The six-gravity acceleration seemed to endure for centuries. Actually,
it lasted for fourteen seconds. In that time it increased the speed of
the little ship by rather more than half a mile per second, something
over 1,800 miles per hour. Before, the ship had possessed an orbital
speed of a shade over 1,470 miles an hour. After the jato thrust, it was
traveling nearly 3,400 miles per hour. It needed to travel something
over 12,000 miles per hour to reach the artificial satellite of Earth.

The intolerable thrust ended abruptly. Joe gasped. But he could allow
himself only a shake of the head to clear his brain. He jammed down the
take-off rocket firing button. There was a monstrous noise and a mighty
surging, and Haney panted, "Clear of cage...."

And then they were pressed fiercely against their acceleration chairs
again. The ship was no longer in its launching cage. It was no longer
upheld by pushpots. It was free, with its take-off rockets flaming. It
plunged on up and out. But the acceleration was less. Nobody can stand
six gravities for long. Anybody can take three--for a while.

Joe's body resisted movement with a weight of four hundred and fifty
pounds, instead of a third as much for normal. His heart had to pump
against three times the normal resistance of gravity. His chest felt as
if it had a leaden weight on it. His tongue tried to crowd the back of
his mouth and strangle him. The sensation was that of a nightmare of
impossible duration. It was possible to move and possible to see. One
could breathe, with difficulty, and with titanic effort one could speak.
But there was the same feeling of stifling resistance to every movement
that comes in nightmares.

But Joe managed to keep his eyes focused. The dials of the instruments