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Subject: SPACE Digest V11 #76

SPACE Digest                                      Volume 11 : Issue 76

Today's Topics:
        Re: New private home satellite network
           Payload Status for 02/22/90 (Forwarded)
                 Say Cheese!
               Re: Say Cheese!
               Re: Say Cheese!
               Re: Spacecraft on Venus
             Galileo's camera "blemishes"
               Giotto Update - 02/22/90
  Pioneer 11 passes Neptune's orbit, leaves Solar System (Forwarded)
              Re: Power Sources
      Re: Fun Space Fact #1: Launcher Development Costs
----------------------------------------------------------------------

Date: 22 Feb 90 16:57:47 GMT
From: snorkelwacker!usc!cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: New private home satellite network

In article <[e-mail]> [e-mail] (Brad Templeton) writes:
>What if a private concern, based on some lax-law island, were to get
>together $300 million an launch one of these things?   They could start
>completely uncensored, unregulated TV -- assuming they got somebody
>(the Chinese?) to launch it.
>
>What would happen?  Would governments let it be?  Would they try to jam
>it?  Shoot it down?  Is there any sort of space law or space treaty that
>would govern something like this?

The government of the country in question is responsible for what its
citizens/businesses do in space.  (What, you thought the citizens were
responsible for their own actions?  Ho ho, not in space law. :-( )  So
diplomatic repercussions could be expected.  The ground station would
be politically vulnerable.  That's the place I'd expect most trouble.
Any US citizens involved could expect personal trouble as well, since
the US government claims jurisdiction over the actions of its citizens
everywhere, not just within US territory.

Jamming microwave transmissions is almost impossible, although I suppose
a sufficiently annoyed government could put a jamming satellite into the
same orbital slot.

There is currently no technology for shooting down Clarke-orbit satellites,
although the Soviet antisatellite systems might perhaps be adapted for it
if you annoyed them sufficiently.  It would be nice to avoid that, since
Clarke orbit is a really lousy place for the debris cloud that would result.

>Of course, space in geosync orbit is limited...  This is a resource
>that will soon become scarce.  I wonder what people will do about it?

It's been scarce for quite a while in prime areas like over North America.
The result is the obvious:  government-regulated rationing.
--
"The N in NFS stands for Not, |     Henry Spencer at U of Toronto Zoology
or Need, or perhaps Nightmare"| uunet!attcan!utzoo!henry [e-mail]

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

Date: 22 Feb 90 20:54:45 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: Payload Status for 02/22/90 (Forwarded)

Daily Status/KSC Payload Management and Operations 02-22-90



- STS-31R HST (at VPF) -

VPF closeout activities were worked yesterday including
access platform removals and solar array closeout.  Today
HST will be powered up for functional testing.


- STS-32R SYNCOM/LDEF (at SAEF-2)

LDEF deintegration continues.


- STS-35 ASTRO-1/BBXRT (at O&C) -

BBXRT clearance checks were worked yesterday and will
continue today.


- STS-40 SLS-1 (at O&C) -

The systems test was active yesterday and will continue today.
Experiment functional checks will also continue today.  ASCS
N2 servicing will start today.


- STS-42 IML (at O&C) -

Racks 3, 9, and 11 staging activities were performed
yesterday.  Today eddy current checks will be performed on
rack 7 and staging will continue on rack 11.


- STS-45 Atlas-1 (at O&C) -

Pallet keel installation and orthogrid hardpoint installation
operations will continue today.


- STS-46 TSS-1 (at O&C) -

PPCU checkout will continue today.

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

Date: 23 Feb 90 07:10:22 GMT
From: pasteur!cory.Berkeley.EDU![e-mail]  (Stefan Marcus Sortland)
Subject: Say Cheese!


    What's the status of the family photogrphic collage Voyager I
        was supposed to have initiated last week?


                Stefan (X) nafetS

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

Date: 23 Feb 90 07:39:07 GMT
From: elroy.jpl.nasa.gov!jato!mars![e-mail]  (Ron Baalke)
Subject: Re: Say Cheese!

In article <[e-mail]> [e-mail] (Stefan Marcus Sortland) writes:
>
>    What's the status of the family photogrphic collage Voyager I
>        was supposed to have initiated last week?
>
Voyager 1 has taken 64 pictures of the solar system and stored them on
its tape recorder. It will slowly transmit the pictures back beginning
around March 16th.

 Ron Baalke                       |    [e-mail]
 Jet Propulsion Lab  M/S 301-355  |    [e-mail]
 4800 Oak Grove Dr.               |
 Pasadena, CA 91109               |

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

Date: 23 Feb 90 13:20:12 GMT
From: cs.utexas.edu!samsung!zaphod.mps.ohio-state.edu!lavaca.uh.edu!uhnix1!nuchat![e-mail]  (Steve Nuchia)
Subject: Re: Say Cheese!

In article <[e-mail]> [e-mail] (Stefan Marcus Sortland) writes:
>    What's the status of the family photogrphic collage Voyager I
>        was supposed to have initiated last week?

Funny you should ask...

Edward Stone, head scientific cheese of the voyager project, spoke
at Rice last week.  It was mostly show-and-tell, he showed some
of the best images and animations from the grand tour.

The answer to the question at hand is that the shots have been
taken and are waiting for high-gain antenna time.  He showed
a skymap from V1's perspective with little squares outlining
each exposure.  Everything but Sol and Jupiter will be point
sources.

When he put up the relative sizes slide he quoted (?)Asimov's
quip about an alien describing our solar system:  You've got
a star, four planets, and debris.  The four planets he was
refering to were _not_ the little bitty inner ones.

He also mentioned that the voyagers got more of a boost from
their Jupiter gravity assist than they did from the chemical
booster at earth.  He didn't specify whether that was heliocentric
total energy, delta-v, or what.  He also use farenheight consistently,
when Kelvins would have been much more useful.  Oh well.

One theme that emerged was the way certain structures -- clouds,
hurricanes, volcanos, migrating ice caps -- recurr in different
temperature regimes with different chemicals.  I'm not going to
be able to remember all the cases, but by the time he got to
Triton's liquid methane (I think) volcanos I was getting convinced.

Oh well, it was 1.5 hours well spent.
--
Steve Nuchia          South Coast Computing Services      [phone]
"You have no scars on your face, and you cannot handle pressure." - Billy Joel

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

Date: 23 Feb 90 17:26:18 GMT
From: cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Spacecraft on Venus

In article <[e-mail]> [e-mail] (Alan Wexelblat) writes:
>What is the major source of the heat that the craft would be subject to?
>And can we shield against it?  For example, if the source of heat is the
>Sun, one gets into a shadow.  On Venus would it be better to, for example,
>burrow into the planet itself?

The problem with Venus is that the ambient surface temperature simply is
very high.  *Everything* there is roasting hot.  Burrowing strikes me as
a mistake, although on reflection I'm not sure how conduction from the
soil would compare to convection in that thick atmosphere.  Anyway, there
is no specific heat source to shield against.
--
"The N in NFS stands for Not, |     Henry Spencer at U of Toronto Zoology
or Need, or perhaps Nightmare"| uunet!attcan!utzoo!henry [e-mail]

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

Date: Thu, 22 Feb 90 11:23:43 +0100
From: mpirbn![e-mail] (Daniel Fischer)
Subject: Galileo's camera "blemishes"

The Venus shot by the Galileo spacecraft in Av.Week 19 Feb. p.25 shows
"several ring-shaped shadows" - who knows what precisely has caused them?
I recall the same phenomenon from Viking Orbiter pictures and from Voyager 2's
camera. In the latter case the rings were seen only in highly enhanced images
(like of Uranus' disk), but the defective Galileo frame doesn't look much
processed.
  Will it be possible to suppress these "blemishes" (AW&ST) by use of a
suitable flatfield or will they spoil every Galileo picture ? I was always a
bit scared by the fact that there's just   o n e   camera going on this big
journey, compared to the 4 cameras on the two Voyagers.

        Daniel Fischer, Max Planck Inst. Radioastron., Bonn, FRG

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

Date: 23 Feb 90 07:35:10 GMT
From: elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov![e-mail]  (Ron Baalke)
Subject: Giotto Update - 02/22/90


                  Giotto Mission Status
                February 22, 1990

     Giotto reactivation support using Deep Space Network's 70 meter
antenna in Madrid, Spain, continues. Downlink was turned on through the
Low Gain Antenna and the tracking station locked up 2-way. Telemetry
modulation was turned on and a two DB drop in the downlink was observed.
The project attempted two different attitude maneuvers on the spacecraft.
Midway into the second maneuver it was determined, based on observed
doppler shifts, that neither manuever really took place. No High Gain
Antenna maneuver was attempted. Processing of previous data by Radio
Science showed no evidence of a spacecraft signal. DSP tapes are being
airmailed to JPL for further processing.

     Further attempts will be made to reactivate Giotto and assess the
status of its subsystems. Following this reactivation a checkout of the
scientific payload will be made to determine how much damage was suffered
during the spacecraft's 1986 encounter with Haley's Comet. If the
reactivation and checkout prove to be successful, Giotto will be
redirected to encounter comet Grigg-Skjellerup. This would be accomplished
by using the 25.45 kg of hydrazine still left on the spacecraft and a Earth
swingby in July, 1990. Giotto would then be in a orbit to encounter
Grigg-Skjellerup in July, 1992.

 Ron Baalke                       |    [e-mail]
 Jet Propulsion Lab  M/S 301-355  |    [e-mail]
 4800 Oak Grove Dr.               |
 Pasadena, CA 91109               |

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

Date: 23 Feb 90 17:12:58 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: Pioneer 11 passes Neptune's orbit, leaves Solar System (Forwarded)

Charles Redmond
Headquarters, Washington, D.C.                  February 23, 1990

Pete Waller
Ames Research Center, Moffett Field, Calif.


RELEASE:  90-29

PIONEER 11 PASSES NEPTUNE'S ORBIT, LEAVES SOLAR SYSTEM


     Pioneer 11 today will cross the orbit of Neptune and become
the fourth spacecraft to leave the solar system, providing a coda
to humanity's first major planetary explorations.  Pioneer 11
will join Pioneer 10 and Voyagers 1 and 2 in searching for the
heliopause, the point at which the Sun's electromagnetic
influence gives way to the galaxy's influence.

     As it crosses Neptune's orbit, Pioneer 11 will be 2.8
billion miles from the Earth.  Neptune's orbit currently marks
one measure of the expanse of the solar system because, for the
next 12 years, Pluto's eccentric orbit carries it inside
Neptune's path.  Some scientists refer to the heliopause as the
edge of the solar system.  By that definition, all four
spacecraft are still within the solar system.

     Launched in 1973, Pioneer 11 provided scientists with their
closest view of Jupiter, passing within 26,600 miles of the cloud
tops in December 1974.  The close approach and the spacecraft's
speed of 107,373 mph, by far the fastest speed ever reached by a
man-made object, hurled Pioneer 1.5-billion miles across the
solar system toward Saturn.

     Before reaching Saturn in 1979, Pioneer 11 reached an
inclination of 17 degrees above the solar equatorial plane, high
enough to illuminate the true character of the sun's magnetic
field.  Now 780 million miles above the ecliptic plane where most
of the planets orbit the sun, the spacecraft recently showed that
many of the solar cosmic rays in the heliosphere originate
outside the Sun's atmosphere in the interstellar gas, the space
between the stars.

     Pioneer 11 flew to within 13,000 miles of Saturn and took
the first close-up pictures of the planet.  Instruments located
two previously undiscovered small moons and an additional ring,
charted Saturn's magnetosphere and magnetic field and found its
planet-size moon, Titan, to be too cold for life.

     Pioneer 11, which will traverse interstellar space in the
same direction as the Sun moves, continues to return good data,
but in 3 years, operating the radio transmitter and scientific
instruments simultaneously will be difficult, says NASA Project
Manager Richard Fimmel.  Technical adjustments may extend the
craft's life through 1995.  Pioneer 10, with a stronger power
supply, may return data through the year 2000, which would extend
its original 30-month design life to 28 years.

     In June 1983, Pioneer 10 made history by becoming the first
human artifact to leave the solar system, travelling in the
direction opposite Pioneer 11's path.  Today, Pioneer 10 will be
4.5 billion miles from Earth.  Returning data to Earth at the
speed of light requires 6 hours, 36 minutes.  Pioneer 10
continues to search for the heliopause for very long-wavelength
gravity waves that would further understanding of Einstein's
Theory of Relativity and for evidence of a 10th planet.

     The Pioneers are managed by the Ames Research Center,
Mountain View, Calif., for NASA's Office of Space Science and
Applications.  The spacecraft were built by TRW Space &
Technology Group, Redondo Beach, Calif.

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

Date: 23 Feb 90 18:44:55 GMT
From: rochester![e-mail]  (Paul Dietz)
Subject: Re: Power Sources

In article <[e-mail]> [e-mail] (Kieran A. Carroll) writes:

>Fuel cells (H2/O2) can apparently produce about 110-130 W/kg, but I
>don't think that that figure includes the mass of the reactants used
>(i.e. it's just the mass of the cell). There is a figure quoted for
>"Energy density mission" of 400-1400 kW-hr/kg; assuming that this
>includes the mass of the reactants, that would give you about 3e12 to
>1e13 J from 2 tonnes of them.

Reality check: 3e12 joules from 2 metric tonnes of chemicals gives
a specific energy of 1.5e9 joules/kilogram, which corresponds to the
kinetic energy of material traveling at 54 km/s.  If hydrogen/oxygen
was *that* good a rocket fuel, we'd be vacationing on Mars by now.

My CRC handbook says the energy of combustion of stoichiometric
hydrogen and oxygen is about 1.5e7 joules/kilogram.  You shifted
the decimal point two places.

    Paul F. Dietz
    [e-mail]

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

Date: 23 Feb 90 00:12:43 GMT
From: texbell!nuchat![e-mail]  (Norman C. Kluksdahl)
Subject: Re: Fun Space Fact #1: Launcher Development Costs

In article <[e-mail]> [e-mail] (William Baxter) writes:
>pacifists.  If only Congress gave NASA enough money everything would be
>fine.  ..........  Go read the congressional
>record around the time of the original shuttle appropriations.
>
>Check your facts *before* you post.

How can you, in good conscience, say, in the same article, 'read the
Congressional record' AND 'Check your facts'?

One of the biggest lies perpetrated on the American public is that the
Congressional record is an accurate accounting of the dealings of our
Congress.  In fact, Congresscritters have the right to edit the contents
of the record AFTER THE FACT.  A five-minute debate might turn into a
thirty+ page thesis, and be completely contrary to what the particular
critter actually said.

Back to the subject, you are quite correct.  While it is certain that
the shuttle would be vastly different, there is no guarantee (or even
credible speculation) that the shuttle would have operated according
to specs with unlimited funding.
=====================================================================
Norman Kluksdahl
  ...!nuchat!moe

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

End of SPACE Digest V11 #76
*******************