On July 17, NASA and SpaceX outlined a plan to deorbit the International Space Station (ISS) and drop its remnants into the ocean, ideally at the beginning of 2031 when the station reaches its 32-year milestone. The space agency rejected other options such as dismantling the station and bringing everything back home or handing over the keys to someone else.
Earlier in June, NASA awarded SpaceX an $843 million contract to deorbit the ISS, the largest structure ever built in space.
Why Destroy the Space Station?
The International Space Station is showing signs of “aging.” Russia and the United States launched the first components of the station at the end of 1998, with astronauts moving in two years later. Europe and Japan contributed their own parts to the station, while Canada provided the robotic arm.
The ISS has grown to the size of a football field, with a mass of approximately 430,000 kg. NASA estimates that the station will remain operational at least until 2030. By then, they hope that private companies will be able to launch their own space stations, with NASA as one of many customers.
The International Space Station flying at an altitude of over 400km above the Nile River plain in Egypt. (Photo: NASA).
This strategy will allow NASA to focus time and resources on lunar and Mars tourism. NASA could also decide to extend the life of the station if no commercial outposts are established there, in order to ensure uninterrupted scientific research.
Why Not Bring the Space Station Back to Earth?
NASA has considered dismantling the space station and bringing each part back to Earth or allowing private companies to salvage individual components for their own planned projects.
However, NASA stated that this space station was not designed for the idea of being dismantled in orbit, and any such efforts would also be costly and pose risks to astronauts handling the disassembly. Furthermore, there are no spacecraft like the Space Shuttle, which was retired in 2011, to bring everything down. Another option was to move the space station to a higher, more stable orbit, but that was also dismissed due to logistical issues and the increased risk of space debris.
How to Deorbit the Space Station?
To maintain its orbit at an altitude of about 420 km, the space station needs to be boosted by visiting spacecraft periodically. If these spacecraft stop visiting, the station will gradually descend until it uncontrollably falls out of orbit.
NASA wants to ensure that the space station safely reenters over a remote area of the South Pacific or possibly the Indian Ocean, meaning that NASA will launch a spacecraft that connects with the station and guides it toward the ocean landing site.
They hope to recover some debris from the station, ranging in size from a microwave to a car, in a landing area up to 2,000 km long. NASA and its partners have considered using three Russian spacecraft for this task but require a more powerful spacecraft. By June, SpaceX had secured the contract for this mission.
What Will the Deorbiting Spacecraft Look Like?
SpaceX plans to use the Dragon spacecraft, which is used to carry supplies and astronauts to the space station but has a larger cabin, equipped with a record 46 engines and over 16,000 kg of fuel.
Sarah Walker from SpaceX stated that the challenge will be to create a spacecraft powerful enough to guide the space station while countering the increasing drag and atmospheric resistance during the final descent. According to NASA, this spacecraft will require a particularly powerful rocket just to reach orbit.
The spacecraft will be launched 1.5 years before the station is scheduled to cease operations. Six months before the station is destroyed, the crew will return home. When the station descends to an altitude of about 220 km, Dragon will bring the station down four days later.
NASA aims to bring back some small items from the space station for display in a museum, such as the ship’s bell and logbook, as well as other memorabilia. These items could be sent down on SpaceX supply missions in the last one or two years of operation.
