NASA is planning a “continuous heartbeat” in space after the International Space Station retires

The International Space Station (ISS) has been home to astronauts for nearly 30 years, but the aging spacecraft is scheduled to retire by the end of the decade, leaving behind a gaping hole in low Earth orbit. NASA hopes to fill this gap with a commercial version of the International Space Station. Until that happens, the space agency is determined to maintain a human presence in a microgravity environment to stay on track for landing astronauts on Mars.

NASA Released The final version of the Low Earth Orbit Microgravity Strategy, which highlights the need for long-duration human missions into space after the retirement of the International Space Station. The space agency called its strategy “continuous heartbeat,” NASA wrote, a seemingly odd choice of words to express the need for “long-duration missions ranging from six months to a year to mitigate the risks of future missions to Mars.” “Flights with a duration of between 30 days and six months will also be of limited value,” the space agency added.

The key to these tasks is the human part. “During the transition from the ISS to future commercial space stations, NASA will maintain a stable and continuous presence in low Earth orbit,” the report said. “This uninterrupted rhythm of human activity will allow NASA to reduce the risks of sending humans to Mars, maintain critical operational skills, maintain a steady transportation cadence, continue to advance science, and maintain engagement with commercial and international partners.”

NASA and its partners plan to retire the International Space Station by 2030; The space station is destined for a fiery return through Earth’s atmosphere, where most of it will burn up. In 2021, the space agency established its commercial low-Earth orbit destinations program to build a replacement in the desired spot left by the International Space Station. But NASA is no longer in the business of building space stations. Instead, it simply wants to be a customer, helping its commercial partners build and operate a space station that its astronauts can use.

Companies like Axiom Space, Blue Origin, and Northrop Grumman hope to replace the ISS with their own versions, but it likely won’t be ready within five years. Instead, NASA’s strategy for those intervening years is to maintain a continued human presence in space through long-duration missions to destinations in low Earth orbit using commercially owned spacecraft. The main goal of the missions will be to continue conducting scientific research in a microgravity environment, in addition to research related to human health in space to prepare for future missions to the Moon and Mars.

“Through the International Space Station, NASA has demonstrated that microgravity research is critical to advancing our knowledge of ourselves and our planet,” the report states. “As we approach the transition from the space station to commercial platforms in low Earth orbit, NASA must enable the government to use these platforms for further research and development across a range of national goals that strengthen economies and enhance the quality of life here on Earth. For all people.”

The new strategy also highlights the need for “provider diversity,” suggesting that NASA wants to rely on more than just SpaceX to transport its crew and payload to low Earth orbit. The space agency is still in Certification process for the Boeing Starliner program After its failed test flight this year.

The retirement of the International Space Station, and the subsequent transition, reflects NASA’s shift to relying on its commercial partners to maintain its presence in space.