Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V10_1/V10_128.TXT

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Subject: SPACE Digest V10 #128

SPACE Digest                                     Volume 10 : Issue 128

Today's Topics:
             Re: Shuttle-Centaur
              The 'Face' of Mars
             Re: Shuttle-Centaur
            Re: Magellan summary?
            Re: Magellan summary?
          WANT ACTION IN WASHINGTON?  WRITE A LETTER
    Re: What to do with the $30 billion (missions): A Plan
            Re: The 'Face' of Mars
       Re: NASA Headline News for 09/29/89 (Forwarded)
        Re: X-30, Space Station Strangles NASP
----------------------------------------------------------------------

Date: 6 Oct 89 14:10:14 GMT
From: hsi!mfci![e-mail]  (Paul Rodman)
Subject: Re: Shuttle-Centaur

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>In article <[e-mail]> [e-mail] (Paul Rodman) writes:
>>I heard the original plan had DUMP VALVES for the Centaur fuel (which
>>put the craft over landing weight if you had to abort)!
>
>Yup.  Most airliners with significant problems will dump fuel before landing
>as well, for much the same reasons:  reduced weight and reduced fire hazard.
>What's the big deal?

Weeeell, I don't know the facts the way you do Henry but what
I was thinking was:

      - dump valves on airliners _are_ perceived as a small risk.
        Sometimes they leak or are deployed by mistake.
        Hopefully, the gain in safety is more.

      - An airliner dumps JP4. I presume the Centaur dumps potent fuel
        + oxidizer (not hypergolic I trust!). What is the probability
        of ignition in the presence of RCS thrusters, hot airframes,
        SRBs, considering that the reason for the dump is that something
        bad already happened to cause the abort?

      - You are awfully busy on a launch abort, are you going to
        allow a computer to decide when to dump? Yech.

I'm not saying it can't (or shouldn't) be done, it just seems like
more dicey scenerios are added to an already hazardous activity. Each
shuttle is worth $1Billion, after all. Seems like the correct approach
would be to have a Space tug (+ IUS on the probe too) to kick things
out of earth orbit. Refuel the tug from unmanned tankers, please.

Another way of looking at it is to observe that truckers, as a group,
are doing something fairly dangerous compared to you or I. But _THEY_
consider the guys that drive the gasoline tankers to be really nuts..:-)

pkr

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

Date: 4 Oct 89 15:25:25 GMT
From: munnari.oz.au!csc!ccadfa!usage!basser!metro!ipso!runxtsa![e-mail]  (Macintosh Users Group)
Subject: The 'Face' of Mars

Does anyone know about the 'face' on Mars? Apparently, a computer-enhanced
image of a place on Mars revealed a humanoid face under layers of red dust.

I don't know about you, but it would appear to me that the ideal way to
leave a library behind for humanoids would be to have a face visible from
orbiting spacecraft.

I know it all sounds weird, but I just woke up with a dream about a library
on Mars.

1:07am and off the planet... :-)

 _____________________________________________________________________________
| Jason Haines                                                                |
| President, Club Mac - Australia's Largest Macintosh Users Group             |
|                                                                             |
| INTERNET:     [e-mail]            UUCP: uunet!runx.oz.au!clubmac  |
| ACSNet:       [e-mail]                                           |
|_____________________________________________________________________________|

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

Date: 6 Oct 89 21:14:11 GMT
From: agate!shelby!portia![e-mail]  (Joseph Brenner)
Subject: Re: Shuttle-Centaur

So what was the problem with launching the Centaur dry and fueling
it up in orbit?

I read a Jerry Pournelle article some years back arguing for this
approach (and actually, complaining that NASA was going to use the
wet launch approach out of bureaucratic inertia).

(My guess: You've got to boost the fuel somehow, and putting it in
a different shuttle launch just moves the risk to another time.
Boosting the fuel with an unmanned rocket might work but in
those days NASA's policy was to do everything with the shuttle.
Also, this gets back to the rendevous in orbit issue, which
I gather is considered too tough by NASA, despite experience with
Gemini, Apollo, Skylab and Apollo/Soyuz.)

-- Joe B.

([e-mail]  Materials Science Dept/Stanford, CA 94305)

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

Date: 6 Oct 89 23:09:12 GMT
From: prism![e-mail]  (Matthew DeLuca)
Subject: Re: Magellan summary?

In article <[e-mail]> [e-mail] (Feulner ... Matt Feulner) writes:
>In article <[e-mail]> [e-mail] (Peter Scott) writes:
>>Some trajectory wizard (who plainly
>>deserves a medal, IMHO) discovered this bizarre track that enabled Galileo to
>>reach Jupiter with the IUS booster.  It's the most creative piece of mission
>>planning I've seen since I started working here (<- this is called a hook).
>
>No doubt a grad student slave who never gets any credit.  I'm
>pretty sure it was a grad student who first realized the Grand
>Tour/Voyager trajectory.
>
>Matthew Feulner

You are quite correct; it was a grad student at CalTech by the name of Flandro
who who came up with it.  He is now a professor of aerospace engineering here
at Georgia Tech; I had him for a course last year.  As I recall, he did get
some credit, at least locally; the Atlanta Journal-Constitution ran quite a
piece on him at the height of the Neptune encounter.


------------------------------------------------------------------------------
Matthew DeLuca                      :   Practice creates perfection
Georgia Institute of Technology     :   Perfection creates power
ARPA: [e-mail]      :   Power conquers law
------------------------------------------------------------------------------

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

Date: Fri, 6 Oct 89 10:57:16 PDT
From: Peter Scott <[e-mail]>
Subject: Re: Magellan summary?

datapg!com50!questar![e-mail]  (Al Viall) writes:

>Looking through the press release for Galileo, to which
>I thank Peter Yee for sending through the net, I had read that the craft
>would make a double earth flyby(i.e. the VEEGA track).
>Why was this track chosen, considering that it would be more fruitfull to
>just get the craft to Jupiter in one piece.
>I am not bunking the experts at JPL and Ames, don't get me wrong, I am sure
>they had there reasons, such as ' While it's out there, let's take advantage'.

Uh, believe me, we wanted to.  We planned to.  We were going to, via the
Centaur upper stage booster, until the Challenger accident, when it was decided
that we really didn't want to run the SSMEs at 109% for longer than any other
mission in order to launch a large bomb.  Some trajectory wizard (who plainly
deserves a medal, IMHO) discovered this bizarre track that enabled Galileo to
reach Jupiter with the IUS booster.  It's the most creative piece of mission
planning I've seen since I started working here (<- this is called a hook).

Peter Scott ([e-mail])

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

Date: 6 Oct 89 17:18:21 GMT
From: dptg!pegasus![e-mail]  (Paul S. R. Chisholm)
Subject: WANT ACTION IN WASHINGTON?  WRITE A LETTER

(I thought this might be of interest to the group.)

(From the Personal Business section of BUSINESS WEEK, October 9, 1989,
p. 172.)

WANT ACTION IN WASHINGTON?  WRITE A LETTER

Every Day, tons of mail arrive on Capital Hill.  But, despite all the
time and attention that goes into handling it, nine out of 10 Americans
never write their representatives or senators.

Maybe it's a feeling that Washington is far away, captive of special
interests, and out of touch with everyday concerns of people.  Perhaps
it's a feeling that, in this information-saturated age, the lawmakers
are too busy to read their mail.  But here's a secret:  If you want
action from Washington, write a letter.  Keep it polite, and concise,
but above all, personal -- making a personal response likely.

MAKE IT BRIEF:  True, your letter may not get read immediately by your
representative.  Put yourself in the shoes of the aid who opens the
mailbag every day.  There lie 1,000 identical protest postcards
generated by some interest group.  The aide counts them, yawns, and
puts them aside.  Then there are the new computerized form letters that
have become the rage among grass-roots lobbying groups.  The staffer
can spot one in a second.  They get put in the pile destined for poetic
justice -- a response from the office computer, which can spew out a
tailored letter in seconds.  And then there's the 50th letter this week
from the guy who writes in red crayon, decrying the lawmaker as a
communist.  You can guess where that goes.

Finally, there's your letter, on real stationary, preferably with your
business letterhead.  Handwritten is best, most experts now suggest.
"Writing on personal stationary distinguishes you from the mass mail,"
says Ira Chaleff of the nonprofit Congressional Management Foundation.
And the aide is more likely to give it special attention.

Keep to one subject, and keep it short.  If you throw in all your
peeves and concerns, it's likely to go to three of four different
aides, each handling a different area.

It's also a good idea to remind the representative or senator of a time
you might have met.  If you get a form letter back from the
congressional office, don't just accept it, says George Gould of the
National Association of Letter Writers.  Write another one saying, "You
sent me a form letter, and you haven't answered my question, or
addressed my concern."  Chances are, you'll get a personal response next
time around.  --Douglas Harbrecht

Paul S. R. Chisholm, AT&T Bell Laboratories
att!pegasus!psrc, [e-mail], AT&T Mail !psrchisholm
I'm not speaking for the company, I'm just speaking my mind.

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

Date: Fri, 6 Oct 89 11:13:57 PDT
From: Peter Scott <[e-mail]>
Subject: Re: What to do with the $30 billion (missions): A Plan

gem.mps.ohio-state.edu!uwm.edu!mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer) writes:

>In the absence of a *plan* (see previous oration), the
>missions get chosen on PR value rather than rational scientific priority.

Ah, but there *is* a plan...  have you seen the Integrated Space Plan from
Rockwell?  I must admit, the first time I saw it, I thought it was a practical
joke.  After all, it's a single piece of paper about 3' by 5' covered with text and
boxes and lines at about the density of VLSI blueprints, covering the entire range
of manned/unmanned activity in space from now past the year 2100.  However, it
does make for some fascinating reading.  [Someone here added a footnote to the
poster at the bottom, between "Human Interstellar Travel" and "Interstellar
Traversing Worldships", just below "Stationary Martian Skyhook", that said,
"Man realizes all this rigamarole was not worth the bother and goes back into caves".]

There is a note saying that comments are welcome and copies can be ordered from
Rockwell International, Space Transportation Systems Division, 12214 Lakewood
Boulevard, Downey, CA  90241, Attn: Ed Repic, Project Manager, Lunar & Planetary
Systems, Mail Code AD21.  Apologies to Rockwell if this results in many more people
requesting said poster than they bargained upon; there is no restriction mentioned
on the plan.

So now there's no need for any more argument about what to do :-)

Peter Scott ([e-mail])

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

Date: 6 Oct 89 19:38:24 GMT
From: agate!sandstorm.Berkeley.EDU![e-mail]  (George William Herbert)
Subject: Re: The 'Face' of Mars

In article <[e-mail]> [e-mail] (Macintosh Users Group) writes:
>Does anyone know about the 'face' on Mars? Apparently, a computer-enhanced
>image of a place on Mars revealed a humanoid face under layers of red dust.

SHort version of the LONG story:
There was a science writer who thought there was a face like object on Mars,
    By the name of Hoagland.  He wrote a book, detailing all his views,
    copnnecting a bunch of interesting surface phenomena.
NASA did enhancements and determined this to be mistaken, and sat on the
negative data for a while, leading any number of people to fall for the
story...
    It has been debunked.

-george william herbert

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

Date: 6 Oct 89 14:43:23 GMT
From: dftsrv!cdc910b21![e-mail]  (Mark R. Schoeberl)
Subject: Re: NASA Headline News for 09/29/89 (Forwarded)

In article <[e-mail]> [e-mail] (Bob Gray) writes:
>In article <[e-mail]> [e-mail] (Peter E. Yee) quotes:
>>This is NASA Headline News for Friday, September 29....
>
>>"greenhouse" warming.  And a NASA atmospheric scientist predicts
>>that the ozone hole over antarctica will get even larger this
>>fall due to the increase of chloroflourocarbons in the
>>atmosphere.
>
>And James Lovelock, of the "Gaia Hypothesis" fame, is
>predicting that the ozone hole will be smaller again this
>year than last year. This was after after reaching its
>maximum size back in 1987.
>
>He blames the volcanic eruption back in 1982 in south
>America for dumping millions of tons of chemicals into the
>atmosphere. These chemicals he believes are now dispersing.
>

  The ozone hole over Antarctica this year is as big as 1987.  Virtually
all the ozone in the region from 12 to 25 km disappeared in 1987 and the same
appears to be holding true for this year. The vertical extent of the
depletion region determines the maximum depth the hole can achieve, and is
determined by polar meteorology.  The size of the hole
is determined by the size of the polar vortex which is set up before the
hole forms.  There is little chance that the polar vortex will increase
in size dramatically from 1987 or 1989 over the next few years.
  Those years (1987 and 1989) represent the most
favorable conditions we have seen for vortex formation.  So much for James
Lovelock....

- Mark Schoeberl
NASA/Goddard Space Flight Center

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

Date: 6 Oct 89 15:08:40 GMT
From: skipper![e-mail]  (Mary Shafer)
Subject: Re: X-30, Space Station Strangles NASP

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

   In article <[e-mail]>, [e-mail] (Mary Shafer) writes:
   ->
   -> The shuttle comes in from the north to north east.  It comes "feet
   -> dry" at about Mach 7 and 145K ft, it's overhead at Edwards at Mach 1
   -> at about 40K ft.  It does a HAC (Heading Alignment Circle) to put it
   -> on the runway heading (usually 17 or 22), so essentially the pattern
   -> is about a 270 teardrop with a longish final.  I think it's a 20 deg
   -> glidepath, with a fairly short flair.  Final is flown at 285 KEAS,
   -> gear deployed at 275 KEAS, touchdown at 185 KEAS.  (I'm taking these
   -> figures from Young and Crippen's 1981 SETP paper on STS-1, so the
   -> speeds may not be exact for any given mission, but they're about
   -> right.)

   Um, I believe that should be *towards* N-NE.

I meant from West to North-West.  The orbits aren't equatorial.  (I
think the angle of inclination can be over 40 deg, but I don't have
one of the ground-track maps to confirm this.)

They usually land on 17 or 22, although they have landed on 15.

   The Shuttle uses *two* glidepaths on final.  They fly most of the
   approach on a 17 degree (as I recall) glideslope, then make an
   abrupt pitch up to the normal 3 degree glideslope.  It looks
   like the two intersect right off the end of the runway (where
   "right off" may be a mile or two at these speeds) and they only
   spend a few seconds (10 or 15?) on the 3 degree slope before
   starting the flare.

They come around the HAC (heading alignment circle) and aim at a point
on the lakebed about 1 mi before the touchdown point.  This point is
identified by a big X in black paint and a set of directional lights.
(Actually they're narrowish spotlights.)  This first portion, known
appropriately as "final", is about a 20 deg glide slope.  When they
get fairly close to the ground they "flare" to a 3 deg glide slope,
using the ball and bar beside the runway.

   Now for the questions!  Is "coming feet dry" the same as extending
   the landing gear?  I'm pretty sure I remember seeing the gear pop
   out *after* the flare, and I can't imagine having to design gear
   (much less gear doors) that could handle Mach 7!

Coming "feet dry" means coming over dry land at the coastline.  (I've
been talking with too many Navy attack pilots.  Sorry.)  You're right
about the gear; they pop it at about 150 ft AGL, maybe lower.  It
_always_ looks like they've left it until too late.

   And what's the "E" in KEAS?  Surely Edwards doesn't have its own
   standard of measurement! :-}

Equivalent.  Ve = Vt * sqrt(rho/rhosl), where Ve is equivalent
velocity, Vt true velocity, rho density at altitude, rhosl sea level
density.  (I need subscripts!)  At sea level, Ve = Vt.  In fact, at
Edwards Ve pretty much equals Vt.  However, at 40 K ft ....

My Flight Test Engineer's Handbook says that Ve is frequently used for
piston-engined aircraft (because it's a direct function of dynamic
pressure, or qbar).  We don't use it commonly here at Dryden, but we
do use qbar itself.  Since qbar is a primary measurement it's more
sensible to use it, rather than Ve, which is a derived term.  We
mostly fly fighters and other military aircraft so we use KIAS or KCAS
for airspeed.

Is anybody interested in how and why we instrument our research
aircraft?  If so, I'll write something.

--
Mary Shafer   [e-mail]  ames!elxsi.dfrf.nasa.gov!shafer
         NASA Ames-Dryden Flight Research Facility, Edwards, CA
                    Of course I don't speak for NASA

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

End of SPACE Digest V10 #128
*******************