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Description of Driving Event:

In order to minimize cost and schedule, the project, after a trade-off analysis, decided to build two fully functional test vehicles as opposed to one with built in redundancy (note: those items deemed critical to safe operation were redundant). The test vehicles were of identical design but manufactured in sequence. Thus, while test vehicle number one was being flight tested, test vehicle number two was being built. The primary drivers for this approach were that the test vehicle was to be unmanned, have an emergency recovery parachute, and be operated in a very controlled and unpopulated area. The risk of losing one vehicle was minimized by the imposition of these stringent test flight constraints. While it was the project's intention to complete the second vehicle as if it were the first and only, its main purpose was for risk reduction (the project's success meant vehicle number two was tested through ground taxi only). The second vehicle was also viewed as a source of parts for vehicle number one.