The man from Wallops Island shrugged. "Nothing very complex about it. It's a simple solid-fuel rocket with star grain, fired by a squib that is commanded from the ground. A squib is simply an igniter to start the fuel burning. Battery power makes it glow red hot when turned on."
"How high an altitude would the rocket reach?" Steve asked.
"It's difficult to be precise, but I'd estimate the balloon carries it to ten thousand feet, then it is fired by signal from the ground at the proper time. The rocket would go to about one hundred thousand feet, plus or minus twenty thousand. In other words, I'd guess its maximum altitude at nearly twenty-three miles."
"Did you say fired at the proper time, or proper altitude?" Rick asked quickly. He wanted clarification of the point, although he was sure McDevitt had said "time."
"The altitude isn't important. I'd say time was the principal factor."
"But if altitude isn't important, why use a rockoon? Why not use a rocket launched directly from the ground?" Scotty demanded. He looked puzzled.
Rick looked at Steve expectantly. The young agent smiled. "Got the answer, Rick?"
"Maybe. It's a matter of secrecy, isn't it? The folks around here were puzzled by the flying stingarees, but they would have been more puzzled by rocket firing. They'd have been curious enough to want to know why the rockets were being fired, and it's certain that an investigation would have resulted. By using rockoons, with balloons that didn't look like balloons, Camillion confused the issue. People who reported seeing things got laughed at, mostly because they call any unidentified flying object a flying saucer. The rockets fired only when high in the air, where people wouldn't notice."
"Two did," Scotty reminded him. "Remember? We had two interviews where the people saw spurts of flame."
"Sure," Rick agreed, "but they had no idea it was a rocket taking off from a balloon. And only two out of the whole bunch even noticed flame at all."