Eight months have passed since NASA astronaut Scott Kelly and Russian cosmonaut Mikhail Kornienko returned to Earth after a nearly year-long mission aboard the International Space Station. During that time, the long-duration fliers have completed a series of follow-up tests, and American and Russian scientists have been busy working on data collected before, during and after the extended space mission. Researchers plan to present preliminary results at a scientific meeting in January.
However, the one-year mission was just the beginning. NASA’s Human Research Program, which supports safe and productive space travel, has begun to devise follow-up missions to ensure it knows enough about extended stays in microgravity before astronauts venture into deep space for extended periods of time. And as important as Kelly and Kornienko’s data are, a study with only two participants leaves scientists unable to draw meaningful conclusions.
“It’s just not enough,” said William Paloski, the director of the Human Research Program at NASA’s Johnson Space Center. “To extrapolate, we need more time in space and more observations. We started additional missions two years ago.” The question is how best to collect that extra data.
Five more missions
Paloski told Ars that the space agency plans to fly five additional one-year missions aboard the International Space Station with a similar setup to the Kelly-Kornienko flight. Each mission includes a Russian and a US or international partner astronaut. NASA hopes to embellish the one-year missions by flying simultaneous six-month and six-week missions to directly compare the astronauts’ health effects. The candidate pool for these one-year missions will be expanded to include female and novice astronauts.
NASA hasn’t finalized those plans yet, Paloski said, because the agency is still working out some logistical issues with Russia and its international partners. But under the current plan, the next one-year mission should begin no earlier than September 2018. The five additional one-year missions would be completed before 2024, the nominal end of the space station’s lifespan. One or more of them may overlap.
In talks with NASA, the Russian space agency has suggested even more dramatic missions, Paloski said. It has proposed a simulated mission to Mars in which a crew would go to the station for six months to replicate the travel time to Mars, land on Earth in isolation for three to six months, and then be launched into space for another six months to complete the flight. back” to Earth from Mars. However, from a scientific and pragmatic point of view, NASA prefers a one-year mission.
Is a year long enough?
At a subcommittee meeting of NASA’s Advisory Committee earlier this month, former Space Shuttle Program Manager Wayne Hale asked Paloski why the space agency was considering missions no longer than a year to truly reflect the time astronauts would have to spend off Earth if they did. . go to Mars or other destinations beyond the cislunar orbit. “It seems to me that you’re not there yet with determining the health factors for a 30-month trip,” Hale said.
In a follow-up interview, Human Research Program chief scientist John Charles explained to Ars that from a logistical and scientific point of view, the one-year missions offered a reasonable compromise. The station likely has seven years to go, and due to advanced scheduling requirements, at most a single mission of two or three years could fly in that time. Not only would this have a negative impact on crew rotation, there is also the issue of statistical significance of just two data points.
“Hell, we biologists like statistical validity,” explains Charles. “We’ve discussed it internally and really think we’ll try our luck getting five more one-year missions over the life of the station, to get a statistically significant database.”
Paloski also said he believes a one-year mission should be enough to absorb most of the physiological and psychological risks associated with long-duration missions. In addition, the station is not the best testbed for some spaceflight hazards, such as radiation and communications delays. For those threats, NASA will likely have to conduct long-duration missions in cislunar space, near the Moon, which is far enough away to be exposed to those hazards but still only a few days from Earth in case of need.
To that end, NASA has begun working with six different contractors on concepts for deep space “habitats,” one of which could be delivered to cislunar space in the 2020s. For now, NASA plans to fly a year-long mission aboard this deep-space habitat by 2030.