The last major payload delivered to the ISS by space shuttle, the AMS was designed to collect and study subatomic particles originating in space.
The international AMS team recently published its first scientific paper, reporting an usually high count of positrons that could lend weight to the theory that the particles are generated when dark matter collides and annihilates itself. But positrons may also be generated by pulsars, and researchers are happy with the long-duration exposure the AMS will receive on the station because it will add data to the statistics that will shape future conclusions about the positron sources.
The ability to repeat experiments in the same low-gravity, high-vacuum environment can also have benefits in biomedical research, materials science and Earth observation, Woerner says. His U.S. colleague, NASA's associate administrator for human exploration and operations William Gerstenmaier, believes the “tipping point” for deeper human exploration in space is likely to be reached on the ISS, since it is the only facility able to support the research that can generate a return on investment for commercial space activities. If an orbiting pot of gold or killer app is found there, it can lower the cost of access to space for all kinds of exploration (AW&ST April 1, p. 56).
Like NASA, which is relying on Casis to promote commercial exploitation of the ISS, Woerner says government's primary role is that of enabler rather than entrepreneur. “I'm not a missionary to convince industry how to make money. That's their job—[as is innovation]. We can help open the doors.”
Gerstenmaier and his colleagues in NASA's human-spaceflight endeavor may soon get a chance to open a door for Dennis Tito's ambitious plan to send a man and woman on a 501-day flight around Mars beginning in 2018. Taber MacCallum, chief technology officer for Tito's non-profit Inspiration Mars venture, says it is likely the closed-loop environmental and life support systems (ECLSS) that will be necessary for the Mars flyaround to succeed are likely to be tested on the space station. An ECLSS expert who spent two years in the Biosphere 2 experimental closed-loop habitat, MacCallum says for simplicity and speed, the Mars ECLSS will be based on station systems. And for the sake of fidelity, they will need to be tested on the station.
“That's what it's for,” MacCallum says.