At Tom's words, the watchers and crewmen who were crowded into the _Recoverer_'s control room stirred restlessly. Its bulkheads were banked with radar and telemetering devices. Tension had been mounting throughout the morning aboard the ships and observation planes of the task force as everyone awaited the return of the planet-circling missile--scientists' deepest penetration into space so far. "What do you mean, a total loss?" Bud argued. "Even if the recovery operation's a flop, the shot will still pay off in valuable information, won't it?" Tom shook his head grimly. "The purpose of this unmanned, exploratory flight around Jupiter was to take and record all kinds of data. But none of the info is being radioed back to us." "How come?" "If we had put in radio gear strong enough to relay signals back, it would have cut down the amount of information-gathering equipment aboard," Tom explained. "We had to make every ounce count." Outwardly calm, Tom was seething with inner excitement. Although only eighteen--the same age as his husky, dark-haired pal and copilot, Bud Barclay--Tom had been given the job of directing the recovery phase of the United States government's Project Jupiter survey. The Swifts and their rocket research staff had built the missile and engineered the space probe for the government. "Whew!" Bud gave a nervous whistle. "I see what you mean, pal. With all our eggs in one basket, we sure can't afford to get butter-fingered with the Jupiter prober." Admiral Walter, a tall, distinguished man, graying at the temples, smiled. "It's what we call in warfare a calculated risk, Bud," he said. "But with Tom in charge, I believe we have nothing to worry about." Mr. Swift's eyes shone with fatherly pride at the admiral's remark. Tom Jr.'s pioneering rocket flights and inventions had won the youth a top rank in American space research. "Guess you're right, sir," Bud agreed. "I'll back genius boy here any day!" Tom winced as Bud whacked him heartily on the shoulder. "Better save your orchids and keep your fingers crossed, fly boy," the young inventor advised. "That rocket's not home yet." Radio telescopes, both on land and aboard the ships of the task force, were following the missile's progress as it drew closer to earth. All were feeding a steady stream of information to the ships' computers. "How soon will you fire the retro-rockets, Tom?" Admiral Walter inquired presently. "In about ten seconds, sir," Tom replied, eying the sweep second hand of the clock. Moments later, a red light flashed on the master control panel. Tom's finger stabbed a button. Far out in space, the retarding rockets in the missile's nose were triggered for a brief burst, slowing its high speed. Without this, the missile would hurtle to flaming destruction in the atmosphere. "We've picked it up!" shouted a radarman.