Multiple-stage rockets had gone the way of square sail and piston engines when a crash program poured twenty-two mega-bucks into a non-mechanical shield. Piles now diverted four per cent of their output into a field which reflected neutrons back onto the pile instead of absorbing them. Raise the reaction rate and the field tightened. Those sudden statewide evacuations in the early years of the century were now remembered only by TV writers.
A liquid metal heat exchanger transferred energy to the reaction mass which a turbine pump was drawing from a fire hydrant. Since the hydrant was fed from a sea water still there was no need for purification.
The last load of provisions went up and an asepsis party rode the gantry, burdened with their giant vacuum cleaners and germicidal apparatus.
"They'll seal everything but the control room," the general said. "When you go aboard there'll only be one compartment to sterilize."
"I still think it's a lot of hog-wash," Aréchaga said.
"They can't have us carrying any bugs with us," van den Burg said tiredly.
"The Martians might put us in quarantine," Hagstrom added sourly.
"If there are any Martians—and if we get there," Aréchaga groused.
"Now boys," the general began.
"Oh, save it, Pop," Hagstrom said. "Let's be ourselves as long as the public relations pests aren't around."