Jonner?"

"Is should, Jonner," agreed Qoqol. "T'an know all about crazy new
engine, I know all about crazy new orbit. Both not know all. You tell."

"I planned to, anyway," said Jonner. "I had figured on having Serj in on
it, but he wouldn't understand much of it anyhow. There's no use in
waking him up."

Serj was the ship's doctor-psychologist and fourth member of the crew.
He was asleep below on the centerdeck.

"For your information, Qoqol," said Jonner, "the atomic engine produces
electrical energy, which accelerates reaction mass. Actually, it's a
crude ion engine. T'an can explain the details to you later, but the
important thing is that the fuel is cheap, the fuel-to-cargo ratio is
low and constant acceleration is practical.

"As for you, Tan, I was surprised at your not understanding why we'll
use low acceleration. To boost the engine power and give us more Gs,
we'd either have to carry more fuel or coast part of the way on
momentum, like an ordinary rocket. This way's more efficient, and our
63-day margin over the _Marsward_ each way is more than enough for
unloading and loading more cargo and fuel."

"With those figures, I can't see how Marscorp expects to win this
competition," said T'an.

"We've got them, flat, on the basis of performance," agreed Jonner. "So
we'll have to watch for tricks. I know Marscorp. That's why I arranged
to take aboard that G-boat at the last minute. Marscorp controls all the
G-boats at Marsport, and they're smart enough to keep us from using
them, in spite of the Space Control Commission. As for refueling for the
return trip, we can knock a chunk off of Phobos for reaction mass."

The meteor alarm bells clanged suddenly, and the screen lit up once with
a fast-moving red line that traced the path of the approaching object.

"Miss us about half a mile," said Jonner after a glance at the screen.
"Must be pretty big ... and it's coming _up_!"

He and T'an floated to one of the ports, and in a few moments saw the
object speed by.

"That's no meteor!" exclaimed Jonner with a puzzled frown. "That's
man-made. But it's too small for a G-boat."

The radio blared: "All craft in orbit near Space Station 2! Warning! All
craft near Space Station 2! Experimental missile misfired from White
Sands! Repeat: experimental missile misfired from White Sands!
Coordinates...."

"Fine time to tell us," remarked T'an drily.

"Experimental missile, hell!" snorted Jonner, comprehension dawning