In the 43rd century, the Walker Expedition was launched by the Second Great and Bountiful Human Empire to bring back the power source that kept the planet Krop Tor in a stable orbit around the Black hole K37 Gem 5.
Its crew were made up of Captain Walker, (WC: Tardisode 8) third officer Curt, Chenna, (WC: Tardisode 9) executive officer Zachary Cross Flane (who became acting Captain after the captain was killed entering Krop Tor) of the Torchwood Archive, science officer Ida Scott, Ethics Committee member Danny Bartock, archaeologist Toby Zed, Security Chief John Jefferson, trainee maintenance officer Scooti Manista, and a male and female security guard. (TV: The Impossible Planet)
Only Zack, Ida and Danny returned alive after the drilling awoke the Beast. (TV: The Satan Pit) Captain Walker had been killed when the rocket entered the gravity field that allowed the expedition to reach Krop Tor (TV: The Impossible Planet) and Mr Jefferson was killed when he asked for the oxygen to be sucked out of the maintenance tunnels before being killed by the Ood when they were possessed by the Beast. (TV: The Satan Pit) Scooti was killed by Toby who, while he was under the influence of the Beast, broke a window, blowing her into space. (TV: The Impossible Planet) Toby himself was killed by Rose Tyler, who blew him into space while he was possessed. (TV: The Satan Pit) The rest of the crew were killed by the Ood. (TV: The Impossible Planet / The Satan Pit) The Ood themselves died when the planet collapsed into the black hole. (TV: The Satan Pit)
Behind the scenes
The non-narrative source Doctor Who: The Time Traveller's Almanac goes into further detail about Curt and Chenna's rank and cause of death. According to volume 53 of The Complete History, The Impossible Planet had dialogue cut referring to the deaths of crew members in the base's command centre.