In the shadow of the Comet

The Melin encounters a temporal rift and is thrown back in time to the year 2025. The ship arrives disabled near Mars and is picked up by various observatories on Earth, and is mistaken for a Comet and named 3 I Atlas. The ship must maintain a distance from Earth and plot a course towards the sun. NASA manage to get better quality images of the ship, and the timeline is in danger of being altered. An away team must travel to Earth and alter the information so that everyone believes it's only a comet while the crew repair the ship and attempts to return to their own time.