Short answers, pulled from the story.
"Space Oddity" was released as a 7-inch single on the 11th of July, 1969, by Philips Records in the UK and Mercury Records in the US. Its B-side was "Wild Eyed Boy from Freecloud," and the label rush-released it to coincide with the Apollo 11 Moon mission.
The song's title and subject matter were influenced by Stanley Kubrick's film 2001: A Space Odyssey, which premiered in May 1968. Two additional events shaped the writing: Bowie seeing the Apollo 8 Earthrise photograph in January 1969 and ending his relationship with dancer Hermione Farthingale the following month. Biographer Marc Spitz cited the loneliness following that break-up as the song's emotional core.
The album version of "Space Oddity" was produced by Gus Dudgeon, who took over after Tony Visconti declined, calling the song "a gimmick to cash in on the moonshot." The session was recorded at Trident Studios in London beginning on the 20th of June, 1969, and cost £500 in total.
"Space Oddity" reached number one on the UK Singles Chart in November 1975, following a reissue by RCA Records, making it Bowie's first British chart-topper. The reissue was a maxi single that included "Changes" and the previously unreleased 1972 outtake "Velvet Goldmine" as B-sides.
Major Tom is a fictional astronaut created by David Bowie for "Space Oddity," described in the song as losing contact with Ground Control and drifting helplessly in space. Bowie revisited the character in "Ashes to Ashes" (1980) and in the Pet Shop Boys remix of "Hallo Spaceboy" (1996), and the character appears to have influenced the video for his final single "Blackstar" (2015).
Canadian astronaut Chris Hadfield, commander of Expedition 35, recorded "Space Oddity" aboard the International Space Station in May 2013. The resulting video became the first music video filmed in space, and Hadfield adapted the lyrics so Major Tom safely receives landing orders and returns to Earth rather than drifting to his death.