Orbiter utilization as an ACRV

Assuming that a Shuttle Orbiter could be qualified to serve long duration missions attached to Space Station Freedom in the capacity as an Assured Crew Return Vehicle (ACRV), a study was conducted to identify and examine candidate attach locations. Baseline, modified hardware, and new hardware design configurations were considered. Dual simultaneous Orbiter docking accommodation were required. Resulting flight characteristics analyzed included torque equilibrium attitude (TEA), microgravity environment, attitude controllability, and reboost fuel requirements. The baseline Station could not accommodate two Orbiters. Modified hardware configurations analyzed had large TEA's. The utilization of an oblique docking mechanism best accommodated an Orbiter as an ACRV

Space Station Freedom contingency reboost and resupply strategies

The objective of this study was to determine the requirements necessary to ensure a viable Space Station Freedom (SSF) in the event of a delay in the date of the first element launch, and/or in the event that the nominal assembly sequence is interrupted, perhaps due to a delay in the Space Shuttle Launch Schedule. Orbit lifetimes, reboost fuel requirements, and controllability requirements were calculated for each stage of the SSF assuming anywhere from a 6 to 24 month delay/interruption in the baseline SSF assembly sequence. These results were assessed in order to formulate strategies to assure SSF viability in the presence of assembly sequence delays and interruptions