Friday, March 26, 1999 Published at 13:14 GMT
Living off the land on Mars
They'll have to make their own fuel to go home
By BBC News Online Science Editor Dr David Whitehouse
Nasa engineers have extracted oxygen from a simulated Martian atmosphere. This feat is a key step in plans for a manned mission to the red planet.
"The concept is to use the resources on Mars to reduce the amount of material that needs to accompany a human mission - to live off the land," said principal investigator David Kaplan of the Exploration Office at Nasa's Johnson Space Centre.
"Producing oxygen using materials readily available on Mars would be an important step toward reducing the costs and risks of an eventual human mission to Mars," he explained.
The experiment, called the Mars In-Situ Propellant Production Precursor, will test the feasibility of using the thin Martian atmosphere to produce oxygen for breathing air and rocket fuel.
Rocket fuel created on Mars could be used to send samples and astronauts back to Earth.
"The oxygen production technology being tested is based on sound, straightforward chemistry," said Jerry Sanders of the Johnson Space Centre's Propulsion and Fluid Systems Branch.
The test took place inside a Martian environment simulator. The Martian atmosphere is 95% carbon dioxide, almost 150 times thinner than the Earth's atmosphere and very cold, -75 Centigrade (-105 Fahrenheit).
The experimental device in the simulator selectively absorbed carbon dioxide and converted it to oxygen.
A wafer-thin ceramic disk made of zirconia is sandwiched between two platinum electrodes and heated to 750 Centigrade (1,380 Fahrenheit).
When carbon dioxide is fed in, the zirconia cell turns the carbon dioxide into carbon monoxide and oxygen. Only the oxygen can penetrate through to the other side of the disk.
The Mars Surveyor 2001 Lander is expected to provide essential information about how to carry out cost-effective human missions to Mars.
The lander's main science goal is to explore the conditions of its landing site, near the Martian equator. It will take visible and infrared pictures of the surrounding terrain and deploy a rover similar to the Mars Pathfinder's Sojourner used in 1997.