d. They had sent
orders instantly to the fastest cruiser in the area, the _Scorpius_, to
stand by for further instructions. Then their personnel machines must
have whirred rapidly, electronic brains searching for the nearest
available Planeteer officer with an astrophysics specialty and
astrogation training.

He could imagine the reaction when the machine turned up the name of a
brand-new lieutenant. But the choice was logical enough. He knew that
most, if not all, of the Planeteer astrophysicists were in either high
or low space on special work. Chances were there was no astrophysicist
nearer than Ganymede. So the choice had fallen to him.

He had a mental image of the Terra base scientists feeding data into the
electronic brain, taking the results, and writing fast orders for the men
and supplies needed. Work at the Planeteer base had probably been
finished within an hour of the time word was received.

When they opened the cases brought aboard by the Martians, he would see
that the method of blasting the asteroid into a course for Earth was all
figured out for him.

Rip was anxious to get at those cases. Not until he saw the method of
operation could he begin to figure his course. But there was no
possibility of getting at the stuff until _Brennschluss_. He put the
problem out of his mind and concentrated on what his men were saying.

"... and he slugged into that asteroid going close to seven AU's," Santos
was saying. The corporal shrugged expressively.

Rip recognized the story. It was about a supply ship, a chemical drive
rocket job, that had blasted into an asteroid a few years before.

Private Dowst shrugged, too. "Too bad. High vack was waiting for him.
Nothing you can do when Old Man Nothing wants you. Not a thing in space!"

Rip listened, interested. This was the talk of old space hands, who
had given the high vacuum of empty space a personality, calling it
"high vack," or "Old Man Nothing." With understandable fatalism, they
believed--or said they believed--that when high vacuum really wanted
you, there was nothing you could do.

Rip had come across an interesting bit of word knowledge. Spacemen and
Planeteers alike had a way of using the phrase "by Gemini!" Gemini, of
course, was the constellation of the Twins, Castor and Pollux. Both were
useful stars for astrogation. The Roman horse soldiers of ancient history
had sworn "by Gemini," or "by the Twins." The Romans believed the stars
were the famou