Here is a nice set of icons by Hide. Availabe in MAC, PC and Linux versions. From Pixture.

 

 

A set of icons in Mac-only binhex format is available. This set is from Iconfactory and is called Sci-Fi Objects. Includes Thunderbirds and Space:1999. Very nice, and some appears to be based on the above set.

 

The list below is another set of Mac-only binhex format icons provided by Jamie Drouin.

• Capt.Scarlet
• Fireball_Junior
• Mole
• Prof._Popkiss
• Robert_Robot
• Sgt.Major_Zero
• Stingray
• TB1
• Terror_Fish
• The_Hood
• Titan
• Troy_Tempest
• UFO

A windows compatable zip file containing all of the icons in psd format is available. PSD is a non-internet graphical format which can be read by most decent image viewers (Fireworks, Paint shop pro, Photoshop, ImageReady, etc.)