Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_6/V15NO624.TXT

Internet Message Format | 1993-07-13 | 34KB

Date: Sat,  2 Jan 93 05:00:00
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #624
To: Space Digest Readers
Precedence: bulk


Space Digest                Sat,  2 Jan 93       Volume 15 : Issue 624

Today's Topics:
                       *** BUSSARD RAMSCOOP ***
                 Aerospike Engines... what are they?
                  Aluminum as rocket fuel? (3 msgs)
                            averting doom
                          DC cost estimates
Government-run programs  Was: Re: Justification for the Space Program
             How many flights are Orbiters designed for?
  Let's be more specific (was: Stupid Shut Cost arguements) (2 msgs)
                        NASA's role in space+
                       Poker Flats, Alaska UAF
                         russian solar sail?+
                         satellite costs etc.
                      Shuttle operational costs
   Stupid Shut Cost arguements (was Re: Terminal Velocity (2 msgs)

    Welcome to the Space Digest!!  Please send your messages to
    "[e-mail]", and (un)subscription requests of the form
    "Subscribe Space <your name>" to one of these addresses: listserv@uga
    (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle
    (THENET), or [e-mail] (Internet).
----------------------------------------------------------------------

Date: 31 Dec 92 19:24:00 GMT
From: Jason Cooper <[e-mail]>
Subject: *** BUSSARD RAMSCOOP ***
Newsgroups: sci.space

[e-mail] (Miles Abernathy) writes:

> I don't know exactly how you will get the hydrogen to fuse in the ramjet.
> So far that problem remains unsolved here on Earth, except for fusion
> reactions catalyzed by atomic explosions.
> = = = = = = = = = = = = = = = = = = = =
>   _     Miles Abernathy, N5KOB        =
>  | |__  [e-mail]       =
> _|    | POB 7580, Austin TX 78713     =
> \  * /  University of Texas @ Austin  =
>   \/    tel. [phone]           =
> = = = = = = = = = = = = = = = = = = = =


The H will be highly compressed by the pressures from the rest of the H
coming in.  It'll be blocked where it stops by magnetic fields...

                                                Jason Cooper

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

Date: Fri,  1 Jan 93 17:02:56 PST
From: Brian Stuart Thorn <[e-mail]>
Subject: Aerospike Engines... what are they?
Newsgroups: sci.space

>Later, the S-IVB's J-2 engine would have been replaced by an aerospike,
>which would double as a heat shield.  The vehicle would then be capable
>of reentering and landing "rightside up" and a Gemini capsule would be
>added on top for manned missions.

   Much has been said recently about aerospike engines, specifically
   in regard to potential use on the DC-1. I've never heard of them
   before, can someone give me (and anyone else in the dark) a brief
   description of what an Aerospike Engine is?

   -Brian


-------------------------------------------------------------------------
Brian S. Thorn                                    "If ignorance is bliss,
[e-mail]                               this must be heaven."
                                                -Diane Chambers, "Cheers"
-------------------------------------------------------------------------

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

Date: Fri, 1 Jan 1993 14:54:12 GMT
From: Paul Dietz <[e-mail]>
Subject: Aluminum as rocket fuel?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Nick Janow) writes:

> It could be mixed with oxygen,
> since molten aluminum forms an oxide slag cover.

Does it?  Aluminum oxide is more dense than aluminum metal (spec. gravity
of 4 vs. 2.7 g/cc.)

    Paul F. Dietz
    [e-mail]

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

Date: Fri, 1 Jan 93 12:32:00 EST
From: John Roberts <[e-mail]>
Subject: Aluminum as rocket fuel?

-From: [e-mail] (Paul Dietz)
-Subject: Re: Aluminum as rocket fuel?
-Date: 1 Jan 93 14:54:12 GMT
-Organization: University of Rochester

-In article <[e-mail]> [e-mail] (Nick Janow) writes:
-> It could be mixed with oxygen,
-> since molten aluminum forms an oxide slag cover.

-Does it?  Aluminum oxide is more dense than aluminum metal (spec. gravity
-of 4 vs. 2.7 g/cc.)

I used to set up little blast furnaces in the back yard and melt aluminum.
I can assure you that molten aluminum very quickly forms an oxide skin -
it takes about a second or two, if I recall correctly. The surface layer
very gradually gets thicker over time after that. I don't recall any
indication that the oxide was sinking to the bottom to any appreciable
extent.

I was never able to come up with a satisfactory way of casting the aluminum -
it tended to react with whatever I was using as a mold. Anybody know of a
way to do it?

(Come to think of it, I never tried making the mold out of fired clay. That's
one approach to the "lost wax" process.)

John Roberts
[e-mail]

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

Date: Fri, 1 Jan 1993 20:02:08 GMT
From: Chris Hall <[e-mail]>
Subject: Aluminum as rocket fuel?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Bruce Dunn) writes:
>
>        Paul Deitz has pointed out in E-mail to me that molten aluminum would
>be an ideal candidate for pressure feeding.  Relative to normal fuels such as
>hydrogen (density 70 kg/m^3) and RP-1 (density 800 kg/m^3), aluminum with a
>density of about 2700 kg/m^3 will require small tanks.  The tanks are very
>hot, meaning that little mass of pressurization gas will be needed.  A useful
>technique might be to have the molten aluminum stored in a spherical steel
>tank pressurized by injecting liquid nitrogen into the tank (which because of
>the heat will immediately vaporize).  Is nitrogen available from the moon?
>
A better choice of pressurizing gas might be helium or argon. Both are inert
and helium is present in reasonable quantities from the solar wind impacting
in the lunar soil. But argon is also present, particularly in old KREEP
deposits, since there has been a considerable length of time for 40K to
decay into 40Ar.

Chris Hall
[e-mail]

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

Date: 1 Jan 93 12:59:26 GMT
From: Herman Rubin <[e-mail]>
Subject: averting doom
Newsgroups: sci.astro,sci.space,sci.physics,sci.environment

In article <[e-mail]> [e-mail] (Jay Scott) writes:
>John McCarthy writes:
>>By the way, it seems to me that if the above idea is sound, it settles
>>the question of the stability of the solar system - in the negative.

            .......................

>Without being so rash as to do any actual calculations, I
>would guess that this does not say much about the stability
>question. I would guess that an asteriod is so much more likely
>to be ejected from the solar system, or smashed to dust by
>collisions, or fall into a planet, than to be captured into
>a destructive resonant orbit that the asteriods will all be gone
>before they destabilize the solar system.

From the standpoint of stability as precisely defined in the theory
of dynamical systems, a gravitational system is not stable; the effects
of a perturbation do not die out.  It is, for example, quite possible
that one of our space probes could alter the orbit of an asteroid so
that the gravitational attraction of another asteroid could cause it
to get a gravity boost from Jupiter which knocks it out of the solar
systme.  Even more so, a change of one micron/second in the earth's
speed will eventually have a non-trivial effect on the paths of
Venus and Mars.  I have not made any attempt to calculate how long
this will take.

--
Herman Rubin, Dept. of Statistics, Purdue Univ., West Lafayette IN47907-1399
Phone: [phone]
[e-mail] (Internet, bitnet)
{purdue,pur-ee}!snap.stat!hrubin(UUCP)

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

Date: Fri, 1 Jan 93 14:41:38 EST
From: John Roberts <[e-mail]>
Subject: DC cost estimates

-From: [e-mail] (Allen W. Sherzer)
-Subject: Re: DC cost estimates
-Date: 31 Dec 92 22:35:17 GMT

-In article <[e-mail]> [e-mail] (John Roberts) writes:
->I should make one additional point regarding Allen's calculations - they
->don't include the large opportunity cost if the Shuttle program should
->be cancelled before DC is fully operational

-I con't follow this. It seems to me that if Shuttle is cancled it could
-more than double the market for DC flights. This could roughly cut DC
-costs in half.

I hope you understand what I mean by the economic term "opportunity cost".
Let me illustrate by an example from an old episode of the comic strip
"Bloom County":
  Opus the Penguin has somehow managed to obtain a military development
  contract worth several hundred billion dollars. That's great, except for
  one problem: there's no way Opus is going to be able to fulfill the terms
  of the contract within the specified timetable. Thus, for however long
  it takes the military to figure this out, they're going to be deprived of
  whatever benefit they expected to gain from the system to be developed.
  [Note 1]

Similarly, with the Shuttle as an operational, manned system with a number
of currently unique abilities, the fact that it's in use indicates that
those who pay for it (NASA, the government in general, and the public in
general) get get some value out of it. There are in fact a considerable
number of missions scheduled over the next few years. If the Shuttle program
were cancelled today, those missions would also have to be cancelled, or at
least deferred. Assuming DC will be a workable system for launching useful
payloads to LEO (which isn't *proven*, though the prospects look favorable),
and even if the program were given all the money expected to be needed for
development right now, they couldn't possibly have a system ready to launch
another TDRS in January, for instance. An extremely optimistic projection
to get one or more DCs in service, with combined payload/year comparable
to the Shuttle fleet (and keeping in mind that they'll probably be pretty
cautious on between-flight service at first) might be five or six years.
That's five or six years in which the US is without the capabilities of
the Shuttle *or* of DC - an enormous opportunity cost. Just as a few
examples, TDRSS might be reduced to one working satellite, HST might have
to shut down for a few years due to further failed gyros (or even break
down entirely), EURECA might reenter and burn up before a DC flight can
get to it to recover or reboost, and all the science missions that have
been waiting for ten or fifteen years already might have to wait another
five or ten years to get a DC berth. Time delay *does* represent a cost -
if it didn't, we could cancel all our current and planned launchers, and
start work on a really spectacular launch system, to be ready in fifty years
or so.

Also bear in mind that many of the upcoming missions have hardware partly
or completely finished that was designed with the capabilities of the Shuttle
in mind, and it's *not* compatible with at least the initial configuration
of DC. So those missions will have to wait even longer for more advanced
"super DCs" to come along, or for DC to expand its capabilities in other
ways (i.e. in-orbit assembly), or they will have to scrap their current
hardware and rebuild for use with DC - more costs and delays.

I also have reservations about the "market" argument. Considering for
example the market for human-tended microgravity science experiments
(by "market" I include government and university programs), I don't see
how shutting off US services for several years would help that market to
grow. Henry has described his views on the measures need to help a particular
market to grow. Price is one factor, but I believe continuous availability
of the services the market uses is also very important. I believe a number
of markets for Shuttle services disappeared due to flagging interest during
the interval between the Challenger accident and the resumption of flight,
for instance, and that was only about three years. If the capability for
human presence in space is one of the things that makes DC valuable, it
doesn't make sense to shut off US capacity to provide this capability for
several years while DC is being developed.

So while I think vigorous pursuit of DC development is a good idea, I think
cancelling the Shuttle program in the meantime is a bad idea. If DC turns
out to be as good as projections indicate, I think it will not suffer from
any lack of business (and no need to artificially double the market to get
costs even lower - that should follow naturally), but given the differences
in capabilities, I expect the Shuttle will continue to be used for a
considerable time following the successful introduction of DC, though
probably with different launch rate and mix of payloads.

There *are* things that should be done in the near term. Designers should
start thinking about payload designs that are compatible with both the Shuttle
and DC, so that we can start taking advantage of the benefits of DC as soon
as it's available. For instance, one might consider a standard payload
size/mass that DC can carry one of, and the Shuttle two (or perhaps two
along with a small third payload). The risk of doing that immediately rather
than waiting a year or two to implement it (as opposed to planning) is
that as I understand it, we don't really *know* what the cargo bay size
and payload mass of DC will be. It would be a terrible shame to build a
batch of 20000 pound payloads and then find out that DC can only lift
15000 pounds. Any such designs started before we have a clearer idea of
the limits should be very conservative on size and mass. (I was somewhat
surprised to hear the recent discussion by you and others that DC-X is
intended to answer relatively few of the many points that must be addressed
before DC can be operational. It's a vitally important first step, but a
step along a longer path than I had envisioned. I still think it's a good
idea, however.)

One question I'm not sure has been addressed before: is the DC-1 expected to
provide for a "shirtsleeve" environment access tube to the cargo bay, like
the Shuttle? In other words, would a "mini-Spacelab" be a viable option for
a DC-1 payload?

[Note 1]: If you'd prefer a more space-related example, consider the chilling
cautionary tale from "Monty Python", in which Mr. Angus Podgorny of Dunbar
has received an order for 48000000 kilts from the planet Skyron in the Galaxy
of Andromeda:
  Mrs. Podgorny: Angus how are y'going to get 48000000 kilts into the van?
  Angus: I'll have t'do it in two goes.
  Mrs. Podgorny: D'you not ken that the Galaxy of Andromeda is two million,
    two hundred thousand light years away?
  Angus: Is that so?
  Mrs. Podgorny: Aye... and you've never been further than Berwick-on-Tweed...
  Angus: Aye... but think o' the money dear...L18.10.0d a kilt... that's...
    L900000000 - and that's without sporrans!
[Obviously, the Blancmanges of the planet Skyron are not going to get their
order filled any time soon. They shouldn't give up their intergalactic
starship program until delivery vans are proven to be adequate to the task.]
:-)

John Roberts
[e-mail]

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

Date: 2 Jan 93 04:54:16 GMT
From: "Simon E. Booth" <[e-mail]>
Subject: Government-run programs  Was: Re: Justification for the Space Program
Newsgroups: sci.space,talk.politics.space

Concerning public opinion about the space program, IHMO those opinions can
and are greatly influenced by the media's depiction of space exploration.
Next time watch news coverage of a shuttle flight.  Invariably some reference
is made to the cost of that particular mission, plus any important technical
information is either watered down or omitted.

I've had people tell me that the media doesn't cover the space program very
much because people aren't interested.

But here's somethin to think about: did people lose interest and the media
reduced it's coverage in response, or did the media cut back coverage and then
convince people that they weren't interested in it?

Simon

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

Date: Fri,  1 Jan 93 17:03:34 PST
From: Brian Stuart Thorn <[e-mail]>
Subject: How many flights are Orbiters designed for?
Newsgroups: sci.space

>In <[e-mail]> [e-mail]
(
>John S. Neff) writes:
>
>>I recall an estimate of 50 flights by a NASA spokesman.
>
>The politically (but not necessarily technically) correct line
>is now that "the Shuttle orbiters will last for longer than their
>original 100-mission design life."
>

   That came from the Rockwell engineers who upgraded Columbia in
   1991-1992. Columbia is the oldest and second-most-flown Shuttle
   and they said there was no reason from an engineering standpoint
   that the Shuttle could not fly 100 or more missions.

   Keep in mind that the Shuttles have been down for heavy maintenance
   twice in the eleven year history of the program: 1986-88 and
   1991-1993 (with each Orbiter being down six to nine months at some
   point in this period.)

   Hopefully, we'll have a DC-1 or better system to replace Shuttle
   long before any hits one hundred missions.

   -Brian


-------------------------------------------------------------------------
Brian S. Thorn                                    "If ignorance is bliss,
[e-mail]                               this must be heaven."
                                                -Diane Chambers, "Cheers"
-------------------------------------------------------------------------

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

Date: 1 Jan 1993 23:56:42 GMT
From: Pat <[e-mail]>
Subject: Let's be more specific (was: Stupid Shut Cost arguements)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>
>If DC flies with anything like the performance and costs that are
>projected, it will be a big commercial success. I think those
>numbers are still optimistic and that the program risks are still
>large, however. Shuttle was a cheap $300 a pound launcher when it
>was a paper airplane too. Even with a 3X stretchout of development time,
>and a 3X increase in projected costs, it'll beat government run Shuttle
>costs, but would have trouble against actual Shuttle costs if Shuttle
>were run under comparable commercial rules. What I'm saying in a nutshell
>is that the proposed DC is expected to be cheaper than the operating Shuttle
>because they are required to operate in different manners by law and by
>government and corporate culture.  Thus your Shuttle bashing rightfully
>should be government operating methods bashing. I'll happily join you in
>*that*. Government can't do anything as efficiently as the private sector.
>



Gary,

    The operating methods of any stackable vehicle are going to
    significantly different from a recoverable single stage vehicle.

    You keep arguing that the russians have high costs for their
    stackables, and that ariane has high costs subsidized by the government.

    I know you believe that cheap stackables can be done,  but those
    are the same paper designs you condemn DC for.

    Shuttle could have lower costs then  NASA currently has,
    but it still needs a tremendous infrastructure.  The OPF,
    the VAB, Tilting bay,  the crawler/transporter.  Launch towers.

    The DC  will not need much more infrastructure, then a
    airline hangar.  Henry, alan and I all believe that eliminating
    all this structure and cost  will make up for any lower
    vehicle lift capacity.

    Please demonstrate how Lockheed could eliminate all these costs
    from commercial shuttle operations.

pat

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

Date: Sat, 2 Jan 1993 04:35:24 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Let's be more specific (was: Stupid Shut Cost arguements)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:

>>engaging in activities which would get you or I put in jail.

>I hammer on this because of your constant claims that
>NASA is doing something illegal or unethical. They are not.

Oh, not illegal. One advantage of being the government is that you get to
make the rules. But government contractors who worked their books the
way NASA does have been barred from doing government work and some
executives have been jailed.

There is also the issue of dumping launch services. We enact all sorts of
sanctions against others who dump.

There are also a number of sections of various commercial space laws
which is at best pushing it and at worst violating the law.

>They are operating exactly as they are chartered to operate.

NASA is chartered as a research organization, not an operational agency.
Shuttle is operations, not research.

>If cost and performance estimates for DC hold up, it may indeed capture
>80% of the MLV market, but not right away. I think most potential customers
>will want to see a track record of successful launches first.

Or provide insurance. Of course, if we add say 3% to the development cost
we can fly three times as many flights as Shuttle needed to be declared
operational.

>The competition, especially Arienne and Long
>March, may be expected to cut prices sharply in response.

That is a problem. Shuttle has shown that a government can dump launch
services quite a bit. But I assume since US launch dumping doesn't bother
you that this wouldn't either.

>to long legal battles over dumping. DC's backers may need deep pockets to
>keep going until they win that 80% market share.

The US market, if fairly awarded, is big enough.

>Pegasus as a current example of the effect of optimistic development
>scheduling. That causes financial problems for a commercial venture
>that government agencies can shrug off.

However, DCX is on budget and has slipped very little (30 days in a three
year contract). It looks like these guys know more than you about how
do schedule launcher development.

>>[6] SSTO launch costs are again, double the estimated costs to add a margin.

>Here's where I have the most problem with your numbers. I accept that
>NASA spends $550 million per launch in total Shuttle program costs.
>I further accept that that's very high. But I would point out that
>it's a government launcher, run under government rules, with government
>overhead.

I'll accept that. It appears that the system, which you have spent so much
effort defending, simply doesn't work very well.

>Estimates of actual variable costs for a Shuttle launch range
>from $37 to $150 million per launch. That makes it look much better in
>comparison to DC numbers.

Amazing how low costs are possible for Shuttle but not for DC. It would
seem to me that this paragraph argues very well for a very low cost DC.

>Is this relevant? Yes if we want to compare
>*vehicles*, no if we want to compare *programs*. It's important to realize
>that DC is projected to operate under a completely different set of rules
>than Shuttle is forced to use.

Which is indeed half the battle. But since you back Shuttle no matter what
it costs, I don't see your point.

>large, however. Shuttle was a cheap $300 a pound launcher when it
>was a paper airplane too.

Yes but *WHY* did Shuttle fail? Mostly it failed because of the system
under which it was built. If that doesn't change, then space will NEVER
be cheap. DC works under a different system.

    Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------113 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 2 Jan 93 02:38:50 GMT
From: [e-mail]
Subject: NASA's role in space+
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] writes:
> The Tethered Satellite System should be a case that fits NASA's role perfectly
> - a research program in a new field. However, even that program was frought
> with the burden of the "old" NASA. The current program managers probably
> couldn't even name the program managers who were responsible for the original
> design.
>
> Howver, there is a big difference between NASA engaging in basic science, and
> NASA operating a launch system.
>
> --- Maximus 2.01wb

Maybe what is needed is a company/organization that acts as a general research
and development, but not as a production organization.. Either NASA become a
private corp for R&D or a organization that is a clearing house or a R&D corp
for many US corps.. Kind of like having Boing, Lockheed, McDonald Douglas, and
other companies have a single company for their R&D and were all benefit. All
will still have their own directs. But.. Talk about Corp Co-Operation..
Maybe give the US more competition with the Japanese, Koreans, Singapore and
other nations..

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

Date: 2 Jan 93 02:06:31 GMT
From: [e-mail]
Subject: Poker Flats, Alaska UAF
Newsgroups: sci.space

Does anyone know anything about "Poker Flats" in Alaska..
Up near Fairbanks, AK.. If I remember right it is run by the
University of Alaska Fairbanks.. Mostly does atmospheric (northern lights, etc)
research..


Michael Adams
Alias: Morgoth/Ghost Wheel
[e-mail]

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

Date: 2 Jan 93 02:12:36 GMT
From: [e-mail]
Subject: russian solar sail?+
Newsgroups: sci.space

In article <ida.725390192@atomic>, ida@atomic (David Goldschmidt) writes:
> I saw something a few months ago about a Russian plan to test a small solar
> sail from the Mir space station on Dec 10. of this year.  I haven't heard
> anything about it since - does anybody know if it happened?
>
> You can email me at [e-mail], or post to the net.
>
> Thanks in advance,
>            Dave Patterson, guest on this account.

New one on me, but I have heard of the supposed race to the moon with solar
sails, to celebrate the 500 anniversary of Columbus, not sure if it
actually came about.. Maybe the olymbics will have a solar sale race or
some other organization will have a solar sail race..

==
==
Michael Adams alias Ghost Wheel/Morgoth [e-mail]

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

Date: 1 Jan 93 16:57:38 GMT
From: Gary Coffman <ke4zv!gary>
Subject: satellite costs etc.
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Gary Coffman) writes:
>>It's the network reconfiguration costs that get you. When NBC had to
>>reconfigure from K2 to SBS 3 due to a control failure on K2, it cost
>>NBC $150,000 a *minute* for 4.5 hours until the major ground systems
>>were re-aimed...   Doing it *unscheduled* because of
>>a failure of the cheapsat, can be really expensive if it only happens
>>once.
>
>Why do you assume that the redundancy will involve repointing?  If you
>*plan* for such handovers, you can put the spare satellite in the same
>orbital slot as the operational one.  (Those slots are over a thousand
>kilometers wide, there's plenty of room.)  Result, no repointing.  Only
>the control room needs to even *know* which bird is live.

Redundancy is always desirable if it's affordable, but there is a practical
difficulty with having *cold* spares in orbit. Will they work when we need
them? They have to be cold spares if they share the same orbital slot and
frequencies. That's why spare capacity is not operated cold. It's located
in another spot where it can be kept as a *hot* spare that can be tested
to assure it's in fully operational condition. With current costs, that
spare capacity is usually *rented* for ad hoc pickups so that it returns
*some* revenue while it's loitering around up there, but if comsats become
cheap enough to be left idle, they still have to pass test signals from
time to time to maintain an assurance their systems are still functional.
That means they can't be in the same slot as the system they are intended
to back up because the testing would interfere with the operations of the
main bird.

>>>>... and since for most orbits
>>>>the satellites aren't retrievable or repairable, and DC won't change
>>>>that...
>>>Again, your assumption, not a self-evident fact.  Cheap launches change
>>>almost everything, including the feasibility of retrieval and repair.
>>
>>I wasn't aware that DC was planned to have a GEO capability, or a large
>>enough cargo bay to retrieve a major comsat.
>
>Why do you assume that DC alone has to do everything?

Oh I *don't*, I don't even assume DC will *work*. It's you folks who
keep saying: "DC is the answer. Now what was the question?"


>The big expense
>of doing most anything in space is getting into LEO; cutting that cost
>massively makes *everything* more feasible.  It becomes much more
>attractive to develop a tug capable of bringing things back down from
>GEO, or a reentry capsule capable of landing a payload too big for a
>DC cargo bay.  Neither of these devices is technologically difficult;
>they don't exist at the moment because operations costs -- mostly
>the cost of launching to LEO -- are too high.

Well if they're too big for DC, then they can't *get* into LEO in
the first place by that "cheap" launch method. So you have development
costs *and* deployment costs to consider in addition to support costs
for your tugs and re-entry capsules. They don't look so cheap anymore.
It's not impossible to deploy mulitple special purpose vehicles in
space, of course, but cheap as an airliner ticket they ain't.

Gary

--
Gary Coffman KE4ZV          |    You make it,     | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems |    we break it.     | uunet!rsiatl!ke4zv!gary
534 Shannon Way             |    Guaranteed!      | emory!kd4nc!ke4zv!gary
Lawrenceville, GA 30244     |                     | emory!ke4zv![e-mail]

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

Date: 1 Jan 93 15:26:30 GMT
From: John McCarthy <[e-mail]>
Subject: Shuttle operational costs
Newsgroups: sci.space

The problem with the shuttle is that the cost of getting the shuttles
ready for the next flight are too large.  It was not anticipated that
so many people would be required.  Indeed it was planned that the
shuttle would be operated like a commercial airplane.  Any future
reusable spacecraft must be planned to reduce these costs.  However,
the almost interminable discussions of shuttle vs. something else
haven't gone into detail on operational costs.  Does anyone have
information relevant to the following questions?

1. What is the distribution of manpower between various functions
of maintaining the shuttle operation?

2. How many people actually lay hands on the shuttles and shuttle
components between flights?

3. How many supervisors are there?

4. What costs are imposed by the split between Cape Canaveral,
Houston and other locations?

5. Would having more shuttles reduce the cost per flight?

6. Does NASA plan to reduce manpower?

7. What shuttle components require the most manpower between
flights?

8. How much expense is due to layers of bureaucracy?

9. How did manpower expended in shuttle operations change
in response to the Challenger crash?
--
John McCarthy, Computer Science Department, Stanford, CA 94305
*
He who refuses to do arithmetic is doomed to talk nonsense.

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

Date: Fri, 1 Jan 1993 18:07:32 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Stupid Shut Cost arguements (was Re: Terminal Velocity
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Gary Coffman) writes:

>>The Space Shuttle is simply the highest cost (per pound) launch vehicle ever
>>operated.

>At $37,500 a pound Pegasus is over three times the cost of Shuttle.

A pegasus flight is more like $12,000 a pound. However, if you used
the same accounting methods, Peagasus would be far far cheaper. Remember
that OSC paid the cost of development for Pegasus and charges it to
customers. Shuttle costomers however aren't required to pay for the
billions spent on Shuttle.

    Allen
--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------113 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 2 Jan 93 00:07:13 GMT
From: Bruce Dunn <[e-mail]>
Subject: Stupid Shut Cost arguements (was Re: Terminal Velocity
Newsgroups: sci.space

> Gary Coffman writes:
>
>  Shuttle *is* expensive to operate, but it offers capabilities not found on
> any other current system.
>



        The apparent high cost per pound of the Shuttle is largely due to
people counting as payload only what is in the cargo bay.  If you allow that
the shuttle itself is a payload (in that it acts as a short term orbiting
workstation for manned spaceflight research), the "cost per pound" drops
sharply.




--
Bruce Dunn    Vancouver, Canada   [e-mail]

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

End of Space Digest Volume 15 : Issue 624
------------------------------