NASA’s Phoenix Mars Lander has ended operations after repeated attempts to contact the spacecraft were unsuccessful. A new image transmitted by NASA’s Mars Reconnaissance Orbiter (MRO), looking down on Phoenix from orbital height, shows signs of severe ice damage to the lander’s solar panels.
“The Phoenix spacecraft succeeded in its investigations and exceeded its planned lifetime,” said Fuk Li, manager of the Mars Exploration Program at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Although its work is finished, analysis of information from Phoenix’s science activities will continue for some time to come.”
Last week, NASA’s Mars Odyssey orbiter flew over the Phoenix landing site 61 times during a final attempt to communicate with the lander. No transmission from the lander was detected. Phoenix also did not communicate during 150 flights in three earlier listening campaigns this year.
Earth-based research continues on discoveries Phoenix made during summer conditions at the far-northern site where it landed May 25, 2008. The solar-powered lander completed its three-month mission and kept working until sunlight waned two months later.
Phoenix was not designed to survive the dark, cold, icy winter. However, the slim possibility that Phoenix had survived could not be eliminated without listening for the lander after abundant sunshine returned.
The MRO image of Phoenix taken this month by the High Resolution Imaging Science Experiment, or HiRISE, camera on board the spacecraft suggests the lander no longer casts shadows the way it did during its working lifetime.
“ ‘Before’ and ‘after’ images are dramatically different,” said Michael Mellon of the University of Colorado in Boulder, a science team member for both Phoenix and HiRISE. “The lander looks smaller, and only a portion of the difference can be explained by accumulation of dust on the lander, which makes its surfaces less distinguishable from surrounding ground.”
Apparent changes in the shadows cast by the lander are consistent with predictions of how Phoenix could be damaged by harsh winter conditions. It was anticipated that the weight of a carbon-dioxide ice buildup could bend or break the lander’s solar panels. Mellon calculated that hundreds of pounds of ice probably coated the lander in mid-winter.
During its mission, Phoenix confirmed and examined patches of the widespread deposits of underground water ice detected by Odyssey, and identified a mineral called calcium carbonate that suggested occasional presence of thawed water. The lander also found soil chemistry with significant implications for life and observed falling snow. The mission’s biggest surprise was the discovery of perchlorate, an oxidizing chemical on Earth that is food for some microbes and potentially toxic for others.