NASA has contracted SpaceX for $843 million to develop the “US Deorbit Vehicle.” This spacecraft will dock with the International Space Station (ISS) in 2029, ensuring a controlled reentry into Earth’s atmosphere and a splashdown in the ocean by 2030.
“Selecting a US Deorbit Vehicle for the International Space Station will help NASA and its international partners ensure a safe and responsible transition in low Earth orbit at the end of station operations,” stated Ken Bowersox, NASA’s Associate Administrator for Space Operations. “This decision also supports NASA’s plans for future commercial destinations and allows for the continued use of space near Earth.”
Reasons for Deorbiting the ISS
- Aging Infrastructure: Parts of the ISS are now 25 years old, with cracks spreading in the Russian segment. Maintaining the station beyond 2030 would demand increasing amounts of crew time for safe operation.
- Fostering Commercial Space Economy: NASA aims to stimulate a commercial economy in low-Earth orbit by working with private companies to develop new space stations capable of housing astronauts and private citizens by or before 2030. Setting a definitive end date for the ISS helps these companies secure investor funding.
Ensuring a Safe Deorbit
The ISS, the largest human-made object in space, weighs 450 metric tons and spans the size of an American football field. An uncontrolled reentry poses significant risks to life and property, necessitating a deorbit vehicle.
NASA explored alternatives to an ocean splashdown. Moving the ISS to a stable orbit at 40,000 km above Earth required too much propellant (900 metric tons) compared to deorbiting it (47 m/s delta-V). Disassembling the ISS before reentry was also deemed too complex and risky.
The Deorbit Vehicle
The announcement did not specify the SpaceX vehicle for the deorbit burn, but insights can be drawn from contract documents. NASA plans to select a rocket by 2026 to support a 2029 launch, with the deorbit vehicle docking one year before the reentry.
Due to the mission’s sensitivity, NASA likely requires a “Category 3” rocket, known for its robust launch history. Candidates include SpaceX’s Falcon 9 and Northrop Grumman’s Pegasus and Minotaur rockets. Given SpaceX’s role, a Falcon 9 or Falcon Heavy is a probable choice. While Starship is another possibility, it’s currently not classified as a Category 3 rocket.
SpaceX’s exact plan remains unknown, but the “Dragon XL” spacecraft, designed for NASA’s Lunar Gateway station, could be a viable option due to its propulsive capability and extended docking duration.
Contract Details
The bidding process was somewhat opaque. Initially, NASA’s contract allowed flexibility in contracting mechanisms, adapting to the number of bidders. NASA Administrator Bill Nelson initially estimated the deorbit vehicle cost at $1.5 billion. However, the final contract price was significantly lower, highlighting a better-than-expected deal for NASA. The contract is a firm-fixed-price arrangement, SpaceX’s preferred contracting method.
For more details on NASA’s plans and SpaceX’s involvement, stay tuned to our updates.