(from the series for all mankind)
Pathfinder (designation OV-201) is a second generation Space Shuttle of NASA. It is the first of its kind and carries the same name as the whole series. Pathfinder first launched in mid September 1983 to escort Sea Dragon 17 to the Moon. By 1995, another second generation Space Shuttle, Vanguard, has been constructed and in operation
Prior to 1983, NASA had begun to develop a next generation of Space Shuttles called "Pathfinder shuttles", which would test the Nuclear Engine for Rocket Vehicle Application (NERVA) which was planned to become the engine used to take astronauts to Mars at some later date. Other than the first generation Space Shuttles, the Pathfinder shuttles use an air-launch system from a C-5 Shuttle Carrier Aircraft, followed by the use of the onboard NERVA to reach orbit or the Moon

1st mission :
In mid September 1983, Pathfinder's planned maiden flight was preponed due to the launch of the Soviet shuttle Buran and their lunar blockade to escort Sea Dragon 17 to the Moon. Pathfinder was hastily modified to carry four long-range Phoenix missiles in the cargo bay and was given targeting systems. The mission was commanded by Ed Baldwin, with his crew being USAF Captain Gary Piscotty and Dr. Sally Ride, who had worked on the Pathfinder engines for years. During a stand-off situation in lunar orbit, Commander Baldwin launched a missile and destroyed the Sea Dragon to avoid a more dangerous confrontation with the Soviet shuttle

Later missions:

During the following years, Pathfinder and her sister ships had become NASA's workhorses, used specifically for the rapid expansion of the Jamestown base on the Moon. Pathfinder shuttles were also used to launch the Thomas Paine Space Telescope into Earth's orbit, and the research station MoonLab into lunar orbit.

In 1989, all Pathfinder shuttles were grounded after one of them unexpectedly depressurized, killing the five Moon Marines on board, including highly decorated Lieutenant Colonel Steven Lopez. By 1992, the Pathfinder fleet was in use again.

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