all
Planeteers have an opportunity to clean up and eat. They will return to
the asteroid in one hour."

Rip asked, "Will I be able to go into space by then?"

The doctor replied, "Your arm will be normal in about twenty minutes. It
will ache some, but you'll have full use of it. We'll bring you back to
the ship in about twenty-four hours for another look at it, just to be
sure."

Sixty minutes later, clean, fed, and contented, the Planeteers were again
on the thorium planet, while the _Scorpius_, riding the same orbit, stood
by a few miles out in space.

The asteroid and the great cruiser arched high above the belt of tiny
worlds in the orbit Rip had set, traveling together toward distant Mars.

CHAPTER TWELVE

Mercury Transit

The long hours passed, and only Rip's chronometer told him when the end
of a day was reached. The Planeteers alternately worked on the surface
and rested in the air of the landing boat compartment, while the asteroid
sped steadily on its way.

When a series of sightings over several days gave Rip enough exact data
to work on, he recalculated the orbit, found the amount that the course
had to be corrected, and supervised the cutting of new holes in the
metal.

Tubes of ordinary rocket fuel were placed in these and fired, and the
thrust moved the asteroid slightly, just enough to make the corrections
Rip needed. It was not necessary to take to the landing boat for these
blasts. The Planeteers retired to their cave, which was now lined with
nuclite as a protection against radiation.

Rip watched his dosimeter climb steadily as the radiation dosage mounted.
Then he took the landing boat to the Scorpius, talked the problem over
with the ship's medical department, and arranged for his men to take
injections that would keep them from getting radiation sickness.

They left the asteroid belt far behind and passed within ten thousand
miles of Mars. The _Scorpius_ sent its entire complement of snapper-boats
to the asteroid for protection, in case Consops made another try, then
flamed off to Marsport to put in new supplies to replace those damaged
when Rip had forced sudden and disastrous acceleration.

The asteroid had reached Earth's solar orbit before the cruiser returned,
though Earth itself was on the other side of the sun. Rip ordered a
survey and found the best place on the dark side to make a new base. The
Planeteers cut out a cave with the torch, lined it with nuclite, and
m