Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V12_5/V12_524.TXT

Internet Message Format | 1991-06-28 | 16KB

Return-path: <[e-mail]>
X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson
Received: from beak.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/[e-mail] (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests)
          ID </afs/andrew.cmu.edu/usr1/ota/Mailbox/sbDD=oG00VcJI57k4D>;
          Sun, 11 Nov 1990 01:43:01 -0500 (EST)
Message-ID: <EbDD=[e-mail]>
Precedence: junk
Reply-To: [e-mail]
From: [e-mail]
To: [e-mail]
Date: Sun, 11 Nov 1990 01:42:32 -0500 (EST)
Subject: SPACE Digest V12 #524

SPACE Digest                                     Volume 12 : Issue 524

Today's Topics:
              Re:you Can't Expect A Spa
             Re: LNLL Inflatable Stations
              SSX and Aerospike
              Ulysses Update - 11/02/90
            Re: Creationists and Moon Dust
             Re: LNLL Inflatable Stations

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
  [e-mail].  Other mail, esp. [un]subscription notices,
  should be sent to [e-mail], or, if urgent, to
             [e-mail]

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

Return-path: <[e-mail]>
X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail
Date: 1 Nov 90 02:33:40 GMT
From: usc!elroy.jpl.nasa.gov!zardoz.cpd.com!dhw68k!ofa123!f2505.n206.z1.fidonet.org![e-mail]  (Charles Radley)
Organization: FidoNet node 1:206/2505 - His Board, Ventura CA
Subject: Re:you Can't Expect A Spa
Sender: [e-mail]
To: [e-mail]

Here is Gary Hudson's reply to your remarks about SSX, RL-10
and aerospike.

From: ghudson
Date: Tue, 30 Oct 90 21:24:34 EST
To: cradley
Message-Id: <memo.51866>
In-Reply-To: <memo.51559>
Subject:  SSX Usenet discussion

It is true that any "SSX" (I obviously prefer "Phoenix") will
require a new plug nozzle or aerospike-type engine, but the
vehicles can use either J2S or RL10 turbomachinery, which is
by far and away the big problem in engine development.  It
didn't take Rocketdyne very long to cobble together a linear
aerospike test bed 15 years ago in like manner.

Any "HLV" will require new engines, built from scratch.  This is
certainly true of ALS, which has a new gas-generator design
proposed by NASA Marshall.  The Shuttle C ain't worth talking about,
since it is dependent on Shuttle technology,

On the matter of EVA...it is certainly true that there will be
more EVA, but so what?  EVA is hard only because we haven't done
much; we'll get better with practice.
  Also, the suits  can be fixed by going to new, all-metal designs which
have
been demonstrated at NASA Ames the AX-5,

Oh yes.  The RL10 has been throttled to as little as 1% thrust,
and Pratt&Whitney has a design which operates fine at sea level.
This was proposed for use on the SSX design when it was called
"X-rocket" and under study at Lockheed.



--
Charles Radley
Internet: [e-mail]
Compuserve: >internet:[e-mail]
--------------------------------------------------------------------------

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

Return-path: <[e-mail]>
X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail
Date: 1 Nov 90 21:00:37 GMT
From: swrinde!zaphod.mps.ohio-state.edu!van-bc!rsoft!mindlink![e-mail]  (Bruce Dunn)
Organization: MIND LINK! - British Columbia, Canada
Subject: Re: LNLL Inflatable Stations
Sender: [e-mail]
To: [e-mail]

> [e-mail] writes:
>
> Msg-ID: <[e-mail]>
> Posted: 2 Nov 90 17:42:06 GMT
>
> Org.  : Evil Geniuses for a Better Tomorrow
> Person: "Allen W. Sherzer"
>
>
> >I like LNLL's idea, but I haven't heard anything about this stuff.
>
> The stuff is out there. Write your Congresscritters and ask!


     Allen, some of us don't have Congresscritters because some of us aren't
American.  This is an international network (this is a reminder, not a flame).
I think that it would be widely appreciated if you would post a summary of what
the LLNL inflatable station is supposed to be like, along with comments on
differences from Freedom where appropriate.  I for one would like to see some
weight figures, and get some sense of what the inflatable looks like relative
to Freedom.  I don't immediately see why having an inflatable structure gives
advantages (aside from the other differences in design from Freedom).
--
Bruce Dunn   Vancouver, Canada    [e-mail]

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

Return-path: <[e-mail]>
X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail
Date: Fri, 2 Nov 90 22:30:31 -0500
From: "Allen W. Sherzer" <[e-mail]>
To: [e-mail]
Subject: SSX and Aerospike
Newsgroups: sci.space
In-Reply-To: <[e-mail]>
Organization: Evil Geniuses for a Better Tomorrow
Cc:


BTW, before this I saw several postings consisting of your
last posting (which I have responded to). If you where posting
a reply, I didn't see your reply part or my last comments.

In article <[e-mail]>:
>Here is Gary Hudson's reply to your remarks about SSX, RL-10
>and aerospike.

Thanks for going to the trouble of contacting him. Mr. Hudson is
another person with the right attitude to make things happen and
I wish him luck.

>It is true that any "SSX" (I obviously prefer "Phoenix") will
>require a new plug nozzle or aerospike-type engine, but the
>vehicles can use either J2S or RL10 turbomachinery, which is
>by far and away the big problem in engine development.

You may be correct. However, aerospike is still an untried technology
and I consider it more risky than the HLV's under consideration.
However, I wold go to bed with a big smile on my face if I could be
proven wrong.

>It didn't take Rocketdyne very long to cobble together a linear
>aerospike test bed 15 years ago in like manner.

Again, a far cry from operational testing of a production one. On
ballance still more risky than HL Delta which only requires the
design on non-moving parts.

But I can't help but wonder why you accept this. You have objected
to what you perceve as a lack of testing by LLNL. How can you accept
Rocketdyne's 'cobbled together' aerospike testbed as the basis for
an operational spacecraft?

>Any "HLV" will require new engines, built from scratch.  This is
>certainly true of ALS, which has a new gas-generator design
>proposed by NASA Marshall.

ALS does indeed use new engines. The HLV's under consideration here
do not. HL Delta, for example, is seven Delta first stages and three
Shuttle SRB's connected together with a streach Titan IV fairing.
NO new engine is needed. The only parts not off the shelf are the
hunks of metal connecting the boosters. I refer the interested reader
to the September 1990 issue of Aerospace America page 40 "The Zenith
Star Launch System".

The Soviets have used this design method (clustering existing launchers)
in the past with great success. The US did it for the Saturn 1B. It's
a good way to leverage existing designs to lift more. It's simple and
it works.

>The Shuttle C ain't worth talking about, since it is dependent on
>Shuttle technology,

I knew he was smart :-).

>On the matter of EVA...it is certainly true that there will be
>more EVA, but so what?  EVA is hard only because we haven't done
>much; we'll get better with practice.

Again, it does add risk which the HLV's do not. I agree that EVA will
become a lot easier but it should be avoided for now except in an
emergency.

>Oh yes.  The RL10 has been throttled to as little as 1% thrust,
>and Pratt&Whitney has a design which operates fine at sea level.
>This was proposed for use on the SSX design when it was called
>"X-rocket" and under study at Lockheed.

I stand corrected.

I still think the HLV's are the lower risk way to go but it won't
bother me to be proven wrong.

  Allen

--
+-------------------------------------------------------------------------+
| Allen W. Sherzer      |         What should man do but dare?            |
|   [e-mail]         |             - Sir Gawain                        |
+-------------------------------------------------------------------------+

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

Return-path: <[e-mail]>
X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail
Date: 2 Nov 90 22:19:09 GMT
From: usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Organization: Jet Propulsion Laboratory, Pasadena, CA.
Subject: Ulysses Update - 11/02/90
Sender: [e-mail]
To: [e-mail]


                        ULYSSES STATUS REPORT
                          November 2, 1990

     As of 10AM (PST), Thursday, November 1, the Ulysses spacecraft is
15,300,000 miles (24,600,000 km) from Earth and 486,540,000 miles
(783,012,000 km) from Jupiter.  The spacecraft is traveling at 89,717 mph
(144,386 kph) relative to the Sun, and 23,291 mph (37,483 kph) relative
to the Earth.  The Sun-Probe-Earth angle is at 66.5 degrees and Ulysses
is spinning at 5 rpm.

     On October 30, activities continued with the monitoring of the HED
(magnetic field), SIM (cosmic rays and solar particles), and KEP (energetic
particles and interstellar neutral gas) experiments.  Following the initial
switch-on of the GRU (cosmic dust) experiment on October 27, further tests
took place.  The final activity of the day was the uplinking of KEP test
sequences for execution on October 31.

     Following the KEP tests on the October 31, activities were limited to
the continued monitoring of experiments which had been previously switched on.
On November 1, further GRU and KEP tests were carried out.

     Today, the second Trajectory Correction Maneuver will take place.
The KEP experiment will be switched off prior to the maneuver.  This will be
followed on November 3 with the switch off of the HED and SIM experiments in
preparation for the release of the cover of the Low Energy Charged Particle
Experiment (LAN).

     Following cover release, the initial switch-on of the Radio and
Plasma Wave Experiment (STO) will commence.  This will involve the deployment
of the wire booms which have a tip-to-tip length of 72 meters.  The X-band
transmitter will be turned on immediately prior to the wire boom deployment.
On Sunday, November 4, the axial boom will be deployed.  Following completion
of these deployment activities, the KEP, HED and SIM experiments will be
switched on again.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|
     | | | |  __ \ /| | | |      Ron Baalke         | [e-mail]
  ___| | | | |__) |/  | | |___   Jet Propulsion Lab | [e-mail]
 /___| | | |  ___/    | |/__ /|  M/S 301-355        |
 |_____|/  |_|/       |_____|/   Pasadena, CA 91109 |

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

Return-path: <[e-mail]>
X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail
Date: 2 Nov 90 10:17:42 GMT
From: [e-mail]  (Jeff Moersch)
Organization: Cornell Theory Center
Subject: Re: Creationists and Moon Dust
References: <s64421.657561762@zeus>
Sender: [e-mail]
To: [e-mail]

In article <s64421.657561762@zeus> [e-mail] (house ron) writes:
>Creationists around here are claiming that before the moon shots,
>scientists were worried about the space craft sinking in metres of
>dust which they thought should have accumulated since the moon was
>formed.  As we know, very little dust was there, and they say this is
>proof that the moon is only six thousand years old.
>
>Does any one know whether their claim about prior expectations is
>correct?  If it is, does any one know why there is so little moon
>dust?

It is true that there was some concern about the possibility that the lunar
surface would not be able to support a spacecraft.  The idea was originated
by Prof. Tommy Gold of Cornell.  The Surveyor spacecraft series put this
idea to rest before the manned Apollo Lunar Modules ever touched down, though.

Surveyor, and later Apollo, did show that there is a fair amount of dust
on the lunar surface (known as the ``regolith'').  The genesis of this dust
is the constant flux of meteor and micrometeor (the only difference
being one of scale) bombardment, which over time has pulverized the lunar
surface.  The regolith extends something on the order of a few meters down
below the surface.  Below that, extending to something like a few kilometers
is a zone some planetary scientists refer to as the ``mega-regolith''.  This
zone is composed of heavily fractured bedrock - also due to impactors (large
ones).

It seems kind of ironic that creationists would use results from lunar
exploration to lend credibility to their cause - one of the most important
scientific results of the analysis of the Apollo lunar samples was their
age determination.  Radiometric techniques showed that the moon is a very
old and long-dead place - ages were in the 3-4 billion year range, depending
on the sample collection location.


Jeff Moersch
[e-mail]

(Gee - maybe I *did* learn something in Malin's moon class!)

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

Return-path: <[e-mail]>
X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail
Date: Fri, 2 Nov 90 12:42:06 -0500
From: "Allen W. Sherzer" <[e-mail]>
To: [e-mail]
Subject: Re: LNLL Inflatable Stations
Newsgroups: sci.space
In-Reply-To: <[e-mail]>
Organization: Evil Geniuses for a Better Tomorrow
Cc:

In article <[e-mail]> you write:
>Sure, the module's themselves won't weigh much, and will be easy to
>launch, but how do you equip them?

The station is launched with everything inside. After inflation the crew
enters and does final assembly. All assembly is done is shirt sleeves
so the environmental system is packed so it works without assembly.

All these procedures will be tested with the actual hardware on Earth.

>On Freedom, everything is simply installed inside the modules before launch.

At the Midwest Space Development Conference two weeks ago an engineer
on Freedom implied that the modules had to be assembled in orbit. They
are too big/heavy to fit on a single Shuttle flight. However, I didn't
get a chance to ask him if my understanding was correct.

>Another question, on all of the artists conceptions I've seen of the
>LNLL station, there are no windows. Are any planned?

There is a window in the central 0G hub of the station. The main modules
will have no windows. Designs exist for inflatable windows and are
documented in the NASA research on inflatables. I gave a reference a
few days ago.

>One thing I did like about LNLL was the ability to spin the station
>if wanted for artificial gravity.

This is an essensial part of the design. Artificial gravity is needed
to qualify hardware for the moon base. It is also assumed that artificial
gravity will be needed for the trip to Mars.

>This will be great to keep the
>astronauts physically fit, but won't the Coriolis effects, even for
>light gravity be pronounced on such a small station?

They quote research which says that the Earth Station spin rate can
be tolerated. If the spin is too high, they can just turn it down.

>I like LNLL's idea, but I haven't heard anything about this stuff.

The stuff is out there. Write your Congresscritters and ask!

   Allen
--
+-------------------------------------------------------------------------+
| Allen W. Sherzer      |         What should man do but dare?            |
|   [e-mail]         |             - Sir Gawain                        |
+-------------------------------------------------------------------------+

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

End of SPACE Digest V12 #524
*******************