Thermal Control Issues of the Assured Crew Return Vehicle (ACRV)

The new challenges of permanently inhabited orbital stations include the need for immediate, safe return to Earth of the station crew. In particular, in the frame of the Space Station Freedom (SSF) program, three potential emergency situations have been identified:

• ill/injured crew member return
• crew evacuation due to uninhabitability of SSF
• crew return due to unavailability of Space Transportation System

It is recognised that station crew rescue/recovery by means of the U.S. Space Transportation System (STS) is not feasible since the time needed to setup the rescue mission would be too long for the assigned requirements.

It has therefore been decided to develop an Assured Crew Return Vehicle, permanently docked to SSF and able to re-enter its crew (in total or in part) within assigned time constraints. This paper concentrates on the description of the three thermal subsystems present inside the ACRV: the Thermal Protection Subsystem (TPS), the Thermal Control Subsystem (TCS) and the Environmental Control and Life Support Subsystem (ECLSS).

The subjects investigated are the system approach in the management of these three subsystems and their major design features. Finally, the open issues are identified and the activities foreseen in the near future are presented.