Conference 7.286::space

From:	US1RMC::"[email protected]" "HILL, DIANNE" 22-SEP-1994 13:22:59.14
CC:	
Subj:	94-159 NASA NAMES SCIENCE TEAM FOR ASTEROID RENDEZVOUS MISSION

Douglas Isbell
Headquarters, Washington, D.C.
September 21, 1994
(Phone:  202/358-1753)

RELEASE:  94-159

NASA NAMES SCIENCE TEAM FOR ASTEROID RENDEZVOUS MISSION

     NASA has selected the science team for the first spacecraft
designed to rendezvous with an asteroid.

     The Near Earth Asteroid Rendezvous (NEAR) mission promises to
answer fundamental questions about the nature of near-Earth objects
such as asteroids and comets.  These objects are believed to consist
of debris from the earliest days of planetary formation 4.5 billion
years ago, so better knowledge of them should provide clues about the
origin and evolution of the Solar System.

     Scheduled for launch in February 1996 aboard a Delta 2 rocket,
the NEAR spacecraft should arrive in orbit around asteroid 433 Eros in
early January 1999.  It will then survey the rocky body for a minimum
of one year, at altitudes as close as 15 miles (24 kilometers).  Eros
is one of the largest and best-observed asteroids whose orbits cross
Earth's path.  These asteroids are closely related to the more
numerous "Main Belt" asteroids that orbit the Sun in a vast
doughnut-shaped ring between Mars and Jupiter.

     The goal of the NEAR project is to carry out a mission with
high scientific return and wide participation at relatively modest
cost.  It will seek the first comprehensive measurements of an
asteroid's mass, structure, geology, mineral composition, and gravity
and magnetic fields.  Science data and related products will be
archived in near real-time in NASA's Planetary Data System (PDS), with
access for the general science community, the public and educators via
the Internet.

     The NEAR Science Payload consists of six instruments:  a
multispectral imager system; a near-infrared spectrograph; an
X-ray/gamma-ray spectrometer; a magnetometer; a laser altimeter; and
the spacecraft's radio, which is also used for gravity measurements.

     The members of the NEAR science team are:

Multispectral Imager/Near-Infrared Spectrograph
Joseph Veverka, Cornell University (Team Leader), Ithaca, N.Y.
James F. Bell III, NASA Ames Research Center, Mountain View, Calif.
Clark R. Chapman, Planetary Science Institute, Tucson, Ariz.
Michael C. Malin, Malin Space Science Systems, Inc., San Diego, Calif.
Lucy-Ann A. McFadden, University of Maryland, College Park, Md.
Mark S. Robinson, U.S. Geological Survey, Flagstaff, Ariz.
Peter C. Thomas, Cornell University

X-ray/Gamma-Ray Spectrometer
Jacob I. Trombka, NASA Goddard Space Flight Center (Team Leader),
Greenbelt, Md.
William V. Boynton, University of Arizona, Tucson
Johannes Bruckner, Max Planck Institut fur Chemie, Mainz, Germany
Steven W. Squyres, Cornell University

Magnetometer
Mario H. Acuna, Goddard Space Flight Center (Team Leader)
Christopher T. Russell, University of California, Los Angeles

Light Imaging Detector and Ranger (LIDAR)
Maria T. Zuber, Goddard Space Flight Center (Team Leader)

Radio Science
Donald K. Yeomans, NASA Jet Propulsion Laboratory (Team Leader),
Pasadena, Calif.
Jean-Pierre Barriot, Centre National D'Etudes Spatiales, Toulouse,
France Alexander S. Konopoliv, Jet Propulsion Laboratory

     The NEAR Project Science Group will be co-chaired by Dr.
Jurgen Rahe, the NASA Headquarters Program Scientist, and Dr. Andrew
F. Cheng, NEAR Project Scientist at the Johns Hopkins University
Applied Physics Laboratory (APL) in Laurel, Md.  APL will build and
operate NEAR, making it the first NASA planetary mission to be
conducted by a non-NASA space center.

     The facility-class Instrument Scientists at APL will be the
main interface between the science team leaders and project engineers.
The Instrument Scientists are:

 - Scott L. Murchie (Multispectral Imager/Near-Infrared Spectrograph)
 - Ralph L. McNutt  (X-ray/Gamma-Ray Spectrometer)
 - Larry J. Zanetti (Magnetometer)
 - Andrew F. Cheng (LIDAR)

     The NEAR project began in late 1993.  NEAR will be the first
launch in NASA's Discovery program, an initiative based on small
planetary science missions with short development cycles and stringent
cost caps.  It requires missions to proceed from development to flight
in less than three years, with total spacecraft and instrument
development costs limited to no more than $150 million (in FY 1992
dollars) and an acceptance of a greater level of technical risk than
on typical NASA missions.

     The Solar System Exploration Division of the Office of Space
Science at NASA Headquarters has program management responsibility for
the NEAR mission.

 -end-

EDITOReS NOTE: A color print of an artistes conception of the NEAR
spacecraft is available to news media by faxing your request to the
NASA Headquarters Broadcast and Imaging Branch on 202/358-4333.  The
photo number for a black and white print is 93-H-474 and for color is
93-HC-426.

NASA press releases and other information are available automatically
by sending an Internet electronic mail message to [email protected].
In the body of the message (not the subject line) users should type
the words "subscribe press-release" (no quotes).  The system will
reply with a confirmation via E-mail of each subscription.  A second
automatic message will include additional information on the service.
Questions should be directed to (202) 358-4043.

% ====== Internet headers and postmarks (see DECWRL::GATEWAY.DOC) ======
% From: "HILL, DIANNE" <[email protected]>
% Subject: 94-159 NASA NAMES SCIENCE TEAM FOR ASTEROID RENDEZVOUS MISSION
% Date: Thu, 22 Sep 94 08:26:00 PDT
% Sender: [email protected]

    What? NEAR get near buts doesn't actually land ... to make a few
    direct soils analysis. Doesn't make sense, the extra capability
    shouldn't cost much and would provide needed "ground truth data"

    Even without specific instruments much could be learned from a
    landing. And if it was done "as an extra" at the end of the mission, 
    nothing would be lost if something went wrong.

    ... I'll never figure those guys out.

    Gil

    re .2
    
    It could be mass restrictions. Sure, it's a tough decision but you
    can't fly every instrument you want. The six have been selected (listed
    in .1) and there don't appear to be any to do direct sample analysis
    (like a mass spectrometer or gas chromatograph or ?).
    
    It seems to me that the current configuration doesn't rule out a
    potentially destructive rendezvous attempt near mission end. What makes
    you think that it won't be attempted? Initial mission plans tend to be
    very conservative.

Who would have taken Magellan seriously if they had played up the windmill test?
There's lots that can be done with a spacecraft at the end of it's lifetime...
I'm sure you could get a bunch of info from a soft docking even without landing
legs. I'll bet there's some end/face of the spacecraft that could be used and
still send back data of the event. I'd rather see that done than a Ranger-type
landing.

I can think of a bunch of problems that would need solving if they were
explicitly planning a landing mission.  I suspect they would not come cheap:

1)  How do you land on a body with so little gravity?  It would probably take a
lot of bizzare flight control that no one has experience with, and more delta-V
than one might expect.

2)  Once landed, how do you stay there?  In particular, how do you stay there
while using some tools to dig or whatever you plan to do.

3)  You need to develop instruments that are more useful on the ground.

Burns

That's why the general choice is a penetrator. You would have to latch onto
something which is why they probably have a "nudge" manuever in the final bag of
tricks. How about something like a penetrator (Mission Anchorbolt) and a grapple
to "hang on and dig"?

    	The Soviet Phobos missions to Mars and its largest moon in 1988
    had one lander which was designed to anchor itself to the surface 
    of Phobos.  Another experiment was to fire a laser into the moon's
    regolith and then fly through the spraying debris for more surface
    analysis.  
    
    	I say it doesn't hurt to check the planetoid from a safe distance
    this time.  That way they will be better prepared for an actual probe
    landing.  Yes, I really wish they would land, too.
    
    	Larry
    

  Speaking of gravity....  How is NEAR going to "orbit Eros"?  Do they mean 
it will actually go into orbit, or simply fly in the same orbit as Eros and 
observe it as Eros rotates?



        

RE: <<< Note 879.8 by MR3MI1::JCAVANAGH "Jim Cavanagh MRO3-3/N20 297-4590" >>>

I'd take the statement on face value that NEAR will orbit Eros. Recall the
moon orbiting Ida. There's also enough gravity on Ida and Gaspara to hold a
modest amount of soil/regolith, which as I recall was somewhat unexpected.

I can't recall the accepted diameter of Eros; anyone know?
						-- Tom

re .5 et al

>1)  How do you land on a body with so little gravity?

    Yes, I wondered about that too. Due to the low gravity I think the
    man�uvre could be better described as docking rather than landing.

>It would probably take a lot of bizzare flight control that no one has
>experience with,
    
    I wonder whether NEAR is near enough for real time commanding or even tele-
    robotics. The imaging capabilities could be good enough. There doesn't
    appear to be radar for automated docking. Still, mission ends are all about 
    "pushing the envelope"!
    
>and more delta-V than one might expect.

    Back of the envelope suggests that delta-V is on the order of metres per
    second, a little more than a typical TCM (which would be < 1 m/s) but
    probably feasible unless propellant margins are minimal and that doesn't
    sound like normal NASA mission planning - even the new "better cheaper
    faster" NASA. If they have the propellant left towards the end of the
    primary mission, why not?
    
    (By way of comparison I would expect the initial orbit insertion to be
     many many times this - but really we have to wait for more details.)
    
    (I haven't taken into account the spin of the asteroid and hence I haven't
     bothered about any plane changes that might be necessary to de-orbit.)

    NEAR was launched this past Saturday at about 3:43 pm on a
    DELTA rocket. It was a clean launch with no real problems. 
    The NASA TV coverage was well done. Some footage was shown before
    the launch of the assembly & erection of the DELTA rocket, along
    with the second stage rocket, shroud, and NEAR assembly. Neat stuff!
    The post launch TV showed the commentator walking through the room
    area where all the strip recorders are for all the telemetry, and
    describing the events as they occured as the solid rocket boosters,
    shut down, were ejected, second stage ignition, describing chamber
    pressures being on the money, describing second stage re-ignition
    for final boost into escape trajectory from earth. The description
    with black-white video of the NEAR crew watching their monitors for
    signs of clean solar-array deploy, health of batteries etc. indicated
    NEAR was healthy & ready to do its thing.
    Compared to past planetary probes, this thing is on a shoe-string
    budget, and it's mission is off to a great start!
    
    Bob :)

Bob, did NEAR do one or more Earth orbits before heading off?

BTW, there is a photo from the Spacewatch telescope of NEAR heading off into
space 16 hours after launch at:

http://www.lpl.arizona.edu/spacewatch/NEAR.html

(It's "just" a streak on a star plate, I should add before anyone gets the wrong
idea.)

Burns

    >>Bob, did NEAR do one or more Earth orbits before heading off?
    
    I didn't get a handle on that from the commentary,, but I *think*
    I may have heard them say one orbit. They had commentary on the
    telemetry being relayed from Ascension (sp?) Island, and the subsequent
    re-ignition of the upper stage rocket, then some commentary on the
    deploy of the solar panels, & activation of some telemetry data stream
    from NEAR, then NASA Select ended the NEAR TV coverage.
    
    Bob

Thanks.  There is a home page for it, but they don't give much status info!

Burns

Article: 42523
Newsgroups: sci.space.shuttle
From: [email protected] (mary-frances  jagod)
Subject: NEAR press kit available
Sender: [email protected] (News Administrator)
Organization: The University of Chicago
Date: Thu, 8 Feb 1996 21:52:30 GMT
 
The NEAR (Near Earth Asteroid Rendezvous) mission press kit is now
available (in plain text format) from:
	ftp://ftp.pao.hq.nasa.gov/pub/pao/presskit/1996/NEARpk.txt
 

    I found more information on the NEAR launch  at JPL's newproducts
    web page. It mentioned that NEAR was launched into a 13 minute
    "parking" orbit, after which the booster rocket was re-ignited,
    and sent on its interplanetary trajectory.
    So a 13 minute parking orbit wouldn't be much of a % of a complete
    orbit around Earth. I'll pull the particulars and post it here.
    
    Bob

Jeez, I wonder if it should be 130?

Burns