NASA plans ‘continuous heartbeat’ in space after ISS retirement

The International Space Station (ISS) has served as home to astronauts for almost 30 years, but the aging spacecraft will retire at the end of the decade, leaving behind a significant void in low-Earth orbit. NASA hopes to fill that gap with a commercial version of the ISS. Until that happens, however, the space agency remains steadfast in maintaining a human presence in the microgravity environment to stay on track toward landing astronauts on Mars.

POT released the final version of its “Low Earth Orbit Microgravity Strategy,” which highlights the need to send long-term human missions to space after the retirement of the ISS. The space agency called its strategy “continuous heartbeat,” a seemingly odd choice of words to convey the need for “long-duration flights of six months to a year to mitigate the risks of future trips to Mars,” NASA wrote. “Flights of 30 days to six months will also have limited value,” the space agency added.

The key to these missions is the human part. “During the transition of the (ISS) to future commercial space stations, NASA will maintain a constant and continuous presence in low Earth orbit,” the report reads. “This uninterrupted pace of human activity will allow NASA to reduce the risk of sending humans to Mars, preserve critical operational skills, maintain a constant transportation cadence, continue advancing science, and maintain engagement with commercial and international partners.”

NASA and its partners plan to retire the ISS by 2030; The space station is destined for a fiery re-entry through Earth’s atmosphere, where most of it will burn up. In 2021, the space agency created its Commercial Destinations in Low Earth Orbit program to build a replacement in the coveted spot left by the ISS. NASA, however, is no longer in the business of building space stations. Instead, it simply wants to be a customer and help its business partners build and operate a space station that their astronauts can use.

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

“Through the (ISS), NASA has demonstrated that microgravity research is essential to advancing both our knowledge of ourselves and our planet,” the report reads. “As we approach the transition from the space station to commercial platforms in low Earth orbit, NASA must allow the government to use these platforms for further research and development across a spectrum of national objectives that strengthen economies and improve the quality of life here on Earth. for all people.”

The new strategy also highlights the need for “supplier diversity,” suggesting that NASA wants to rely on more than just SpaceX to transport its crew and cargo to low-Earth orbit. The space agency is still in the process of certifying Boeing’s Starliner program following its failed test flight this year.

The ISS retirement and subsequent transition phase reflect NASA’s own transition to relying on its commercial partners to maintain its presence in space.