[meteorite-list] Phoenix to Bake Ice-Rich Sample Next Week

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Sat, 5 Jul 2008 21:35:51 -0700 (PDT)
Message-ID: <200807060435.VAA10385_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.cfm?release=2008-125

Phoenix to Bake Ice-Rich Sample Next Week
Jet Propulsion Laboratory
July 02, 2008

The next sample delivered to NASA's Phoenix Mars Lander's Thermal and
Evolved-Gas Analyzer (TEGA) will be ice-rich.

A team of engineers and scientists assembled to assess TEGA after a
short circuit was discovered in the instrument has concluded that
another short circuit could occur when the oven is used again.

"Since there is no way to assess the probability of another short
circuit occurring, we are taking the most conservative approach and
treating the next sample to TEGA as possibly our last," said Peter
Smith, Phoenix's principal investigator.

A sample taken from the trench informally named "Snow White" that was in
Phoenix's robotic arm's scoop earlier this week likely has dried out, so
the soil particles are to be delivered to the lander's optical
microscope on Thursday, and if material remains in the scoop, the rest
will be deposited in the Wet Chemistry Laboratory, possibly early on
Sunday.

The mission teams will mark the Independence Day holiday with a planned
"stand down" from Thursday morning, July 3, to Saturday evening, July 5.
A skeleton crew at the University of Arizona in Tucson, at NASA's Jet
Propulsion Laboratory in Pasadena, Calif., and Lockheed Martin Space
Systems in Denver, Colo., will continue to monitor the spacecraft and
its instruments over the holiday period.

"The stand down is a chance for our team to rest, but Phoenix won't get
a holiday," Smith said. The spacecraft will be operating from
pre-programmed science commands, taking atmospheric readings and
panoramas and other images.

Once the sample is delivered to the chemistry experiment, Smith said the
highest priority will be obtaining the ice-rich sample and delivering it
to TEGA's oven number zero.

In a few days, the Phoenix team will conduct tests so the instruments
can deliver the icy sample quickly, so no materials sublimate, or change
from a solid to a vapor, during the delivery process.

The short circuit was believed to have been caused when TEGA's oven
number four was vibrated repeatedly over the course of several days to
break up clumpy soil delivered to oven number 4. Delivery to any TEGA
oven involves a vibration action, and turning on the vibrator in any
oven will cause oven number 4 to vibrate as well.

The Phoenix mission is led by Peter Smith of the University of Arizona
with project management at JPL and development partnership at Lockheed
Martin, located in Denver. International contributions come from the
Canadian Space Agency; the University of Neuchatel, Switzerland; the
universities of Copenhagen and Aarhus, Denmark; Max Planck Institute,
Germany; and the Finnish Meteorological Institute. More about the
Phoenix Mars Lander is online at 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

2008-125
Received on Sun 06 Jul 2008 12:35:51 AM PDT