The Tobermoon was an Earthling Cruiser Captained by I. Burton. It was part of the research project in the Vela system. The Tobermoon attempted to return to Earth with news that the Precursor station there was not destroyed, but it was disabled (killing all aboard, including the acting captain Chi) in the Oort Cloud surrounding Vela.
Once the SIS was sent to head to Earth, the Tobermoon's wreck was recovered before the push to HyperSpace. Commander I. Burton recrewed and captained the ship herself, but she was killed in an attack by a Slylandro Probe on the Tobermoon. The ship itself survives, and is the SIS's initial escort at the start of the game.