as only a short distance
away by spaceship. It was the largest thing in space, except for the sun,
as seen from the asteroid.

Past the orbit of Mercury, the sun side of the asteroid grew dangerously
hot for men in space suits. Rip and the Planeteers stayed in the bitter
cold of the dark side, which ceased to be entirely dark. The temperature
rose somewhat. They were close enough to the sun that the prominences,
great flaming tongues of hydrogen that sped many thousands of miles into
space, gave them light and enough heat to register on Rip's instruments.

Mercury was left far behind, and Earth could not be seen because of the
sun. There was nothing to do now but ride out the rest of the trip as
comfortably as possible, until it was time to throw the asteroid into
a series of ever-tightening elliptical orbits around Earth, known as
braking ellipses. The method would use Earth's gravity to slow them down
to the proper speed. A single atomic bomb and a half dozen tubes of
rocket fuel remained.

Then, as Rip was enjoying the comfort of air during his off-watch hour in
the boat compartment, Koa beat an alarm on the door.

Rip and the Planeteers got into suits and opened up.

"It's Terra base calling on the communicator, sir," Koa reported. "Urgent
message, they said, and they want to talk to you personally."

Rip hurried to the cave. The communicator indicator light was glowing
bright red. He plugged in his helmet circuit and said, "This is
Lieutenant Foster. Go ahead."

A voice crackled across space from Earth. "This is Terra base. Foster,
a Consops cruiser has apparently been hiding behind the sun waiting for
you. Our screens just picked it up, heading your way. We've sent orders
to the _Sagittarius_ on Mercury to give you cover, and the _Aquila_ has
taken off from here. But get this, Foster. The Consops cruiser will reach
you first. You have about one hour. Do you understand?"

Rip understood all right. He understood too well. "Got you," he said
shortly. "Now what?"

The communicator buzzed. "Take any appropriate action. You're on your
own. Sorry. Sending the cruisers is all we can do. We'll stand by for
word from you. If you think of any way we can help, let us know."

Rip asked, "How long before the cruisers arrive?"

"You're too close to us for them to move fast. They'll have to use time
accelerating and decelerating. The _Sagittarius_ should arrive in
something less than two hours and the _Aquila_ a few m