Phoenix Lander termina

Enviado por admin el Mar, 2008-11-11 23:00.

Nov. 10, 2008

NASA RELEASE: 08-284

MARS PHOENIX LANDER FINISHES SUCCESSFUL WORK ON RED PLANET

WASHINGTON -- NASA's Phoenix Mars Lander has ceased communications after
operating for more than five months. As anticipated, seasonal decline in
sunshine at the robot's arctic landing site is not providing enough
sunlight for the solar arrays to collect the power necessary to charge
batteries that operate the lander's instruments.

Mission engineers last received a signal from the lander on Nov. 2.
Phoenix, in addition to shorter daylight, has encountered a dustier sky,
more clouds and colder temperatures as the northern Mars summer
approaches autumn. The mission exceeded its planned operational life of
three months to conduct and return science data.

The project team will be listening carefully during the next few weeks
to hear if Phoenix revives and phones home. However, engineers now
believe that is unlikely because of the worsening weather conditions on
Mars. While the spacecraft's work has ended, the analysis of data from
the instruments is in its earliest stages.

"Phoenix has given us some surprises, and I'm confident we will be
pulling more gems from this trove of data for years to come," said
Phoenix Principal Investigator Peter Smith of the University of Arizona
in Tucson.

Launched Aug. 4, 2007, Phoenix landed May 25, 2008, farther north than
any previous spacecraft to land on the Martian surface. The lander dug,
scooped, baked, sniffed and tasted the Red Planet's soil. Among early
results, it verified the presence of water-ice in the Martian
subsurface, which NASA's Mars Odyssey orbiter first detected remotely in
2002. Phoenix's cameras also returned more than 25,000 pictures from
sweeping vistas to near the atomic level using the first atomic force
microscope ever used outside Earth.

"Phoenix not only met the tremendous challenge of landing safely, it
accomplished scientific investigations on 149 of its 152 Martian days as
a result of dedicated work by a talented team," said Phoenix Project
Manager Barry Goldstein at NASA's Jet Propulsion Laboratory in Pasadena,
Calif.

Phoenix's preliminary science accomplishments advance the goal of
studying whether the Martian arctic environment has ever been favorable
for microbes. Additional findings include documenting a mildly alkaline
soil environment unlike any found by earlier Mars missions; finding
small concentrations of salts that could be nutrients for life;
discovering perchlorate salt, which has implications for ice and soil
properties; and finding calcium
carbonate, a marker of effects of liquid water.

Phoenix findings also support the goal of learning the history of water
on Mars. These findings include excavating soil above the ice table,
revealing at least two distinct types of ice deposits; observing snow
descending from clouds; providing a mission-long weather record, with
data on temperature, pressure, humidity and wind; observations of haze,
clouds, frost and whirlwinds; and coordinating with NASA's Mars
Reconnaissance Orbiter to perform simultaneous ground and orbital
observations of Martian weather.

"Phoenix provided an important step to spur the hope that we can show
Mars was once habitable and possibly supported life," said Doug
McCuistion, director of the Mars Exploration Program at NASA
Headquarters in Washington. "Phoenix was supported by orbiting NASA
spacecraft providing communications relay while producing their own
fascinating science. With the upcoming launch of the Mars Science
Laboratory, the Mars Program never sleeps."

The University of Arizona leads the Phoenix mission with project
management at JPL and development partnership at Lockheed Martin
Corporation in Denver. International contributions came from the
Canadian Space Agency; the University of Neuchatel, Switzerland; the
universities of Copenhagen and Aarhus in Denmark; the Max Planck
Institute in Germany; the Finnish Meteorological Institute; and Imperial
College of London.

For additional information about Phoenix mission findings, visit:

Phoenix Mars Mission, NASA