Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V11_1/V11_179.TXT

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Subject: SPACE Digest V11 #179

SPACE Digest                                     Volume 11 : Issue 179

Today's Topics:
               Re: Spacecraft on Venus
             Re: Shuttle Escapes
      Re: NASA Finds Major Flaw in Space Station Design
               Diesels/railguns
       Re: NASA Headline News for 03/21/90 (Forwarded)
             Mars Rover Update - 03/22/90
                Re: Engineers
                  Challenger
           Re: space news from Feb 26 AW&ST
                 Mooney books
      Re: NASA Finds Major Flaw in Space Station Design
      Re: NASA Finds Major Flaw in Space Station Design
----------------------------------------------------------------------

Date: 22 Mar 90 17:32:38 GMT
From: [e-mail]  (Eugene Miya)
Subject: Re: Spacecraft on Venus

It is amusing for me to read the many technological "solutions" to
the Venus heat sink electronics problem.  However, just so you don't
lose sight, you should look at Venus in perspective:

1) Everybody else is talking Mars missions.
2) There is a finite budget.
This is a case of Einstein's
    The perfection of means and the confusion of aims seems to be
    our problem.
This isn't to advocate massive space budgets.  There are finite
numbers of people who build, or launch, or control, or communicate.
That is the dilemma of those planning missions.  All part of the subtle
dance of players who try to get these things done.
Thoreau said
    The simplification of means and the elevation of ends is the solution.

Another gross generalization from

--eugene miya, NASA Ames Research Center, [e-mail]
  resident cynic at the Rock of Ages Home for Retired Hackers:

  "You trust the `reply' command with all those different mailers out there?"
  "If my mail does not reach you, please accept my apology."
  {ncar,decwrl,hplabs,uunet}!ames!eugene
  Do you expect anything BUT generalizations on the net?
  [If it ain't source, it ain't software -- D. Tweten]

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

Date: 22 Mar 90 22:01:37 GMT
From: skipper![e-mail]  (Al Bowers)
Subject: Re: Shuttle Escapes

In article <[e-mail]> [e-mail] (Christopher Neufeld) writes:

>In article <[e-mail]> [e-mail] (John Hogg) writes:
>>However, a ``reasonably well protected human'' needn't wear a spacecraft.
>>Station crew-escape systems have been proposed which amount to a
>>spacesuit, a retrorocket pack, a heatshield, and a parachute.  The
>>
>   You mean this is a real idea??? I saw this described in the SF novel
>_Orbital Decay_ by Allen Steele and brushed it off as a fabrication by
>the author.

This isn't as ludicrious as it sounds.  there was a lot of work done
in the early 1960's that showed this to be a very viable way to return
from space.  the real parameters of interest are what thermal
environment can be withstood, the required wingloading and the reentry
Mach number (velocity actually but everyone thinks Mach number any
more).

--
Albion H. Bowers  [e-mail]  ames!elxsi.dfrf.nasa.gov!bowers
         NASA Ames-Dryden Flight Research Facility, Edwards, CA
                  Aerodynamics: The ONLY way to fly!

                     Live to ski, ski to live...

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

Date: 22 Mar 90 13:54:36 GMT
From: noose.ecn.purdue.edu!mentor.cc.purdue.edu!l.cc.purdue.edu![e-mail]  (Herman Rubin)
Subject: Re: NASA Finds Major Flaw in Space Station Design

In article <[e-mail]>, [e-mail] (Paul Dietz) writes:
> In article <[e-mail]> [e-mail] (Tim Maroney) writes:
> >In article <[e-mail]> [e-mail]
> >(Paul Dietz) writes:
< >>Yesterday's (3/19) NY Times reports that a NASA special
< >>investigation team has concluded that the space station, as
< >>currently designed, would require 2,200 hours of EVA per year
< >>for repairs and preventive maintenance.  This figure, which amounts
< >>to about 2 EVAs per week, is described as "alarmingly high";
< >>an acceptable rate would be one per month.
> >
> >Two EVAs per week at 20+ hours per EVA?  Eh?
>
> I screwed up; it's > 3 per week (with > 1 person, I think; the figure
> is 2,200 person-hours).  About an order of magnitude too much.
>
>     Paul

What can anybody expect?  We know very little about the problems of
space station construction and maintenance.  We will have to learn much
of it up there.  True, we do have some information from the American
and Russian small stations, but these have been small enough to have
been sent up as a unit.

If we cannot afford to have the equivalent of one person working a 40-hour
week for EVA repairs and preventive maintenance, we are penny wise and
pound foolish.  We have to do our space engineering in space, not on
earth.
--
Herman Rubin, Dept. of Statistics, Purdue Univ., West Lafayette IN47907
Phone: [phone]
[e-mail] (Internet, bitnet, UUCP)

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

Date: Thu, 22 Mar 90 08:27:11 CST
From: [e-mail] (Mahan)
Subject: Diesels/railguns

I know that this is getting rather far afield from Space, but the US Navy
runs diesels in the 15K hp range.  For example, the LSD-41 ship class uses
two of these (v-16's) for main propulsion.  They stand about 12 feet high,
about 15 feet long, maybe 10 feet max width (from memory of a walkthrough).
I have no idea the weight of these engines.  Also, remember that piston
engine output falls off as a function of available oxygen density
(not considering super/turbocharging) and there's not a whole lot of air
at 40K feet.  As a Diesel relies on heat of compression for ignition and the
ambient at this altitude is rather cool it may become a problem to sustain
operation.

     I seem to recall that naturally aspirated gasoline engines produce about
50% of sea level horsepower at 15-20K feet and there is no reason to expect
Diesel performance to be noticeably better.  Using engine bleed air from a
turbine engine REALLY hurts the performance of the jet.  Turbocharging will
help but I thing that further investigation should concentrate on other types
of power plants (perhaps a turbshaft engine mounted in the slipstream driving a
generator.)

More random thoughts from:
Stephen Mahan
[e-mail]
Naval Coastal Systems Center
Panama City, FL   32408-5000

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

Date: 22 Mar 90 05:00:46 GMT
From: bfmny0![e-mail]  (Tom Neff)
Subject: Re: NASA Headline News for 03/21/90 (Forwarded)

Gee, nothing about the NYTimes article.  They're usually so *thorough*.
Maybe they missed their paper delivery?  :-)
--
"Of course, this is a, this is a Hunt, you   |*==|  Tom Neff
will -- that will uncover a lot of things.   |===|  [e-mail]
You open that scab, there's a hell of a lot
of things... This involves these Cubans, Hunt, and a lot of hanky-panky
that we have nothing to do with ourselves." -- RN 6/23/72

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

Date: 22 Mar 90 16:49:50 GMT
From: orion.oac.uci.edu!uci-ics!jarthur!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Mars Rover Update - 03/22/90


                        Mars Rover Update
                         March 22, 1990

     Engineers at the Jet Propulsion Lab began tests last week on a prototype
of a Mars rover vehicle, the first step step toward establishing a manned
outpost on the moon and sending a manned flight to Mars. The Planetary
Rover Navigation Test Bed Vehicle, nicknamed "Robby", is a self-navigating
vehicle about the size of a small car that can pick up samples or
manipulate tools and equipment with its robotic arms. The testing this week
was to determine whether the rover can be made self-thinking so that it
does not have to rely on human commands. The prototype's computer systems
must be autonomous and self-navigating because commands sent from Earth
at the speed of light takes 30 minutes to reach Mars. Initial tests went
well, and plans are being made to move from the prototype to a fully
operational production model of the planetary rover.

     The Exporation Technology program to develop the rover grew out of
a study known as the Mars Rover Sample Return (MRSR), an effort to design
a self-thinking machine to collect ground samples from Mars. Last October,
JPL folded the 2 year old sample return effort into the Exploration
Technology program so that the machine could be designed to do more than
pick up ground samples, such as building a capsule on the moon in which
astronauts could live in. $5 million is allocated to the rover itself and
about $500,000 is devoted to the development of autonomous navigation.

     In response to Bush's call to go back to the moon, and from there on to
Mars, JPL is drawning up plans to dispatch a series of robots to Mars. The
first step is the launch of the Mars Observer in 1992 to measure the
atmosphere and planetary surface of Mars to find possible landing and outpost
sites. A Mars Observer II launch may aslo occur in 1996. The Global Network
Mission, scheduled for launch in 1998, calls for two spacecraft to place
24 instruments at different sites to study Mars' surface. Some would
be designed to last several years and would serve as meteorological stations.

     A mission to bring back Martian soil is scheduled for launch in 2001.
The trip is dedicated to learning more about the planet's history and
searching for signs of life. Soil samples would be returned to Earth by
the year 2003. Another spacecraft will be launched to Mars in 2003 used to
help support future manned missions to Mars. The spacecraft will bear
a communications satellite to serve as an orbiting data relay link for
future mission. The spacecraft will also carry a site reconnaissance orbitor
to perform mapping, high resolution photography and radio science instruments.
 Ron Baalke                       |    [e-mail]
 Jet Propulsion Lab  M/S 301-355  |    [e-mail]
 4800 Oak Grove Dr.               |
 Pasadena, CA 91109               |

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

Date: 22 Mar 90 21:56:49 GMT
From: skipper![e-mail]  (Al Bowers)
Subject: Re: Engineers

In article <[e-mail]> hicksm@spock (Michael Hicks) writes:


>        For those of you who work as aero/mech engineers at one of
>        the NASA centers such as AMES, KSC, LEWIS,  etc, could you
>        answer this following question for me please?

>        Approximately how many new engineers fresh out of school does
>        your center hire per year?  Do openings come up year round or
>        are there certain periods when most of the hiring is done?
>        Pros and cons of your work?

>        If you can answer any of these questions,  I'd be grateful.

Here at Dryden we usually average 2 to 4 fresh outs per year.  This is
in the civil service, there are also a number of contractor jobs and
their hiring rate varies depending on demand.  Most of our slots go to
coops that have worked here during their schooling, next are
minorities.  Congress controls alot of our hiring practices as does
the upper managment.  This is mostly a function of what management
percieves as the correct complement to get the job done.

Advantages are job stability, lots of responsibility real fast,
exciting programs, a great deal of diversity and a fair degree of
autonomy.  The disadvantages are low (initial) pay, benefits are
getting worse (as Congress and the public think we get it too easy),
tolerating the diverse mix of people (getting stuck with a less than
enthusiastic person in a critical area is a real pain), government
schedules, beauracracy (although this is not as bad as most people
think).

--
Albion H. Bowers  [e-mail]  ames!elxsi.dfrf.nasa.gov!bowers
         NASA Ames-Dryden Flight Research Facility, Edwards, CA
                  Aerodynamics: The ONLY way to fly!

                     Live to ski, ski to live...

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

Date: Thu, 22 Mar 90 08:03:04 CST
From: [e-mail] (Mahan)
Subject: Challenger


     It was just pointed out to me that most of the special Challenger plates
being issued here in Florida have numbers starting with the letters 'ASH'.
Guess the DMV wasn't as alert as they should have been.  (no :-))

[e-mail]

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

Date: 22 Mar 90 14:39:24 GMT
From: pilchuck!seahcx!phred![e-mail]  (Pete Jarvis)
Subject: Re: space news from Feb 26 AW&ST

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>
>Viktorenko and Serebrov return to Earth after 22 weeks aboard Mir [not
>a long stay by Soviet standards, although it's nearly twice the US record].
>

Nothing new here. Their record is 4.35 times our longest stay. We're
not worried about it.

Peter Jarvis..........

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

Date: 22 Mar 90 18:18:49 GMT
From: thorin!homer.cs.unc.edu![e-mail]
Subject: Mooney books


    I'm trying to identify some books I read when I was a kid.    The
protagonist was named Matt Mooney; he lived on the moon and became a
cabin boy on a space ship that visited Earth in response to the
"invasion" of a Surveyor probe.  I seem to recall there was an entire
series of these.  Can anyone help me out with author/title/etc.?  I
can't find them in Books in Print or our library's juvenile
collection, but without a title, it's hard to be sure.
    Please respond by email.
--
    Jon Leech ([e-mail])    __@/
    ``There ain't hardly nothin' cuter nor a sleepin' baby tad
      lessen it's a pork chop'' - Churchy La Femme

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

Date: 23 Mar 90 02:02:28 GMT
From: agate!headcrash.Berkeley.EDU![e-mail]  (George William Herbert)
Subject: Re: NASA Finds Major Flaw in Space Station Design

In article <[e-mail]> [e-mail] (Herman Rubin) writes:
>< >>Yesterday's (3/19) NY Times reports that a NASA special
>< >>investigation team has concluded that the space station, as
>< >>currently designed, would require 2,200 hours of EVA per year
>< >>for repairs and preventive maintenance.  This figure, which amounts
>< >>to about 2 EVAs per week, is described as "alarmingly high";
>
>What can anybody expect?  We know very little about the problems of
>space station construction and maintenance.  We will have to learn much
>of it up there.  True, we do have some information from the American
>and Russian small stations, but these have been small enough to have
>been sent up as a unit.
>
>If we cannot afford to have the equivalent of one person working a 40-hour
>week for EVA repairs and preventive maintenance, we are penny wise and
>pound foolish.  We have to do our space engineering in space, not on
>earth.

Firstly; given Russian experience with EVA's that's two people for six to eight
hours EVA every other day [it's physically exhausting].  That's a significant
amount of crew.

And, to seal the coffin, NASA has no space suit that can be reused.  They had
been planning on using the Shuttle suits, which need something like a thousand
man hours of repair work after every five hours of average EVA per flight.
It's not that we can't necessarily run those EVA schedules, but it's going to
difficult to return the suits to earth for repairs after each use :-)

-george

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

Date: 23 Mar 90 02:21:38 GMT
From: agate!headcrash.Berkeley.EDU![e-mail]  (George William Herbert)
Subject: Re: NASA Finds Major Flaw in Space Station Design

In article <[e-mail]> [e-mail] (Robert McGwier) writes:
>
>
>This is incorrect.  The KVANT modules, etc. are being brought up one
>at a time as they are too large to be boosted all at once.
>
>They are facing EXACTLY the same problems we  will be.  I hope some
>data sharing will happen.

I fail to see the connection between
    KVANT, where the russians are flying additional cannisters up and
    attaching them via docking ports, still using completely internal
    wiring etc. and
    FREEDOM where we're planning on
    a>building a truss in space,
    b>running wiring and cables and pipes along it and
    c>having the majority of the systems exposed to vaccum, where both
        its difficult to fix and it's harder to design and build.



*******************************************************************************
George William Herbert     JOAT For Hire: Anything, Anywhere: My Price
UCB Naval Architecture undergrad: Engineering with a Bouyant Attitude :-)
-------------------------------------------------------------------------------
[e-mail]       |||||||||| "What do I have to do to convince you?"-Q
[e-mail]      |||||||||||||||||||||||||||||||||||||||| "Die."-Worf
[e-mail] |"Very good, Worf. Eaten any good books recently?"-Q

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

End of SPACE Digest V11 #179
*******************