y, Dan." Ben glanced at the clock. "Hit the sacks, boys."

By the time Feldman could settle into the sacklike hammock, the
_Navaho_ began to shake faintly, and weight piled up. It was mild
compared to that on the shuttle, since the big ships couldn't take high
acceleration. Space had been conquered for more than a century, but the
ships were still flimsy tubs that took months to reach Mars, using
immense amounts of fuel. Only the valuable plant hormones from Mars made
commerce possible at the ridiculously high freight rate.

Three hours later he began to find out why spacemen didn't seem to fear
dying or turning pariah. The tube quarters had grown insufferably hot
during the long blast, but the main tube-room was blistering as Ben led
the men into it. The chief handed out spacesuits and motioned for Dan.

"Greenhorn, aincha? Okay, I'll take you with me. We go out in the tubes
and pull the lining. I pry up the stuff, you carry it back here and
stack it."

They sealed off the tube-room, pumped out the air, and went into the
steaming, mildly radioactive tubes, just big enough for a man on hands
and knees. Beyond the tube mouth was empty space, waiting for the man
who slipped. Ben began ripping out the eroded blocks with a special
tool. Feldman carried them back and stacked them along with others. A
plasma furnace melted them down into new blocks. The work grew
progressively worse as the distance to the tube-room increased. The tube
mouth yawned closer and closer. There were no handholds there--only the
friction of a man's body in the tube.

Life settled into a dull routine of labor, sleep, and the brief relief
of the crude white mule from the still.

They were six weeks out and almost finished with the tube cleaning when
Number Two tube blew. Bits of the remaining radioactive fuel must have
collected slowly until they reached blow-point. Feldman in Number One
would have gone sailing out into space, but Ben reacted at once. As the
ship leaped slightly, Feldman brought up sharply against the chief's
braced body. For a second their fate hung in the balance. Then it was
over, and Ben shoved him back, grinning faintly.

He jerked his thumb and touched helmets briefly. "There they go, Dan."

The two men who had been working in Number Two were charred lumps,
drifting out into space.

No further comment was made on it, except that they'd have to work
harder from now on, since they were shorthanded.

That rest period Fel