Mark Carreau Houston

U.S. and Russian medical experts will draw from seven broad areas as they establish a research agenda in early 2013 for a one-year mission aboard the International Space Station (ISS) flown by NASA astronaut Scott Kelly and Mikhail Kornienko, test cosmonaut from RSC Energia.

The ISS veterans were selected in late November by the U.S. and Russian space agencies to train for the long flight expected to launch in March 2015 and potentially reveal health or performance concerns for deep-space exploration by humans.

The flight, the first of its kind since cosmonaut Sergei Avdeyev returned from a 380-day mission to what was Russia's Mir space station in August 1999, will serve as a “checkpoint” for the studies now carried out on the multinational crews that spend 4-7 months aboard the six-person ISS, according to Julie Robinson, NASA's ISS program scientist, and Igor Ushakov, director of the Institute for Biomedical Problems in Moscow.

Kelly, 48, and Kornienko, 52, will be monitored closely for the emergence of health issues not seen in their previous shorter-duration missions—impairments that could influence discussions over expeditions to the Moon, a near-Earth asteroid and Mars. An expedition to Mars, the most challenging of those destinations, would require 2-3 years roundtrip, using current propulsion technologies.

The focus areas include an intracranial pressure rise blamed for blurred vision—a recent concern discovered by U.S. researchers and affecting one-third to one-half of astronauts logging an average of 108 days in space—as well as nutrition and bone loss. The latter, first noted among NASA's Gemini crews, appears to have been overcome through diet, adequate vitamin D intake and regular, vigorous, in-space, load-bearing exercise involving resistive exercise devices.

Other focus areas include degraded immune function; neuro-vestibular changes that affect astronauts as they re-adapt to gravity; behavior, performance and interpersonal interactions; radiation exposure; and the ability to retain preflight training on missions lasting many months.

The merits of a “checkpoint” mission have yet to fully emerge. There are no plans to repeat the marathon prior to 2020, the scheduled end of station operations agreed to by the U.S.-led, 15-nation ISS partnership.