However, during the shakedown cruise, the Prometheus passed through a massive gravity wave from a collapsing star, while it was in hyperspace, which severely damaged the reactor's buffer. In order to fix it, Prometheus made a brief hyperspace jump to the closest planet with a Stargate. This, however, overloaded the hyperdrive engines and forced the crew to eject the reactor into space before it went critical. When it eventually overloaded, the EMP energy from the reactor core greatly damaged the Prometheus despite the ship having Asgard shields which ultimately stranded the ship on an alien world until a replacement could be procured. (SG1: "Memento")