“2000 Light Years from Home” (Rolling Stones)
“In the Year 2525” (Zager & Evans)
“Starship Trooper” (Yes)
“Watcher of the Skies” (Genesis)
“Starrider” (Foreigner)
Any others? (I’m not thinking of science-fiction TV show or movie themes, just regular songs that happen to have this theme.)
I’ve always wondered why songs about space travel often have that acoustic-folk-guitar strumming. What is it about the acoustic guitar sound that arragners associate with outer space? I first heard it in the Stones’ “2000 Light Years from Home” and then Foreigner used the same sound in “Starrider” (one of the most pretentious, vapid excuses for a song, ever).
Just the other day All Things Considered was telling about the 75th anniversary of Robert Goddard’s first rocket launch, and Goddard’s aspirations of space travel. The music they played afterward was the usual science-fiction soundtrack stuff, and sure enough there was the acoustic guitar strumming along with spacy synthesizers.
Whoa, almost forgot Elton John’s “Rocket Man.”
And David Bowie’s “Space Oddity,” “Ashes to Ashes,” “Starman.”
Starship Trooper (Yes)
Time (the entire album, by ELO. A lot of their stuff, actually)
Planet P (The whole album was a science fiction concept album)
Starman (David Bowie)
… and I’m sure I’ll think of several more eventually.
Then there was Jimi Hendrix’s “Up from the Skies” (prefaced by “EXP”).
Earth Girls are Easy - Julie Brown (this was written years before a movie was made about it)
Yellow Submarine - The Beatles
War of the Worlds - The Moody Blues
Now that it is stuck in my head, I feel the need to share it -
Mr. Roboto - Styx
Let’s see,
Klaatu - “Anus of Uranus”, “Little Neutrino”
Queen - “'39” (acoustic as a bonus), “Machines (Back to Humans)”
Radiohead - pretty much all of “OK Computer”
Pixies - “Planet of Sound”
Domo arigato Mr. xizor. Now I’m infected.
Does “Major Tom (Coming Home)” by Peter Shilling count?
Prism did a song called “Spaceship Superstar” back in the 1970s, and a group called FM did one called “Phasers on Stun” during that decade also. Both were Canadian bands, IIRC, so I’m not sure if these songs were ever heard in the US or Europe.
And we can’t forget Jeff Wayne’s album War of the Worlds either, with Richard Burton, David Essex, and Julie Covington on it.
Rick Wakeman’s 1974 Journey to the Center of the Earth and his more recent Return to the Center of the Earth
I think Stellar by Incubus is sci-fi themed. Something on Make Yourself is at the very least.
There’s no lyrics, but Joe Satriani did Surfing With the Alien, the alien being the Silver Surfer.
There’s also Children of the Sun, but I can’t remember who did that one.
There’s also one from Rush, I can’t remember the title, but the lyrics go something like:
*1001001 - SOS
1001001 - in distress
He replays all the days,
100 years of routines
He bows his head and prays
to the mother of all machines.*
Is it The Body Electric?
[sub]Sheesh, I’m just full of facts today, aren’t I?[/sub]
Good answers, folks. 
How about Pink Floyd’s “Interstellar Overdrive” and “Set the Controls for the Heart of the Sun”?
Then there’s the long-forgotten first album by Jefferson Starship, Blows Against the Empire. (This was in fact where the name “Starship” for the band came from.) The concept of this album was that when the United States builds the first starship, Paul Kantner and Grace Slick and their band of stoned anarchists will “HIJACK THE STARSHIP” and blast off and have a big interstellar party.
Can’t think of any non-Musical songs that haven’t been named yet, but there are a bunch of SF musicals (and if you include fantasy, there are a TON more than I’ve listed). All of these have SF songs:
The Rocky Horror Picture Show
Shock Treatment
Metropolis was turned into a surprisingly good musical
It’s a Bird, It’s A Plane, It’s Superman! really isn’t an SF musical, even though it should be. And it only has one good song. (A young Linda Lavin is fiddling with the buttons on Clark’s shirt as she sings about how “underneath” there’s a real man)
James Tiptree’s “The Girl Who Was Plugged In” became 1/2 of the musical Weird Romance. (The other half, “Her Pilgrim Soul” is a so-so fantasy work). This musical is excellent.
Starmites is a (mediocre) Space Opera musical,
Starmania is in French, so I’m not sure what it’s about…but the bits I’ve understood and the pics I’ve seen are clearly SF
um…
Journey To the Center of the Earth was a cast album.
Not SF at all, but it has an SF feel in a Soylent Green sort of way: Eating Raoul, The Musical
Oh yeah: one last (sort of) SF musical. Are radioactive, undead Prom dates considered SF? If so: Zombie Prom
“I Sing The Body Electric” from Fame has the same title as a Bradbury short story collection, but they both swiped the line from the poem by…um…Whitman?
There was also, if you stretch the definition a lot, a Spider-Man concept album called “Reflections of a Rock Super-Hero” which is unGodly bad. I mean, peel the paint from the wall bad. You’ll have nightmares.
Fenris
How 'bout the whole album ‘Children of the Sun’ by …um… I think it was Billy Thorpe.(?)
How about “Wooden Ships,” a postapocalyptic story written by David Crosby in conjunction with Paul Kantner & Grace Slick and released both by Crosby, Stills & Nash as well as Jefferson Airplane
“After the Gold Rush” by Neil Young, which proposes that “the loading had begun/flying mother nature’s silver seed/to a new home in the sun.”
“One Armed, One Horned Flying Purple People Eater” by Sheb Wooley.
“Flying Saucer, Parts 1&2” by Dickie Goodman
Also seems that there was a Jefferson Airplane “B” side on a 45 called “Have You Seen the Saucers?”
Jefferson Airplane actually quotes lines from John Wyndham’s “Re-Birth”: “Life is change-how it differs from the rocks.” and “I have seen their ways too often for my liking.” Quotes are from memory and thus approximate
“Space Cowboy” by Steve Miller
Of course the “Star Wars Cantina Theme” from Meco
A Few more:
Royal Guardsmen: Something like “The Smallest Astronaut” or “The Littlest Astronaut”
God help us all, The Carpenters “Calling Occupants of Interplantatry Craft” <barf>
Schoolhouse Rock had at least one “Interplantary Janet (She’s A Galaxy Girl!)”
Fenris
Most of Gary Neuman’s stuff is sci-fi based, like Down in the Park.