Major Matt Mason on wikipedia.org
A 8 inch action figure in a white astronaut suit with black ridged joints. He had a removable helmet with a yellow blast shield. Also available was a "jet pack" that was actually a spring wound 3' string which would attach to a chair or table top and "jet" Major Matt up the string. Usually you pulled the string to far and broke the spring! A slew of accesories were also available from battery powered lunar crawlers and 3' tall space stations to alien creatures like "Skorpion".