Mars Probe 6

Mars Probe 6 was a British spacecraft and probe sent on a mission to Mars. George Carrington and Jim Daniels were among the crew on the mission. When it arrived on Mars, Daniels was killed when aliens touched him. (TV: The Ambassadors of Death) The probe was later taken to the Vault. (PROSE: The Scales of Injustice)

Behind the scenes
The Mars Probe missions are ignored by the Doctor Who television story The Waters of Mars, which referred to the human colony founded in 2058 as being made up of the "very first humans on Mars". Further complicating matters, an on-screen obituary in The Waters of Mars mentions that the captain of the Bowie Base One colony, Adelaide Brooke, along with two other unidentified astronauts, had already landed on Mars when Adelaide was 42 in the year 2041.