WASHINGTON — NASA expects to spend nearly $1 billion on a tug to deorbit the International Space Station at the end of the decade to provide a surplus for safe disposal of the station.
NASA released additional details on March 13 about its fiscal year 2024 budget proposal. The outline of the proposal, released by the White House on March 9, asked for $27.2 billion for the agency, up 7.1% from 2023 and roughly keeping pace with inflation.
One of the biggest new initiatives in the budget is the International Space Station’s Dorbit tug, which will be used to perform the final lowering of the station’s orbit to ensure its re-entry over the South Pacific. NASA first indicated its plans for the locomotive in a request for information last August, but provided few details about the vehicle in the budget request.
NASA’s $180 million request for the tug “gives us a healthy start” for the project, NASA Associate Administrator for Space Operations Kathy Lueders said at a budget briefing about the budget.
While the budget documents did not include a spending profile for the project, Lueders said the agency came up with a cost estimate “just under about $1 billion.” She said the exact amount will depend on what proposals the agency receives from industry from an upcoming request for proposal (RFP).
“Our goal is to come up with an RFP,” she said. “Hope to get a better price than that.”
NASA had earlier planned to use space cargo ships, in particular the Russian Progress, to deorbit the station. In its request for information last year, the agency said it had concluded that “additional spacecraft may provide more powerful de-orbiting capabilities” and decided to ask industry for its concepts.
“We’re always looking for redundancy,” Lueders said, with NASA continuing to work with Roscosmos on using Progress vehicles to de-orbit. “We’re also developing this US capability as a way to gain redundancy and the ability to better assist vehicle targeting and safe vehicle return, especially as we add more units.”
The tugboat was one of the few new projects in the budget request, primarily continuing previously announced science, exploration, and technology efforts. The budget proposal also supports NASA’s role in ESA’s ExoMars mission, providing components such as thrusters, radiant heaters and launch services needed for ESA’s Rosalind Franklin rover after ESA ended its collaboration with Roscosmos a year ago.
The budget documents didn’t spell out funding for ExoMars, but Nikki Fox, NASA’s associate administrator for science, said the budget proposal includes $30 million in fiscal year 2024 for ExoMars. She added that the agency was still working on determining the full cost of its contributions.
Artemis Gap
the View budget It included an updated schedule of the Artemis lunar exploration campaign. That included a November 2024 date for Artemis 2, the Space Launch System/Orion’s first crewed mission, the date NASA officials gave in a March 7 briefing about the uncrewed Artemis 1 mission.
This schedule shows the launch date of Artemis 3 in December 2025, which will include the first human moon landing of Artemis using SpaceX’s lunar lander and spacesuits developed by Axiom Space. “We’re still pushing to make Artemis 3 in 2025 and go forward from there,” NASA Associate Administrator Bob Cabana said at the briefing.
However, Artemis 4, previously expected for 2027, has been pushed back to September 2028 in the new statement. This will also include landing on the Moon using the Starship as well as using the Lunar Gate. It will also be the first launch of the Block 1B upgraded version of the SLS with additional payload capacity, which will be used on that mission to deliver a habitable I-Hab module to the gateway.
NASA officials at the press conference did not discuss the Artemis 4 slip, but Cabana did mention the complexity of the mission. “We’re doing everything we can to keep it on schedule,” he said. “Yes, it slipped a little bit, but there is a lot that has to come together for Artemis 4, between the improved upper stage, the gateway, the logistics of the gateway, the second mobile operator. It all has to work.”