Contact Information: K.R. Sridhar
[email protected]

Landmark experiment produces oxygen for human use from Martian atmosphere Professor K.R. Sridhar and his 20-member team at The University of Arizona Aerospace and Mechanical Engineering (AME) Department are building an Oxygen Generating Subsystem (OGS). In January 2002, it will suck in Martian atmospheric gases -- predominately carbon dioxide -- and process them to produce pure oxygen.

"This is a landmark experiment," Sridhar says. "It is the first time in human history that we will produce a consumable of use to humans from extraterrestrial resources."

It will be the space exploration equivalent of standing on the brink of the Industrial Revolution, but with a gigantic resource base -- all the materials found on planets, their satellites, and asteroids in the solar system.

The oxygen could be used as propellant in rocket motors or for life support for humans on Mars. Since this is a demonstration experiment, the oxygen will not be put to immediate use on the Mars Surveyor 2001 lander.

But Sridhar hopes to have an experiment aboard the Mars Surveyor 2003 mission that will produce both fuel and oxygen from Martian resources. In that case, the oxygen and fuel would be used to launch a small rocket from the surface of Mars or to power a drill that would take core samples of the Martian surface.

"In the larger scheme of things, in 2007 we hope to perform a sample return mission that will rely on the propellant production technology we are developing to produce both the fuel and oxygen for a rocket to bring the sample back to earth," Sridhar says. "We are working very vigorously on this."

The OGS will fly to Mars aboard Mars Surveyor 2001, which is scheduled to land on the Red Planet on Jan. 22, 2002.

Once on Mars, it will use solid oxide electrolysis to produce oxygen. The technology is based on an electrochemical cell that works as a solid state filter for oxygen. The electrolyte used in the OGS will transfer only oxygen ions across its crystal structure.

The unit weighs about two pounds and will consume less than 15 watts of electrical power to produce more than one cubic centimeter of oxygen per minute. This is twice the amount NASA specified in its contractual requirements for the oxygen generator.

"The challenges were to miniaturize the technology and to make the process very energy efficient, while producing a device that is rugged enough to withstand launch loads up to 35 Gs (35 times the force of gravity at sea level)," Sridhar says.

The space-qualified OGS is being built entirely in the UA AME Space Technologies Laboratory, where Program Manager Matthias Gottmann is supervising a team made up of staff engineers, graduate students, undergraduates, post docs, and exchange students.

OGS construction includes producing ceramic heating elements from scratch that heat up faster and go to higher temperatures than commercially available ones.

Producing resources in situ has many advantages, Sridhar explains. "By using extraterrestrial resources, you lower the launch mass from Earth and thereby reduce the cost. You also reduce the overall risk of a mission because you can produce safety caches of valuable consumables that will be available to humans at the destination."

But, he adds, perhaps the most significant aspect of in situ resource utilization is that it is the enabling technology that will make possible permanent settlements on other planets and their satellites.

PHOTO/ASSIGNMENT EDITORS: The AME Space Technologies Laboratory includes equipment that will make good visuals. Photos of the Oxygen Generating Subsystem can be viewed online at the web site,


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