How about The Orb?
The Orb’s Adventures Beyond the Ultraworld & U.F.Orb.
If you don’t mind filk music, “Carmen Miranda’s Ghost” by Leslie Fish is definitely in that vein.
*Carmen Miranda’s Ghost is haunting Space Station 3.
Half the staff has seen her, plus the Portmaster and me.
And if you think we’ve had too much of Cookie’s homemade rum,
then tell me where those basket hats of fruit keep coming from.
Don’t go down to the cargo-bay when there’s no ship in dock.
You just might hear maracas clack and get a nasty shock
And if you hear a rumba-beat, don’t pass the messroom door;
You just might see a tangerine come rolling down the floor.*
Well, Vangelis wrote “Mythodea: Music for the NASA Mission: 2001 Mars Odyssey.”
Sorry, that’s all I got.
If you want instrumentals, there’s
They Might Be Giants: “Space Suit”
and possibly some of the Alan Parsons Project’s instrumental tracks.
For vocal tracks, in addition to those already mentioned, I can think of the Beach Boys’ goofy “Solar System,” and “Interplanet Janet” from Schoolhouse Rock.
There was once a great album called Minus Ten and Counting: Folk Music for the Space Age. If you can find any of those songs, they’re just great for evoking a love of the space program and exploration. Unfortunately, they’re rare since the publisher went out of business.
I particularly like Surprise!, The Phoenix, Hope Eyrie, Planetbound Lovers, The Witnesses Waltz, and The Light Ship.
Also look for a song called Outward Bound. I don’t know where I got the copy I’ve got or who sings it, but it’s great. I found a site with the lyrics:
http://www.echoschildren.org/CDlyrics/OUTBOUND.HTML
Editing to add: Prometheus Music has their versions of some of the Minus Ten songs available for free download (plus a CD you can buy).
Keep 'em coming! The boy’s only seven, so the poppier ones like Walking on the Moon and Rocket Man will prevail.
Thanks also for reminding me about Telstar - I can’t get it out of my head now. 
Ah. Okay, please disregard all of my recommendations except maybe for the Explaining the Unexplained album. A few tracks on that one could still be appropriate.
Have you maybe considered Bruce Haack if you can locate any of his material? Not necessarily space qua space oriented, but kewl nonetheless.
How…uh…laid back do you want this music? There is an entire genre of music called electro (along with electrobass and electrobreaks) that is pretty underground still, but is comprised of futuristic themes of machines vs humans…pretty bass heavy, with futuristic effects, robotic vocals, etc…I’m not sure you want an underground afterhours club vibe at your son’s birthday party, but much of the softer, more minimalist electro would sound ok as background music.
go to Anthony Rother (anthonyrother) on Myspace -scroll down, play the video for an example. This one is pretty laid back, if you want more along those lines, look at Boris Divider, Miguel Mendoza, or Drexciya.
I could point you to a mix or two at either Vocode.com or electroalliance.net that would be clean enough for a party, and are downloadable for free, and run from 45-90 minutes each.
note-there is ALOT of the electrobass and breaks that would not be appropriate because of language, but much of the straight electro would be fine. There are a ton of them that are huge underground hits that sample Star Wars, Battlestar Galactica, The Transformers, etc(especially robotic Cylon and Transformer voices)
Another vote for Mythodea and Prometheus Music’s filk.
Anyway, on my “space” iTunes playlist, I’ve got…
•Rocket’s Tail—Kate Bush
•Countdown—Rush
•The Launch (from Apollo 13)—James Horner
•Space Oddity—David Bowie
•On the Beautiful Blue Danube—Hillary Duff, obviously
Ladies and Gentlemen We are Floating in Space—“John Coxon, Kate Radley, Sean Cook, Spiritualized & The London Community Gospel Choir”
•Rocketman—Elton John
•Main Theme to “The Right Stuff”
•Where Is the X-38?—The Phenomenauts
•Silver Machine—(Mine’s the cover by The Church)
•The Construction—Explorers soundtrack (Out of Print, may, ahem, be hard to find.)
•The extended “Doctor Who Theme” from the 2007 soundtrack.
:mad: Foiled! So much for good intentions and wanting to do it legit. I can’t register an iTunes account because I’m outside the US, even though my cc billing address is in the US and I can provide a matching phone number… and I can’t get Limewire to work either. Any alternatives?
How about “Star Trekkin’” by The Firm? It’s hilarious–perfect for a 7 year old.
You can’t get into one of the foreign iTunes stores, or eMusic?
you could try a bit torrent program, or ask a fellow doper to burn a few CDs and stick them in the mail, but if you are in a foreign country I don’t know they would make it in time.
Not iTunes - my country isn’t on the list.
I got the eMusic free trial but as far as I can see there are very few original versions - some of the cover versions are OK but there are several where it would have been better to have the original. It’s good enough for soundtracks and techno versions of classics though.
This is what I have so far:
Distant Sun (Crowded House, from my own CD)
ET theme
Starman (cover version)
Telstar (dance cover version)
Here comes the Sun (guitar instrumental, but I have Abbey Road on CD so I can copy it from there)
Mr Moonlight (Merseybeats, but I may have the Beatles version on CD)
Fly me to the Moon (In Other Words) (instrumental)
Sleeping Satellite (trancey cover version of early 90s song by Tasmin Archer)
Satellite of Love (cover version)
Another Girl Another Planet (Original version)
Star Trekkin’
Walking on the Moon (cover)
Planet Earth (cover)
2001 A Space Odyssey
Dr Who theme
Mars, from the Planets Suite
Rocket Man (cover version)
Space Oddity/Life on Mars (cover version by Rick Wakeman)
Star Trek theme
Star Wars theme
ETA Lucy in the Sky with Diamonds?
Verve - Star Sail
Inspiral Carpets - Saturn 5 (the organ riff in this song will probably be popular with youngsters).
Fresh Aire V by Mannheim Steamroller is entirelt Space-themed instrumental.
That would be the one-hit wonder Billy Thorpe.
One of my favorite bands, Camel, has a couple songs that would fit: “Earthrise” (from the “Mirage” album) and “Lunar Sea” (from “Moonmadness” - hey, even the album name fits!).
And also I just thought of Rush’s “Cygnus X-1”.
If ya don’t mind my asking, what country is it?
“Poor Boy” - Split Enz
“Moons of Jupiter” - Scruffy the Cat
“There’s a Moon in the Sky (Called the Moon)” - The B-52’s
“Planet Claire” - The B-52’s
“Stars Fell on Alabama” - Jimmy Buffett
No one has mentioned the Deep Purple classic: “Space Truckin”. So I will.