Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_5/V15NO553.TXT

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Date: Wed, 16 Dec 92 05:16:50
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #553
To: Space Digest Readers
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Space Digest                Wed, 16 Dec 92       Volume 15 : Issue 553

Today's Topics:
                          Apollo Astronauts
                      DC vs Shuttle capabilities
                               Jet Lag
                             Sea Dragon?
       Terminal Velocity of DCX? (was Re: Shuttle ...) (4 msgs)
               what the little bird told Henry (2 msgs)

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Date: Tue, 15 Dec 1992 17:46:16 GMT
From: Jeff Szmyd <[e-mail]>
Subject: Apollo Astronauts
Newsgroups: sci.space.shuttle,sci.space

In article <[e-mail]> [e-mail] (I F Gow) writes:
>
>Anyone have addresses of the whereabouts of the surviving Apollo
>Astronauts?
>
John Young still works here at JSC.  I've talked to him a few times.  He's
a real nice guy.

--
*********************[e-mail]*******************
 Jeff Szmyd  -  Lockheed Robotics Department                  **
 Houston, Texas 77058                    [phone]       **
****************************************************************

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

Date: Tue, 15 Dec 1992 17:50:23 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: DC vs Shuttle capabilities
Newsgroups: sci.space

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

>>    You missed my point.  If your crew compartment is in the cargo
>>bay, where do you put the satellite?

>If it turns out that this isn't roomy enough, then you use the technology
>developed under DC to build a larger vehicle. After all, DC will be a usefull
>piece of technology but it isn't the only spaceship which will ever be built.

A completely new vehicle probably isn't justified unless you need
a *lot* more room.  "Stretching" an existing plane is common practice
in the aircraft industry.  (Rockwell even studied a stretched version
of the Shuttle orbiter.)  However, as a practical matter, I don't
think there will be many missions that require cargo and passengers
to go up in the same vehicle.


>Yes it would take roughly 10 DC flights to carry up the fuel. Soon however
>the availability of lunar oxygen and perhaps hydrogen will greatly reduce
>that cost.

Oxygen, definitely.  But even if discover water ice on the Moon,
I don't think hydrogen will be plentiful enough that you'd want
to throw it away at the rate rocket engines do.

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

Date: Tue, 15 Dec 1992 22:43:56 GMT
From: Dillon Pyron <[e-mail]>
Subject: Jet Lag
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (John Roberts) writes:
># Henry's approach requires that you spend a day or more either before or after
>  the flight to adapt your schedule. In theory that makes sense, but in
>  practice it is likely to take considerable mental discipline (which Henry
>  has, no doubt, but I'm not so sure about the rest of the population).
>  Before the trip, you're busy getting ready, taking care of last-minute
>  details, etc. And if you have limited vacation time, it might seem silly
>  to take an extra day of leave just to stay at home sleeping during the
>  day. Once you get to your destination, the natural incliniation is to
>  rush around doing things, rather than "waste" a day sleeping. A longer
>  travel time *forces* you to start adjusting (with various unpleasant side
>  effects, as Henry pointed out).

Light experiments have pointed at ways to trick the body into resynching using
bright lights and darkness.  But, again, this takes precious time.

>
># Many people tend to wake up at local dawn, regardless of how much sleep
>  they got. So it might be necessary to put black paper over the bedroom
>  window in order to adjust properly.

Experience agrees with this, see below.
>
># Humans are really only efficient at adjusting their sleep cycles forward -
>  it's much easier to stay up a little later and sleep a little later than to
>  go to bed earlier and get up earlier. So if the direction of travel is such
>  that backward adjustment is required, the fatigue brought about by sitting
>  for many hours in an uncomfortable seat might help you to sleep when you
>  ordinarily would not. But I wouldn't say that this is a real benefit of
>  prolonged travel time - it's more a *perceived* benefit.

My wife and I have found that, travelling to Europe, we typically feel shitty
for a day or so after getting there, but do quite well coming home (to Dallas),
while our travels to Hawai'i wind up with us doing very well when we get there
(up early in the morning, enjoying the day, etc) and not so hot when we return
home (admittedly, leaving vacation is a bummer).  I also felt much better after
a trip in first class (f-f miles) than any trip in catt- erh coach class.
>
--
Dillon Pyron                      | The opinions expressed are those of the
TI/DSEG Lewisville VAX Support    | sender unless otherwise stated.
[phone] (when I'm here)     |
[phone] (when I'm home)     |"Pacts with the devil are not legally
[e-mail]          |binding!"
PADI DM-54909                     |-Friar Tuck   _Robin Hood:The Hooded Man_

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

Date: 15 Dec 92 09:27:28 GMT
From: Dennis Newkirk <[e-mail]>
Subject: Sea Dragon?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Thomas Clarke) writes:
>I see many references to Bob Truax's Sea Dragon design.
>
>Can anyone point me at a reference, or post a summary
>of the Sea Dragon?

Do you mean the 1965 Aerojet proposal for a heavy lift
water launched booster?  There is a short summary in
US Civilian Space Programs 1958-1981, Vol. 1, Congressional
Research Service, Jan. 1981. pp 251. Also summarys for
Roost and CLOV Big Dumb Booster (Project Scrimp).

Sea Dragon:
lift-off weight 45,360,000 kg.
2 stage, water launched, pressure fed motors.
both stages reusable
recovered by unaided atmospheric and hydrodynamic deceleration only

The book says little more about it but talks about benefits
of reusable design.


Dennis Newkirk ([e-mail])
Motorola, Land Mobile Products Sector
Schaumburg, IL

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

Date: Tue, 15 Dec 1992 18:06:18 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

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

>SSTO masses 100 times it's payload while a supertanker's payload masses
>100 times the vehicle mass.

No it doesn't.  The dry weight of an SSTO is very small.  Most of
the loaded weight is liquids.  Just like a supertanker.  Tankers
do not (normally) draw fuel from their cargo stores because a) the
customers don't like that and b) crude oil has a tendancy to explode
if you use it as bunker fuel.  That does not change the fact, however,
that a supertanker, like an SSTO, is mainly a big liquid storage tank.

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

Date: Tue, 15 Dec 1992 18:15:46 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

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

>And electrical engineers were building and operating multi-megawatt
>power systems long before aircraft ever left the drawing board. We
>know something about reliability engineering too. We like things simple
>and robust. Every safety critical circuit has a separate backup, usually
>using a different design that is unlikely to share common failure points.
>Simple redundancy is all fine and good, but can lead to redundant failures.

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.




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

Date: Tue, 15 Dec 1992 13:42:24 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Brian Stuart Thorn) writes:

>>Not quite. It wold take about 1.5 years of Shuttle funding to develop DC. Now

>Assuming everything works right, Allen.

No, if everything works right then it would take about .8 years of Shuttle
funding to build DC-1.

>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

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------130 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

Date: Tue, 15 Dec 1992 13:49:36 GMT
From: "Allen W. Sherzer" <[e-mail]>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Michael V. Kent) writes:

>That a DC-X and a Titan IV launch could be had for the cost of a Shuttle
>mission I believe.

Oh this is over and above the DC-X. DC-X doesn't answer all the open
questions but the effort I talk about would. It would include finishing
the tests of prototype cryogenic tanks and test the composite structures.
In addition, it would verify most of the engine components needed to
build the DC-Y engine.

DC-X development was actually a lot cheaper. Put the cost of a Shuttle
flight in a CD for a year and the interest you earn will pay for the
DC-X development effort.

>What I don't believe is that you'd get any knowldgeable
>volunteers to fly a Spacelab mission on a Titan IV.

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

--
+---------------------------------------------------------------------------+
| Allen W. Sherzer | "A great man is one who does nothing but leaves        |
|  [e-mail]     |  nothing undone"                                       |
+----------------------130 DAYS TO FIRST FLIGHT OF DCX----------------------+

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

From: "Edward V. Wright" <[e-mail]>
Subject: what the little bird told Henry
Newsgroups: sci.space

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In <[e-mail]> [e-mail] (Henry Spencer) writes:

>(Maybe I'm just cynical, but I suspect we'd know more about hypersonic
>flight if we'd flown the X-30 through X-35 as fast-track experimental
>hypersonic craft, instead of spending ten years on the ground "preparing"
>for an X-30 that will never fly.)

At the very least, we might now if those multibillion-dollar computer
models are right.

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

Date: 15 Dec 92 17:41:40 GMT
From: "Edward V. Wright" <[e-mail]>
Subject: what the little bird told Henry
Newsgroups: sci.space

In <[e-mail]> [e-mail] (Brad Whitehurst) writes:

>Promoting the first X-30 as a "real" space-plane was not a good idea.
>We work on SCRAMjet technology (not the actual engines) and can tell
>you that there is a lot of work yet to do to really understand the
>physics of fluid flow and combustion in that environment.  Unless you
>want to spend seriously painful sums making and breaking engines
>(these puppies AIN'T easy to test!), we need detailed info on the
>physics so that what is built has a higher chance of success.

Interesting NASA and the US Air Force were quite ready to test
a scramjet-powered plane (the X-15C) during the 1960's, except
that Congress wouldn't appropriate the money.  But today, we
can't even try without developing a lot of new physics.  Guess
somebody must have misplaced a lot of data in the last 30 years.
(Or maybe just misplaced his cajones....)


>Even so, the performance of the first article is likely to disappoint
>(ref.: XP-59 Airacomet), so overblowing the first one, like was done
>with NASP, is risky to the program as a whole.  I think this lesson
>also can and will apply to the DC.

If, instead of building the XP-59, we had embarked on a long research
program like the X-30, the first US jet aircraft would have flown
sometime after the Korean War.  Meanwhile, Russian MiGs would been
blasting our Mustangs out of the sky.

You're right.  There is a lesson to be learned there.

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

End of Space Digest Volume 15 : Issue 553
------------------------------