ve done as
much as anyone to help this ship get into space, Dave," he said. "Thank
you!"

"Think nothing of it, Professor," replied Barret airily.

"Well, shall we begin the first series of tests?" asked Connel.

"By all means!" said the professor enthusiastically. "If you and Dave
will check the firing stations, I'll take care of the paper work!"

"Right," replied Connel. "Let's go, Barret!"

"I'll work outside, Major," said Barret, turning toward the air lock.
"You see that all the firing chambers are properly loaded."

"Anything you say, Barret."

The two men turned away from the smiling professor and left the control
deck. They separated in the companionway, Connel hurrying to the
starboard firing chambers and Barret going to the midships air lock
where he put on a space suit for his task out on the hull.

In two minutes the young scientist was out on the odd-looking blisters
that marked the exterior of the firing chambers ringing the hull.

At each blister Barret examined the hollow firing tube carefully. In
several he made delicate adjustments to a small metallic ring extending
from the opening of the tube. The ring was one of the most important
parts of the firing unit, emitting the long-range electronic beam
controlling the flight of the projectile.

Meanwhile, inside the ship, Connel checked the loading of each of the
chambers, making certain that each of the ten-foot-long torpedolike
projectiles was properly secured in its blasting cradle. After fifteen
minutes and a complete trip around the ship, the major was satisfied
that all was in readiness. He returned to the control deck, meeting
Barret on the way, and they found Professor Hemmingwell just completing
his calculations for the initial test. He turned to them, waving a paper
in front of their eyes.

"Gentlemen," he said proudly, "we are almost ready. If you will adjust
course fifteen degrees to port, we'll be in proper position for the
test!"

"Right," nodded Connel. "Stand by below, Barret."

"On my way," replied Barret, disappearing through the hatch.

"Well, Professor," said Connel, walking to the controls, "this is the
big moment!"

"Yes," nodded Hemmingwell. "If these rocket projectiles prove workable
now, there's nothing to stop us from carrying on with our test of the
ground receivers on Mars immediately."

"Power deck to control deck, check in!" Barret's voice suddenly crackled
over the intercom.

"Control deck, aye," replied