After six years of silence, the thunder of manned space flight is heard again as the successful launch of the first Space Shuttle ushers in a new concept in utilization of space. The April 12 launch at Pad 39A, just seconds past 7 a.m., carries astronauts John Young and Robert Crippen into an Earth orbital mission scheduled to last for 54 hours, ending with unpowered landing at Edwards Air Force Base in California. STS-1, the first in a series of shuttle vehicles planned for the Space Transportation sysstem, utilizes reusable launch and return components