NASA Calls for Proposals for a "Space Tug" to Safely Deorbit Space Station

 

NASA Calls for Proposals for a "Space Tug" to Safely Deorbit Space Station

NASA has recently issued a call to US companies, inviting them to conceive and construct a specialized $1 billion spacecraft, colloquially referred to as a "space tug," tasked with safely guiding the International Space Station (ISS) back to Earth. The objective of this endeavor is to facilitate a controlled deorbiting process for the ISS, minimizing any risks to populated areas on our planet. The responsibility for orchestrating the secure descent of the ISS lies with the five space agencies that have jointly overseen its operations since its inception in 1998: NASA, CSA (Canadian Space Agency), ESA (European Space Agency), JAXA (Japan Aerospace Exploration Agency), and Roscosmos (State Space Corporation Roscosmos).

NASA's extensive research into deorbiting strategies led to the conclusion that a new or adapted spacecraft is necessary to enhance the robustness of the deorbiting process. Consequently, NASA has initiated discussions with the US commercial sector and is actively pursuing the acquisition of a spacecraft, designated as the "US Deorbit Vehicle" (USDV), specifically designed to execute the crucial final deorbit maneuver for the ISS.

NASA clarified, "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 reported by ABC News, the call for spacecraft designs was officially launched on September 20, with proposals required to be submitted no later than November 17. Kathy Lueders, NASA's Associate Administrator for Space Operations, mentioned in a press conference earlier this year that the estimated cost for this spacecraft project is approximately $1 billion.

Space.com has confirmed that proposals for the USDV are expected to be received by NASA on November 17. The International Space Station Program has maintained a continuous human presence aboard the microgravity laboratory for over 22 years, with assembly missions commencing in 1998. Throughout this extensive period, NASA and its international partners have collaboratively managed, maintained, and upgraded various components of the station.

NASA has explored several alternatives for decommissioning the ISS, encompassing methods such as disassembly and return to Earth, boosting it to a higher orbit, permitting natural orbital decay with random re-entry, and controlled targeted re-entry into a remote oceanic region.

The agency has delineated its strategy for deorbiting the ISS. This plan entails focusing on ensuring the responsible re-entry of the station's structure into an uninhabited oceanic area. To achieve this, the chosen approach combines natural orbital decay, intentional reduction of the station's altitude, and the execution of a re-entry maneuver for precise targeting and debris control. This final maneuver is expected to necessitate a new or modified spacecraft equipped with a significant amount of propellant.

It's important to note that the ISS represents the largest single structure ever constructed in space. Additionally, NASA has taken steps to contract commercial modules that can be attached to a space station docking port, with plans to detach them at a later date. The agency has also awarded three Space Act agreements to foster the development of free-flying commercial space stations.