Space & Astronomy/Space and Astronomy (October 1993).iso/pc/text/spacedig/v13_2/v13_206.txt

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Subject: SPACE Digest V13 #206

SPACE Digest                                     Volume 13 : Issue 206

Today's Topics:
         Re: Pioneers 7 & 8 Update - 02/11/91
         Re: Pioneers 7 & 8 Update - 02/11/91
         NASA Headline News for 02/22/91 (Forwarded)
             Re: NASA technology choices
                 Re: dynasoar
            Mars 'face' reference
             Re: NASA technology choices
         Re: Whither Lunar Observer in FY92?
             space news from Jan 14 AW&ST

Administrivia:

    Submissions to the SPACE Digest/sci.space should be mailed to
  [e-mail].  Other mail, esp. [un]subscription requests,
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----------------------------------------------------------------------

Date: 25 Feb 91 19:42:44 GMT
From: usc!elroy.jpl.nasa.gov!jato!mars![e-mail]  (Ron Baalke)
Subject: Re: Pioneers 7 & 8 Update - 02/11/91

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
>And if you count the Pioneer Venus missions as part
>of the numbered series, then Pioneer 12 is on the surface of Venus in
>pieces (by design!) and Pioneer 13 is still active in Venus orbit.
>--

You've got your numbers reversed for the Pioneer Venus spacecraft.  Pioneer
12 is the Pioneer Venus orbiter, while Pioneer 13 is the Pioneer Venus
spacecraft that split into 4 probes before impacting on Venus.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|      Ron Baalke         | [e-mail]
     | | | |  __ \ /| | | |      Jet Propulsion Lab | Is it mind over matter,
  ___| | | | |__) |/  | | |___   M/S 301-355        | or matter over mind?
 /___| | | |  ___/    | |/__ /|  Pasadena, CA 91109 | Never mind.
 |_____|/  |_|/       |_____|/                      | It doesn't matter.

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

Date: 25 Feb 91 19:37:35 GMT
From: sdd.hp.com!elroy.jpl.nasa.gov!jato!mars![e-mail]  (Ron Baalke)
Subject: Re: Pioneers 7 & 8 Update - 02/11/91

In article <[e-mail]> [e-mail] (Wayne Hayes) writes:
>In article <[e-mail]>
>[e-mail] (Ron Baalke) writes:
>>
>>                     PIONEER 7 & 8 STATUS REPORT
>>                         February 22, 1991
>>  Attempts to command the
>>spacecraft were unsuccessful.  Three attempts were made at an uplink power of
>>18 kW.  Telemetry received during the pass is being analyzed to evaluate the
>>communications subsystem.  At the next tracking opportunity the uplink power
>>will be increased.
>
>I don't quite understand this.  Does "telemetry" require any active
>participation by the spacecraft?  I would have thought that in order to
>know precisely where the craft is (that's what telemetry is, right?)
>you would need a signal coming from it.  If that's the case, what
>is the problem?  Is it just mosying along saying "HERE I AM!" but not
>responding otherwise?
>

     Of all the spacecraft in the Pioneer 6-9 series, only Pioneer 9 is
inoperative.   Useful scientific data (telemetry data) is still being obtained
from the other three spacecraft, though they are tracked intermittently.
Pioneer 6 is is the oldest surviving spacecraft (launched in 1965), and is
still in good shape.  On Pioneer 7, the role rederence is inoperative so no
directional data is available.  Also, the solar array is weak on Pioneer 7 so
instruments cannot be run at aphelion.  On Pioneer 8, the sensors work only
near the Sun, so directional data cannot be obtained for the rest of the orbit.
      ___    _____     ___
     /_ /|  /____/ \  /_ /|      Ron Baalke         | [e-mail]
     | | | |  __ \ /| | | |      Jet Propulsion Lab | Is it mind over matter,
  ___| | | | |__) |/  | | |___   M/S 301-355        | or matter over mind?
 /___| | | |  ___/    | |/__ /|  Pasadena, CA 91109 | Never mind.
 |_____|/  |_|/       |_____|/                      | It doesn't matter.

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

Date: 25 Feb 91 20:38:47 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: NASA Headline News for 02/22/91 (Forwarded)


             Headline News
Internal Communications Branch (P-2) NASA Headquarters

  Monday, February 25, 1991    Audio Service: 202 / 755-1788

This is NASA Headline News for Monday, February 25, 1991

Launch processing on Discovery continues at Kennedy Space Center.
The hypergolic fuels for the orbital maneuvering system were successfully
loaded this weekend.  Activity today on the hypergolic system includes
circulation tests and sampling of gases in the circulation lines.  Other
activities today involve aft closeout activities and preparation for
installation of ordnance.  The ordnance devices are currently scheduled
for installation late on Wednesday.  Discovery is still on a schedule which
would support a launch for its Department of Defense STS-39 mission on
March 9.

In support of ongoing analysis activities associated with Discovery's
cracked fuel line door mechanism hinges, technicians tested the fuel
line doors on Columbia by cycling them open and closed this
weekend.  The door mechanism on Columbia had been modified to
simulate the cracked hinges on Discovery's mechanism.  These tests have
been completed and analysis of the results is underway.  A telecon has
been scheduled for tomorrow to review both the Discovery hinge
assessment and the Columbia hinge test.

KSC technical staff continue to process Atlantis toward its scheduled roll
over to the Vehicle Assembly Building next Monday, March 4.  Work over
the weekend included the retest of the lefthand power drive unit on
Atlantis' fuel line door, and the waste containment system functional test.
Workers plan a flight control system test today.  Atlantis is currently
scheduled to deploy the Gamma Ray Observatory on the STS-37
mission set for launch in April.

                   * * * * * * * * * * * * * * * *

Continuing observations by the Total Ozone Mapping Spectrometer
(TOMS), aboard the Nimbus 7 spacecraft, have confirmed that the
depletion of stratospheric ozone over Antarctica in 1990 matched
the lowest levels ever observed in 1987 and 1989.  The TOMS has
monitored Antarctic ozone concentrations since 1979.  NASA scientists at
Goddard Space Flight Center have found that the 1990 Antarctic ozone
hole matched the record 1987 ozone depletion in depth, duration and area.
During the formation of the hole last August, the total ozone values were
the lowest yet recorded.  The hole is a large area of ozone depletion that
usually occurs between late August and early October, typically breaking
up in mid-November.  Ozone is a molecule made up of three atoms of
oxygen which comprises a thin layer of the Earth's upper atmosphere.
Ozone absorbs harmful ultraviolet radiation from the Sun.  But, in
the presence of sunlight, atoms of chlorine and other chemicals can strip
an oxygen atom from an ozone molecule, leaving behind an oxygen
molecule which does not absorb ultraviolet.



Here's the broadcast schedule for Public Affairs events on NASA Select
TV.  All times are Eastern.  NASA Select TV is carried on GE Satcom
F2R, transponder 13, C-Band, 72 degrees W Long., Audio 6.8, Frequency
3960 MHz.

Monday 2/25/91
     2:00 pm        STS-37 flight crew briefing, live from Johnson
            Space Center, with mission commander Michael Coats,
            mission pilot Blaine Hammond, Jr., and mission
            specialists Guion Bluford, Richard Hieb, Charles
            Veach, Gregory Harbaugh, and Donald McMonagle.

Tuesday, 2/26/91
    12:00 pm    NASA Productions will be transmitted.



All events and times may change without notice.  This report is filed daily,
Monday through Friday, at 12:00 pm, EST.  It is a service of NASA
Headquarters Office of Public Affairs.  Contact:  CREDMOND on
NASAmail or at 202/453-8425.

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

Date: 25 Feb 91 23:02:09 GMT
From: zephyr.ens.tek.com!tektronix!sequent!crg5![e-mail]  (Nick Szabo)
Subject: Re: NASA technology choices

In article <[e-mail]> [e-mail] writes:
>As a matter of a fact the Flight Telerobotic Servicer bears more
>than a passing resemblance to a Discovery pod; it's just squashed
>because it doesn't have a person inside.  After all, if you're
>going to restrict your dexterity to that available with waldos,
>then there's no point in adding life-support; just use teleoperation
>from the space station (no communication delay there), you're not
>losing a thing.

Or just do teleoperation from earth (with a good circuit there is no
large communications delay).


--
Nick Szabo            [e-mail]
Forward in all directions!

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

Date: 25 Feb 91 17:56:58 GMT
From: usc!cs.utexas.edu!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: dynasoar

In article <[e-mail]> [e-mail] (Steven King) writes:
>>... Its problem was the lack of a mission, since the
>>wingless spacecraft had already proved capable of doing almost everything
>>Dyna-Soar could have done.
>
>   I'm afraid I'm going to disagree with Henry on this. DynaSoar had a
> mission; its the same mission that the Air Force currently uses aircraft
> for in the atmosphere...

And which the aircraft were, by and large, perfectly capable of doing. :-)

I slightly mis-stated the situation.  DynaSoar's big problem was the same
one that killed MOL:  the lack of any clear requirement for military manned
spaceflight.  The unmanned military spacecraft were far more successful, in
the end, than their early history suggested, and the need for military
astronauts gradually evaporated.  Such missions as did remain -- more R&D
than operational -- could be flown quite adequately by Gemini, if necessary.
Since DynaSoar used the same launcher, there was little advantage in areas
like launch readiness, and Gemini had a demonstrated capability for orbit
changes and rendezvous.  The need for a recovery force was a nuisance,
especially since said force had to be supplied by (ugh) the Navy :-), but
had this ended up being a major issue, the original scheme of landing
Gemini on land by paraglider could have been revived.
--
"But this *is* the simplified version   | Henry Spencer @ U of Toronto Zoology
for the general public."     -S. Harris |  [e-mail]  utzoo!henry

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

ReSent-Message-ID: <[e-mail]>
Resent-Date:  Mon, 25 Feb 91 16:09:42 EST
Resent-From: Harold Pritchett <[e-mail]>
Resent-To: Space discussion group <[e-mail]>
Date:     Mon, 25 FEB 91 17:10:06 GMT
From: [e-mail]
Subject:  Mars 'face' reference

Well, if no one else is going to supply references I might as well...

Every so often, when I say something about being interested in space to
people I meet at parties they start wittering about The Face, so I shut
them up by handing them

"Monuments of Mars: A City On The Edge of Forever" by Richard Hoagland

Despite the off-putting title, it has the appropriate pictures & lots of
references and looks intriguing on the book-shelf.

Regarding the 3D aspect, I saw an article in the Journal of Applied Optics
(I think) about two years ago by someone called Carlotti (?) who claimed
the info in the header allowed fairly accurate reflected light to
terrain attitude mappings, from which a true surface can be constructed.

On the side of credence, I don't for a moment believe they're more than
coincidental rock formations: as a child I used to notice faces in the
patterned linoleum in our bathroom.
Nevertheless, if MO's camera happens to be pointing in the right direction,
I see no reason to intentionally avoid taking a photo, if only to put
people's mind at rest.

Besides, you never know...     :-)                 <PIGEON>[CAT]<PIGEON>
_________________________________________________________________
Mike Salmon, Climatic Research Unit    | R: "But there aren't any
Univ. of East Anglia, Norwich, England | real people here at all"
[e-mail]   [phone] | Z: "So what's new?"

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

Date: 25 Feb 91 17:51:37 GMT
From: usc!elroy.jpl.nasa.gov!euclid.jpl.nasa.gov![e-mail]  (Peter Scott)
Subject: Re: NASA technology choices

In article <[e-mail]>, [e-mail] (Paul Blase) writes:
> Philosophical question of the week.
>
> I recently watched 2001: A Space Odessey again.  I rather like the
> EVA pods that astronauts used to repair the Discovery.  One of the
> recent 'problems' discovered with Space Station Freedom is that the
> number of hours of EVA required to repair the station was unacceptably
> high.  Thusly, NASA is spending gobs of money on telefactor and robotic
> widgetry so that the astronauts don't have to leave the station.  Why
> doesn't NASA develop a space pod like those used in 2001?  It would almost
> have to be cheaper and less risky (from an R&D point of view).  Any
> thoughts?

As a matter of a fact the Flight Telerobotic Servicer bears more
than a passing resemblance to a Discovery pod; it's just squashed
because it doesn't have a person inside.  After all, if you're
going to restrict your dexterity to that available with waldos,
then there's no point in adding life-support; just use teleoperation
from the space station (no communication delay there), you're not
losing a thing.

--
This is news.  This is your       |    Peter Scott, NASA/JPL/Caltech
brain on news.  Any questions?    |    ([e-mail])

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

Date: 25 Feb 91 21:30:42 GMT
From: bonnie.concordia.ca!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Whither Lunar Observer in FY92?

In article <[e-mail]> [e-mail] (jack hagerty) writes:
>>the Moon's gravitational field is so lumpy that objects
>>left in orbit generally crash on the surface within a few years.
>
>Why is this? I realize that the moon's gravity field causes the nodes of
>any orbit around it to precess wildly, but what causes the decay? ...

It's not just precession.  For most purposes, Earth can be treated as a
point mass plus some precessions caused by the equatorial bulge.  The Moon
is too complex for such a straightforward view.  There are large lumps of
dense matter -- the "mascons" -- under most of the maria, and these turn
the gravitational field into a hopeless mess.  It bears only a passing
resemblance to that of a point mass, so there is no such thing, really,
as a simple orbit around it.  Even the relatively short Apollo missions
needed some scratching of heads and tearing of hair on the ground to cope
with orbital perturbations; they eventually gave up on trying to model
the orbits precisely and settled for correcting for the errors more or
less in real time during the landing approaches.

(One of the secondary missions of Lunar Prospector, in fact, is precise
mapping of the lunar gravitational field using modern techniques.)

As far as I know, there isn't really any systematic statement that can
be made about the long-term effects of the Moon's field on orbits; it's
just complex.  However, applying random perturbations to a low orbit
has a high probability of altering it to intersect the surface before
too very long, since the surface is not far away.
--
"But this *is* the simplified version   | Henry Spencer @ U of Toronto Zoology
for the general public."     -S. Harris |  [e-mail]  utzoo!henry

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

Date: 26 Feb 91 06:32:30 GMT
From: magnus.ircc.ohio-state.edu!zaphod.mps.ohio-state.edu!wuarchive!cs.utexas.edu!news-server.csri.toronto.edu!utzoo![e-mail]  (Henry Spencer)
Subject: space news from Jan 14 AW&ST

[This is an unusually thin issue, almost as if they were saving space in
case something particularly newsworthy happened just before press time... :-)]

NASA astronauts experimenting with using very bright lighting to shift
their circadian rhythms for night-shift operations in space.  Simply
going to bed earlier and earlier does not work very well because the
body still sees the day-night cycle.  Very bright lights in workplaces
and living quarters imitate sunlight well enough to make the body shift
gears.  The night-shift crew for Astro-1 report better results from
four days of bright lights before launch than from up to six weeks of
shifting sleep schedules before earlier launch attempts.

Intelsat governors authorize the Intelsat 7A series contract going to
Space Systems / Loral.

Hughes and Spar selected to supply two satellites for US/Canada mobile
communications starting in the mid-1990s.

USAF asks Martin Marietta design bureau, er oops I mean Martin Marietta Inc,
for a preliminary cost estimate for 20 more Titan IVs.  The current contract
is for 41, plus 8 options that would be among the new 20.

First (British-built) NATO 4 comsat launched by Delta Jan 7.  It will not
be operational until April or May, because the older NATO birds are still
functioning well and there is no rush.

USAF is trying to figure out exactly what went wrong with the first
advanced Navstar.  On Dec 12, a fuse blew in the solar-panel control
circuitry, and the bird has lost its ability to automatically control
the position of its solar panels.  For the moment the panel position is
being controlled from the ground, but this is considered unsatisfactory
in the long run.  The big question is, is this a generic problem?  The
advanced Navstars use essentially the same solar panels and control
systems as the earlier ones, but...  The next Navstar launch was listed
for February, but it is now considered likely that there will be a delay
of at least six months to make changes to the birds now in the pipeline.

Northwest Airlines receives two Soviet-built Glonass receivers for
experimental use in evaluating the Glonass navsat system.  This is part
of a joint Soviet-Honeywell project aimed at a receiver that can use
both Navstar and Glonass.  The Soviets admit reliability problems with
the Glonass satellites, but say they are being solved.  The Soviets have
given no indication of intent to deliberately degrade Glonass accuracy
the way the US does with the Navstars, a matter of concern to some users.

Inmarsat is still thinking about how to use the Navstar/Glonass-like
signal transmission capability planned for the Inmarsat 3 series.  The
overall plan is to provide supplementary coverage plus a broadcast of
up-to-date information on which Navstar and Glonass satellites are
functioning correctly [something neither system does on its own].
One question is who's going to monitor the satellites (and accept
responsibility for the accuracy of the information) and who's going
to pay for it.  Inmarsat is hoping that regional consortia of civil-
aviation agencies will do the work for navsats over their regions,
and pay a modest fee for the privilege.

Department of Slightly Unbelievable News:  Consortium of US government
agencies, headed by SDIO, plans to buy a Soviet Topaz 2 space reactor.
Even more remarkable, the Soviets like the idea.  The agencies (DoE,
NASA, USAF, SDIO) hope to get the US space nuclear power program going
again with a transfusion of Soviet technology [!!!].  [There must have
been steam coming from the ears of the technology-transfer paranoids
in the Pentagon when this was proposed.]  The Topaz 2 will be bought
through International Scientific Products, a California company which
has negotiated an agreement with the relevant Soviet bureau.  It will
be a fully workable reactor minus the actual fuel; electric heaters
will substitute for the fission fuel during testing and evaluation.
The price for the reactor plus Soviet-supplied test facilities will
be circa $10M.  Delivery date is tentatively midsummer.  The Soviets
are insisting that the technology be restricted to "peaceful,
commercial" purposes, and safeguards are being negotiated.  Later
sales for in-space use are considered a possibility.

SDIO intends to fund a five-year program costing about $100M to study
the Topaz 2.  This will be the first part of a two-phase program to
build a US version that meets US safety and reliability standards.
SDIO says that US research on thermionic power conversion, considered
a backup technology to the thermoelectric system being built for SP-100,
has been on a "starvation budget" that will never produce working hardware.
SP-100 itself is not in good shape, with $400M+ already spent and flight
hardware still "many years" away.  SP-100 is aimed at 100kW power output;
the Soviets say that relatively minor changes could get 30-40kW out of
Topaz 2.

US space-reactor experts who have toured the Kurchatov Institute of
Atomic Energy are very impressed.  "We couldn't reproduce their development
facilities for a billion dollars, and the Soviets employ 1000 people where
we have twelve."  They have developed a number of supporting technologies,
e.g. a single-crystal molybdenum-niobium alloy for core parts (a sample of
which is now being tested at NASA Lewis, with results so far confirming
Soviet claims of superior properties).
--
"But this *is* the simplified version   | Henry Spencer @ U of Toronto Zoology
for the general public."     -S. Harris |  [e-mail]  utzoo!henry

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

End of SPACE Digest V13 #206
*******************