posted 03-13-2023 06:51 PM               

NASA and its partners have evaluated varying quantities of Russian Progress spacecraft and determined that three can accomplish the de-orbit. Additionally, Northrop Grumman has been expanding the propulsion capabilities of its Cygnus spacecraft, and NASA has been evaluating whether Cygnus could also be part of the vehicle capability needed to the de-orbit the ISS.

The deorbit vehicle shall attach (via docking or berthing) to the ISS at least one (1) year prior to the planned ISS reentry date to enable adequate time for on-orbit tests and checkouts. ISS altitude lowering can occur naturally via atmospheric drag or via Russian propulsive control from the deorbit vehicle rendezvous altitude to the final circular holding altitude at approximately 270 km, where maneuvers will be performed as necessary to establish proper ground tracks prior to the final deorbit burn sequences.

Below 270 km, a combination of natural decay and/or propulsive maneuvers will reduce the ISS perigee to approximately 150 km. Shortly thereafter, the deorbit vehicle will perform the final reentry burn resulting in a controlled reentry of the ISS within a pre-defined, uninhabited entry corridor. Throughout the final series of deorbit events, the deorbit vehicle will be responsible for providing both delta-v and attitude control of the ISS.

Although nominal ISS EOL [end of life] is late 2030, the Government requires that this deorbit capability be available as soon as possible to protect for contingencies that could drive early re-entry and beyond 2030 in the event of further ISS mission extensions.

The $180 million NASA is requesting for the tug "gives us a healthy start" for the project, said Kathy Lueders, NASA associate administrator for space operations, in a media teleconference about the budget.

While budget documents did not include a spending profile for the project, Lueders said the agency came up with a cost estimate "a little bit short of about $1 billion." The exact amount, she said, will depend on what proposals the agency receives from industry from an upcoming request for proposals (RFP).

"Our goal is to go out with an RFP," she said. "We're hoping to get a better price than that."

posted 12-05-2023 04:26 PM               

NASA Seeks Proposals from US Industry for Station Deorbit Spacecraft

NASA has updated a request for proposal from U.S. industry for the U.S. Deorbit Vehicle (USDV), a spacecraft meant to safely deorbit the International Space Station as part of its planned retirement.

To maximize value to the government and enhance competition, the acquisition will allow offerors flexibility in proposing Firm Fixed Price or Cost Plus Incentive Fee for the Design, Development, Test and Evaluation phase, as well as for the Production, Assembly, Integration, and Test phase. The agency also has extended the deadline for proposals to Feb. 12, 2024. At this time, the USDV contract award is planned for late May/early June 2024, and the final contract value will be determined at contract award.

Since 1998, five space agencies (the Canadian Space Agency, the European Space Agency, the Japan Aerospace Exploration Agency, the National Aeronautics and Space Administration, and the State Space Corporation "Roscosmos") have operated the International Space Station, with each responsible for managing and controlling the hardware it provides. The station was designed to be interdependent and relies on contributions from across the partnership to function. The United States, Japan, Canada, and the participating countries of ESA (European Space Agency) have committed to operating the station through 2030, and Russia through at least 2028.

At the conclusion of the International Space Station program, the station will be deorbited in a controlled manner to avoid populated areas. The safe deorbit of the International Space Station is a shared responsibility of all five space agencies through partner contributions based on mass percent ownership by agency. In the future, the United States plans to transition its operations in low Earth orbit to commercially-owned and -operated platforms to ensure continued access and presence in space for research, technology development, and international collaboration.

In a years-long effort, NASA and its partners studied deorbit requirements and previously developed a preliminary strategy and action plan that evaluated the use of multiple Roscosmos Progress spacecraft to support deorbit operations. These efforts now indicate a new spacecraft solution would provide more robust capabilities for responsible deorbit. To initiate development of this new spacecraft, NASA released the request for proposal.

The USDV is focused on the final deorbit activity. It will be a new spacecraft design or modification to an existing spacecraft that must function on its first flight and have sufficient redundancy and anomaly recovery capability to continue the critical deorbit burn. As with any development effort of this size, the USDV will take years to develop, test, and certify.