry. More likely it was a cold-related problem.
>
> This is not supposed to be a troll or being picky, but is a genuine
> question.
>
> Is it still really called re-entry when it is arriving for the first time?
> I thought re-entry was to earth's atmosphere.
Many books refer it as "atmospheric entry". However, most of the
original literature refers to the scenario as re-entry so it's not
unreasonable to refer to it as such. It's not as if there's any room
for confusion.
-- -o)
Dave Michelson /\\
dmich...@ieee.org _\_v
Tim Johnson
>
> . . . unless a
> significant design flaw can also be found in the DS2 probes. A single
> problem must explain *all three* failures, not just one.
>
One plausible explanation could be that the cruise stage failed to
separate from the aeroshell. According to the MPL press pack,
the DS2 probe deployment would have occured 18 seconds after this
event (10 minutes before landing), but the cruise stage separation
had to occur to initiate the deployment. With the cruise stage
attached, the aeroshell might have reentered ok, but the chute would
not have deployed and all three spacecraft would have smacked into
the Red Planet together. Maybe Mars Observer will find a new crater!
Tim Johnson
could be that the cru
rk
> >Well, Mars Pathfinder, Cassini, Deep Space 1, Lunar Prospector,
> >to name a few, argue that it can be done. And we don't even know that
> >the failure is attributable to "faster, better, cheaper." Remember
> >that the last major Mars mission before "faster, better, cheaper,"
> >the $1 billion Mars Observer, was also lost without a trace. Sometimes
> >things are just going to go wrong. After all, this *is* rocket science.
>
> First drop Cassini. It's the last of the "BIG$" missions.
>
> That leaves Pathfinder, Deep Space and Prospector as successful. Climate
> Orbiter and
> Polar Lander as failures. I don't think three out of five is very good. If you
> separate the Deep Space 2 probes your down to 50%
there are also other "fbc" missions. i believe the small explorer project would
fit into that ... 4 out 5 were successful, one was a total loss (or near total
loss, as they are doing some science with the star tracker.
------------------------------------------------------------------------
rk The world of space holds vast promise
stellar engineering, ltd. for the service of man, and it is a
stel...@erols.com.NOSPAM world we have only begun to explore.
Hi-Rel Digital Systems Design -- James E. Webb, 1968
David Lesher
>Okay, I'll bite.. what makes "Space Age Soldering" different from
>regular soldering?
A rigorous approach to quality, I guess would be the way to
describe it....
Nothing dramatically different, just doitright everytime...
New Mexico Resident
Henry Spencer <he...@spsystems.net> wrote in message
news:FMGF4...@spsystems.net...
> Also, it means that Congress starts to dial
> your budget up and down at random, whereas a fast project can usually get
> the thing done and launched before they get much chance.
Surely, then, it would be cheaper, faster, and better for Congress to fully
fund most of these projects in one year: "Here, we've deposited the full
amount you asked for in this bank account, here's the passbook, don't ask
for any more." That way, the project managers *know* with certainty what
they have to work with. Also, if the project comes in under budget, any
excess funds go into a pool to handle projects that are going over budget.
This way, we don't have the costs from continually stretching projects, and
there is a tiny buffer against cost overruns. Since this would force some
budgets to increase (you don't get any more money from Congress), there
would be fewer projects, but there should be a greater chance of success and
overall less money needed (since Congress won't keep diddling with the
funding).
Whatever happened to the deal Goldin made with Congress a few years back,
which permanently settled NASAs budget through 2001?
Justin Wigg
news:384f06dd$0$2...@nntp1.ba.best.com...
> Well, Mars Pathfinder, Cassini, Deep Space 1, Lunar Prospector,
Cassini? That isn't part of the "Better, Faster, Cheaper" program is it?
Anyway, I don't really think you can call a spacecraft that has not yet
reached it's target much less performed its mission a 'success'.
--
Dogs believe they are human. | Justin Wigg - Hobart, AUSTRALIA
Cats believe they are God. | Reply to: justi...@yahoo.com
- Unknown | http://www.geocities.com/~justinwigg
Darren C. Bly
>the failure is attributable to "faster, better, cheaper." Remember
>that the last major Mars mission before "faster, better, cheaper,"
>the $1 billion Mars Observer, was also lost without a trace. Sometimes
>things are just going to go wrong. After all, this *is* rocket science.
First drop Cassini. It's the last of the "BIG$" missions.
That leaves Pathfinder, Deep Space and Prospector as successful. Climate
Orbiter and
Polar Lander as failures. I don't think three out of five is very good. If you
separate the Deep Space 2 probes your down to 50%
I think NASA is trying to fly and prep to many missions at once. One of the
reasons for Climate Orbiter's failure was a lack of staff. Not enough checks
and balances.
I don't know if we need to send a Mars mission and EVERY opportunity. Slow
down abit. Cross all the "t's" and dot all the "i's". Spending abit more money
is not a bad thing if we get something for it. Right now were about 600 mil in
the hole with no data.
NASA is also taking much higher risks.
Polar Lander was going to be the first lander to be out of contact until after
it landed and it was the first to use non-throttleable descent engines. Now
we're already trying to land at a difficult site, when you add the lack of
contact and new engines you need alot of luck. Add to all that if something
goes wrong we have no way of knowing what happened and your begging for a
failure.
Darren in Bakersfield
Derek Lyons
>regular soldering?
>
Among other things, the hobbyist adage of 'the bigger the blob, the
better the job' does not apply.
If it's like the Navy courses I took, I bet site prep and tool prep
were a *major* item.
Derek Lyons
>A bit more than that, as I understand it. Also the understanding
>that to a much larger degree in spacecraft than in normal electronics,
>the solder is structural, so the bond has to be reliably full pad rather
>than just enough that it won't pop off during shipping and will conduct.
>But reproducability and cleanup are very important.
I thought most early space craft used potted electronics?
OM
>David Shaw <Use-Author-Address-Header@[127.1]> writes:
>
>
>>regular soldering?
>
>describe it....
...The way it was explained to me way back when, it was a deviation
from the Navy way - read: the bigger the blob, the better the job.
Each and every solder joint had to be done with a minimal amount of
solder to reduce the amount of contaminants should a joint break or
melt. During construction, a heat sink was attached to every part,
with the iron set to specific temperature settings. In addition, every
joint was inspected for cold solder, and every drop of flux was
removed before the board was put into power testing. Once that was
done, the joint check process was repeated before the board was put
into the capsule.
...Rigorous. but necessary.
OM
rk
> David Shaw <Use-Author-Address-Header@[127.1]> wrote:
> >Okay, I'll bite.. what makes "Space Age Soldering" different from
> >regular soldering?
> >
> >David
>
> Among other things, the hobbyist adage of 'the bigger the blob, the
> better the job' does not apply.
>
> If it's like the Navy courses I took, I bet site prep and tool prep
> were a *major* item.
a few things that i have seen, so probably not totally complete:
- esd grounded workstation
- esd grounded soldering tip
- controlled temperature of the tip
- requirements on the amount of solder ... i.e., heel fillets for
flat packs
- for high voltage connections, no sharp edges
- heat sinking when appropriate
- trained and certified technicians
- inspections, inspections, inspection
- limits on temperature and humidity
- etc., etc.
also, a lot of the work is done under a microscope.
more recently, some work has moved to automated soldering methods with
some surface mount components. for leadless chip carriers (lcc) that's
more or less required ... and leadless chip carriers, depending on
their size, have various level of success ... and require careful pcb
design and special materials for manufacture, as the thermal
coefficient of expansion of the board and package must match.
personally i'm not a fan of
there's guidelines for this, it's part of the "nhb" (nasa handbook)
which describes things like soldering, printed circuit board design,
polymerics, etc. etc.
Henry Spencer
New Mexico Resident <rebi...@uswest.net> wrote:
>Surely, then, it would be cheaper, faster, and better for Congress to fully
>fund most of these projects in one year: "Here, we've deposited the full
>amount you asked for in this bank account, here's the passbook, don't ask
>for any more." That way, the project managers *know* with certainty what
>they have to work with.
Yes, it would make tremendous sense to do all-at-once budgeting, or at
least to settle several years at once. All-at-once budgeting worked very
well for the construction of Endeavour... but that was an unusual case.
Congress historically has been extremely reluctant to make any sort of
financial commitment more than a year in advance. They *want* to be able
to meddle.
>Also, if the project comes in under budget, any
>excess funds go into a pool to handle projects that are going over budget.
Again, a reasonable way to do things, but not the way the government now
operates...
>Whatever happened to the deal Goldin made with Congress a few years back,
>which permanently settled NASAs budget through 2001?
The White House changed its mind.
Vincent Seifert
>In article <1999120823...@akamai.com>,
>David Shaw <Use-Author-Address-Header@[127.1]> wrote:
>
>>Okay, I'll bite.. what makes "Space Age Soldering" different from
>>regular soldering?
>
>careful attention to side issues like post-soldering cleanup.
Yes. Back around 1980, when I was an electronics tech for the Hawaii
Institute of Geophysics, hand-assembling circuitry for probes that went to
the bottom of the sea (and below), one of my resources was a slim manual
from NASA on soldering. Essentially, it described in detail (with
illustrations, including micro-photographs) the various things that could
go wrong with various types of soldered connections, and how to avoid
them. It was very practical, and I found it very useful.
Vince Seifert Network Analyst seif...@csus.edu
http://webpages.csus.edu/~seifertv/
CSUS hired me to build their network, not to speak for the university.
--
Jens Lerch
>>Well, Mars Pathfinder, Cassini, Deep Space 1, Lunar Prospector,
>>to name a few, argue that it can be done. And we don't even know that
>>the failure is attributable to "faster, better, cheaper." Remember
>>that the last major Mars mission before "faster, better, cheaper,"
>>the $1 billion Mars Observer, was also lost without a trace. Sometimes
>>things are just going to go wrong. After all, this *is* rocket science.
>First drop Cassini. It's the last of the "BIG$" missions.
>That leaves Pathfinder, Deep Space and Prospector as successful. Climate
>Orbiter and
>Polar Lander as failures. I don't think three out of five is very good. If you
>separate the Deep Space 2 probes your down to 50%
You forgot NEAR (Discovery 1) which failed to rendevouz with Eros last
December, but it will get a second chance on next Valentine's Day, so it
could still become an almost complete success.
And Stardust (Discovery 4) was launched early this year. It is currently
collecting particles of the solar wind, while being on target to fly
through the coma of a comet to collect dust for return to Earth.
In the last 4 years the track record of interplanetary FBC probes has
been:
Success: M.Pathfinder, M.Global Surveyor, Lunar Prospector, Deep Space 1
Failure: Mars Climate Orbiter, Mars Polar Lander, Deep Space 2
Pending: NEAR, Stardust
Since 1980 the rather short track record of the big budget
interplanetary missions has been:
Success: Magellan, Galileo
Failure: Mars Observer
Pending: Cassini
Within the accuracy possible by the small sample size the reliability of
FBC and big budget probes is the same, but due to FBC more probes are
launched now per year than formerly in an entire decade.
rk
> dc...@aol.comnospam (Darren C. Bly) wrote:
>
> >>Well, Mars Pathfinder, Cassini, Deep Space 1, Lunar Prospector,
> >>to name a few, argue that it can be done. And we don't even know that
> >>the failure is attributable to "faster, better, cheaper." Remember
> >>that the last major Mars mission before "faster, better, cheaper,"
> >>the $1 billion Mars Observer, was also lost without a trace. Sometimes
> >>things are just going to go wrong. After all, this *is* rocket science.
>
> >First drop Cassini. It's the last of the "BIG$" missions.
>
> >That leaves Pathfinder, Deep Space and Prospector as successful. Climate Orbiter
> and
> >Polar Lander as failures. I don't think three out of five is very good. If you
> >separate the Deep Space 2 probes your down to 50%
>
> You forgot NEAR (Discovery 1) which failed to rendevouz with Eros last
> December, but it will get a second chance on next Valentine's Day, so it
> could still become an almost complete success.
> And Stardust (Discovery 4) was launched early this year. It is currently
> collecting particles of the solar wind, while being on target to fly
> through the coma of a comet to collect dust for return to Earth.
>
> In the last 4 years the track record of interplanetary FBC probes has
> been:
>
> Success: M.Pathfinder, M.Global Surveyor, Lunar Prospector, Deep Space 1
> Failure: Mars Climate Orbiter, Mars Polar Lander, Deep Space 2
> Pending: NEAR, Stardust
first, m. pathfinder had a lot of "investment" from mars explorer; if you add that
in, does it really count as "fbc?" perhaps it's a small mars explorer?
secondly, perhaps we can include clementine, which seemed to have "fbc" attributes.
================================
> Since 1980 the rather short track record of the big budget
> interplanetary missions has been:
>
> Success: Magellan, Galileo
> Failure: Mars Observer
> Pending: Cassini
you can increase the sample size by going back two more years, where we had pioneer
venus 1 and 2 (with probes). moving back some more, we get voyager (1, 2) and
{viking (1, 2) each with a lander}.
==================================
> Within the accuracy possible by the small sample size the reliability of
> FBC and big budget probes is the same, but due to FBC more probes are
> launched now per year than formerly in an entire decade.
of course, i am a big fan and supporter of "fbc."
it's tough to classify spacecraft as "fbc" or not "fbc". faster and cheaper is
easier, but how do we define "better?"
George Herbert
>You forgot NEAR (Discovery 1) which failed to rendevouz with Eros last
>December, but it will get a second chance on next Valentine's Day, so it
>could still become an almost complete success.
>And Stardust (Discovery 4) was launched early this year. It is currently
>collecting particles of the solar wind, while being on target to fly
>through the coma of a comet to collect dust for return to Earth.
>
>In the last 4 years the track record of interplanetary FBC probes has
>been:
>
>Success: M.Pathfinder, M.Global Surveyor, Lunar Prospector, Deep Space 1
>Failure: Mars Climate Orbiter, Mars Polar Lander, Deep Space 2
>Pending: NEAR, Stardust
I personally would take DS2 off the list; it wasn't a completely
seperate mission, it was a subpayload and should be counted as
a MPL experiment. The failure that got MPL probably got DS2
as well.
>Since 1980 the rather short track record of the big budget
>interplanetary missions has been:
>
>Success: Magellan, Galileo
>Failure: Mars Observer
>Pending: Cassini
Galileo was only around 2/3 successful. If you count experiment
time at place and key imaging, it's over 90% successful, but the
limitations and overall data loss due to the antenna got a good
chunk of its mission objective data return.
>Within the accuracy possible by the small sample size the reliability of
>FBC and big budget probes is the same, but due to FBC more probes are
>launched now per year than formerly in an entire decade.
Good point.
-george william herbert
gher...@crl.com
Brian Thorn
wrote:
>Success: Magellan, Galileo
And Ulysses. But Galileo is a very qualified success. 10% of planned
data collected looks great compared to MPL and MCO, but that's
definitely not good by any other measure.
rk
> On Fri, 10 Dec 1999 22:52:46 GMT, jle...@geocities.com (Jens Lerch)
> wrote:
>
> >Success: Magellan, Galileo
>
> And Ulysses. But Galileo is a very qualified success. 10% of planned
> data collected looks great compared to MPL and MCO, but that's
> definitely not good by any other measure.
i would most definitely use another measure; typically, for these sorts
of missions, they have science requirements which must be met and goals
which is desired to be met. this is distinctly different than the amount
of data downloaded. while the mission is more expensive than planned
(reprogramming computers for data compression, etc.) and there will be
less data than planned, i wouldn't be tempted to say that the success of
the mission is in direct proportion to the amount of data downloaded; a
comparison needs to be made of science goals met vs. required. i also
note that the spacecraft has returned data from extended periods of
operations.
since we have a scientist that does galileo analysis on the newsgroup,
i'll shut up now and perhaps he'll chime in. :-)
have a good evening,
Frank Crary
George Herbert <gher...@crl3.crl.com> wrote:
>>>Okay, I'll bite.. what makes "Space Age Soldering" different from
>>>regular soldering?
>>Basically, a lot more care to get all the details reproducibly right, and
>>careful attention to side issues like post-soldering cleanup.
>A bit more than that, as I understand it. Also the understanding
>that to a much larger degree in spacecraft than in normal electronics,
>the solder is structural, so the bond has to be reliably full pad rather
>than just enough that it won't pop off during shipping and will conduct.
>But reproducability and cleanup are very important.
Another issue is the shape of the solder, although that isn't always
an issue. Some instruments apply high voltages over small distances
(e.g. 1 kV/mm), which simply isn't possible on Earth. (Even getting
a vacuum chamber good enough to test this sort of thing isn't easy.)
As anyone who has ever soldered electronics knows, it is fairly
easy to end up with a ball of solder that has a point on it, rather
than being a nice, smooth sphere. A conductor with a sharp point on
it arcs at a much lower electric field strength than a smooth
surface. So there are subdivisions of ``space age soldering''
(i.e. different qualification ratings for soldering flight electronics)
and working on high voltage systems requires more training and tricks.
>Frank, didn't you do that class? Or did you just work closely with
>someone who had taken it?
That would be David Brain, one of the graduate students here at
Colorado. Once upon a time he worked for Mario Acuna at GSFC, and
did that class so he could help put together some flight magnetometers.
I'm not qualified to solder flight hardware, but I might end up
being: I'm moving to U. Mich. to work with someone who builds
flight instruments, so I may end up needing to do some soldering.
(Probably not, since that's usually done by technicians, not
research scientists, but it might come up building test articles.)
Frank Crary
CU Boulder
Tom Abbott
wrote:
>dc...@aol.comnospam (Darren C. Bly) wrote:
>
>>>Well, Mars Pathfinder, Cassini, Deep Space 1, Lunar Prospector,
>>>to name a few, argue that it can be done. And we don't even know that
>>>the failure is attributable to "faster, better, cheaper." Remember
>>>that the last major Mars mission before "faster, better, cheaper,"
>>>the $1 billion Mars Observer, was also lost without a trace. Sometimes
>>>things are just going to go wrong. After all, this *is* rocket science.
>
>>First drop Cassini. It's the last of the "BIG$" missions.
>
>>That leaves Pathfinder, Deep Space and Prospector as successful. Climate
>>Orbiter and
>>Polar Lander as failures. I don't think three out of five is very good. If you
>>separate the Deep Space 2 probes your down to 50%
>
>You forgot NEAR (Discovery 1) which failed to rendevouz with Eros last
>December, but it will get a second chance on next Valentine's Day, so it
>could still become an almost complete success.
>And Stardust (Discovery 4) was launched early this year. It is currently
>collecting particles of the solar wind, while being on target to fly
>through the coma of a comet to collect dust for return to Earth.
>
>In the last 4 years the track record of interplanetary FBC probes has
>been:
>
>Success: M.Pathfinder, M.Global Surveyor, Lunar Prospector, Deep Space 1
>Failure: Mars Climate Orbiter, Mars Polar Lander, Deep Space 2
>Pending: NEAR, Stardust
>
>Since 1980 the rather short track record of the big budget
>interplanetary missions has been:
>
>Success: Magellan, Galileo
>Failure: Mars Observer
>Pending: Cassini
>
>Within the accuracy possible by the small sample size the reliability of
>FBC and big budget probes is the same, but due to FBC more probes are
>launched now per year than formerly in an entire decade.
And we seem to be getting more scientific data about the solar
system and beyond from the "BattleStar Gallactica" space probes and
satellites like Hubble and Galileo, than from the smaller, faster
probes.
TA
Henry Spencer
Tom Abbott <tab...@intellex.com> wrote:
> And we seem to be getting more scientific data about the solar
>system and beyond from the "BattleStar Gallactica" space probes and
>satellites like Hubble and Galileo, than from the smaller, faster
>probes.
Nobody's ever disputed that you get more science return from a Battlestar
class probe... if it works. The problem is that they are too expensive to
be launched very often -- pretty nearly too expensive to be launched at
all, any more -- and also it puts far too many eggs in one basket.
How much scientific data about the Moon or Mars have we gotten from
Battlestar-class probes in the last twenty years?
Tom Abbott
wrote:
>In article <mbdSOOoc8d07HH...@4ax.com>,
>Tom Abbott <tab...@intellex.com> wrote:
>> And we seem to be getting more scientific data about the solar
>>system and beyond from the "BattleStar Gallactica" space probes and
>>satellites like Hubble and Galileo, than from the smaller, faster
>>probes.
>
>Nobody's ever disputed that you get more science return from a Battlestar
>class probe... if it works. The problem is that they are too expensive to
>be launched very often -- pretty nearly too expensive to be launched at
>all, any more -- and also it puts far too many eggs in one basket.
>
>How much scientific data about the Moon or Mars have we gotten from
>Battlestar-class probes in the last twenty years?
Well, we've gotten qute a bit of data actually, as some of them fly
past the Moon for other destinations. No doubt if we had put a
Hubble-type telescope to orbiting the Moon, we would know a whole lot
more about the Moon than we do now.
TA
Frank Crary
rk <stel...@NOSPAM.erols.com> wrote:
>> And Ulysses. But Galileo is a very qualified success. 10% of planned
>> data collected looks great compared to MPL and MCO, but that's
>> definitely not good by any other measure.
>i would most definitely use another measure; typically, for these sorts
>of missions, they have science requirements which must be met and goals
>which is desired to be met. this is distinctly different than the amount
>of data downloaded. while the mission is more expensive than planned
>(reprogramming computers for data compression, etc.) and there will be
>less data than planned, i wouldn't be tempted to say that the success of
>the mission is in direct proportion to the amount of data downloaded; a
>comparison needs to be made of science goals met vs. required. i also
>note that the spacecraft has returned data from extended periods of
>operations.
>since we have a scientist that does galileo analysis on the newsgroup,
>i'll shut up now and perhaps he'll chime in. :-)
I'm not sure if I want to. I agree with everything you said, but I'm
also unwilling to attach a percent to how successful a mission is.
JPL and NASA say that Galileo accomplished 80% of its science goals,
and they got that number (as I understand it) by going through the list
of science goals, giving each a yes/no value, and dividing the number
of yes's by the number of items. Usually, it isn't that simple. There
is, ``yes, but not as well as we wanted'',``definitely yes, but we
could have done better'', ``no but we still got some good data along
those lines'', etc. Nor were all the goals of equal value, although
you could argue endlessly about which were worth more than others.
Then you get into the never-never land of things that were not on that
list. I'm fairly sure that magnetometer data on the existence of an
ocean on Europa wasn't on the list, and I'm quite sure that similar
data on an ocean within Callisto definitely wasn't (just to use one
example I'm familiar with.) Often, when you observe something, you
discover something you did not expect to find. In several cases, Galileo
has done that. Would there have been more unexpected discoveries if
the high gain antenna had opened? Yes, definitely. But how many and
how important? How can you attach a number to something like that?
I would say that Galileo is a success, but not a complete success,
and that the sum total of the scientific results is between 50 and
100% of what it might have achieved. I don't know, and I don't even
know how to figure out, where between 50 and 100% the ``real'' value
is.
Frank Crary
CU Boulder
rk
getting back to the original poster, stating "10% of planned data collected
looks great compared to MPL and MCO" sort of implies 10% of the mission
goals. for some missions, that may be true, if the requirements were
something like, "image 80% of the planet with 100 meter resolution" and only
8% was done. from some missions i have seen hard science requirements + goals
listed ... and i stated previously, per cent complete can be higher than data
wanted. i don't know how to factor in the extended missions, but they'll add
to the science return, too.
looking at things financially, if we did get only 10% of the goals, than we
got (rounding) about $100K worth of science ... less then then cost of a
discovery spacecraft (or is that mission) and slightly more than a small
explorer. while i can't interpret the science at all, i believe from what
i've read and what you posted the mission was considerably more successful
than that.
Michael J. Gallagher
>Remember back in the good old days? It took 7 tries before they got
>the Ranger lunar probes to work.
>
>So lets figure out what probably went wrong with teh MPL and get on
>with exploring Mars.
Well said! And we should remember that failures also plauged
non-exploration programs. The early recon satellite program, "Corona"
(? if I spelled that wrong, let me know) which had the civilian cover
name "Discoverer," endured at least _ten_ failures in a row before
everything worked right. President Eisenhower was unwavering in his
support, and let the program continue on until it succeeded. Some of
today's Monday Morning Quaterbacks could learn from that example,
IMHO.
om
wrote:
>How much scientific data about the Moon or Mars have we gotten from
>Battlestar-class probes in the last twenty years?
...Henry, old pal, that's a partially loaded question. There haven't
been *any* Ponderosa-class probes to the moon in the past 20 years,
and even during the heydays there weren't any launched with the
heavy-duty size and configuration along the lines of Cassini or even
Viking. Surveyor was probably the closest we've come sending such.
OM
OM
<mik...@odyssey.net> wrote:
>
>The early recon satellite program, "Corona"
>(? if I spelled that wrong, let me know) which had the civilian cover
>name "Discoverer," endured at least _ten_ failures in a row before
>everything worked right.
...Actually, "Corona" was only part of a series of special DOD
spysats. After "Corona", the DOD launched several other series,
including "Schlitz", "Lone Star", "Pearl", "Coors", "Jax", "Michelob",
"Miller High Life" (A really High Altitude optics testbed),
"Budwiser", and the ambitious "Dos Equis", which was specifically
targeted at observing Cuba.
...In 1965, the DOD launched "Molson" and a follow-on, "Moosehead",
with both birds having been farmed out to Avro as compensation for a
couple of lost Avro Disk contracts. The Brits jumped in on the
co-funding bandwagon, with the "Guiness" series of spysats, all of
which were used to spy on the French and the Belgians. The
Australians, having no real space program of their own and a lot of
money to spend, even did some combination biosatellite tests using
Tasmanian Devils in lieu of monkeys. Flying under the "Fosters Oil
Can" codename, this series was instrumental in determining once and
for all whether or not New Zealand was, in fact, an island
subcontinent and not just a part of Australia separated by a really
big creek.
...The DOD didn't just stop at teaming up with national governments,
they even went to the state, local and educational levels. The best
example was, of course, the "White Lightnin'" series, which were used
by Alabama coach Bear Bryant to spy on Auburn's practice sessions in
the early 70's.
OM
Justin Wigg
--
Dogs believe they are human. | Justin Wigg - Hobart, AUSTRALIA
Cats believe they are God. | Reply to: justi...@yahoo.com
- Unknown | http://www.geocities.com/~justinwigg
OM <om@RE_MOVE_THIS.ccsi.com> wrote in message
news:3866e466....@news.ccsi.com...
<snip>
Henry Spencer
Tom Abbott <tab...@intellex.com> wrote:
>>How much scientific data about the Moon or Mars have we gotten from
>>Battlestar-class probes in the last twenty years?
>
>past the Moon for other destinations.
"Some"? I count one. (Cassini made no significant lunar observations,
last I heard.) And the Galileo observations, while of some interest,
are minor footnotes compared to what Clementine and Lunar Prospector --
missions which *together* cost literally an order of magnitude less --
yielded.
>No doubt if we had put a
>Hubble-type telescope to orbiting the Moon, we would know a whole lot
>more about the Moon than we do now.
Oh, undoubtedly. And if there were exploring parties setting out from
Luna City twice a week, we'd know still more. But neither of those "ifs"
has anything to do with the real world. Like I said, nobody disputes that
Battlestar missions are better, other things being equal... but other
things are *NOT* equal, and a flying F/B/C is lots better than a cancelled
Battlestar. And that is the choice.
Henry Spencer
om <om@REMOVE_THIS.ccsi.com> wrote:
>>How much scientific data about the Moon or Mars have we gotten from
>>Battlestar-class probes in the last twenty years?
>
Yep, quite true. And there's a reason for that, and it's not that there's
no interesting lunar science left to do. (There was one *planned* --
Lunar Observer, the second in the Observer series -- but it died with the
truncation of Observer.) Battlestar-class missions are hard to fund.
>and even during the heydays there weren't any launched with the
>heavy-duty size and configuration along the lines of Cassini or even
>Viking. Surveyor was probably the closest we've come sending such.
The early Rangers were, *for their day*, the equivalent: ambitious
missions with bunches of experiments, right at (or a little beyond) the
limits of what was reasonable then. For that matter, the original
Surveyor was also rather ambitious. (The Surveyors that actually flew
were severely trimmed down because of Atlas-Centaur performance
shortfalls, among other things, and the program was terminated before it
could work back up to the more ambitious configurations.)
Frank Crary
Henry Spencer <he...@spsystems.net> wrote:
>>>How much scientific data about the Moon or Mars have we gotten from
>>>Battlestar-class probes in the last twenty years?
>> Well, we've gotten qute a bit of data actually, as some of them fly
>>past the Moon for other destinations.
>"Some"? I count one. (Cassini made no significant lunar observations,
>last I heard.)
As I understand it, Cassini made quite a few lunar observations during
the encounter, but they were of the Earth-facing hemisphere. That
hemisphere has been studied to death (I was going to say since Galileo,
but that would be ambiguous...), so I doubt Cassini made any new discoveries.
On the other hand, those observations are very significant: As calibration
images of a very well-known object.
>...And the Galileo observations, while of some interest,
>are minor footnotes compared to what Clementine and Lunar Prospector --
>missions which *together* cost literally an order of magnitude less --
>yielded.
Sure, but those observations were basically a free bonus to the Galileo
mission. Someone (I don't feel like doing so myself) could make
an argument about the incremental costs of making those observations
compared to the value of the results. A much better case could be
made for the Ida and Gaspra observations, but you did start this
off by saying ``of the Moon or Mars.''
Frank Crary
CU Boulder
Geoffrey A. Landis
>> In the last 4 years the track record of interplanetary FBC probes has
>> been:
>>
>> Success: M.Pathfinder, M.Global Surveyor, Lunar Prospector, Deep Space 1
Deep Space 1 has to be listed as "pending" if you're calling it an
interplanetary probe and not a technology demonstration. Remember it did
*not* image asteroid Braille on the flyby. It will be interesting,
though, if it does successfully make it to the comet
>> Failure: Mars Climate Orbiter, Mars Polar Lander, Deep Space 2
>> Pending: NEAR, Stardust
In article <38518736...@NOSPAM.erols.com> rk,
stel...@NOSPAM.erols.com writes:
>...secondly, perhaps we can include clementine, which seemed to have "fbc" attributes.
Right. You will have to include it under the "Failure" column, however--
do recall that Clementine was an *asteroid* mission which stopped by the
moon on the way, and then failed before it made it to the asteroid.
--
Geoffrey A. Landis
Frank Crary
Geoffrey A. Landis <geoffre...@sff.net> wrote:
>>> In the last 4 years the track record of interplanetary FBC probes has
>>> been:
>>> Success: M.Pathfinder, M.Global Surveyor, Lunar Prospector, Deep Space 1
>Deep Space 1 has to be listed as "pending" if you're calling it an
>interplanetary probe and not a technology demonstration. Remember it did
>*not* image asteroid Braille on the flyby.
Actually, it did image the asteroid, as well as getting IR spectra. It's
``just'' that the resolution of the images was something like 50 times
worse than expected... (about 10 pixels across the disk.)
>...It will be interesting,
>though, if it does successfully make it to the comet
Actually, I think the Wilson-Harrington encounter will be more interesting:
Wilson-Harrington is the only asteroid ever observed with a tail, and
is the best known candidate for an comet/asteroid transition object.
Frank Crary
CU Boulder