The workhorse of the Lunar Run, and the backbone of Project Argosy to Mars, was the long-duration 4th stage of the NOVA booster- the N IV NERVA, also known as Hercules. With its 175.000 lb thrust NERVA nuclear thermal engine, the stage, once put into low Earth orbit by the NOVA booster, could be refueled and begin a many-year career, ferrying men and supplies from the LEO space stations to Clarke orbit, in support of the Solar Powersat project, to Lunar orbit to supply the Lunar bases on near and farside, and as the boosters and main mission propulsion for the International Argosy missions to Mars and Venus.
Here, Hercules 5 is depicted on Lunar approach, as 2 crew members conduct an EVA to conduct experiments in the cislunar enviroment.
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