s he outside than the synthetic gravity generators lost their
pull on his body and he started into space. Tightly grasping two metal
handles in the hull, the big cadet performed a quick somersault and
planted his feet firmly on the hull. His magnetic-soled space boots held
him fast and he called Roger over his helmet intercom.

"I'm outside, Roger," he reported. "On my way down to the exhaust."

"Right," came Roger's voice over the intercom. "Let me know when you're
ready."

Without replying, Astro made his way slowly and carefully down the
length of the rocket scout toward the main drive rocket assembly.
Stopping at the trailing edge of the hull, where it enclosed the four
rockets, the big Venusian squatted on his heels, making certain the
soles of his space boots stayed in contact with the metal of the hull.
He peered over the edge and braced himself in a position where he could
observe the individual rocket exhausts.

"O.K., Roger!" he called into his intercom. "Open up number one."

"Number one, aye," replied Roger. "And watch yourself, you big baboon.
Don't burn your nose!"

"Go ahead, go ahead!" growled Astro in reply.

A long tongue of flame shot out of the exhaust of the number one tube
and, after drawing back momentarily, Astro watched the tube keenly.

"You know," he commented idly as he kept his eyes fixed on the tube, "I
still can't figure out what's so different about these tubes. They're
exactly the same as any others I've ever seen."

[Illustration]

"That's how much you know, Astro," snorted Roger. "Dave Barret said they
were using a new duralumin alloy in the tubes."

"Still doesn't look any different to me," persisted Astro. "And for us
to spend four whole days out here testing them"--he paused and shook his
head--"seems like an awful waste of time," he concluded.

"What do you care? We're out in space, aren't we? Or would you rather be
back on guard duty?"

"No, of course not," replied Astro. "But even space gets dull after a
while with nothing to do. Barret sure gave us an old crate. Not even a
long-range receiver aboard."

"What do you want to listen to?" snorted Roger. "Flight orders and all
the rest of that rocket wash?"

"Be a relief to listen to somebody else beside you for a change,"
snapped Astro. "Anyhow, suppose something important happened. Suppose
our orders were changed. How would we know about it?"

"What difference does it make?" replied Roger. "We've got our
orders-