News of Mars Water Discovery Is Just What ODU Aerospace Engineer Wanted to Hear

The announcement by NASA on Thursday, July 31, that its Phoenix lander had identified water in a Mars soil sample was just what Old Dominion University aerospace engineer Robert Ash has been waiting to hear.

Phoenix's robotic arm, after some false starts, was able to deliver a soil sample to a tiny oven, and, when heated, the sample produced water vapor. This was confirmation that a large band of water ice sits just under the surface of the plain where the lander set down.

For a variety of reasons, NASA has a stated goal in Mars exploration to "follow the water." Discoveries of widespread deposits of water ice will encourage scientists who believe life exists or has existed on the fourth planet from the Sun. Also, easy access to water at suitable landing sites might also promote the notion that Mars could support a human colony.

To Ash, however, H2O is more than just a molecule essential for life on Mars. The water ice (differentiated from frozen CO2 gas, or dry ice) scooped up by the Phoenix robotic arm could spark new interest in a 30-year-old report he wrote while he was a researcher at the Jet Propulsion Laboratory (JPL) in Pasadena, Calif.

The report was produced after he and two colleagues were asked to investigate the possibility of making rocket fuel from materials found on the Martian surface. For NASA to manage a return mission from Mars to Earth, carrying samples collected or mined by robots, and also perhaps carrying the first humans to set foot on the planet, the fuel for the return trip more than likely would have to be created on Mars.

Fuel weighs too much to be easily transported from Earth to Mars for the return trip, and, besides, NASA prefers not to have a spacecraft make a 200-day trip to Mars carrying both astronauts or hard-to-replace equipment together with highly volatile rocket fuel.

In their 1978 report, Ash, with JPL's Warren Dowler and Giulio Varsi, explain how rocket fuel could be produced from the CO2-rich Martian atmosphere and available water. (Ash, R. L., W. L. Dowler and G. Varsi, "Feasibility of Rocket Propellant Production on Mars," Acta Astronautica, Vol. 5, pp. 705-724, 1978.)

The proposed approach came to be known as in situ resource utilization, or ISRU, but it didn't get much attention until NASA published a baseline manned Mars mission design in 1997 that incorporated the researchers' approach. "Still, in situ resource utilization seems always to be just over the horizon for NASA," Ash explained in an interview earlier this summer. One reason is the lack of proof that sufficient water could be tapped at sites selected as Mars staging locations.

Ash noted that water in clouds over Mars or in surface samples tested during previous Mars missions is present in very small amounts and could not be exploited for fuel production. On the other hand, big deposits of polar ice are inaccessible. So for his in situ plan to work, large bands of water ice need to be fairly close to the Mars surface in locations such as the flat plain where Phoenix landed. It could be dug up and heated by solar energy or some other heat source for the rocket fuel production and for other uses at a Mars station, he explained.

For now, Phoenix will put samples dug up by its robotic arm through more tests that will show, among other things, whether the water ice has ever been in liquid form, which could mean that Mars once was warmer than it is now. (Temperatures at the Phoenix landing site have ranged from around minus-22 to minus-112 degrees Fahrenheit.) The samples also will be tested for organic materials that are the building blocks of life.