An exploration team was sent to the Mars, but suddenly the unexpected had happened as the ship that the used to went there exploded unknowingly. Fortunately for them that they are able to send a distress signal back to Earth. NASA sent another team to retrieve the missing astronauts using a moon buggy to gather them and bring them to the new ship.
Drive the moon buggy in every corner of Mars and try to get every last bit of them. However, if you can’t get them then just let them be as there would be other moon buggy that can pick them up.