Space & Astronomy/Space and Astronomy (October 1993).iso/mac/TEXT/SPACEDIG/V15_5/V15NO552.TXT

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Date: Wed, 16 Dec 92 05:13:00
From: Space Digest maintainer <[e-mail]>
Reply-To: [e-mail]
Subject: Space Digest V15 #552
To: Space Digest Readers
Precedence: bulk


Space Digest                Wed, 16 Dec 92       Volume 15 : Issue 552

Today's Topics:
                   absolutely, positively overnight
                          Apollo Astronauts
                                Aurora
             Chicken Guns (was Re: "trivial engineering")
                          D-21 recon drones
                    Does Sun have magnetic poles?
           Galileo's Atmospheric Probe Passes Health Checks
         LGA-only mission (was Re: Relay to Follow Galileo?)
             Need information on Infinite Universe Models
 No asteroid flybys (was Re: Cassini Undergoes Intense Design Review)
  Profit in space activities (was: absolutely, positively overnight)
                        Range Safety and DC-X
                  Relay to Follow Galileo? (4 msgs)
                            Safety margin
                      Terminal velocity of DC-X?
           Terminal Velocity of DCX? (was Re: Shuttle ...)

    Welcome to the Space Digest!!  Please send your messages to
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----------------------------------------------------------------------

Date: Tue, 15 Dec 1992 20:45:34 GMT
From: Phil Ngai <[e-mail]>
Subject: absolutely, positively overnight
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>But they didn't call the SR-71 the Recon-STRIKE-71 before LBJ's mangling for
>nothing.

And the F-111 and the F-117 are fighters...

--
My opinions are my own.

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

Date: 15 Dec 92 10:28:03 -0600
From: Bill Higgins-- Beam Jockey <[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?

My understanding from previous dealings with NASA is that the
Astronaut Office at Johnson Space Center keeps track of them and will
forward mail to them.  That's probably the simplest answer to your
question.

The address:

NASA Johnson Space Center
Astronaut Office
Houston, TX 77058

Sorry, don't know the mail code.

Engineer of Hijacked Train:      Bill Higgins
"Is this a holdup?"
                                 Fermi National Accelerator Laboratory
Masked Gunman:
(Hesitates, looks at partner,    Bitnet: [e-mail]
looks at engineer again)         SPAN/Hepnet/Physnet: 43011::HIGGINS
"It's a science experiment!"     Internet: [e-mail]

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

Date: 15 Dec 92 14:17:54 GMT
From: Colin Tinto <[e-mail]>
Subject: Aurora
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>Some other reports on Aurora from southern California:
>
>On many Thursday mornings, this area is being shaken by earthquake-like
>tremors which are supposedly sonic booms from some secret plane.
>

In todays Scottish Daily Express, there was a small report about Aurora.

I don't have the paper here with me, but I'll quote from memory:

People of the Shetlands and Orkney Islands (Far north of Scotland) have
recently been hearing a lot of rumbles etc, which some experts suggest may
be the Aurora.

For the last couple of years, people of the Western Isles (Last islands of
Scotland before the open Atlantic) have been plagued by loud noises and
rumblings which rattle the windows of their houses.

Technical stuff :   Mach 8, (Picture shows Delta shaped craft, relatively
small wings), Spokesman from "Janes Defence Weekly" said he thinks it
may run on liquid methane, and have a range of 5000 miles.
An aircraft of this speed takes a while to get up to speed, and the experts
suggest the noises could be the plane getting up to speed for trans-Atlantic
crossing.

---

Hang on - 5000 miles - that means it can just reach Scotland from the East
Coast USA before having to turn back ?   Something not quite right...


--
/-----------------------------------------------------------------------------\
!   Colin Tinto            !  Time Travel Parcel Deliveries Inc          !
!   [e-mail]        !  The only courier with previous day service.!
\-----------------------------------------------------------------------------/

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

Date: Tue, 15 Dec 1992 17:04:52 GMT
From: Edmund Hack <arabia!hack>
Subject: Chicken Guns (was Re: "trivial engineering")
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (John Roberts) writes:
>By the way, somebody told me that tolerance to bird ingestion is tested by
>means of a compressed air gun that shoots dead chickens into the engine,
>to determine whether engine damage will result.

A former co-worker of mine worked at Pratt & Whitney on the F-100 (?)
engine program in data acquisition for the test programs.  He said they
all looked forward to the visit of the Air Force Chicken Cannon with
both anticipation and dread.  Dead, fully feathered chickens are
procured and shot into the front at high speed.  He said the noise and
smell were quite remarkable.

--
Edmund Hack - Lockheed Engineering & Sciences Co. - Houston, TX
[e-mail] - I speak only for myself, unless blah, blah..
"You know, I think we're all Bozos on this bus."
"Detail Dress Circuits" "Belt: Above A, Below B" "Close B ClothesMode"

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

Date: Tue, 15 Dec 1992 21:46:15 GMT
From: Josh 'K' Hopkins <[e-mail]>
Subject: D-21 recon drones
Newsgroups: sci.space

Kevin William Ryan <[e-mail]> writes:

>[e-mail] (Henry Spencer)
>>[e-mail] (Anthony J Stieber) writes:
>>>>But they didn't call the SR-71 the Recon-STRIKE-71 before LBJ's mangling for
>>>>nothing.

Kelly Johnson claims that SR-71 (and its siblings) would have been competitive
with F-15 and B-1 programs but they were kept out by political considerations.

>>>Yep.  And I also heard about the drone launch accident that downed both
>>>the drone and the host SR-71...
>>
>>That actually happened in pre-SR-71 days, to an M-12 (the drone-carrier
>>variant of the A-12).  However, the problems are felt to be manageable,
>>last I heard:  Lockheed was saying "feasible" when NASA Dryden talked
>>to them about carrying HALO up to Mach 3 on SR-71-back.

>    The drone in that case was quite a package, too. As I recall, the drone
>was a Mach 3+ ramjet design, intended to be a drone recon plane for doing
>flyovers of hostile territory.

Right, though in the SR-71 realm some people say that Mach 3+ is shorthand
for Mach 4.

>It was (bear with me here, it's been a while
>since I read this) fueled by boron hydride, with roughly twice the energy
>density of regular jet fuel, built almost entirely of magnesium, and intended
>to fly a photo run, return to friendly territory, eject a photo package, and
>self destruct with explosive charges. In fact, the charges were set to blow
>if the altimeter read below 10,000 feet in operational use.

What I read suggests that the drone was supossed to ditch at sea near Hawaii.
The payload would be recovered in the air similar to the process used with the
Discoverer capsules.

>At any rate, during
>the first test the separation went bad, the drone either flew into the carrier
>or blew up immediately adjacent, and the carrier went down.

The drone suffered an engine malfunction during seperation and pitched into the
midsection of the carrier aircraft killing one of the two crewmen and
destroying both vehicles.  The drones were later flown from B-52H pylons over
China several times but the results were mixed.

>    I wish I could remember where I read this... anyone else out there able
>to confirm this?

My source is William Burrows' _Deep Black_.
Since this has migrated from the original topic I suggest interested persons
hit the library or take discussion to sci.aeronautics and sci.military.

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

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

Date: Wed, 16 Dec 1992 03:37:47 GMT
From: John Hagerman <[e-mail]>
Subject: Does Sun have magnetic poles?
Newsgroups: sci.physics,sci.electronics,sci.space

[e-mail] (Babak Sehari) writes:
>
> ... Could someone give us some idea about the sun's magnetic field?

In two words, it varies.  This and many other interesting properties
of the sun can be found in any good encyclopedia.  Mine has a really
good entry titled "Sun," from which I extracted the above two words.

- John
--
[e-mail]

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

Date: Wed, 16 Dec 1992 01:03:19 GMT
From: Ron Baalke <[e-mail]>
Subject: Galileo's Atmospheric Probe Passes Health Checks
Newsgroups: sci.space,sci.astro,alt.sci.planetary

Paula Cleggett-Haleim
Headquarters, Washington, D.C.               December 15, 1992
(Phone: [phone])

Pete Waller
Ames Research Center, Mountain View, Calif.
(Phone:  [phone])

RELEASE:  92-224

GALILEO'S ATMOSPHERIC PROBE PASSES HEALTH CHECKS

     The Galileo spacecraft and its atmospheric probe are now
halfway on their complex trip to Jupiter, and the first full tests
since launch 3 years ago show that the probe is in good shape, say
NASA officials.

     "We have, for the first time since launch 3 years ago, checked
out the entire probe spacecraft system and run it through a full
mission sequence," said Benny Chin, Probe Project Manager, NASA's
Ames Research Center, Mountain View, Calif.

     "All systems working together, including the seven scientific
instruments, are functioning well and will meet mission
objectives," he said.

     The probe is being carried over most of the half billion miles
to Jupiter by the Galileo orbiter.  At 51,358,400 miles from the
planet, the probe will separate from the orbiter and fly on by
itself.  This will occur on July 10, 1995, 5 months before arrival
at Jupiter.

     The probe will make history's first entry into the atmosphere
of an outer planet on Dec. 7, 1995.  It will slam into Jupiter's
atmosphere at 115,000 mph, fast enough to jet from Los Angeles to
New York in 90 seconds.  Deceleration to about Mach 1 -- the speed
of sound -- will take just a few minutes, causing a buildup of heat
so intense it will be like flying through a nuclear explosion.

     The Galileo probe then will plunge 400 miles through the
planet's brilliantly colored cloud layers into the hot, dense
atmosphere below -- making history's first direct measurements of
Jupiter.  As it descends, the probe will gather scientific data
about the giant planet's swirling clouds, violent winds and star-
like composition, providing clues to the origin of the solar
system.

     Health of the Galileo probe was checked in a mission sequence
test on Nov. 20, 1992, and a functions test on Dec. 2.  Data
analysis since then has confirmed that all of the craft's systems
are in good condition.  A suspected loss of battery power, for
example, did not occur.  Battery voltages are at the levels of
launch day, Oct. 18, 1989.

     Entry into Jupiter's atmosphere is the most hazardous in the
solar system because the planet's immense gravitational pull
creates tremendous speeds.  At maximum deceleration, as the craft
slows from 115,000 mph to 100 mph, the probe will hurtle against a
force 350 times Earth's gravity.

     Its incandescent shock wave will be as bright as the sun and
reach temperatures up to 28,000 degrees Fahrenheit.  After entry,
the fore and aft heat shields of the deceleration module will be
shed by deploying a small pilot parachute and then a large main
chute, exposing the descent module to Jupiter's hydrogen/helium
atmosphere.

     The probe's total weight is 747 pounds.  The deceleration
module weighs 484 pounds.  The inner descent module carries seven
scientific instruments, weighing 66 pounds.

     "The tests show that all the instrument parameters are within
normal limits," said Ames' Dr. Richard Young, Probe Project
Scientist.

     To make the first direct measurements of Jupiter, he said, the
probe carries  an atmosphere structure instrument, a mass
spectrometer for atmosphere composition, a cloud instrument, an
energetic particle instrument, a lightning detector, a helium
detector and a radiometer to chart energy flow in the atmosphere.

     Together, they will characterize Jupiter's ionosphere and its
atmosphere (composition, temperature, and density), measure wind
speeds, cloud characteristics, lightning, the important ratio of
helium to hydrogen and the atmosphere's energy balance.

     "Because of its size, make-up of original solar system
material, and being the biggest of the 'gas giant' outer planets,
Jupiter is a scientific treasure trove," said Young.  "On the
science side, everything is fine so far.  We can't wait to get
there," he said.

     As the probe passes through Jupiter's colored cloud layers,
its computer will receive information, process it and transmit the
coded signal to the Galileo orbiter, which will relay the data by
radio to Earth.  The probe descent mission will last about 75
minutes.  At this point, a combination of extreme heat, high
pressure and degraded battery power will silence the probe forever.

     The probe project is managed by the Ames Research Center.  The
overall Galileo mission is managed by NASA's Jet Propulsion
Laboratory, Pasadena, Calif.
- end -

NOTE TO EDITORS:  Dramatic mission animation, with new segments on
Jupiter's deep atmosphere will be telecast via NASA-Select on
Tuesday, Dec. 15, 1 p.m. EST and repeated at other times during the
day.  This will be carried on Satcom F-2R, Transponder 13, 72
degrees west longitude, 3960 MegaHertz; audio 6.8 MHz, vertical
polarization.
     ___    _____     ___
    /_ /|  /____/ \  /_ /|     Ron Baalke         | [e-mail]
    | | | |  __ \ /| | | |     Jet Propulsion Lab |
 ___| | | | |__) |/  | | |__   M/S 525-3684 Telos | Choose a job you love, and
/___| | | |  ___/    | |/__ /| Pasadena, CA 91109 | you'll never have to work
|_____|/  |_|/       |_____|/                     | a day in you life.

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

Date: 15 Dec 92 11:15:20 -0600
From: Bill Higgins-- Beam Jockey <[e-mail]>
Subject: LGA-only mission (was Re: Relay to Follow Galileo?)
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] (Chris Jones) writes:
> In article <[e-mail]>, wlmss@peg writes:
>>This is astonishing! Surely to NOT chase the thing is too costly! Dosen't
>>the media, public & govt understand?

[Very good explanation by Chris deleted, giving reasons to be hopeful about
Galileo, including:]

> 1. The attempts to succeed in opening the antenna may still succeed.  [...]
>
> 3.  [...] the descent probe mission is unaffected by the lack of an  HGA

I have a small nit to pick with:

> 2. A combination of beefing up the Deep Space Network on earth and improving
> the compression software on the spacecraft should allow
> 70% of the science data
> to be returned over the Low Gain Antenna even if the HGA deployment fails.

It's not "should allow 70% of the science data to be returned," it's
"should allow 70% of the `scientific objectives' to be met."  Weasel
wording, but the project scientists carefully explained the
distinction in their press conference last 11 June.   Major objectives
include direct measurement of the Jovian atmospheric structure and
composition (the descent probe), satellite science (mostly a series of
brief flybys, with many weeks in between to send back recorded data
slowly), magnetospheric studies (data rates are not very high compared
with imaging, can get much of original science), and remote-sensing
studies of the Jovian atmosphere.  This last objective takes a big
hit, since it relies on movies of the "weather--" lots of images (like
many tens of thousands), therefore lots of bits.

They're cutting back on the planned acquisition of data in all these
areas and the final accounting the Galileo folks announced went like
this:

    Science objectives summary

        Atmospheric - 80% (probe mission unaffacted)
        Satellites - 70% (don't need that many pictures)
        Magentosphere - 60% (continuous coverage available)
        Mission total - 70%

Bill Higgins, Beam Jockey              | The restaurant's architect
Fermi National Accelerator Laboratory  | said every effort had been
Bitnet:           [e-mail]  | made to build McDonald's
Internet:       [e-mail]  | 15th outlet in Italy
SPAN/Hepnet:           43011::HIGGINS  | in harmony with Pompeii.
                                       | --Reuters story in *Chicago
                                       |  Sun-Times*, 18 June 92

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

Date: 15 Dec 92 13:41:03
From: Steinn Sigurdsson <[e-mail]>
Subject: Need information on Infinite Universe Models
Newsgroups: sci.space,sci.physics,talk.philosophy.misc

In article <[e-mail]> [e-mail] (Samir Chopra) writes:


   I would appreciate any information on cosmological models that
   consider the universe to be infinite i.e not just infinitely
   expanding but actually existing in infinite space. Would
...
   Book references, pointers to online sources of information, article
   refrences, archived discussions are all welcome. If someone feels
   like enlightening me via E-mail please do so.


Heh, check out A. Linde's stochastic inflation
models - they're brilliant ;-)

See any article by Linde in the last 4 years, I think there
might even be a Sci Am article on it.

|  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: Tue, 15 Dec 1992 16:35:54 GMT
From: Steve Flanagan <[e-mail]>
Subject: No asteroid flybys (was Re: Cassini Undergoes Intense Design Review)
Newsgroups: sci.space,sci.astro,alt.sci.planetary

[e-mail] (Richard A. Schumacher) writes:

>>Nope.  It was announced in *Aviation Leak* that the policy of seeking
>>asteroid flybys has been dropped to keep costs down on Cassini. :-(

>Swell. WIth our luck the damn thing will probably wind up colliding
>with an asteroid, which collision would have been recognized had
>we but continued the search for flyby possibilities...

Actually, one of the main reasons for dropping the asteroid flyby for Cassini
is that there really aren't any good flyby opportunities for the baseline
trajectory.  The best we could come up with was a 22 km/s flyby of asteroid
1987 SJ4.  This is due to the fact that the only time Cassini enters the
asteroid belt is on the Earth to Jupiter leg of the trajectory.  This leg
follows the "double gravity assist", the fast (8 week) transfer from Venus
to Earth, which dramatically increases the spacecrafts heliocentric velocity.
As a result, Cassini's velocity relative to *any* main belt asteroid is going
to be very high, which makes the flyby less attractive scientifically and more
challenging operationally.


Steve Flanagan
Cassini Mission Design Team
[e-mail]
Standard disclaimers apply.

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

Date: Tue, 15 Dec 1992 16:57:47 GMT
From: Edmund Hack <arabia!hack>
Subject: Profit in space activities (was: absolutely, positively overnight)
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Michael V. Kent) writes:
>In article <[e-mail]> [e-mail] (Mitchell E. Gold) writes:
>
>>The last I'd heard, the companies flying Concordes (British Air, anyone else?)
>>had decided to write off the amount of money that was used in development of
>>the aircraft, but the aircraft do make a good profit over operational costs.

Very true.
>
>Sounds like a good accounting method to use for a certain Space Shuttle NASA
>has.

As I pointed out in another post, this accounting method is frequently
used in military programs.  The R&D cost, tooling and special facility
setup is treated as a "sunk" cost and written off.  After that, the ops
and production costs are accounted for.  The air branches use the
"flyaway" cost for appropriations and accounting of aircraft.

In fact, the SSX/DC-X proponents are advocating this accounting method
for pitching the SSTO.  In an article in "The Journal of Practical
Applications in Space", V1, #1, Max Hunter specifically calls for
"Military Cost Rules: Development, Production and Site Activation
Accepted as Sunk Costs" on one of the bullet charts in an article on
SSX.  (This chart shows at the extreme, $30/lb to LEO for 12 million
lb/year operations with propellant at $3/lb,  20k lb/launch, staff
levels equivalent to the SR-71.) So, this method of accounting is
consistent with other branches of government.  Of course, few private
firms would want to use this model for all their accounting.  The IRS
might take a dim view of it.

One of the sad legacies of the post-Apollo crash at NASA is that the
full civil service rules for staffing and DOD-style procurement rules
were imposed on NASA.  Previously, low level managers has speding
authority that today requires a signature from the managers just below
the center directors.
--
Edmund Hack - Lockheed Engineering & Sciences Co. - Houston, TX
[e-mail] - I speak only for myself, unless blah, blah..
"You know, I think we're all Bozos on this bus."
"Detail Dress Circuits" "Belt: Above A, Below B" "Close B ClothesMode"

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

Date: Tue, 15 Dec 1992 14:44:42 GMT
From: Marcus Leech <[e-mail]>
Subject: Range Safety and DC-X
Newsgroups: sci.space

In article <[e-mail]>, [e-mail] writes:
> Those of us who do go out and fly our own 'big' (at least by our standards,
> 5-30ft long) rockets in the desert don't have range safety either - just lots
> of range and someone to yell 'duck' if required. At BlackRock this year the
> altitude record for a 'cardboard' (really non-metalic) rocket was set at ~53,0
00
> feet - we regularly get FAA waivers to 100,000. Flights to ~20,000 are becomin
g
> pretty common and 10,000 is easy.
>
> Of course what we do is all drive out into the middle of a flat lake, stand
> together and launch them straight up - maybe we should paint bulls-eyes all
> around :-).
>
[I tried a personal reply, but my mailer didn't grok how to get to taniwha's
 mailer].

Hmmmm, back when I used to fly cardboard rockets [20 years ago--yikes!!], the
  NAR altitude record was around 11,500 ft, using an F-class engine, fins,
  and a prayer.  I guess things have gotten better since then.
  Is this with standard commercial solid engines, or homebrew?

--
Marcus Leech, 4Y11             Bell-Northern Research  |opinions expressed
[e-mail]                  P.O. Box 3511, Stn. C   |are my own, and not
[e-mail]             Ottawa, ON, CAN K1Y 4H7 |necessarily BNRs

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

Date: Mon, 14 Dec 1992 15:01:34 GMT
From: Ed McCreary <[e-mail]>
Subject: Relay to Follow Galileo?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] writes:
>
>Why not send a craft along behind Galileo to relay information back to
>Earth at a suitable rate?
>

The team at JPL have reprogrammed Galileo with new compression techniques
that will allow retrieval of about 90% of the planned science data,
if I'm not mistaken.  Also, I doubt we could put one together by
'95 with the current management.  Technically it's probably doable,
but it's hard enough getting the funding for the currently planned missions.


--
Ed McCreary                                               ,__o
[e-mail]                       _-\_<,
"If it were not for laughter, there would be no Tao."  (*)/'(*)

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

Date: Mon, 14 Dec 1992 15:11:20 GMT
From: Ed McCreary <[e-mail]>
Subject: Relay to Follow Galileo?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Ryan Korniloff) writes:
>Well why did the HGA have to be cloed up in the first place? If it is too
>big, then couldn't they have used a more powerful transmitter? I would
>have rather tried to avoid such a chance for failure. If thay don't get
>that HGA open then %30-%40 of the mission objectives will be lost. Or is
>the radio frequncy have something to do with he size of the HGA???
>

So it would fit in the shuttle's cargo bay.  But, even if NASA had
used an expendable (say a Titan/Centaur) I think it would have had
to be furled.  The HGA is 4.8m across.  Wcould that fit inside the
shroud of a Titan/Centaur?  I don't have any figures handy.

--
Ed McCreary                                               ,__o
[e-mail]                       _-\_<,
"If it were not for laughter, there would be no Tao."  (*)/'(*)

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

Date: 15 Dec 92 07:58:26 EST
From: Chris Jones <[e-mail]>
Subject: Relay to Follow Galileo?
Newsgroups: sci.space

In article <[e-mail]>, wlmss@peg writes:
>
>
>Subject: Re: Relay to Follow Galileo?
>
>Further to the above I hear per email ( and I thank the Sender):
>
>> This was discussed to death several months ago, so people probably didn't
>> re-open the discussion. The optimum time to launch a relay satellite is
>> NOW (galileo is on the optimal hoffman trajectory). Launching it next year
>> will take considerably more fuel, and no such craft is even on the planning
>> books.
>
>This is astonishing! Surely to NOT chase the thing is too costly! Dosen't
>the media, public & govt understand?

Understand what?  I hope I'm not putting words in your mouth, but it seems to
me you're assuming that not launching a relay means the Galileo mission is a
total loss.  This is far from true, for several reasons:

1. The attempts to succeed in opening the antenna may still succeed.  NASA, of
course, seems confident that their strategy of pulsing the deployment
motor will succeed in opening the antenna in the next couple of months (after
that they will abandon the attempt, since they feel that this distance from the
sun provides the optimal temperature).

2. A combination of beefing up the Deep Space Network on earth and improving
the compression software on the spacecraft should allow 70% of the science data
to be returned over the Low Gain Antenna even if the HGA deployment fails.

3. Although it would turn out to be a ridiculously expensive mission for the
results obtained, the descent probe mission is unaffected by the lack of an
HGA, and that portion of the mission should return data even absent any kind of
high data rate relay.

>If a relay is feasible the issue is the need to alert the uninformed wider
>public to what is being lost.

It's probably already too late.  I haven't heard any work has been done on a
relay, I haven't heard anyone seriously lobbying for one, and launch windows
are becoming impractical.

>                   The media. The public. And what about
>commercial sponsorship? Have any or all channels been exhausted? What if a
>few high profile persons spoke up at once? To think the galilean vistas were
>within reach of humanity - and now this!
>                                   ****

Now WHAT?  A more complicated, perhaps somewhat degraded but certainly still
scientifically interesting mission versus the opportunity for a more
scientifically interesting mission if we spend who knows how many millions of
dollars?  It sounds like a tough selling job to me, and I'm not surprised NASA
went with a different plan.

--
Chris Jones    [e-mail]

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

Date: Tue, 15 Dec 1992 15:10:40 GMT
From: Ed McCreary <[e-mail]>
Subject: Relay to Follow Galileo?
Newsgroups: sci.space

In article <[e-mail]> [e-mail] (Brian Stuart Thorn) writes:
>  Ryan...
>
>  Galileo's umbrella-type High Gain Antenna was left in the folded
>  position because it was thought that the high temperatures it would
>  encounter during the Venus flyby portion of the mission could warp
>  the antenna. They attempted to open the antenna only after the Venus
>  flyby, when Galileo flew farther from the Sun. It was jammed.

JPL planned from the start to furl the HGA.  The original flight path
went straight to Jupiter with a broken-plane manuver in the middle.
The VEEGA path is a result of using the smaller IUS instead of a
Centaur.

>  Cassini, I think, will have a standard hard HGA, similar to the
>  Voyager and Magellan antennae. I hope the Galileo problem does not
>  prevent future spacecraft from using the folding antenna design. It
>  worked quite well on the TDRS satellites.
>

True, and the test antenna for Galileo worked fine also.  I don't know
what the details are for Cassini though.  Is it still considered to
be Mariner Mk II or have they dumped that plan.


--
Ed McCreary                                               ,__o
[e-mail]                       _-\_<,
"If it were not for laughter, there would be no Tao."  (*)/'(*)

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

Date: Wed, 16 Dec 92 00:10:55 EST
From: John Roberts <[e-mail]>
Subject: Safety margin

-From: [e-mail] (Pat)
-Subject: Re: Terminal Velocity of DCX? (was Re: Shuttle ...)
-Date: 15 Dec 92 20:25:53 GMT
-Organization: UDSI

-Right now,  all staged rockets are vintage 60's/50's designs.  they have
-absolutely no margin for safety.  neither does the shuttle.

Those last two statements are not correct.

John Roberts
[e-mail]

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

Date: Tue, 15 Dec 92 23:56:30 EST
From: John Roberts <[e-mail]>
Subject: Terminal velocity of DC-X?

-From: [e-mail] (Allen W. Sherzer)
-Subject: Re: Terminal Velocity of DCX? (was Re: Shuttle ...)
-Date: 15 Dec 92 13:49:36 GMT

-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?

There are a sufficient number of good arguments to support continuation
of the DC program that there's no need to resort to bad arguments. Are
you seriously suggesting that Pegasus could put a 400 kg (not lb) satellite
into a 5617 km x 5950 km x 52.6 degree orbit?

(I thought the post-introductory price of Pegasus was more like $16 M.)

John Roberts
[e-mail]

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

Date: Tue, 15 Dec 1992 21:19:52 GMT
From: Josh 'K' Hopkins <[e-mail]>
Subject: Terminal Velocity of DCX? (was Re: Shuttle ...)
Newsgroups: sci.space

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

>(Michael V. Kent) writes:

>>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, it's a good idea to be subtle when you know your evidence is flawed.
That way we're less likely to notice.
--
Josh Hopkins                                          [e-mail]
                        Ho^3     !=L

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End of Space Digest Volume 15 : Issue 552
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