Mission scientists are treating the UA-led Phoenix Lander’s much-anticipated delivery of ice-rich soil to its test ovens with extra caution after the team discovered a short circuit in the instrument.
According to a statement released July 1, a team assessing ‘Phoenix’ discovered a short circuit in its Thermal and Evolved Gas Analyzer (TEGA) and concluded that another short circuit could occur when it 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 in the statement. Smith leads the mission as its principal investigator.
‘Phoenix’ was sent to Mars in large part to analyze ice just underneath the surface of its polar regions and to determine if the Martian soil supports the conditions necessary for life. TEGA is used to “”bake”” soil samples in its ovens and then “”sniff”” any gases that they might release to analyze the soil’s content.
‘Phoenix’ team members believe that the short circuit was caused when one of TEGA’s ovens was vibrated repeatedly over several days in order to break up clumpy
Martian soil and deliver it to the oven.
Delivery to any TEGA oven requires
vibration, but the first soil samples taken by ‘Phoenix’ needed a few extra shakes because the soil was clumpier than what scientists had expected.
Even if TEGA cannot be used after its next experiment, ‘Phoenix’ has a host of other scientific instruments at its disposal for its 90-day mission, including an optical microscope, wet chemistry lab and meteorological station.
Mission officials said that extensive tests are going to be conducted to make sure that TEGA gets an oven full of ice-rich soil. The team has to prepare ‘Phoenix’ to deliver any samples quickly so that no ice evaporates in the extremely cold and dry Martian environment during the delivery process.
According to a statement released yesterday, ‘Phoenix’ started scraping for ice on Monday to find the best way to deliver a sample to TEGA. Sampling Martian ice is easier said than done, however, because of its hardness, said Ray Arvidson who leads the mission’s robotic arm team. He compared scraping up Martian ice to scraping up a sidewalk.
“”We expected ice and icy soil to be very strong because of the cold temperatures. It certainly looks like this is the case,’ Arvidson said.
‘Phoenix’ did manage to scrape up two small piles of icy material after scraping the surface 100 times on Monday. Because the piles were so small, less than four teaspoonfuls of material, the lander’s robotic arm had difficulty collecting the samples into its scoop.
“”It’s like trying to pick up dust with a dustpan, but without a broom,”” said Robotic Arm team member Richard Volpe.
In the meantime, the ‘Phoenix’ team will continue practicing to find the best way to sample the long-sought-after ice. The team will begin testing ways that ‘Phoenix’ can use a high-speed motorized rasp on its robotic arm to scrape at the collect samples from the hard surfaces. Team members will begin testing these methods at their Payload Interoperability Testbed which uses a working model of ‘Phoenix’ to practice mission maneuvers here on Earth.
Currently, ‘Phoenix’ continues to analyze the Martian surface with its other available instruments. Mission officials announced Sunday that a second soil sample was delivered to the lander’s wet chemistry lab, which will be analyzed this week. The results will be compared to the lab’s first sample, which showed that the Martian soil contains some of the basic nutrients needed for life.
