Modern high-altitude rockets are not always complex monsters like their ancestral V2. They are steadily growing smaller, simpler and cheaper. This week Republic Aviation Corp. told about a non-military rocket that it is manufacturing for a Defense Department project administered by the University of Maryland. Called the Terrapin (after the university's mascot), it is a two-stage, solid-propellant rocket that climbs 80 miles.
The extraordinary thing about the Terrapin is its small size and simplicity. It is less than 15 ft. long, 6¼ in. in diameter, and weighs only 224 lbs. It has none...