Gavin and the Villain
In this legend, a moon miner who worked on various satellites in Earth's solar system named Gavin is challenged by a "strange, ugly man" (referred to as "the villain") to a test of bravery during a miners' party. As the best of them, Gavin will be given a shot at him with any weapon. Gavin does so, using a bulldozer to knock the villain off the planetoid, only for that villain to return and tell Gavin that the next time they meet, Gavin will be the one receiving the blow on the one year anniversary of their fight.
Uncertain of how this will occur, Gavin spends the year in between searching for the villain, ending up on Earth's moon itself. Upon the day of their second encounter, Gavin encounters an old hag who instructs him, and reveals the villain's location: an orbiting castle above the moon. She tells Gavin that he must launch himself in a mass driver towards the castle, for any form of safe conveyance leads him to this castle will be considered undeniable proof of cowardice.
Gavin uses this mass driver to hurl himself at the orbiting castle, expecting to be killed upon impact, when he is safetly captured by the villain's green space castle while in flight. He comes to the bedchamber of his host, the villain, who offers Gavin friendship and mentions that his debt has been paid: Gavin has proven his bravery is beyond reproach (Battlestar Galactica TOS novelization).