Powered flight tests are slated later this year for SpaceShipTwo, a craft built to carry humans on brief excursions more than 100 kilometers into space. And although publicity indicates that these travelers will be rich thrill-seeking "space tourists," some of them are, in fact, going to be scientists, engineers, and probably even graduate students on funded research programs, according to S. Alan Stern, a scientist now spearheading the development of this new concept.
SpaceShipTwo is the descendant of SpaceShipOne, the X-Prize–winning craft designed by Burt Rutan and Scaled Composites. Now funded by Virgin Galactic, the space company owned by British aviation mogul Sir Richard Branson, the new vehicle was geared to wealthy adventurers willing to pay US $200 000 for a ride into space.
But an entirely new category of passengers has recently emerged. These space commuters would use the flights to expand on research that has been performed since the 1950s aboard unmanned sounding rockets. The combination of the advantages a human experimenter has over a robotic one and the competitive cost of a ticket on SpaceShipTwo make such research flights an attractive idea.
Stern intends to be one of those experimenters and to fly on multiple missions in support of research customers. A veteran planetary scientist and once the director of NASA's sounding rocket program, Stern is now an associate vice president with the Southwest Research Institute (SWRI), headquartered in Austin, Texas. He recently helped organize a conference in Orlando, Fla., to promote the concept of expanding standard lab work to the space environment. Stern sees this new era of human space research as revolutionary in its ease and economy. "The infrastructure is like flying on the K-bird" [NASA's KC-135 zero-g aircraft], he says. "It's never complicated or burdensome," as space shuttle–based science has proved to be. Repeated flights with fast turnaround will revolutionize the field, he believes.
As with all space science, robots and other automation are options, but Stern thinks they are not good ones. Automation takes time, costs money, and restricts what is likely to be learned, he asserts. "NASA spends $50 million a year on sounding rockets and performs 20 to 25 missions," he told IEEE Spectrum. "That's an average cost of $2.5 million per flight." A single seat on a space tourist vehicle provides the equivalent duration and altitude for one-tenth as much.
Like scientific sounding rockets, tourist flights on SpaceShipTwo could perform observations of the upper atmosphere and of the sun and other celestial objects. Onboard apparatus could also exploit the approximately 4 minutes of pure microgravity to explore physical features ranging from fluid and flame dynamics to simulations of the dust clumping that led to the formation of planets.
Beyond that, such flights could help troubleshoot and validate crew equipment—including scientific instruments, tools, and other mechanisms—intended for later long-term use on the International Space Station. This process alone, says Stern, could speed up improvements to space gear while significantly reducing costs.
SWRI has signed a contract with Virgin Galactic for a number of flights by Stern and two other researchers, beginning as early as next year. Already, SWRI has developed three flight-ready experiments to help characterize the capabilities of on-the-scene researchers as well as produce genuine scientific results. One is a self-contained ultraviolet telescope that's aimed and activated manually.
In addition to Virgin Galactic, other carriers, such as XCOR Aerospace, in Mojave, Calif., have begun designing payload accommodation features on their vehicles. These include in-cabin experimental setups and racks for mounting instruments outside the pressurized cabin. There could also be dispersal mechanisms for chemical tracer releases that allow measurements of the upper ionosphere—the most poorly explored region of Earth's atmosphere.
"There is a market for commercial payload specialists," Stern says. In addition to performing experiments for clients, his team will provide flight escorts for those who want to fly themselves, with assistance.