Original URL: http://www.theregister.co.uk/2007/07/10/nasa_mars_water/
NASA packs bucket and spade for new Mars mission
Going digging for ice
NASA is packing its things and getting ready for an ice-hunting trip to Mars. The space agency says it is preparing for the August 3 launch of the Phoenix lander, the first NASA mission specifically designed to touch and analyse water on the midget planet. The aim is to discover whether or not there are areas on the Martian surface that could, even now, harbour Martian microbes.
The plan is for Phoenix to land on a region of Mars with plenty surface ice: the northern, arctic plains. Once there it will dig down into the icy soil and look for signs that liquid water once flowed. The other main objectives of the mission are to determine if arctic soil could support life and to study the weather at a Martian pole.
"Phoenix has been designed to examine the history of the ice by measuring how liquid water has modified the chemistry and mineralogy of the soil," said Peter Smith, the Phoenix principal investigator at the University of Arizona.
"In addition, our instruments can assess whether this polar environment is a habitable zone for primitive microbes. To complete the scientific characterisation of the site, Phoenix will monitor polar weather and the interaction of the atmosphere with the surface."
NASA says it expects the ice layer to begin just inches below the soil. Once Phoenix has unfurled its 18 foot wide solar panels, it will start to dig down using its robotic arm. The arms is tipped with a camera and a conductivity probe to examine the surface before samples are collected and lifted to the lander's two analysis instruments.
At least one sample will be heated to check for volatiles such as water and organic molecules. The second instrument will examine the chemistry of the soil.
"Our 'follow the water' strategy for exploring Mars has yielded a string of dramatic discoveries in recent years about the history of water on a planet where similarities with Earth were much greater in the past than they are today," said Doug McCuistion, director of the Mars Exploration Program at NASA's HQ in Washington.
"Phoenix will complement our exploration of Mars by being our first attempt to actually touch and analyse Martian water water in the form of buried ice."
The timing of the launch is critical, because it determines the landing zone on Mars, and the best route to the planet. NASA has a three week launch window, opening on August 3, in which to get the lander into space on a trajectory that will hit the target. Each day of the two weeks has two possible launch times, separated by between 36 and 42 minutes.
Earth has a tighter orbit than Mars, and so once every 26 months or so it "laps" the smaller planet, passing a point of closest approach known as opposition. The best time to launch a mission to the Red Planet is a few months ahead of opposition, NASA explains, so that the amount of fuel required is minimised, and journey time is kept manageably short. The next opposition is of December 18 2007.
If Phoenix makes its launch window it will travel to Mars via the most direct route possible, and make its landing between May 25 and June 5 2008. ®