Roman Groom created Gadget using parts from the drones which originally constructed the Bowie Base One. It was primarily used for exploring the harsh environment of Mars and collecting data from the planet's surface. It had a vast selection of tools and a camera lens for an eye and stood at approximately 3ft tall. Gadget had no sentience and little autonomy. It was controlled using wired up gloves from the Central Dome of Bowie Base One, and so had similar level of dexterity to a human. When receiving or acknowledging commands, it said, "Gadget! Gadget!", which its creator said amused him, though the Doctor found it annoying. Gadget could also talk, but only through someone else's voice, acting like a speaker. At least two people could ride it much as they could a Segway.
Prior to the Tenth Doctor's using the sonic screwdriver to give it the power to travel at prodigious speeds, Gadget could travel at approximately two miles per hour. After this adjustment, the Doctor and Adelaide Brooke rode Gadget to escape from Flood-infected Andy Stone and Tarak Ital. The Doctor said he didn't like funny robots, but saved Gadget from the Flood. Adelade criticised this, saying, "I thought you didn't like funny robots!" The Doctor later sent it with his TARDIS key to the TARDIS to bring the TARDIS into Bowie Base One. After arriving on Earth, Gadget lost contact with its control signal and finally shut down. (TV: The Waters of Mars)