Curiosity takes first whiff of Martian atmosphere

After having successfully landed on Mars, the NASA rover, Curiosity has been busy fulfilling its mission parameters, having already sent dozens of pictures of the Martian service back to mission HQ as well as conducting numerous diagnostics on itself to see just how its equipment fares on the red Planet.

Now the rover has taken its first whiff of the Martian atmosphere, having conducted its first chemical test on Mars, using its onboard sensors to ‘sniff’ the Martian air. Using its Sample Analysis at Mars (SAM) instrument, the rover, much like a human would do, took in a ‘breath of Martian air, feeding into the SAM so that a chemical composition test could be conducted. This is the first time since the Viking probes of the 1970s that a chemical test of Mars’ atmosphere has been conducted. The test will reveal the different concentration of gases in the Martin atmosphere and while scientists already know that the air on Mars is predominantly carbon dioxide, NASA scientists are keen to note whether Curiosity will pick up any traces of the gas, methane.

Methane is of importance the scientists because it suggests that there is a source on the planet that is producing it. Because it is a gas that is ‘short-lived’ it needs a source to replenish it, either biological or geochemical and while satellites and telescopes have both detected methane in the Martian atmosphere, it will be interesting to see what Curiosity reveals.

Curiosity deputy principal scientist Joy Crisp spoke about the methane finding, saying that announcement of the results will most likely be next week but that nothing definitive will be offered for the time being,”When SAM is at its best it can measure various parts per trillion of methane, and the expected amounts based on measurements taken from orbit around Mars and from Earth telescopes should be in the 10 to a few 10s of parts per billion. But it's so early in the use of SAM, which is a complicated instrument, and we have to sort through the data."

Meanwhile the Mars Science Laboratory has been conducting a couple of diagnostic tests to see how its equipment works on Mars, which has reduced gravity. Presently engineers are testing Curiosity’s 2m-long robotic arm. Housing 30kg’s worth of equipment, the arm is being tested to see its function in Mars’ reduced gravity. Lead engineer on Curiosity's arm, Matt Robinson explains, "Mars has about 38% of Earth gravity. Under Earth gravity, the arm sags to a certain position. On Mars, if you were to command the arm to the exact same joint angles, the turret would be at a higher position than it was on Earth. To compensate, we have flight software that does the mathematics to position the arm lower to recreate the exact same pose of the turret with respect to the hardware on the rover. So a big part of this exercise is to verify that flight software is doing that compensation properly.”

Engineers will next start testing the array of instruments on the arm including the MAHLI (Mars Hand Lens Imager), the APXS, an X-ray spectrometer as well as the arms scooper, used for collecting soil samples.