Boilerplate (spaceflight)

A boilerplate spacecraft, also known as a mass simulator, is a nonfunctional craft or payload which is used to test various configurations and basic size, load, and handling characteristics of rocket launch vehicles. It is far less expensive to build multiple, full-scale, non-functional boilerplate spacecraft than it is to develop the full system (design, test, redesign, and launch). In this way, boilerplate spacecraft allow components and aspects of cutting-edge aerospace projects to be tested while detailed contracts for the final project are being negotiated. These tests may be used to develop procedures for mating a spacecraft to its launch vehicle, emergency access and egress, maintenance support activities, and various transportation processes.

Boilerplate spacecraft are most commonly used to test manned spacecraft; for example, in the early 1960s, NASA performed many tests using boilerplate Apollo spacecraft atop Saturn I rockets, and Mercury spacecraft atop Atlas rockets (for example Big Joe 1). The Space Shuttle Enterprise was used as a boilerplate to test launch stack assembly and transport to the launch pad. The development of NASA's Project Constellation used boilerplate Orion spacecraft atop an Ares I rocket for initial testing.

Mercury boilerplates were manufactured "in-house" by NASA Langley Research Center technicians prior to McDonnell Aircraft Company building the Mercury spacecraft. The boilerplate capsules were designed and used to test spacecraft recovery systems, and escape tower and rocket motors. Formal tests were done on the test pad at Langley and at Wallops Island using the Little Joe rockets.

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