it."

Marlowe went back to his graphs. Machines could be changed, but the
human body clung stubbornly to the old patterns. He couldn't select his
crews any younger--but was there perhaps a racial type more resistant to
radiation? Where? No place that he knew of. Maybe the biologists could
produce one, he thought hopefully, and knew he was fooling himself.
Human beings weren't fruit flies; by the time enough generations rolled
around for the resistant strain to breed true--and leave a surplus to
man the ships--he would be long dead and the problem solved.

The best of humanity would be dead, too, wiped out by sterilization.

Or the Solar System would be peopled by mutant monstrosities.

* * * * *

Far away, and not concerned with the problem, Ethan shrugged resignedly.
"Guess we'll have to get used to the idea--we just won't see him till he
grows up--if we'll still be around."

"You've got years and years ahead of you, and not worth a thing the
whole time!" Amantha snapped.

"Damnation," said Ethan wistfully, "I'd like to dandle him."

"Won't be the same when he grows up and comes here," Amantha conceded.
"There I go agreein' with you! What's got into me?"

"Maybe we can get on the next slow ship. They run them once in a while
for people with weak hearts." He considered. "Don't know whether Retired
Citizens' Home will let us go, though."

"Retired Citizens!" She blew her nose scornfully. "They think we don't
know it's just a home for the aged!" She threw away the tissue. "Think
they'll let us?"

"It won't be them so much that'll stop us. Our hearts ain't too good and
we haven't got much space time to use. We shouldn't have gone to Venus."

"We had to see Edith and Ed and their kids and we had to come back to
Mars so we could be near John and Pearl and Ray. Let's not regret what
we've done." She picked at the chair arm. "We've been here a long time,
ain't we?"

Ethan nodded.

"Maybe they've forgotten we've only got a month left," she said eagerly.

"You sure it's a month?"

"Figure it out. It took longer when we went."

"Then it's no use. A slow ship is all we'd be allowed to take--and we
wouldn't be allowed because it'd be more than a month."

"They won't remember every last minute we spent in space."

"They will, too," he stated. "They've got records."

"Maybe they lost them."

"Look, we've got kids and grandchildren here. They come around and see
us. Do we have