drilling
straight down. He pointed to it. "Let's have a hole straight in for six
feet. And keep it straight, Kemp. Allow enough room for a lining of
nuclite. Koa, pull a sheet of nuclite out of the cave and cut it to size."

Kemp's torch already was slicing into the metal. Rip asked, "Can you weld
with that thing, Kemp?"

"Just show me what you want, sir."

"Good." Rip motioned to Trudeau. "Frenchy, we'll need a strong rod at
least eight feet long."

The French Planeteer hurried off. Rip consulted his chronometer. Less than
ten minutes had passed since the call from Terra base.

He went over his plan again. It had to work! If it didn't, asteroid and
Planeteers would end up as subatomic particles in the sun's photosphere,
because he had calculated his blast to drive the asteroid past the limit
of safety. It was the only way he could be sure of putting them beyond
danger from Connie landing boats or snapper-boats. The Connie would have
only one chance--to bring his cruiser down on the asteroid.

If he tried that, Rip thought grimly, he would get a surprise. The second
nuclear charge would be set, ready to be fired. The Connie cruiser was so
big that no matter how it pulled up to the asteroid, some part of it would
be close enough to the charge to be blown into space dust. No cruiser
could survive an atomic explosion within five hundred yards, and the
Connie would have to get closer to the nuclear charge than that.

Dominico reported that the bomb had been dismantled. Rip went to it and
examined the raw plutonium, being careful to keep the pieces widely
separated.

This particular bomb design used five pieces of plutonium which were
driven together to form a ball. Rip made a quick estimate. Two were enough
to form a critical mass. He would use two to blast into the sun and three
to blast out again. He would need the extra kick.

There was only one trouble. The pieces were wedge shaped. They would have
to be mounted in thorium in order to keep them rigid. Only Kemp could do
that. They had no cutting tool but the torch.

Santos appeared, carrying a rocket head under each arm. They had wires
wound around them, ready to be attached to an electrical source.

Rip hurried back to where Kemp was at work. The private was using a
cutting nozzle that threw an almost invisible flame five feet long. In
air, the nozzle wouldn't have worked effectively beyond two feet, but in
space it cut right down to the end of the flame.