Boeing’s SRB-X Space Shuttle Derived Unmanned Launch Vehicle Concept

The SRB-X study was initiated by NASA in response to preliminary investigations that suggested future launch requirements could best be satisfied by a mixed fleet of manned and unmanned launch vehicles. Manned requirements are expected to be met by the space shuttle, at least to the turn of the century, but requirements for the unmanned vehicle are not specific at this time. The following, however, represent potential uses or benefits that indicate, when viewed collectively, that an unmanned vehicle could be a valuable addition to the space transportation system (STS). Such a vehicle could a. Provide shuttle contingency or backup in the event of an out-of-service orbiter, a major accident, or failure to achieve acceptable turnaround time. b. Deliver payloads that exceed the size and mass constraints imposed by the shuttle. C. Free the shuttle for missions unique to its capabilities, thus extending the life of the orbiter fleet. d. Supplement the shuttle flight rate in the event launch needs increase appreciab