Gravity bubble
From Tardis Wiki, the free Doctor Who reference
A Gravity Bubble was a form a Dalek technology that allowed an object to beat the boundries of gravity and travel in space.
Dr. Bracewell applied this technology to three english world war Spitfire's allowing the pilots to travel around the orbit of planet Earth to help with destroying the Dalek Saucer. (DW: Victory of the Daleks).