The Sanctuary Base 6 rocket was the last chance of escape from Krop Tor for the Sanctuary Base 6 crew. It travelled to the planet via a gravity funnel and could escape by the funnel.

When the Beast's prison was broken by the Tenth Doctor, the rocket was nearly sucked into the black hole K37 Gem 5, until the Doctor used the TARDIS to tow away the rocket. (TV: The Satan Pit)