Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT_ZIP/spacedig/V15_5/V15NO557.ZIP/V15NO557

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Date: Thu, 17 Dec 92 05:02:11
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #557
To: Space Digest Readers
Precedence: bulk


Space Digest                Thu, 17 Dec 92       Volume 15 : Issue 557

Today's Topics:
                    Re : Relay to Follow Galileo?
                       Relay to Follow Galileo?
                    Request for "Space News" info
      Terminal Velocity of DCX? (was Re: Shuttle ...) (11 msgs)
                   what the little bird told Henry

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----------------------------------------------------------------------

Date: 16 Dec 92 05:25:54 GMT
From: Brian Stuart Thorn <[e-mail]>
Subject: Re : Relay to Follow Galileo?
Newsgroups: sci.space

>But we're talking about a multi-Billion dollar program here. I just
>wouldn't want to take that risk. That is a lot of money the throw away
>because the "stupid" antanna won't open.. And this will further make the
>image of NASA tarnish even more. Yet another American blunder.. we don't
>need it. How are we going to argue that we need to go to this planet and
>that planet if we can't build the hardware to do the job???
>
>
>        -- Ryan Korniloff
>        -- [e-mail]

Let me try again.

The folding, umbrella-type antennae have been used at least ten times
in space (that is, two each on TDRS-A, TDRS-C, TDRS-D, and TDRS-E, one
on ATS-6 (late-70s pathfinder comsat) and one on Galileo.

Only the one on Galileo failed to open on command, and there is still
hope it will be coaxed open. (They haven't tried brute force yet.)

Lesson:  OPEN THE DAMNED ANTENNA IMMEDIATELY AFTER LAUNCH!!!

-Brian

------------------------------

Date: 16 Dec 92 05:25:18 GMT
From: Brian Stuart Thorn <[e-mail]>
Subject: Relay to Follow Galileo?
Newsgroups: sci.space

>It's probably already too late.  I haven't heard any work has been done on a
>relay, I haven't heard anyone seriously lobbying for one, and launch windows
>are becoming impractical.
>
>>                              The media. The public. And what about
>>commercial sponsorship? Have any or all channels been exhausted? What if a
>>few high profile persons spoke up at once? To think the galilean vistas were
>>within reach of humanity - and now this!
>>                                   ****
>
>Now WHAT?  A more complicated, perhaps somewhat degraded but certainly still
>scientifically interesting mission versus the opportunity for a more
>scientifically interesting mission if we spend who knows how many millions of
>dollars?  It sounds like a tough selling job to me, and I'm not surprised NASA
>went with a different plan.
>
>--
>Chris Jones    [e-mail]
>

  About a year ago, I posted a message asking why NASA did not begin a
  quick-and-dirty conversion to one of the TDRS satellites. TDRS-F was
  in a good place for this. My suggestion included stripping the TDRS
  of everything except the frequencies used by Galileo, and replacing
  the solar arrays (no good for Jupiter distances) with one of the
  Cassini RTGs (which if I understand correctly, have already been
  built, per AvLeak, I think). Add a PAM stage to the stripped-down
  TDRS for Jupiter orbit insertion. Launch Galileo/TDRS on a Shuttle
  with IUS right about now, chasing Galileo all the way out.

  TDRS-F was already paid for, and TRW's TDRS production line is still
  open. TDRS conversion would cost a lot less than a newly designed
  relay probe. It already has the relay systems and software, the
  steerable high gain antennas, and quite a bit of the radiation
  hardening (thanks to the military's insistence on this).

  I'm no engineer, but this seemed plausible to me.

  -Brian


------------------------------

Date: 16 Dec 92 17:53:16 GMT
From: Josh 'K' Hopkins <[e-mail]>
Subject: Request for "Space News" info
Newsgroups: sci.space

[e-mail] (Mark Budd) writes:

>  I have a friend who has a subscription to a weekly newspaper called
>Defense News.  He has told me that the same publishers produce a paper
>called Space News.  Could anyone who has heard of this please pass on
>any opinions as to what it's like?  Preferably people who don't work for
>the paper :-).  E-mail responses would be preferred.

Space News is an almost weekly (44 issues/year) newspaper published by Army
Times Publishing Co.  It's about 30 pages long with color pictures and a
respectable number of adds.  IMHO their coverage is very good - better than
Av Week if all you want is space stuff.  They do tend to spend more time on
commercial developments than you may be used to, but that's their market. A
one year subscription costs $75 in the US, $105 in Canada and $120 for
international subscribers.  The address is 6883 Commercial Dr., Springfield, VA
22159-0500.

--
Josh Hopkins                                          [e-mail]
                        Ho^3     !=L

------------------------------

Date: Wed, 16 Dec 1992 11:56:04 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Edward V. Wright) writes:
>In <[e-mail]> [e-mail] (Gary Coffman) writes:
>
>>If the cost per pound of space transportation drops enough, we won't want to
>>do *any* space assembly since that's very expensive, difficult, and time
>>consuming. Only if space transport remains high cost will space assembly
>>be worthwhile, at least until we are much further down the learning curve
>>of doing assembly work in space.
>
>Difficult?  Nah.  No more so than working under water.  How many
>man-hours of SCUBA experience and experimentation were required
>before divers started to get much work done?  How does that compare
>with the number of man hours that have been spent in EVA?  How often
>do astronauts have their work interrupted by a passing shark.

I believe that astronauts, who do train underwater for EVA, would
tell you that it is different. As I said above, when we get further
down the learning curve some of these tasks may become easier, or
be done in a different way because they aren't easy at all.

>Expensive?  If it becomes inexpensive to get workers into space,
>to get materials into space, and to get equipment into space,
>why should assembly and construction work be expensive?

The CIS quotes $5 million an hour suited time, and their guys are
already in space. Now that may be simple profiteering on their part,
but it should be obvious that it's more expensive to ship materials,
crews, their life support, tools, etc, to orbit than to simply ship
a finished product assembled in shirtsleeves on the ground if per
pound launch costs become relatively low. Only if you can only launch
little bits cheaply, and need a big bit in orbit is assembly justified.
Such an example is SSF. Of course most assembly is still done on the
ground and the modules simply plugged together in space with the robot
arm. Reducing EVA time has been a priority for the SSF program. I
don't see welders, pipefitters, and electricians plying their trades
in space any time in the next few decades simply because their support
on orbit costs too much. Never mind launch costs, suits are expensive,
pre-breathe time is expensive, crew quarters are expensive, special
zero G tools are expensive, skilled manhours are expensive, etc. It's
simple fact that a skilled worker on the ground can do more work in
an hour than a skilled worker in space and labor costs are not
inconsequential. In fact, labor costs dominate every other cost of
space activity. Reducing the standing army is the major cost savings
projected for the DC program. Standing armies *in space* will remain
more expensive than standing armies on the ground. This leads to the
conclusion that cheap heavy lift is more cost effective than cheap
light lift for large space structures. For small structures, cheap
lift of any kind negates the need for in space assembly.

>>>True, a passenger version of the DC-1 couldn't carry more than
>>>about 20 people.  Of course, the Shuttle can only carry 7-10.
>>>What's your point?
>
>>The Shuttle can carry large *working* crews while the proposed DC would
>>carry sardine packed *passengers* because there's no room for them to work.
>>That point should be obvious.
>
>Well, you got me there.  Yeah, the DC will be just like the old
>DC-3, or the modern B-747.  Passengers are crammed in like sardines.
>No room for them to work.  But I'll think you find that most people
>who fly on business don't do their business on the plane anyway. An[
>airliner makes a poor factory and a lousy hotel.

Indeed. And since there are no factories or hotels in space, and
the one being designed is neither large enough for more than
4 occupants, nor cost effective enough for redneck assembly workers,
DC is moot for those tasks requiring in space assembly.

>The complicated part of the arm is the joints.  Shortening the
>length of the pipes between the joints shouldn't be a major undertaking.

But that reduces reach which reduces capability. Telescoping arm sections
should be rather easy to design, and a new arm to fit DC is a very real
possiblity. It reduces the need for EVA. If DC works, an arm is almost
certainly in it's future.

>>Spending two days in a spacesuit isn't likely to be either practical
>>or cost efficient. As we've found out from Shuttle, work in a suit is
>>slow and cumbersome.
>
>Yeah.  We've got tens of hours of experience, so that settles that....
>Obviously there are no new ideas left to try.

If you have a suggestion on how spending two days in a spacesuit can be
made tolerable, please speak up. You can't do that with current suits,
and there are no funds to develop a suit to allow it.

>>Some things are just easier with a bigger vehicle that has both a crew
>>space *and* a cargo bay at the *same* time and that can stay in orbit
>>for 10 to 30 days.
>
>A service station needs a repair bay, a work crew, and enough
>time to do the job.  I don't understand why it needs to be a
>transportation system also.  Most garages own a tow truck.  I've
>never seen a garage that was a tow truck.

Well first we don't *have* a garage. And second DC isn't a tow
truck, nor is there any assurance that a repair mission would
be in the same orbital plane as any orbital garage. You fix
them where you find them because it's too expensive to move
them somewhere else to fix them and then bring them back where
they were. An example is heavy farm equipment. Nearly every
service shop for farm equipment goes to the job rather than
trying to trailer the equipment to the shop. It's cheaper and
easier to fix it on the spot than to transport it. Thus you
have service trucks complete with welders, compressed air,
and tools. Most of the things we might want to fix are in
GEO anyway and DC can't get there, so the point is moot.


>>Jets have massive amounts of "free" air to feed them oxygen and to
>>cool them.
>
>But LOX is cheap, and you've just said that propellents are a small
>part of the cost.

Yes, propellants are relatively cheap, but having to *carry* them
is not. Every pound of oxidizer you carry is a pound of payload you
can't carry.

>>They have the benefit of wings to bear most of the loads so that
>>they don't have to support the vehicle by brute force as well as
>>move it horizontally to it's destination.
>
>Wings also produce drag.

Are you seriously contending that wing drag consumes more fuel than
the lift they provide saves?

>>They operate at lower temperatures and pressures than
>>rocket engines. And their fuel is non-corrosive and storable at
>>room temperature (though some lower performance rockets share this
>>feature)
>
>Liquid hydrogen, methane, propane -- none of those are corrosive.
>LOX is corrosive, but so is the gaseous O2 used by turbojets.  Look
>in the Yellow Pages under "bottled gas" and find out how hard it is
>to store liquid propane at room temperature.

Now look in the Yellow Pages and find out how expensive it is to
store liquid hydrogen and liquid oxygen in tankage that is very
light weight and capable of surviving G loads.

>>Man has been building rockets for 2,000 years while he has
>>only been building jets for 50,
>
>I think the ancient Greeks, who built a working jet engine,
>lived a little more than 50 years ago.

Oh? I'd like to hear about this Greek jet. All I know about is
an external combustion steam *reaction* engine, (IE a form of

rocket).

Gary

------------------------------

Date: Wed, 16 Dec 1992 12:19:33 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Edward V. Wright) writes:
>In <[e-mail]> [e-mail] (Gary Coffman) writes:

>>>Oh.  I thought you were talking about the reentry.  No, the controlled
>>>powered landing was demonstrated, again in the 1960's, by a vehicle
>>>called the LEM.  Which had the additional requirement of landing solely
>>>in unprepared fields.
>
>>In 1/6th G in vacuum, single engine, with a vehicle that massed less than
>>1/10th of DC. A totally different environment, totally different control
>>problem, and totally different scale.
>
>Yes, I'm prepared to assume that engineers can remember to multiple by
>6 or 10.  Totally different environment?  But, Gary, you just got through
>telling me that the environment of space is much more hostile than the
>Earth's atmosphere.  If that's the case, landing on the Earth should be
>a cinch compared to landing on the Moon, should it?

If all things were as simple as multiplying by 6 or 10, aircraft and
spacecraft design would be trivial child's play. Of course that isn't
true so your sarcasm is lost. Operating in atmosphere is a different
environment from operating in vacuum. I didn't say that vacuum was
more hostile, I said that having to operate in *both* was more difficult
than having to work in one. The variable geometry nozzle they intend to
*try* on the DCY prototype is one of the complications of having to
work in both environments. Powered rocket landings in atmosphere also
have ground effects that are different from landings in vacuum. Having
multiple engines to throttle instead of just one adds to control complexity.
Scale does matter too with both a 6 times higher G field and a vehicle
that masses 10 times as much, the problem is sufficiently different that
transferring design experience from one to the other is not just a matter
of multiplication.

Gary

------------------------------

Date: Wed, 16 Dec 1992 12:30:30 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Edward V. Wright) writes:
>
>There are different ways of designing redundancy into a system.  Some
>reduce the probability of a failure, others increase it.  Engineers
>are taught to recognize the difference, maximize the former, and minimize
>the latter.  Your multi-megawatt generators wouldn't work very well,
>either, if the engineers were the kind of blithering idiots that you
>assume everyone who works on SSTO must be.

No, I don't assume the engineers working on SSTO are blithering idiots,
just some of the posters making bizzare claims comparing 747s and LEMs
to DC fit that description. I expect that the engineers actually working
on the program fully realize what new ground they are breaking and what
risks their program represents.

Gary

------------------------------

Date: Wed, 16 Dec 1992 12:56:38 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:
>In article <[e-mail]> [e-mail] (Michael V. Kent) writes:
>>What about Mephisto?  The Lambda point experiment?  The United States Micro-
>>gravity Payload (which carried the two aforementioned experiments)?
>
>Let's fly them on Mir and use the hundreds of millions saved on some other
>worthwhile project.

You seem to think that the Mir Cosmonauts are just floating around up
there waiting for paying work. That may be true, but I rather suspect
they have their own experiments that they are running and would charge
a pretty penny to stop that work and do yours. Last I heard they're
willing to rent Cosmonaut time at $5 million an hour plus launch costs
for any experimental equipment you want them to use.

Shuttle flies 5-7 day missions with 5-7 astronauts. That's about $145,000
an hour for astronaut time, or about 34 times cheaper than CIS rates.

Gary

------------------------------

Date: Tue, 15 Dec 92 21:22:45 PST
From: Brian Stuart Thorn <[e-mail]>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

>That a DC-X and a Titan IV launch could be had for the cost of a Shuttle
>mission I believe.  What I don't believe is that you'd get any knowldgeable
>volunteers to fly a Spacelab mission on a Titan IV.
>
>Mike

Ever hear of the "Manned Orbiting Laboratory"? A Gemini with a very
Spacelab-like module launched together by Titan III.

-Brian

------------------------------

Date: Tue, 15 Dec 92 21:23:17 PST
From: Brian Stuart Thorn <[e-mail]>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

>>In the history of spaceflight, that has seldom been the case.
>
>True, but that has far more to do with the design process we use for
>spacecraft. Shuttle is the most complex vehicle ever built according
>to NASA PR (I have no idea just why NASA thinks that is worth boasting
>about). There is no reason to think that building for simplicity won't
>work. That is why everybody who has studied the problem believes that
>a SSTO can be built either now or in the near future. Even NASA internal
>assessments say it can be done.
>
>  Allen

 That it can be done, I am more or less with you. (But I fully expect
 a design problem or two to slow things down...) That it can be done
 at the price you quote, that's another story. Say I'm from Missouri.
 Show me.

 -Brian


------------------------------

Date: 16 Dec 92 14:26:33 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Pat) writes:
>
>Certainly, a staged rocket designed with clean sheet approach can carry
>more weight to orbit at a better mass ratio then an SSTO.   That does not
>mean that you want to take that approach,  if an SSTO CAN!!!  important point
>deliver cargo to LEO  for significantly less cost then any staged rocket
>then why go with staged rockets for routine access to space?

Why no reason at all. The problem as I see it is that those low costs
have yet to be demonstrated with the reusability, lack of ground support,
and quick turnaround required of the DC proposal to meet those cost goals.
Suppose flight experience shows that rebuilds are needed every 10 flights,
or that the ground manpower has been underestimated because of tighter
than expected government flight rules requiring more inspection between
flights. Shuttle looked cheap too at a similar stage of development because
it's components were expected to be reused again and again with minimal
ground manpower for inspection and repair. That didn't pan out, DC may not
either.

>Gary,  use your brain.    Just because a staged rocket can be built with
>greater margins then a SSTO, does not mean that is the way to go.
>
>Right now,  all staged rockets are vintage 60's/50's designs.  they have
>absolutely no margin for safety.  neither does the shuttle.  All the
>models for rocket costing indicate a major cost item is in the building/
>stacking operation related to launch.   The russians turn these guys out
>like sausages and still expand thousands of hours on stacking ops.

Yes again, I agree that stacking is currently expensive with 50's era
designs. That doesn't say that a fresh design *with low launch preparation
cost* as a design goal couldn't cut that expense by a large fraction.
A big dumb booster that just goes up can be cheap to build and cheap to
launch. The keys are cheap mass produced engines, simple modular stacking,
and easy fueling, the rest is just bent aluminum and some cheap silicon.
Since it's payload fraction can be higher than the reusable SSTO, the
costs it does have are spread over more pounds of payload.

>If a 747 had to change engines every time it flew,  a ticket would
>cost 10 times as much.  asirlines are cheap to fly, cuz most items only
>need routine maintenance.   literally, you can gas up a 747, clean the
>cabin and turn right around.  i've seen it done.

And as someone pointed out, running the Shuttle at 80% throttle could
reduce engine rebuilds on it too. Shuttle and flyback SSTO have the
advantage of reusing components from one flight to another. DC intends
to run at part throttle to extend that reuse even further, but because
it *is* SSTO, the payload fraction becomes proportionately smaller.

Now reusing components can be good. For example Shuttle would cost only
$20 million per flight if it lasted 100 flights based on component
reuse. Of course fixed ground costs, fuel, and rebuilds of some
components push that back up to around $170-$270 million per flight
at current flight rates. But component rebuilds don't dominate
costs. It's that damned standing army needed to launch it with man
rated safety checkers checking the work of checkers checking the work
of workers and many levels of supervision on top of that. Shuttle is
expensive because it's labor intensive, not because it's two stage.
It was designed to a performance spec instead of a cost spec. Now DC
is supposed to be designed to a cost spec, and that's good, but it's
also exploring new territory by being SSTO which thins payload margins
and that's tricky.

>Sure,  a NASP, could probably be built with  170% margin of load,  but why?
>and if it costs 4 times what DC-1 could deliver, then you are wasting money.

Agreed, *if* it costs 4 times DC-1 to operate, which it may well do, I'm
no fan of current NASP approaches either.

>My belief is that the DC-1, will deliver loads to orbit cheaper then anything
>else flying.  if it can,  then we are in great shape.

And my belief is that big dumb boosters designed to cut costs can cut the
cost to orbit to under $300 a pound, and I don't think DC can touch that in
the real world. The best numbers I've seen for DC work out to $666 per pound.
Shuttle was quoted as cheaper than that at a similar stage of development.
I think expendibles offer a better path to cheap access to space. DC may turn
out to be cheaper than Shuttle for ferrying crew up *and* down, but I don't
think it can compete with big dumb boosters on a cost basis for pounds of
payload to orbit. And neither are replacements for Shuttle's unique
capabilities. DC may be the answer, but to what question?

Gary

------------------------------

Date: 16 Dec 92 14:38:34 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Paul Dietz) writes:
>>In <[e-mail]> [e-mail] (Gary Coffman) writes:
>
>> Snide remarks not withstanding, chamber pressure isn't the only form
>> of stress on a vehicle. While I like Truax's Sea Dragon proposal
>> on several grounds, the low chamber pressures lead to very high
>> loads on the turbopumps because so much more fuel per unit time
>> has to flow to achieve the high thrust required with low pressure
>> engines. Reducing stress in one area can lead to increased stress
>> in another area when the objective remains to get a vehicle from
>> surface to orbit in a single leap. The high speed pumps, not combustion
>> chamber stresses, are the main reliability concern of liquid fuel rockets
>> anyway.
>
>
>Uh, Gary, the Sea Dragon concept used *pressure fed* engines, which
>don't *have* pumps.  Instead, it used big, dumb, strong fuel tanks,
>pressurized with compressed gas.  This limits you to lower chamber
>pressures than in pump fed engines (otherwise the tanks are too
>heavy), but can be much simpler.

Hmmm. I knew that. I must have been thinking of something else at
the time I posted.

>Moreover, your comment is nonsense even without this fact.  Lower
>chamber pressure lowers thrust mainly because it lowers the mass flow
>rate through the engine (the coefficient of thrust also decreases a
>bit, but not enormously).  Viewed another way, the mass flow required
>to get a given amount of thrust is proportional to one over the Isp.
>Isp does increase somewhat with increasing chamber pressure, but
>rather slowly.  The load on a pump increases linearly with the
>pressure it is required to supply, however.

The load on a pump also increases linearly with the volume of material
it has to move. Naturally I was assuming larger combustion chambers for
the low pressure design so that the mass flow, and thrust, remained nearly
the same. The two designs lead to different stresses, though. A low volume,
high pressure pump has different failure modes than a low pressure, high
volume pump. One is not necessarily better than the other.

Gary

------------------------------

Date: 16 Dec 92 14:52:21 GMT
From: Gary Coffman <ke4zv!gary>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Pat) writes:
>In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>>on several grounds, the low chamber pressures lead to very high
>>loads on the turbopumps because so much more fuel per unit time
>>has to flow to achieve the high thrust required with low pressure
>>engines. Reducing stress in one area can lead to increased stress
>>
>I dont think that is an unsolvable problem.   THe Saturn F-1's sucked
>fuel like no tomorrow.   The soviet's haul fuel to feed those
>big protons and energiya engines.

I agree. My point was that low pressure engines don't necessarily mean
lower stress, just different stresses.

>Horizontal take off  is not simple.   while it makes people comfortable
>it means the bird has to sit a long time in the soup,  sucking in
>O2  and feeding the engines.   The stress is high.  the heat buildup
>is enormous.     NASP is going berserk on this problem.
>Flight near MACH 12  can be a real trick.
>
>McDaC, chaose to just fly right out of this soup  and take a simpler
>approach.

I basically agree with this too. MACH 12 is a tough thing in heavy
atmosphere, but most flyback booster designs didn't try to achieve
MACH 12 before switching to rocket power. Note that I'm not wedded
to SSTO concepts here.

>Wings are not useful if they only generate lift up to abou;t  20 miles,
>and you have to keep climbing another 130 miles.

Well that sort of depends. If you can get above most of the atmosphere
with wing assist and air breathing engines, your job of getting to orbit
is made much easier. Again I'm not wedded to SSTO, the jets don't have
to continue to orbit with you. They can be part of a flyback booster.

>Also if an HTHL, is going to be mostly lifting body,  then so will the DC.
>
>As i understand it, it will blunt fly down to mach 3 and then roll
>tail first.  engines will provide terminal management.  most velocity
>will be shed by passive shielding.

That sounds more like a re-entry capsule, ala Apollo, than a classic
lifting body that can glide all the way down to a landing. The only
difference with Apollo seems to be substituting rockets for parachutes
in the terminal phase.

Gary

------------------------------

Date: Tue, 15 Dec 92 21:24:36 PST
From: Brian Stuart Thorn <[e-mail]>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

>What about Mephisto?  The Lambda point experiment?  The United States Micro-
>gravity Payload (which carried the two aforementioned experiments)?  What
>about the Space Vision System and all of the rest of the CanEx payloads?
>Could these all have been launched on the Pegasus?  The same $10 million
>Pegasus?  Could they also have flown the Lower Body Negative Pressure appar-
>atus and several astronauts to wear it?  Could that Pegasus have returned the
>robot arm, USMP, and our brave Pegasus-riding astronauts?
>
>Can't you just admit that a lot more happened on STS-52 than the launch of
>LAGEOS so we can put this issue to rest?
>
>Mike

 Nope. Just about everything on that mission could have been divied up
 and flown on other Shuttles. The Space Vision System on any flight which
 has the RMS. No RMS scheduled? Add it to a mission and then add SVS.
 USMP? That's one pallet. LAGEOS was another. What was Columbia carrying
 in the rest of the payload bay? Room for two more pallets, at least.
 Put differently, LAGEOS and USMP-1 could have been flown on any mission
 with space for one pallet in the payload bay. That's most missions.
 Even the TDRS/IUS flights have room for one more pallet or good-sized
 payload. 51L had TDRS/IUS and the Spartan satellite in the payload bay,
 so the capabilty is there. The LBNP? That's a middeck experiment, suitable
 for just about any Shuttle mission. The crew was too busy? Okay, then
 fly the EDO pallet for the mission and spread the work out over four or
 five more days. This was Columbia, afterall.

 By the way, now NASA is planning to fly STS-62 carrying ONLY the USMP.
 At least, that's all that appears on the manifest for the mission posted
 here a couple of weeks ago. How on Earth is NASA going to justify THAT?

 -Brian



------------------------------

Date: 16 Dec 92 05:23:55 GMT
From: Brian Stuart Thorn <[e-mail]>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

>Well we will launch that 400 pound Italian satellite. You remember, the
>one NASA spent half a billion launching instead of putting it on a $10M
>Pegasus?
>
>  Allen

 LAGEOS-II? It weighs 900 lbs (405 kg.) not 400 lbs. Besides, it went
 to high orbit (not GEO, but higher than LEO) and the upper stage it
 needed to get there weighed another 4,000 lbs. The Shuttle was overkill
 for LAGEOS, but Pegasus would have been pressed. A Delta II would have
 been fine. A loaded Shuttle including LAGEOS would have been okay,
 too. But a mission carrying LAGEOS and one pallet? Bad idea!

 (On this point I totally agree that the NASA brass in this case has
 its collective head up its... um, you know. All that bull about 'the
 crew was very busy', gimme a break. If Columbia had gone the way of
 Challenger on that mission, NASA could NEVER have justified it.)

 -Brian

------------------------------

Date: Wed, 16 Dec 1992 12:46:40 GMT
From: Gary Coffman <ke4zv!gary>
Subject: what the little bird told Henry
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Edward V. Wright) writes:
>In <[e-mail]> [e-mail] (Gary Coffman) writes:
>
>>Success oriented has always been a pejorative phrase in any complex
>>developmental program that isn't tolerant of major program slippages
>>and that doesn't have practically unlimited funding to fix problems
>>as they appear. IE any non-military or commercial program.
>
>Actually, commercial projects tend to be very success oriented,
>because (unlike the public sector) failure does not bring in
>more money and when the money's gone, the project's over.  The
>failure-oriented, "cover your butt" mentality only ensures
>failure, and that doesn't go over big with investors and financial
>people.

Actually operating without contingency planning for failures of
particular developmental parts of your program is what's "failure
oriented" because you're going to get bit in the butt when some
promised system doesn't pan out and your project *depends* on
it working for the project to succeed. That then makes your total
project a *failure* rather than a success. Success orientation
says every planned system is going to work just hunky dory and
we don't need no stinkin' contingency planning. A realistic
approach on the other hand *expects* some things not to work
and has viable alternatives in progress to cover their butt
and make the system work.

>>Any realistic development program *expects* problems along the way
>>and plans for alternative approaches if one of the developmental
>>technologies fails to live up to it's promise. Apollo took extraordinary
>>risks in the Saturn booster program and suffered near catastrophe at
>>least twice, either of which could easily have been like the Soviet N-1
>>failures instead of the successes they were.
>
>Oh, I see.  You aren't afraid the project will ultimately fail.
>You're afraid that someone will get killed along the way.  In
>that case, we'd better put an end to all large industrial projects.
>Have you ever heard the saying, "every bridge kills a man?"

Where did I say that? If Saturn had pogoed just a little harder,
the Apollo program would have been dead in the water with no one
killed, and no one on the Moon either. Development is a risky
business. Not to plan for failures, and work arounds to those
failures is extremely risky business. Neither the Soviets nor
the US had serious contingency plans in place in the race to the
Moon. Either critical systems worked as planned, or the program
failed. One of the Soviet critical systems did fail, ours did
not. So we "won", but it wasn't a rational way of running a
developmental program to deliver a reliable, economical launch
system. That's why we don't fly Saturns today.

Gary

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End of Space Digest Volume 15 : Issue 557
------------------------------