like a mask.

"Into each life some rain must fall. Let's go out and see what's been
accomplished since I went to sleep. All right?"

They went out of the Platform together. And as soon as they reached the
floor of the Shed it was plain that the stage had been set for stirring
events.

The top five or six levels of scaffolding had already been removed, and
more of the girders and pipes were coming down in bundles on lines from
giraffelike cranes. There were some new-type trucks in view, too, giants
of the kind that carry ready-mixed concrete through city streets. They
were pouring a doughy white paste into huge buckets that carried it
aloft, where it vanished into the mouths of tubes that seemed to replace
the scaffolding along the Platform's sides.

"Lining the rockets," said Sally in a subdued voice.

Joe watched. He knew about this, too. It had been controversial for a
time. After the pushpots and their jatos had served as the first two
stages of a multiple-rocket aggregation, the Platform carried rocket
fuel as the third stage. But the Platform was a highly special ballistic
problem. It would take off almost horizontally--a great advantage in
fueling matters. This was practical simply because the Platform could be
lifted far beyond effective air resistance, and already have
considerable speed before its own rockets flared.

Moreover, it was not a space ship in the sense of needing rockets for
landing purposes. It wouldn't land. Not ever. And again there was the
fact that men would be riding in it. That ruled out the use of eight- and
ten- and fifteen-gravity acceleration. It had to make use of a long
period of relatively slow acceleration rather than a brief terrific
surge of power. So its very special rockets had been designed as the
answer.

They were solid-fuel rockets, though solid fuels had been long abandoned
for long-range missiles. But they were entirely unlike other solid-fuel
drives. The pasty white compound being hauled aloft was a self-setting
refractory compound with which the rocket tubes would be lined, with the
solid fuel filling the center. The tubes themselves were thin
steel--absurdly thin--but wound with wire under tension to provide
strength against bursting, like old-fashioned rifle cannon.

When the fuel was fired, it would be at the muzzle end of the rocket
tube, and the fuel would burn forward at so many inches per second. The
refractory lining would resist the rocket blast for a cer