The International Space Station (ISS) hits 20 years of continuous human habitation this fall, and NASA aims to make the most of the years the orbiting lab has left.
The astronaut complex is in great shape, agency officials have stressed, and it just received a set of battery upgrades to keep going for a while. Within months, operational commercial crews will expand the station's capacity for research as more astronauts per spacecraft pour into the facility. The Trump administration and NASA are also ramping up efforts to fly private astronauts and add private modules to the ISS.
While activity hums along on station, the end of the station program is still officially pegged at 2024. But NASA and other international partners are discussing an extension to at least 2028.
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"The ISS is an amazing tool, and of course where we are right now, we're going to use it for the maximum extent possible for as many years as we have left with it," NASA Administrator Jim Bridenstine said today (Aug. 27) during a presentation at the ISS Research & Development conference, which was broadcast online.
"We don't know when it [the station program] will end," he added. "We know it can't last forever."
Such discussions about the future of the ISS come as NASA plans an ambitious agenda in space in the coming years. NASA will celebrate the 20th anniversary of a continuous human presence on the space station on Nov. 2, marking two decades since Expedition 1 began on a much-smaller version of the ISS for a multi-month stay. (Assembly of the orbiting lab began in 1998, but it would be another two years before the ISS started hosting crews continuously.)
For the future, NASA is working to land astronauts on the moon again in 2024, with the help of commercial spacecraft funded through the Commercial Lunar Services Program. The agency also plans, outside the "critical path" of moon landings, to build a small space station near the moon called Gateway. Gateway has already attracted some international partners, such as Canada's commitment to provide a Canadarm3 robotic arm.
All of these projects, however, are dependent upon ongoing Congressional funding. NASA doesn't yet have its budget finalized for fiscal year 2021 as it is still being approved by the House and the Senate, and challenges loom due to the uncertain economic environment from the coronavirus pandemic, along with the outcome of the presidential election this November.
The ISS R&D conference did not focus on these uncertainties, instead discussing how NASA can make the most of the opportunities available on the orbital lab while the agency's funders and partners discuss the station's future.
Kathy Lueders, the newly appointed leader of NASA's human spaceflight efforts, said the station has supported over 3,000 investigations from 108 countries since its foundation, a scientific record she deemed "amazing." Lueders paid tribute to the station's legacy of running long missions for astronauts, which typically range between six months and a year each.
The ISS is the first facility capable of supporting multi-month crew expeditions since the Soviet/Russian Mir space station, which was deorbited in 2001. Such long-term flights investigate astronaut health metrics such as muscle strength, bone density and gene expression alterations in space and will prepare NASA and its partners for human missions to the moon and Mars, agency officials have said.
"We are still figuring out the way, and we'll be unlocking the secrets of long-duration spaceflight," Lueders said. "This [ISS] is a critical place for us to continue to figure out how to fly people in space for a long time."
What happens to U.S. research in space in the post-ISS era, whenever that comes, remains to be determined, although NASA officials emphasized in the conference that the agency will not be in charge of whatever orbiting facility takes its place. Commercializing research was also a focus of several discussions.
That said, Marybeth Edeen, the manager of the ISS research integration office, urged NASA and its partners to continue with fundamental research "in the interim." Fundamental research is distinct from commercial research, as the fundamental work is performed without immediate expectation of a financial return.
"At this point, there is a lot of work going on to commercialize low Earth orbit and create commercial activities and services, but those commercial capabilities need to be tempered to continue the research we started in the last decade," Edeen said.
She noted that future research should also consider "NASA's needs for exploration" and the needs of government partners such as the U.S. National Science Foundation that study medical applications of space research.
"We're trying to facilitate … commercial capabilities when available, but also to continue the research," Edeen added.
Crew time has traditionally been the brake on research, Edeen said. Space station crews have been smaller since the seven-astronaut space shuttle retired in 2011, meaning that routine station maintenance such as cleaning and minor repairs take a greater share of crew time. She said she is hoping that larger commercial crews will address the situation in the near term.
Related: The Expedition 63 mission to the International Space Station (photos)
Key metrics overall for research should increase in the next five years, however. Alex MacDonald, NASA's chief economist and ISS National Lab Program executive, said the agency is expecting more money from other government agencies, more money from the private sector for early-stage research, more students engaging with ISS science and more applications in space that can be used on Earth.
Ken Shields, chief operating officer of the Center for the Advancement of Science in Space (CASIS), which manages the U.S. National Laboratory on the station, added that a new external user advisory committee will help tweak the laboratory's needs for users in the coming years.
At least one NASA official warned that there's at least one other potential danger to the ISS in addition to funding and political uncertainties — mechanical failure.
"ISS could have an unrecoverable major contingency at any time," said Phil McAlister, NASA's commercial spaceflight program director. McAlister didn't say what would constitute a dramatic failure, but common dangers in human spaceflight include fire, depressurization and failure of major systems.
ISS does have an ace in its pocket, as crews and robots alike can perform repairs when systems fail. Astronauts (working with ground teams) have overcome large problems on the station before, such as repairing critical ammonia coolant leaks from time to time, and securing the station's power by fixing a ripped solar panel that initially refused to deploy properly in 2007.
NASA cannot say how long the ISS will last because that is up to the stakeholder partnership, McAlister said. (NASA is one of 15 partners in the ISS program.) But he noted the agency is looking ahead to having other commercial facilities available in space after the ISS.
"At some point, we will incrementally phase down ISS operations," he said.
At the same time, NASA will work with commercial partners to have new commercial-run facilities ready to take the station's place, he said.
"It will not be a turn-the-light-switch kind of situation," McAlister said.
Follow Elizabeth Howell on Twitter @howellspace. Follow us on Twitter @Spacedotcom and on Facebook.