t change course!"

"Right," drawled Roger. "And if we can't change course, the one we're on
now will take us straight into Mars's gravity and we crash!"

"Send out an emergency call right away, Roger," said Tom.

"Can't, spaceboy," replied Roger in his lazy drawl. "Not enough juice to
call for help. Or haven't you noticed you're standing in the dark?"

"But how--how could this happen?" asked Tom, puzzled. "We were only
going at half speed and using just three rockets!"

"When we got rid of that hot tube back in space," explained Astro
grimly, "we dumped the main reactant mass. There isn't a thing we can
do!"

"We've got one choice," said Tom hollowly. "We can either pile out now,
in space suits and use the jet boat, and hope for someone to pick us up
before the oxygen gives out, or we can ride this space wagon right on
in. Make up your minds quick, we're already inside Mars's gravity pull!"

There was a pause, then Astro's voice filled the control deck. "I'll
ride this baby right to the bottom. If I'm going to splash in, I'll take
it on solid ground, even if it is Mars and not Venus. I don't want to
wash out in space!"

"That goes for me, too," said Roger.

"O.K.," said Tom. "Here we go. Just keep your fingers crossed that we
hit the desert instead of the mountains, or we'll be smeared across
those rocks like applesauce. Spaceman's luck, fellas!"

"Spaceman's luck, both of you," said Astro.

"Just plain ordinary luck," commented Roger, "and plenty of it!"

The three boys quickly strapped themselves into acceleration seats, with
Tom hooking up an emergency relay switch that he could hold in his hand.
He hoped he would remain conscious long enough to throw the switch and
start the water sprinkler in case the ship caught fire.

The _Lady Venus_ flashed into the thin atmosphere from the void of space
and the three cadets imagined that they could hear the shriek of the
ship as it cut through the thin air. Tom figured his speed rapidly, and
counting on the thinness of the atmosphere, he estimated that it would
take eleven seconds for the ship to crash. He began to count.

" ... One--two--three--four--five--" he thought briefly of his family
and how nice they had been to him " ... six--seven--eight--nine--ten--"

The ship crashed.

[Illustration]

CHAPTER 17

"Astro! Roger!" yelled Tom. He opened his eyes and then felt the weight
on his chest. A section of the control board had fallen across him
p