Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_5/V15NO590.TXT

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Date: Thu, 24 Dec 92 05:06:40
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #590
To: Space Digest Readers
Precedence: bulk


Space Digest                Thu, 24 Dec 92       Volume 15 : Issue 590

Today's Topics:
                        Acceleration, cats...
                              aerospikes
                            Article on DC
                       asteroids beyond Jupiter
                          Biosphere 2 update
     I thinI see our problem. (Was Re: Terminal Velocity of DCX?
        Pilots must be stupid? (Re: DC vs Shuttle capabilities
                           SSTO vs. 2-Stage
                           SSTO vs. 2 Stage
Stupid Shut Cost arguements (was Re: Terminal Velocity of DCX? (5 msgs)
              The Appendix? (Re: Acceleration, cats...)
             The Real Justification for Space Exploration

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

Date: Wed, 23 Dec 1992 18:46:54 GMT
From: Josh 'K' Hopkins <[e-mail]>
Subject: Acceleration, cats...
Newsgroups: sci.space

[e-mail] ("Phil G. Fraering") writes:

>Anyone here seen that special they did on TV a while back, about
>how some cats have fallen from ten or twenty stories and sometimes
>survived (don't try this at home! don't try it with a cat! and especially,
>it doesn't work well with humans!)?

>What I want to know is, how the ability to fall from 100-150 feet
>up was _selected for_ by evolution. It implies that they went through
>a period of development where cats that could do that were outcompeting
>cats that weren't, to the extent that a large number of cats today can
>do it.

>Especially since this isn't something that can be done gradually:
>the adaptations don't help in falls of 30-60 feet, or much higher than
>somewhere around 100 feet (I think)...

I'm not a biologist or even a cat owner but what the hell.  This is better than
the Terminal Velocity thread.

Two things come to mind.  First, you can't blame everything on evolution.  The
apendix comes to mind.  Some things are around simply because they weren't
selected against.

Second, cats being hunters and able to climb trees, they must have had some
way of getting down before they invented firemen.  Jumping sounds like a
possibility.  I believe that the constraint on hights is not so much a question
of shock absorbing ability but one of coordination.  The test I believe you are
refering to was studying just why it is that "cats always land on their feet."
If you toss one of the second story window they don't have time to twist into
the right position.  A higher fall may sound more dangerous but it gives the
cat time to get into landing position.  Thus it's actually safer.

One of these days, cats will have to adapt to space so maybe there is some
value to this post.  Probably not.


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

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

Date: Wed, 23 Dec 1992 19:59:12 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: aerospikes
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Doug Mohney) writes:

>Contrast this with one (or more) flights out of Nevada or White Sands which may
>or may not be significant (helps if you've been running up and back to LEO for
>a while as a regular habit) and kicking out the sat on one of those runs.

Well, if they (whoever "they are") don't know your flight is "significant"
enough to shoot down, why are you in a hurry to reenter?


>The cheap-sat may be in a predictable orbit, but you are now faced with
>detecting it without the benefit of CNN coverage.

If they can't detect a cheapsat without CNN coverage, how can they detect
the launch vehicle?


>Now, unless you have information from umm.. SPACETRACK? in NORAD, you have to
>pick cheap-sat out of all the other man-made objects in orbit via some optical
>means (hope it's not a cloudy night, but that cuts both ways) or with radar.

Anyone who has an operational ASAT must, by definition, have some means
of targeting.

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

Date: 23 Dec 92 18:52:10 GMT
From: Paul Dietz <[e-mail]>
Subject: Article on DC
Newsgroups: sci.space

The Dec. 1992 issue of Mechanical Engineering has a 4 page
cover story on the Delta Clipper.  It has a few details I had
not seen before.  Can someone explain in more detail Aerojet's
proposal for the DC-Y, the "integrated modular platelet engine"?
The description in the article was a bit too terse.

    Paul F. Dietz
    [e-mail]

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

Date: 23 Dec 92 18:00:24 GMT
From: Greg F Walz Chojnacki <[e-mail]>
Subject: asteroids beyond Jupiter
Newsgroups: alt.folklore.urban,sci.space

From article <[e-mail]>, by [e-mail] (Joel K. Furr):
> In article <[e-mail]> [e-mail] (bill nelson) writes:
>>[e-mail] (Dave Jones) writes:
>>: bill nelson ([e-mail]) wrote:
> [incipient flamage]

>>
>>The statement was asteroid - not planetoid. The asteroids originate in the
>>asteroid belt. It is doubtful if any of them could be perturbed enough to
>>reach the orbit if Neptune.
>>

[emergent flamage]

Although it might seem like I'm paying out rope here, I'm curious about the
usage of the terms "asteroid" and "planetoid." Bill, since yours is the first
time I saw the distinction made, care to define these? (I hope it's more than
asteroids being those things that lie where asteroids were first discovered.)

THanks.

Greg

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

Date: 23 Dec 92 16:52:35 GMT
From: Tim McCaffrey <[e-mail]>
Subject: Biosphere 2 update
Newsgroups: sci.space

Since B2 gets most (all?) of its power from solar, through the
glass, I just gotta ask the obvious question:

    Does anybody/anything clean the windows? (outside)

                    Tim McCaffrey

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

Date: Wed, 23 Dec 1992 16:58:35 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: I thinI see our problem. (Was Re: Terminal Velocity of DCX?
Newsgroups: sci.space

In <![e-mail]> [e-mail] (Greg Moore) writes:

>    In reality it sounds more like you are talking about DC-10,
>DC-12, etc.
>    Unless you are saying that a 747 is the same plane as a DC-3
>was.
>    If your claims are about 50 years from now, or even 20
>eyars from now, I'll buy them.

I think it would do you a world of good to go out to your local
airport and look around.

Do you have any idea how many DC-3s are still flying?  After 50
years?

And the 747, which you cite as an example of a modern airplane,
is well over 20 years old!

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

Date: Wed, 23 Dec 1992 17:02:55 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: Pilots must be stupid? (Re: DC vs Shuttle capabilities
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Greg Moore) writes:

>>You can walk from one place to another carrying a four-ton
>>cargo container?  On Earth?  I doubt it.

>    Carry it while walking? no, but I can drive it.

If you have a flat tire?

See, for every "greater difficulty" you can think of in
space, I can think of one on Earth.


>    Again, I think I see were we are differing.  See my other
>post on timeframes.  But to recap, I agree, after a couple thousand
>more hours of EVA time, we'll have a lot more down.

If the cost of putting one man into space was $50,000, instead
of $5,000,000, you'd be able to rack up a thousand man-hours
of EVA time pretty fast.


>A diver can swim back.  Or, with enough air (which they should
>always have) resurface.

Not if they're SEALs in a combat zone.  Or cave divers.  Or
under ice.  Or working in an underground sewer system.  All
of which are done routinely today.


>>What makes you think a DC-1 can't accomplish a hard docking.
>>
>    I wasn't aware that it could.  This I understand would
>have to be an added capability?  HOw does it dock? through the
>nose? or along the side?

The McDAC illustration shows it docked alongside.  I'm sure
the docking adapter would be an added capability, carried in
the cargo bay.  Why carry it along on flights where you don't
need it?

If you consider this a problem, well, the Shuttle's docking
adapter works the same way.

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

Date: Wed, 23 Dec 1992 17:07:00 GMT
From: Bruce Dunn <[e-mail]>
Subject: SSTO vs. 2-Stage
Newsgroups: sci.space

        The point has been made that using the DC-1 as an upper stage of a
two-stage vehicle adds the complication of mating the two vehicles.  I feel
that this is not likely to be a very time consuming job, but am willing to
listen to any evidence.  I think that the closest analogy might be the mating
of a Shuttle to its carrier aircraft, which is done on a routine basis. I
don't know if the current mounting allows in-flight separation, but the
mounting used for the Enterprise glide tests certainly did.  Does anyone have
information on how long it takes and how many people it takes to put the
Shuttle on the carrier aircraft?

        The point has also been made that the advantages of the two stage
system are negated if the booster cannot return to the launch site.  Flyback
boosters, with wings, have been assumed in many hypothetical two-stage
systems (and indeed a winged fly-back variant of the Saturn first stage was
examined as a possible booster early in the design process for the Shuttle).
In the case of the DC-1 first stage, I have been assuming no wings and only
limited aerodynamic maneuverability (similar to that of the DC-1).  To
examine what would happen if the booster flight were ***entirely*** vertical,
I have run a stepwise numerical simulation on a spreadsheet.  The results are
as follows:

(rounded numbers)
Assumptions:

Booster Total Mass             1000 tons
Booster Ascent Propellant       800 tons
Booster Isp                     300
Booster Initial acceleration    1.5 g
DC-1 Total Mass                 500 tons
Payload                          58 tons

Results:

Total Booster Burn Time         100 sec
Total gravity losses            980 m/s^2
Booster Altitude at Burnout      46 km
Velocity at Burnout            1190 m/s^2
Coasting Height                 120 km

        The "coasting height" is what the DC-1 (and the booster) will get to
if there are no further rocket burns.  Since the DC-1 has enough vertical
velocity from the booster to keep it clear of the atmosphere for some
minutes, it can then perform its burn horizontally and avoid further gravity
losses.  The booster of course will drop right back towards the launch site.

        The above picture is an over simplification of the process, but I
think that the general idea is clear.  If there is anyone who has software
which models ascent trajectories for launchers, it would be interesting to
see proper calculations for such a "bent" ascent trajectory (vertical ascent
for a first stage, followed by a largely horizontal burn from a second
stage).

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

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

Date: 23 Dec 92 20:08:27 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: SSTO vs. 2 Stage
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Bruce Dunn) writes:

>     Agreed.  Failure of second and third stage engines of conventional
>launchers to ignite after staging has historically been a common cause of
>launch failures.  However, I presume that the DC-1 will have the capability
>of surviving at least 1 engine failure when at near maximum fuel load
>(otherwise failure of any one out of multiple engines would cause a crash in
>the period immediately following an SSTO takeoff).

However, you've overloaded the DC-1 to get that 5x payload capacity
you talk about.  It's going to be over max takeoff weight.

>        I grant that no amount of engine out capability will help a DC-1 if
>it separates from the booster and none of the engines fire because of a fuel
>problem.

Or if you have negative separation, or separation followed by a
collision, or several other scenarios you need to worry about.

The problems of staging are not nearly as trivial as you make
them out.

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

Date: Wed, 23 Dec 1992 16:39:31 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: Stupid Shut Cost arguements (was Re: Terminal Velocity of DCX?
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Greg Moore) writes:

>    I thought you said that McDac or SDIO was going to treat
>development costs of DC-1 as sunk costs.

That depends on exactly who funds DC-1, doesn't it?  SDIO has said
that it won't fund that part of the program, although it could change
its mind.  The Air Force or some other agency might be interested -- too
early to say.  McDonnell Douglas isn't in great shape right now, so I
don't think there's much chance they could develop it as a commercial
project without external funding.  A joint venture, maybe, like Boeing's
777 venture with the Japanese?

If it's done as a commercial project, the R&D will have to be recouped.
McDonnell Douglas is in business to make money.  This doesn't appear too
hard.  Suppose the development program costs $1.5 billion.  If McDAC can

build DC vehicles for $100 million after than, and sell them for $200
million, it can pay off the R&D on the first 15 copies and be making
a profit after that.  (I'm ignoring interest, which would bump the figures
up a little bit, but not a lot.)

It's also possible McDAC might find a customer that wants just the
first few vehicles off the assembly line and wants them badly enough
to foot the bill for the entire R&D program.  This, actually, isn't
uncommon with high-tech projects, though probably only the Federal
government has the money to do it on this scale.



>As for amortization of the orbiter, the same rule applies to that
>as any aircraft or spacecraft, including, DC-1.  The more you
>fly it, the less this matter.  Right now, if you stopped all flights,
>you could argue this cost (excluding interest) is about $150 million
>a flight. (10 flights/orbiter, $1.5 Billion per orbiter).  This
>number will shrink.

That is by no means certain.  There's a good chance someone else
will fly an orbiter into the ground in the next few years and the
whole fleet will be grounded permanently.  And while the increasing
number of flights tends to bring the average cost down, Shuttle
improvement programs tend to push it back up again.

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

Date: 23 Dec 92 10:29:52
From: Steinn Sigurdsson <[e-mail]>
Subject: Stupid Shut Cost arguements (was Re: Terminal Velocity of DCX?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:

   In article <[e-mail]> [e-mail] (Greg Moore) writes:

   >    I thought you said that McDac or SDIO was going to treat
   >development costs of DC-1 as sunk costs.  Or is that just DC-X (in
   >which case, what exactly does that mean?).

   DCX and DCY are proof of concept vehicles which the government is paying
   for. Nither are operational vehicles. DC-1 will likely be a very different
   sort of craft altogether. It will incorporate lessons learned on DCY, it

   >Right now, if you stopped all flights,
   >you could argue this cost (excluding interest) is about $150 million
   >a flight. (10 flights/orbiter, $1.5 Billion per orbiter).

   You left out the $34 billion (in 86 $$) development costs which must
   be amortized.

Does this include the cost of the Enterprise? If so, why is it not a
sunk cost as you argue the DC-Y should be? Does it include
construction of wind tunnels, the (Grumman?) glide simulator and
operations thereof? What about the software development costs for
doing a lot of the aerodynamic simulations, are they shuttle costs or
generic NASA costs that would have been incurred regardless.
You've said you want to bill all manned space program costs to the
shuttle, does that include suit development? If so, what are the DC
personnel going to wear for EVA?
Hell, will a DC groundstaff include any janitors? Haven't seen
those costed... (and if not, who will mop up spills? ;-)

I think you are quite inconsistent in how you assign costs to
the DC and Shuttle. For instance you explicitly said tank farm
operation for LOX and LH2 should not be included, only the marginal
cost of loading each DC - yet you necessarily inlcude those costs
for KSC operations. Similarly your costs do not include software
support (is the DC going to use JPL or JSC software for trajectory
projecting? are those sunk costs? Will they use whatchamcallits
database for LEO objects to avoid collisions, and will the DC then
pay for the radars that do the tracking? Amortised over how many
flights?). You also haven't included any cost estimates for ground
support? Will there be TDRS(type) links in-orbit? Will it use existing
groundstations and satellites (with sunk costs) or build its own
(with sunk development costs!).

The DC is a really nice concept, I hope it works, but at least
try to be fair in assigning costs when you compare it with the shuttle!

|  Steinn Sigurdsson    |I saw two shooting stars last night        |
|  Lick Observatory    |I wished on them but they were only satellites    |
| [e-mail] |Is it wrong to wish on space hardware?        |
| "standard disclaimer"    |I wish, I wish, I wish you'd care - B.B. 1983    |

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

Date: 23 Dec 92 19:13:06 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Stupid Shut Cost arguements (was Re: Terminal Velocity of DCX?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Steinn Sigurdsson) writes:

>   You left out the $34 billion (in 86 $$) development costs which must
>   be amortized.

>Does this include the cost of the Enterprise?

When Boeing built the first 747 it was a non-flying test aircraft just
like Enterprise in most important respects. Since Boeing didn't count
this first 747 as a sunk cost (they would be bankrupt if they did) I
don't think Enterprise should be considered a sunk cost.

>If so, why is it not a
>sunk cost as you argue the DC-Y should be?

DC-Y is a proof of concept for a very limited market (SDI deployment). The
DC-1 will likely be a very different vehicle and will be a new one for all
practical purposes. That cannot be said for Enterprise.

>Does it include
>construction of wind tunnels, the (Grumman?) glide simulator and
>operations thereof?

Since Boeing charges those things to development and passes those on to
customers, I think NASA should as well for its operational vehicles.

>What about the software development costs for
>doing a lot of the aerodynamic simulations,

Boeing also writes software for aerodynamic simulations when it developes
aricraft. The cost of this is included in development and is passed on
to customers. NASA should as well for its operational vehicles.

Fair enough?

>You've said you want to bill all manned space program costs to the
>shuttle,

No, that is not what I said. That is what Dennis put into my mouth.

>does that include suit development? If so, what are the DC
>personnel going to wear for EVA?

Well, I think they should pay their fair share of the development costs
for whatever suit they use.

>I think you are quite inconsistent in how you assign costs to
>the DC and Shuttle.

I disagree. However, it is a minor point since if you use the same rules
(pick any you like) DC comes out far far ahead of Shuttle. In fact, you
could amortize DC-Y development, DC-X development, and DC-1 development
and it STILL comes out cheaper than the operational costs of Shuttle
(~$6,000 per pound for DC vs $10,000 per pound for Shuttle). All three
efforts cold be funded with the interest you would get by putting Shuttle
development money in the bank at 5%.

>For instance you explicitly said tank farm
>operation for LOX and LH2 should not be included, only the marginal
>cost of loading each DC

No, I have never said that. I think DC will get fuel from the same
source that airliners get fuel. American Airline doesn't produce its
own fuel, not do they get it at marginal cost. Instead they buy it
from suppliers who include the cost of tank farms in the price they
charge. DC will be no different.

   Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------122 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 23 Dec 92 12:14:15
From: Steinn Sigurdsson <[e-mail]>
Subject: Stupid Shut Cost arguements (was Re: Terminal Velocity of DCX?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Allen W. Sherzer) writes:

Sheesh, that was fast! Doesn't anyone break for holidays any more?

   In article <[e-mail]> [e-mail] (Steinn Sigurdsson) writes:

   >   You left out the $34 billion (in 86 $$) development costs which must
   >   be amortized.

   >Does this include the cost of the Enterprise?

   When Boeing built the first 747 it was a non-flying test aircraft just
   like Enterprise in most important respects. Since Boeing didn't count
   this first 747 as a sunk cost (they would be bankrupt if they did) I
   don't think Enterprise should be considered a sunk cost.

A gliding body with no engines and no heat shield is comparable
to the operational system? And are you sure that the first 747 didn't
fly? Even the first 707 flew and that was a far more groundbreaking
test article (despite the B-47 and B-52 which sunk some of the
development costs - and it still crashed before taking off!).
Henry, you there to arbitrate?

   >If so, why is it not a
   >sunk cost as you argue the DC-Y should be?

   DC-Y is a proof of concept for a very limited market (SDI deployment). The
   DC-1 will likely be a very different vehicle and will be a new one for all
   practical purposes. That cannot be said for Enterprise.

   >Does it include
   >construction of wind tunnels, the (Grumman?) glide simulator and
   >operations thereof?

   Since Boeing charges those things to development and passes those on to
   customers, I think NASA should as well for its operational vehicles.

Really, did Boeing pay for the development of winglets (those little
dinky wingtip things the latest models have)? Did they pay for the
aerodynamic studies of ducted vs unducted fans? Did they even pay
for the development costs of the basic jetliner airbody designs
or did they sink it to military contracts?
[as I understand it, the developments I mentioned above were largely
done by NASA, under its first "A" - and, no, I don't think those
studies included to any "real" science [sic] - including some work done at NASA
Ames using the windtunnel that did the shuttle 1/3 scale simulations.

   >What about the software development costs for
   >doing a lot of the aerodynamic simulations,

   Boeing also writes software for aerodynamic simulations when it developes
   aricraft. The cost of this is included in development and is passed on
   to customers. NASA should as well for its operational vehicles.

   Fair enough?

Nope, not when a lot of the algorithm development is done
by NASA and Universities under NASA contracts and then
handed over to the aerospace companies at below cost (or for
free).

   >You've said you want to bill all manned space program costs to the
   >shuttle,

   No, that is not what I said. That is what Dennis put into my mouth.

I thought you quoted a (Pike?) study saying $500 M per flight
charging all costs to shuttle, $750 M if (sunk) development costs
were included. Apologies if it was Dennis...

   >does that include suit development? If so, what are the DC
   >personnel going to wear for EVA?

   Well, I think they should pay their fair share of the development costs
   for whatever suit they use.

Yeah, right. Is there still a line in the budget to recoup Apollo and
Mercury sunk costs? Sometimes you just have to write some costs off
as sunk and not try to recoup them...

   >I think you are quite inconsistent in how you assign costs to
   >the DC and Shuttle.

   I disagree. However, it is a minor point since if you use the same rules
   (pick any you like) DC comes out far far ahead of Shuttle. In fact, you
   could amortize DC-Y development, DC-X development, and DC-1 development
   and it STILL comes out cheaper than the operational costs of Shuttle
   (~$6,000 per pound for DC vs $10,000 per pound for Shuttle). All three

Over how many flights??? At the moment, with zero flights the DC is
inifintely more expensive than the shuttle! What flight rate and
amortization period are you using?

   efforts cold be funded with the interest you would get by putting Shuttle
   development money in the bank at 5%.

No, you'd have to use it for severance pay...

   >For instance you explicitly said tank farm
   >operation for LOX and LH2 should not be included, only the marginal
   >cost of loading each DC

   No, I have never said that. I think DC will get fuel from the same
   source that airliners get fuel. American Airline doesn't produce its
   own fuel, not do they get it at marginal cost. Instead they buy it
   from suppliers who include the cost of tank farms in the price they
   charge. DC will be no different.

Again over how many flights to you propose to amortise the
infrastructure for? What throughput will you guarantee whoever
capitalises the tank farm construction and pays for operation?
That will critically determine the cost.

|  Steinn Sigurdsson    |I saw two shooting stars last night        |
|  Lick Observatory    |I wished on them but they were only satellites    |
| [e-mail] |Is it wrong to wish on space hardware?        |
| "standard disclaimer"    |I wish, I wish, I wish you'd care - B.B. 1983    |


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

Date: 23 Dec 92 21:21:00 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Stupid Shut Cost arguements (was Re: Terminal Velocity of DCX?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Steinn Sigurdsson) writes:

>A gliding body with no engines and no heat shield is comparable
>to the operational system?

It's called a structural test article. They are frequently built to test
aspects of an aircraft design.

>Really, did Boeing pay for the development of winglets (those little
>dinky wingtip things the latest models have)? ...

Look, if your trying to say that research has been done in the past and
that research should be treated as a sunk cost, then you are partly
correct. The concept is correct but the word is 'depreciated'.

Sure there is lots of depreciated costs going into airliner development.
Much of that does come from government funded research. I have no problem
with that. You will note that I didn't say the money used to build the
X-24, an important vehicle for Shuttle, should be charged to Shuttle.

The fact remains however that we did spend $34 billion to develop Shuttle
and that cost should be accounted for. If we are going to pick and choose
what costs we include and which we don't then why not say Shuttle is
free?

>for the development costs of the basic jetliner airbody designs
>or did they sink it to military contracts?

To some extent I'm sure they did. This happens all the time however
in the civilian world. The first signal processing chips where built
for customers willing to pay development. They where then sold to
whoever. The point is that unlike Shuttle, all costs where accounted
for.

>I thought you quoted a (Pike?) study saying $500 M per flight
>charging all costs to shuttle, $750 M if (sunk) development costs
>were included. Apologies if it was Dennis...

That was Dennis misquoting Pike. Pike said that if you add up all the
manned costs you get a figure of ~$750M. I claim the cost of a Shuttle
flight to be $500M plus the then year development costs amortized over
say, 20 years. I don't remember what that comes to but it is easially
over a billion.

This is the formula American uses to sell most tickets so I think
Shuttle should do the same. I also insist on DC doing the same, I'm
not giving it a free ride.

>   could amortize DC-Y development, DC-X development, and DC-1 development
>   and it STILL comes out cheaper than the operational costs of Shuttle
>   (~$6,000 per pound for DC vs $10,000 per pound for Shuttle). All three

>Over how many flights??? At the moment, with zero flights the DC is
>inifintely more expensive than the shuttle!

Please let's be resaonable here. By your arguement every new vehicle
is infinitely more expensive than existing ones and so shouldn't be
built.

>What flight rate and amortization period are you using?

I just looked up the exact numbers. At 10 flights per year (roughly 80%
the US MLV market) a DC-1 should (if it works) cost $2700 per pound. This
is a third the cost of Shuttle and about 25% less than existing expendables.
If flight rate goes to 12 a year then costs drop to about $2300 per pound.
This assumes a $3B (twice McD's estimate) DDT&E cost over 10 years.

Now if we amortize over 25 years we get $1890 (10 flights) to $1658 (12
flights) per pound. Again, this compares to $3900 for Titan III and
$10,000 for Shuttle. This still leaves plenty of room for error.

After development is amortized (which can happen with the existing market)
costs drop to $100 to $500 per pound.

    Allen

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------122 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: 23 Dec 92 18:55:47 GMT
From: Paul Dietz <[e-mail]>
Subject: The Appendix? (Re: Acceleration, cats...)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Josh 'K' Hopkins) writes:

> Two things come to mind.  First, you can't blame everything on
> evolution.  The appendix comes to mind.  Some things are around simply
> because they weren't selected against.

Actually, I was under the impression the appendix was thought
to have some role in the immune system (say, for acting against
GI infections).  Given that appendicitis can be lethal, evolution
*should* have gotten rid of it unless it had some compensating
benefit.

(Note followup.)

    Paul F. Dietz
    [e-mail]

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

Date: Wed, 23 Dec 1992 20:02:40 GMT
From: Ken Arromdee <[e-mail]>
Subject: The Real Justification for Space Exploration
Newsgroups: sci.space,talk.politics.space

In article <[e-mail]> [e-mail] (David Toland) writes:
>It seems to me that all of these spinoff arguments, Malthusian
>arguments, and "dinosaur killer" arguments miss the point.
>Asking "why explore space?" is like asking "why feed the starving?",
>"why create art?", or "why do basic science?"  It all comes down to
>basic human drives, and I would argue that the drive to explore is
>just as basic as the drive to help, to create, or to learn.

I would argue that there are a lot of other things that are basic human drives,
some a lot less benign.  (You can name your own examples.)

We humans have the capability to decide to override our instincts when we can
figure out that following them is not good for us.  To claim that exploration
is a basic drive is not a justification--if anything, it reduces space
exploration to the human equivalent of lemmings running over a cliff.  (No
posts about staged lemming marches, please.)

>When Sir Edmund Hillary was asked why he climbed Everest, he answered,
>"Because it's there."  The same answer is just as appropriate for why
>we explore space -- because the entire universe is out there...

If you must succumb to your animal instincts, go ahead.  I suggest not using
public money, taxed from me whether I want to support your instincts or not.
If you're getting the money from me, you had better argue that the program is
actually beneficial, not just that your personal instinct commands it.
--
"the bogosity in a field equals the bogosity imported from related areas, plus
the bogosity generated internally, minus the bogosity expelled or otherwise
disposed of."  -- K. Eric Drexler

Ken Arromdee ([e-mail], [e-mail])

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End of Space Digest Volume 15 : Issue 590
------------------------------