NASA's Phoenix to collect soil sample in advance of winter

London, September 6 : NASA's Phoenix Mars Lander will take a second stab at collecting ice from the bottom of the 'Snow White' trench on the Red Planet, in advance of winter.

According to a report in New Scientist, this time, researchers will attempt to keep the sample out of direct sunlight so the sample does not stick to the scoop.

The Phoenix Lander will try to stockpile soil samples as quickly as possible to make the most of diminishing solar power as the Martian winter approaches. But making full use of the Lander's instruments may require an additional extension of the mission.

Less sunlight and new technical problems have prompted Phoenix team members to revise their strategy for the Lander's TEGA (Thermal and Evolved Gas Analyzer) instrument, which cooks soil samples and looks for evidence of organic compounds as well as minerals that have been formed by liquid water.

The new plan is to place samples in the remaining four TEGA ovens, or cells, and conduct preliminary analysis by the end of September.

"The strategy is to get all the cells filled as quickly as possible," said project manager Barry Goldstein of NASA's Jet Propulsion Laboratory in Pasadena, California.

Each sample will be heated at the lowest setting to vaporise any water - a key target of study - and dry out the sample for more analysis.

But experiments at higher temperatures, which can reveal the presence of chemicals such as perchlorate, will wait until October.

Since Phoenix's mission, which was already extended once, is set to end at the end of September, NASA is currently working on an agreement to extend the mission further to accommodate those tests, according to Goldstein.

The next sample to be delivered will be icy soil from one of the first trenches Phoenix ever dug, dubbed 'Snow White'.

Phoenix's first attempt to deliver ice to TEGA was foiled in July, when the Sun seemed to partially melt the ice-bearing soil, causing it to stick to the walls of the scoop at the end of the Lander's robotic arm.

"To circumvent the problem, the digging in Snow White is planned for early in the Martian morning," said robotic arm lead scientist Ray Arvidson.

The grinding rasp at the end of the robotic arm will be used to shave off bits of the ice, which the scoop will then collect.

To deliver the sample to TEGA, the arm will be manoeuvred so it will keep the sample out direct contact with the Sun as much as possible.

ANI