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Date: Thu, 14 Sep 89 19:49:25 -0400 (EDT)
Subject: SPACE Digest V10 #40

SPACE Digest                                      Volume 10 : Issue 40

Today's Topics:
      Re: Was Voyager another damaging Apollo one-shot?
           NASA Prediction Bulletin Format
               Re: Apollo 8, 9, and 10
           Voyager Status for 07/18/89 (Forwarded)
    NASA awards grants for future exploration studies (Forwarded)
              Re: Neptune fly-by
----------------------------------------------------------------------

Date: 2 Sep 89 11:48:52 GMT
From: b.gp.cs.cmu.edu![e-mail]
Subject: Re: Was Voyager another damaging Apollo one-shot?

In article <[e-mail]>, [e-mail] (Tom Neff) wrote:
 >be hard to come by.  I'm just a little afraid that NASA has managed to
 >outsmart itself by doing such a comprehensive job with a couple of
 >probes.

Granted, they managed to do an incredible job with a single half-crippled
spacecraft*.  But....  The original "Grand Tour" concept (killed by lack of
funding) was for two probes to fly Jupiter-Saturn-Pluto, and two probes to fly
Jupiter-Uranus-Neptune (or was it J-S-U-N?).  The first two probes would be
arriving at Pluto just about now <sigh>.

Voyager started as Mariner Jupiter-Saturn.  Voyager 2 continuing on to Uranus
and Neptune was only a possibility if Voyager 1 performed flawlessly at
Saturn, which it luckily did.

* the litany of failures:
   primary receiver dead
   backup receiver tracking loop capacitor failed.  As a result, V2 can only
      receive on an extremely narrow band, which changes with the craft's
      internal temperature.  Not only do the controllers have to compute the
      frequency at which their signal arrives (the earth's rotation is enough
      to doppler-shift the signal out of the receive window!), but they also
      have to guess at where the receive window *is*.
   photopolarimeter spectrometer nearly burned out (human error, it was left
      pointing at a bright calibration plate while set to highest sensitivity)
   a filter wheel which stuck several times
   narrow-angle camera's sensitivity fading
   stuck bit in the memory for the computer doing the image compression
   scanning platform seized up at Saturn, could no longer be used at the high
      slew rate, and only limited use at the medium speed to prevent another
      seizure.

There may be other problems which I don't recall off-hand.  There were also
problems on the ground.  That they managed to get so many good results anyway
is a real tribute to the Voyager team's skill and dedication.
--
UUCP: {ucbvax,harvard}!cs.cmu.edu!ralf -=-=-=-=- Voice: [phone] (school)
ARPA: [e-mail]  BIT: ralf%cs.cmu.edu@CMUCCVMA  FIDO: Ralf Brown 1:129/46
FAX: available on request                      Disclaimer? I claimed something?
You know it's going to be a bad day when...
        ...your birthday cake collapses from the weight of the candles.
        ...you wake up face down on the pavement.

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

Date: 5 Sep 89 04:55:50 GMT
From: ncis.tis.llnl.gov!blackbird![e-mail]  (TS Kelso)
Subject: NASA Prediction Bulletin Format


As a service to the satellite user community, the following description
of the NASA Prediction Bulletin's two-line orbital element set format is
uploaded to sci.space on a monthly basis.  The most current orbital elements
from the NASA Prediction Bulletins are carried on the Celestial RCP/M, (513)
427-0674, and are updated several times weekly.  Documentation and tracking
software are also available on this system.  The Celestial RCP/M may be
accessed 24 hours/day at 300, 1200, or 2400 baud using 8 data bits, 1 stop
bit, no parity.

==============================================================================

Data for each satellite consists of three lines in the following format:

AAAAAAAAAAA
1 NNNNNU NNNNNAAA NNNNN.NNNNNNNN +.NNNNNNNN +NNNNN-N +NNNNN-N N NNNNN
2 NNNNN NNN.NNNN NNN.NNNN NNNNNNN NNN.NNNN NNN.NNNN NN.NNNNNNNNNNNNNN

Line 1 is a eleven-character name.

Lines 2 and 3 are the standard Two-Line Orbital Element Set Format identical
to that used by NASA and NORAD.  The format description is:

Line 2
Column     Description
 01-01     Line Number of Element Data
 03-07     Satellite Number
 10-11     International Designator (Last two digits of launch year)
 12-14     International Designator (Launch number of the year)
 15-17     International Designator (Piece of launch)
 19-20     Epoch Year (Last two digits of year)
 21-32     Epoch (Julian Day and fractional portion of the day)
 34-43     First Time Derivative of the Mean Motion
        or Ballistic Coefficient (Depending on ephemeris type)
 45-52     Second Time Derivative of Mean Motion (decimal point assumed;
           blank if N/A)
 54-61     BSTAR drag term if GP4 general perturbation theory was used.
           Otherwise, radiation pressure coefficient.  (Decimal point assumed)
 63-63     Ephemeris type
 65-68     Element number
 69-69     Check Sum (Modulo 10)
           (Letters, blanks, periods = 0; minus sign = 1; plus sign = 2)

Line 3
Column     Description
 01-01     Line Number of Element Data
 03-07     Satellite Number
 09-16     Inclination [Degrees]
 18-25     Right Ascension of the Ascending Node [Degrees]
 27-33     Eccentricity (decimal point assumed)
 35-42     Argument of Perigee [Degrees]
 44-51     Mean Anomaly [Degrees]
 53-63     Mean Motion [Revs per day]
 64-68     Revolution number at epoch [Revs]
 69-69     Check Sum (Modulo 10)

All other columns are blank or fixed.

Example:

NOAA 6
1 11416U          86 50.28438588 0.00000140           67960-4 0  5293
2 11416  98.5105  69.3305 0012788  63.2828 296.9658 14.24899292346978

Note that the International Designator fields are usually blank, as issued in
the NASA Prediction Bulletins.

--
Dr TS Kelso                           Asst Professor of Space Operations
[e-mail]          Air Force Institute of Technology

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

Date: 15 Aug 89 13:46:48 GMT
From: grits![e-mail]  (Doug Davey)
Subject: Re: Apollo 8, 9, and 10

In article <[e-mail]> [e-mail] (Henry Spencer) writes:
> orbit, Apollo 10 flew a dress rehearsal of the landing (including LM
> descent to 10 miles above the Moon), and Apollo 11 was the big one.

The line that sticks in my mind from Apollo 10 was:

    "We're really down among 'em!"

It must have been quite a sight to be in orbit, but be only 10 miles
above the surface.

Does anybody remember whether the ascent or descent engine was used
during Apollo 10's return from low orbit to rendezvous with the CSM?
Either option seems difficult.  On the one hand, I would not expect
the descent engine to be restartable.  On the other, firing the
ascent engine and getting the ascent stage cleanly separated from the
descent stage would be tricky since the descent stage was deigned to
be firmly on the lunar surface during this operation.

                                  |     ___  ___         ___ ___  __   ___
Doug Davey                        |    /__/ /__ /   /   /   /  / /__) /__
bellcore!rruxi!ddavey             |   /__/ /__ /__ /__ /__ /__/ /  \ /__
                                  |

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

Date: 15 Aug 89 17:46:55 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: Voyager Status for 07/18/89 (Forwarded)


                    Voyager Status Report
                        July 18, 1989


     Neptune's new moon, 1989 N1, is becoming a new guidepost

for the Voyager navigation team and is a candidate to help
better determine the location of Neptune itself.

     Neptune was discovered in 1846, and the planet takes 165

years to orbit the Sun; thus, Neptune won't return to the
position where astronomers first saw it until 2011.  This
leaves great uncertainty in the precise knowledge of
Neptune's orbit that Voyager navigators need to get the
spacecraft to the targeted area of the planet at the right
time.  But the new Neptunian moon, 1989 N1, will provide the
navigation team with a better idea of Neptune's exact
location.

     The discovery of the moon fulfilled expectations of
Voyager navigators who were hoping to find at least one new
object in the Neptune system whose orbit could potentially be
used to gauge the relative positions of Triton, Neptune and
various background stars, said Don Gray, Voyager Navigation
Team Chief.

     Many of the images coming back from the spacecraft are
optical navigation frames.  Ideally, the frames show a moon
against a field of stars.  Using stars as dim as 10th
magnitude as reference points, the Voyager navigators
progressively update and refine the location of Neptune and
its moons.  This new information is then integrated into
commands that adjust Voyager's flight path and retarget the
spacecraft's observations, if necessary.

     The next trajectory correction maneuver is being
designed and will be uplinked to the spacecraft late next
week.  The maneuver is one of the final three that will be
conducted between now and closest approach to bring the
spacecraft within about 100 miles (150 kilometers) of the
point at which it's aimed -- about 3,000 miles (4,850
kilometers) from Neptune's cloud tops.


DISTANCE TO EARTH:  2,686,949,000 miles
DISTANCE TO NEPTUNE:  33,805,000 miles
HELIOCENTRIC VELOCITY: 42,192 mph

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

Date: 15 Aug 89 19:53:30 GMT
From: trident.arc.nasa.gov![e-mail]  (Peter E. Yee)
Subject: NASA awards grants for future exploration studies (Forwarded)

Edward Campion                                   July 18, 1989
Headquarters, Washington, D.C.


RELEASE:  89-118

NASA AWARDS GRANTS FOR FUTURE EXPLORATION STUDIES


     NASA's Office of Exploration has awarded a series of study
contracts to various organizations to provide NASA with ideas,
concepts, devices, systems, trajectories, operations or
implementations which could be applied to furthering human
exploration of the solar system.

     The 20 winners, selected from 115 proposals submitted in
response to the April 12, 1989, NASA Research Announcement, are
located in 12 different states and come from various occupations
with five industry-related firms, two space support-related
organizations and 13 universities receiving awards.

     In selecting the winners, the criteria applied to all the
submissions was the experience of the principal investigator, the
relevance of the proposal to programs of human exploration of the
solar system, the performance improvement or complexity reduction
possibilities and the uniqueness of the idea or concept.


           Space Support-Related Organization Winners

  o  Oregon L-5 Society, Inc., Oregon City, Ore. - "Site
Characterization of the Oregon Moonbase."

  o  Tether Applications, La Jolla, Calif. - "Preliminary Design
of a 1KM/SEC Tether Transport Node."


                    Industry-Related Winners

  o  Martin Marietta Strategic Systems, Denver, Colo. - "Study of
Nuclear Thermal Rockets Utilizing Indigenous Martian
Propellants."

  o  Dean & Associates, Alexandria, Va. - "An Early Warning
System for Monitoring Large Projects."

  o  Titan Systems, Inc., San Diego, Calif. - The Evolution of
Design Alternatives for the Exploration of Mars by Balloon."

  o  Engineering Development Laboratory, Inc., Newport News, Va. -
"Determination of the Concentration of Spacecraft Cabin Gases using
Laser Spectroscopy."


  o  Orbitec, Madison, Wis. - "Aluminum/Oxygen Rocket Engine for
Lunar Transport Applications" and "The Use of Tethered Platforms to
Recover, Store, and Utilize CO2 from the Mars Atmosphere for On-
Orbit Propellants."

                    University-Related Winners

  o  Energy & Mineral Research Center, Grand Forks, N.D. - "Further
Investigation of the Feasibility of Applying Low-Temperature Plasma
Technology to a Closed-Loop Processing Resource Management System."

  o  Texas Engineering Experiment Station, College Station, Texas -
"Design of a General Purpose, Mobile, Multifunctional Radiation
Shield for Space Exploration."

  o  Boston College, Chestnut Hill, Mass. - "Design Considerations
of a Lunar Production Plant."

  o  Michigan Technological University, Houghton, Mich. -
"Planetary Materials and Resource Utilization."

  o  The Regents of the University of California, Santa Barbara,
Calif. - "A Small Particle Catalytic Thermal Reactor (SPCTR) for
the Conversion of CO and CO2 to Methane in a Gravity-Free
Environment Vehicle."

  o  The University of Michigan, Ann Arbor, Mich. - "Advanced Fuel
Cycles for the MICF - Fusion Propulsion System."

  o  Boston University, Boston, Mass. - "Pneumatic Structures for
Lunar and Martian Habitats."

  o  State University of New York at Stony Brook, Stony Brook,
N.Y. - "Artificial Intelligence to Simulate the Green Thumb."

  o  The Regents of the University of Colorado, Boulder, Colo. -
"Mars Tethered Sample Return Study."

  o  The University of New Mexico, Albuquerque, N.M. -
"Teleprospector:  A Teleoperated Robotic Field Geologist."

  o  Duke University, Durham, N.C. - "Deployable Magnetic Radiation
Shields using High Tc Superconductors:  A New Concept."

  o  International Space University, Boston, Mass. - "International
Lunar Polar Orbiter (ILPO)."

  o  The University of Texas, Houston, Texas - "Emergency Surgery
and Surgical Critical Care to Support Human Exploration of the
Solar System."


     The Office of Exploration intends to follow these selections
with future solicitations for other innovative ideas and
concepts.  These follow-on studies could be to refine concepts
studied this year or to deepen NASA's understanding or reexamine
using different conditions or ground rules; or these future studies
could be aimed at finding more new ideas.

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

Date: 5 Sep 89 05:49:25 GMT
From: mailrus!jarvis.csri.toronto.edu!utgpu!utzoo![e-mail]  (Henry Spencer)
Subject: Re: Neptune fly-by

In article <[e-mail]> [e-mail] (Jon Monsarrat "Dr. Who") writes:
>Could someone explain the reasoning behind having Voyager 2 fly off
>out of the solar system? I'm not under the delusion that a course
>change could be effected for it now. I was just wondering why the
>scientific information gathering benefits of leaving the solar system
>outweigh those of going into orbit around Neptune and shooting some
>better pictures of the moons. This would have been possible with enough
>"braking" around Neptune, am I wrong?

Sorry, you are.  Well, it would be possible with enough braking, but
Voyager had no way to get that much -- it's not designed to dip into
the atmosphere to brake that way, and its fuel supply is quite small.

If it had been possible, it would have been done.
--
V7 /bin/mail source: 554 lines.|     Henry Spencer at U of Toronto Zoology
1989 X.400 specs: 2200+ pages. | uunet!attcan!utzoo!henry [e-mail]

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

End of SPACE Digest V10 #40
*******************