In a virtuoso feat that is rapidly becoming standard operating procedure, an Air Force C-119 cargo plane equipped with a grappling hook last week snagged in mid-air a third Discoverer satellite a 300-lb. gold-plated capsule that had traveled more than a million miles in polar orbit before being parachuted near Hawaii upon pushbutton command from a control room in Sunnyvale, Calif.
Discoverer XVIII's primary mission was another step in the perfection of two space-age military reconnaissance techniques: the Samos system for camera detection of such ground-level activity as troop movements, and the Midas early missile-warning system, which is said to detect rocket firings anywhere on earth by means of infra-red sensors.
The satellite's second purpose was to help determine the effects of outer-space radiation on future astronauts. Inside the recovered capsule were human bone marrow, blood cells and tissue from the underside of a human eyelid, as well as fungus spores and algae. After analysis, the results will be compared with similar materials which were recovered from Discoverer XVII, when it was snatched in mid-air last month.