NASA announced the $1b tender for a spacecraft that will dock with the International Space Station and pull it down into Earth’s atmosphere as it completes its final decommissioning phase. The spacecraft is called United States De-Orbit Vehicle (USDV). The re-entry is set to take place in December of 2031. Astronauts from the U.S., Japan, Canada, and the European Space Agency (ESA) are set to move out in 2030; the Russians have opted to leave in 2028 instead.
Various plans were explored for how to dispose of the ISS safely and in the most cost-effective fashion. Pushing into a higher orbit is unfeasible due to fuel constraints & concerns over the potential failure of the station’s structural integrity; atmosphere reentry quickly emerged as the only viable path.
Originally, the plan was to use Russian Progress vessels to push the station into the new orbit. Progress model ships are unmanned cargo vessels that have frequently been used to carry supplies to the ISS; they predate the station by 20 years though and have been the workhorse of the Soviet Space Program since 1978.
Initial hopes for this plan were further explored through a year-long study NASA conducted in conjunction with its ISS partners. Ultimately, due to the results of the study, the plan was shown to be ineffective in achieving the desired result and abandoned. Doubts exist in the ether as to whether the worsening state of Russian-American relations, as well as the Russian’s plan for early departure from the ISS, played a role in the plan’s dismissal.
Instead, NASA has created the aforementioned tender for a spacecraft dubbed USDV. Due to orbit decay, the ISS is set to descend in altitude naturally and continuously in the coming years; until now the ISS would re-boost itself at intervals to stay in orbit. Once it reaches the specific altitude threshold of 280 km the final phase of the de-orbit plan will commence and the USDV will dock with the station to pull it back into Earth’s atmosphere. USDV’s final part to play is in guiding the ISS throughout the reentry process; the structures will face heavy winds and course-correcting maneuvers depend entirely on the USDV and its muscle.
The risk in the reentry process is that the station, along with the attached USDV, will begin to tumble and lose steering capabilities as they are no longer able to effectively point their engines in a given direction.
The tender for the USDV, open to American companies, allows for either a modified design of an existing spacecraft or a completely newly designed model. Bidders are offered a firm fixed price of cost plus initiative agreement to cover design, development, testing, and evaluation, then finally construction and deployment.
As the ship represents the only attempt at bringing the station down safely, NASA is making it a point to stress redundancy capabilities within the spacecraft’s systems. In addition, the USDV’s rocket engines have their own special requirements; unlike normal fuel consumption in rocketry, the USDV will need to burn through its fuel at a way faster pace to effectively steer the station on its reentry course. Proposals for the USDV tender are due by November 17th.
The ISS retirement plan begins its initial stages in 2026; NASA and its international partners will allow the station’s natural decay to proceed without interference.
ISS is aiming to make landfall around Point Nemo, a spot in the middle of the Pacific Ocean between New Zealand and South America. Colloquially known as the global spacecraft graveyard, more than 250 crafts have been put down in the area. Despite the remoteness of the region, preventative measures will be in place to clear the airspace ahead of the reentry window. Such a warning is not unusual in the world of aviation, they get at least one a month for spacecraft much smaller than the ISS, mostly resupply ships.
The rendezvous between the ISS and the USDV is just above the “point of no return”, 175 miles above the surface of the planet; After docking they will descend together towards the surface.
The structure of the ISS will begin to melt and vaporize as the 100-ton vessel careens through our atmosphere at approximately 18,000 miles per hour.
The ISS was announced in 1984 by Ronald Reagan along with a timeline to completion of ten years. The first pieces, however, only began going up in 1998, the station was completed just two years later in 2000. Since then, the ISS has been home to over 250 astronauts and visitors from 20 different countries. It has gone well beyond its originally planned operational window of 15 years.
Responsibility for future space stations will fall to private companies. Axiom Space, Blue Origin, and Northrup Grumman have already expressed interest in potential projects. When Elon takes a break from his antics on Twitter he’ll likely throw SpaceX’s name in the ring as well.
