The UK-201 was a human spacecraft which operated in the 25th century. It bore a Union Flag on its hull. In 2493, whilst carrying Vicki, her father, Bennett and other passengers to the planet Astra, it crash-landed on Dido.
Vicki stayed within the ship, using its radio to send out distress signals. Bennett occasionally ventured out in secret to disguise himself as Koquillion, then visit the ship in this guise to confront Vicki and convince her that Bennett was keeping her safe. Bennett rigged the door to his cabin aboard the ship with a tape recorder so that when the door was opened, recordings of his voice saying phrases such as "You can't come in!" and "Go away!" were played.
After the First Doctor, Ian Chesterton and Barbara Wright landed on Dido, they visited the ship and befriended Vicki. When the appearance of two surviving Dido natives caused Bennett to fall over a cliff to his death, the Doctor took Vicki away with him in the TARDIS, leaving UK-201 empty. (TV: The Rescue)