The cadet in charge led them up to the surface into a concrete trench about four feet deep. Matt blinked at the sunlight. His depression was gone; he was anxious to start. On each side and about two hundred yards away were training rockets, lined up like giant birthday candles, poised on their fins with sharp snouts thrusting against the sky.
"If anything goes wrong," the cadet said, "throw yourself flat in the trench. Don't let that get your goat-I'm required to warn you.
"The jump lasts nine minutes, with the first minute and a half under power. You'll feel three gravities, but the acceleration is only two gravities, because you are still close to the Earth.
"After ninety seconds you'll be travelling a little faster than a mile a second and you will coast on up for the next three minutes for another hundred miles to an altitude of about one hundred fifty miles. You fall back toward the earth another three minutes, brake your fall with the jet and ground at the end of the ninth minute.
"A wingless landing on an atmosphere planet with gravity as strong as that of Earth is rather tricky. The landing will be radar-robot controlled, but a human pilot will stand by and check the approach against the flight plan. He can take over if necessary. Any questions?"
Someone asked, "Are these atomic-powered ships?"
The cadet snorted. "These jeeps? These are chemically powered, as you can see from the design. Monatomic hydrogen. They are much like the first big rockets ever built, except that they have variable thrust, so that the pilot and the passengers won't" be squashed into strawberry jam as the mass- ratio drops off."
A green signal flare arched up from the control tower. "Keep your eyes on the second rocket from the end, on the north," advised the cadet.
There was a splash of orange flame, sun bright, at the base of the ship. "There she goes!"
The ship lifted majestically, and poised for an instant, motionless as a hovering helicopter. The noise reached Matt, seemed to press against his chest. It was the roar of an impossibly huge blowtorch. A searchlight in the tower blinked, and the ship mounted, up and up, higher and faster, its speed increasing with such smoothness that it was hard to realize how fast it was going-except that the roar was gone. Matt found himself staring straight at the zenith, watching a dwindling artificial sun, almost as dazzling as Sol himself.