Flight spare

A complete copy of Mariner 10 was constructed but never used. NASA gave it to the Smithsonian Institution in 1982, which currently displays it in the Time and Navigation exhibition at the National Air and Space Museum.[1]

A flight spare is a copy of a spacecraft or spacecraft part which is held in reserve in case it is needed for the mission. Flight spares are built to the same specifications as the original equipment (the "flight model"), and can be substituted in the case of damage or other problems with the flight model, reducing launch delays. The extra cost of building a flight spare can be justified by the enormous cost of delaying a launch by even a short amount of time.

  1. ^ "Spacecraft, Mariner 10, Flight Spare". Retrieved 2020-10-18.