UFO 2: Flying (sometimes called simply UFO 2 or Flying; also subtitled Space Rock) is the second studio album by English hard rock band UFO. It was released in October 1971 on the Beacon label. It was issued on CD in 1999 on Repertoire Records.
The album is distinctive for its title track, which was one of the longest tracks recorded in rock music up to that point (The longest track was "A Plague of Lighthouse Keepers" by Van Der Graaf Generator's album "Pawn Hearts" from 1971) and easily the longest track the band ever recorded. The track finishes with a backmasked reading from Rudyard Kipling's Gunga Din, "Tho' I've belted you an' flayed you, By the livin' God that made you, You're a better man than I am, Gunga Din!", and a slowed phrase, "Yes we know, it's all been done before before before".
The album was reissued on the Flying, The Early Years compilation, along with all of the band's other work from before guitarist Michael Schenker joined the group after brief stints with Larry Wallis and Bernie Marsden.