SPACECRAFT NEWS Vital Data From Pegasus Satellites

Press, Volume CVI, Issue 31085, 14 June 1966, Page 12

SPACECRAFT NEWS Vital Data From Pegasus Satellites

The three huge Pegasus satellites launched into orbit last year are providing vital data on the amount of damage

caused by meteoroids when they collide with space vehicles. They have proved that the Apollo astronauts

will be adequately protected when they travel to the moon. Meteoroids are small fragments of matter travelling in orbits around the sun. When one strikes the upper atmosphere of the earth a brief streak of light appears in the sky. This phenomenon is known as a meteor and is commonly described as a “falling star." The streak of light is caused by the meteoroid vaporising completely as i it rams into the atmosphere at a collision speed of around 30 miles a second. A meteoroid which strikes a space vehicle at such a speed behaves as if it is made of dynamite, blasting a crater roughly as deep as its own size. Fortunately the vast majority of meteorites are no larger than sand grains and can be stopped by the outer skin of a spacecraft. I

The two-ton Pegasus satellites each of which has a wingspan of 96 feet, have been hit by more than 1100 meteoroids. The hits are recorded by special panels in the wings. Each hit causes an electrical short circuit in one panel and the number of hits is radioed back to earth. By employing three different panel skins ranging in thickness from one and a half to sixteen thousandths of an inch, the amount of damage can be estimated by counting the number of penetrations of the various panels. While the results so far obtained show that there will be little chance of trouble on a trip as short as that to the moon, there is a clear warning that thicker walls will be needed on spacecraft venturing on prolonged, missions into space.