New Space and Tech

NASA Requests Funding for $1 Billion ‘Space Tug’ to Deorbit the ISS

By Sharmila Kuthunur
November 21, 2023
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NASA Requests Funding for $1 Billion ‘Space Tug’ to Deorbit the ISS
The ISS is too large to entirely burn up in the atmosphere.
Image credit: NASA.

NASA is developing a plan to deorbit the International Space Station (ISS) at the end of its lifetime, currently scheduled for 2030. Since the 356-foot-wide laboratory is too big to completely vaporize if left to naturally burn in Earth’s atmosphere, the space agency intends to send a US spacecraft to help deorbit the station and direct its reentry over the unpopulated South Pacific.

Earlier this year, NASA requested ideas from the industry for a new spacecraft design or a modification of an existing vehicle to fit this purpose. Due Friday (November 17), the proposals outline design, development, manufacturing, testing, and integration of the U.S. Deorbit Vehicle (USDV) such that it would, in theory, rendezvous and dock with the ISS. The goal is to give the ISS an extra “space tug” to help it move more than it could with its own thrust, and guide the final burns for ISS to re-enter Earth’s atmosphere.

“As with any development effort of this size, the USDV will take years to develop, test, and certify,” NASA said in a September announcement.  

The space tug is expected to cost $1 billion, agency officials had said earlier this year. In its budget request for fiscal year 2024, the agency requested $180 million to start developing the technology for the space tug. 

The White House also requested unspecified amounts of initial funding for the U.S. Deorbit Vehicle in a recent emergency domestic supplemental appropriations request to Congress to meet “critical domestic needs.” Explanations of the requested funds do not mention NASA or the ISS, but NASA administrator Bill Nelson confirmed the newly requested funds earlier this month in an email to SpacePolicyOnline.

“The funding will help ensure continued U.S. leadership in space, especially as we plan for the safe transition of our operations in low Earth orbit to commercially-owned and -operated platforms that continue access and presence in space for research, technology development, and international collaboration,” Nelson said in the email.

Although the funding focuses on technology development in the U.S., NASA had previously said the ISS deorbiting effort is “a shared responsibility” of the five space agencies collaborating on the station: those of the US, Russia, Canada, Japan, and Europe.

Earlier this year, Russia agreed to stay onboard ISS through 2028, rather than its previous timeline of 2024, after which it may focus on building its own station in low-Earth orbit. Other partner countries have agreed to continue their presence through 2030, but it is not clear precisely how they will contribute to retiring the ISS.

Sharmila Kuthunur.

Sharmila is a science journalist covering the cosmos. Her work has appeared in, Astronomy Magazine, EarthSky, and the Indian print magazine Science Reporter. She received a master's degree in journalism from Northeastern University in 2022.