posted 08-04-2022 04:29 PM               

The plans drafted by U.S. officials laid out ways to pull all astronauts off the station if Russia were to abruptly leave, keep it running without crucial hardware provided by the Russian space agency, and potentially dispose of the orbital laboratory years earlier than planned, according to three of the sources, all of whom asked not to be identified. ...

Multiple space companies have been pulled into the planning, with Boeing, one of the station's key private contractors, assigning a team of engineers to examine ways to control the space station without Russia's thrusters, one of the sources said.

In recent weeks, NASA has worked on drafting a formal request to contractors for ways to deorbit the space station earlier than planned in case Russia withdraws from the alliance, two of the sources said.

posted 08-22-2022 08:47 AM               

NASA issued the request for information (RFI) late Aug. 19, asking companies to supply information about how they could develop a spacecraft that would be used to perform the final reentry maneuvers at the end of the station's life, pushing it into the atmosphere to break up over the South Pacific Ocean.

Under a nominal deorbiting scenario provided by NASA in the RFI, the spacecraft would attach to the forward port on the Node 2 module a year before reentry. During this time, the station's altitude would gradually decay from atmospheric drag and maneuvers from thrusters on the station's Russian segment, descending below 220 kilometers, the altitude below which only thrusters can provide attitude control for the station.

The deorbit vehicle would first place the ISS into an elliptical orbit of 145 by 200 kilometers to minimize the period in which the station has to rely on thrusters for attitude control. It would then make a final burn to lower the perigee to 50 kilometers, ensuring "atmospheric capture" or breakup of the station upon reentry.