Both Halo Nation and Halopedia as well as the timeline in Halo Wars state that the Spirit of Fire is list as lost with all hands as of February 10th 2534. Also, please correct me if I am wrong, the Spirit of Fire was not out of power, they overloaded their Shaw-Fujikawa Translight Engine not their reactor, so the ship still had power. Therefore, the Spirit of Fire is not drifting in space but is using it's engines to travel to a certain location, as eluded to by the final view of the Spirit of Fire right before Halo Wars credits and there was no references to the regular engines of the Spirit of Fire being damaged. However, it is fully possible that the Spirit of Fire's reactor and/or it's engines could have been damaged as a result of traveling so close to a star.
In all due respect,
-Guest
