Astrobiology on a Dime (… Relatively)


December 12, 2010

By Danny Freedman

Riding a blast of fire, a rocket carrying experiments for a GW researcher shot into space last month, streaking across the Alaska sky until it finally disappeared into the blue.

“So far so good,” says Pascale Ehrenfreund, a research professor of space policy and international affairs, after contact was established with the satellite a few days following its Nov. 19 launch.

Dr. Ehrenfreund is the project scientist for the six-month NASA mission, which researchers hope will help pave the way for broader use of pint-sized “nanosatellites” in astrobiology—the study of life in the universe—as they emerge as useful tools in other scientific fields.

The autonomous nanosatellite (named Organism/Organic Exposure to Orbital Stresses, or O/OREOS) is carrying two independent scientific experiments—a first for a NASA nanosatellite.

Just 19 minutes or so after the launch, O/OREOS separated from the rocket and entered orbit some 400 miles above the Earth.

There, both experiments initiated automatically. One is growing and monitoring two microorganisms—including a “salt-loving bacteria” (Halorubrum chaoviator), which thrives in such extreme environments that some think it could exist on Mars—as they are exposed to intense radiation and weightlessness; the other experiment is studying the stability of four organic molecules under various types of radiation in space.

These molecules range from amino acids—which are among the building blocks of life on Earth, and have been found in meteorites—to polycyclic aromatic hydrocarbons, which form whenever organic materials are burned (like fuel, toast, meat and cigarettes) and are found throughout the universe.

The experiments are planned to last for six months, with data sent back to Earth weekly. The satellite will slowly veer toward a fiery end using NASA’s first de-orbit mechanism to require no propellant: when it separated from the rocket, an extension deployed from the satellite’s back end that increased the satellite’s surface area and drag, sending O/OREOS into a 22-year fall back toward Earth’s atmosphere.

O/OREOS is among a class of nanosatellites known as “cubesats,” owing to their boxy shape, which typically measures just under four inches per side. These tiny flyers are of great interest to researchers, who see them as opening the door to less expensive cosmic research that can be conducted much more frequently.

Case in point: O/OREOS, which comprises three cubes together—one for electronics, and one for each of the two experiments—is roughly the size of a loaf of bread and weighs just 12 pounds; it was able to essentially hitchhike into space on a rocket already heading there to deliver a Department of Defense satellite.

Beyond the cost savings of piggybacking (O/OREOS was among several satellites on the rocket), Dr. Ehrenfreund says the NASA mission builds on two earlier cubesats and offers scientists a new platform for space-based astrobiology research.

Constructing and launching a full-scale satellite can cost in the ballpark of $200 million, according to a recent paper co-authored by Dr. Ehrenfreund and collaborators at GW and NASA’s Ames Research Center. “Cubesats are a relative bargain,” the authors write in the article, published online in October in the journal Advances in Space Research.

By comparison, O/OREOS cost $2.5 million—other cubesats, including ones built by college students, have cost even less.

Looking ahead, the authors write, cubesats have the potential to become “aerospace technology for the masses.”

While the number of cubesats in orbit is fewer than three dozen, the authors write, around 80 universities worldwide are aiming to develop them, as are governments. “Many countries in the world, from Azerbaijan to Venezuela, are trying to build cubesats,” says Dr. Ehrenfreund.

Developing countries for now are focusing on gaining tangible human benefits, she says, like utilizing cubesats for communications and disaster management. But over the long-term, this new realm also is giving them a toe-hold on space-based research and an opportunity to foster home-grown scientists, engineers and businesses.

The sting of the current economic climate—“nobody has enough money anymore”—is encouraging collaboration among nations, says Dr. Ehrenfreund, in order to further explore the space around Earth, the Moon and Mars.

“You need a grand support structure,” she says, and involving interested developing countries will help. “It’s like a bottom-up approach for global space exploration.”

But even more than a way around financial constraints, cubesats are a boon for the relatively quick access they provide to space science. “What’s so cool on this kind of mission,” she says, “is that a student can actually work on it … and then actually see it fly and analyze the data.”

At a time when full-scale space missions require a running start of perhaps a decade or more—Dr. Ehrenfreund is now working with NASA on a Mars mission slated for 2018—and involve relatively few people, these smaller missions in-between keep “the community active and educate a new generation so the knowledge isn’t lost.”