[meteorite-list] NASA's Phoenix Mars Lander to Begin Rasping Frozen Layer

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue, 15 Jul 2008 17:53:49 -0700 (PDT)
Message-ID: <200807160053.RAA27708_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.cfm?release=2008-133

NASA's Phoenix Mars Lander to Begin Rasping Frozen Layer
Jet Propulsion Laboratory
July 15, 2008

TUCSON, Ariz. -- A powered rasp on the back of the robotic arm scoop of
NASA's Phoenix Mars Lander is being tested for the first time on Mars in
gathering sample shavings of ice.

The lander has used its arm in recent days to clear away loose soil from
a subsurface layer of hard-frozen material and create a large enough
area to use the motorized rasp in a trench informally named "Snow White."

The Phoenix team prepared commands early Tuesday for beginning a series
of tests with the rasp later in the day. Engineers and scientists
designed the tests to lead up to, in coming days, delivering a sample of
icy soil into one of the lander's laboratory ovens.

"While Phoenix was in development, we added the rasp to the robotic arm
design specifically to grind into very hard surface ice," said Barry
Goldstein, Phoenix project manager at NASA's Jet Propulsion Laboratory,
Pasadena, Calif. "This is the exactly the situation we find we are
facing on Mars, so we believe we have the right tool for the job.
Honeybee Robotics in New York City did a heroic job of designing and
delivering the rasp on a very short schedule."

The rasp bit extends at a shallow angle out of an opening on the back of
the scoop at the end of the 2.35-meter-long (7.7-foot-long) robotic arm.
To use it, the back surface of the scoop is placed on the ground, and a
motor rotates the rasp. The angle of the rasp is increased from nearly
horizontal to slightly steeper while it is rotating, so the tool kicks
shavings sideways onto a collection surface just inside the opening.
After the rasp stops, a series of moves by the scoop then shifts the
collected shavings from the back of the scoop, past baffles, to the
front of the scoop. The baffles serve to keep material from falling out
of the rasp opening when the scoop is used as a front loader.

The commands prepared for Phoenix's activities Tuesday called for
rasping into the hard material at the bottom of the Snow White trench at
two points about one centimeter (0.4 inch) apart. The lander's Surface
Stereo Imager and robotic arm camera will be used to check the process
at several steps and to monitor any resulting sample in the scoop for
several hours after it is collected.

Collecting an icy sample for an oven of Phoenix's Thermal and
Evolved-Gas Analyzer (TEGA) may involve gathering shavings collected at
the rasp opening and scooping up additional shavings produced by the
rasp. The Phoenix team has been testing this combination on simulated
Martian ice with a near-replica model of Phoenix in a test facility at
the University of Arizona, Tucson.

The Phoenix mission is led by Peter Smith of the University of Arizona
with project management at JPL and development partnership at Lockheed
Martin, Denver. International contributions come from the Canadian Space
Agency; the University of Neuchatel; the universities of Copenhagen and
Aarhus, Denmark; Max Planck Institute, Germany; and the Finnish
Meteorological Institute. For more about Phoenix, visit:
http://www.nasa.gov/phoenix and http://phoenix.lpl.arizona.edu.

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

Media contacts:
Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster at jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown at nasa.gov

Sara Hammond 520-626-1974
University of Arizona, Tucson
shammond at lpl.arizona.edu

2008-133
Received on Tue 15 Jul 2008 08:53:49 PM PDT