CBS News Correspondent Elizabeth Kaledin reports.
On Jan. 31, 1961, a carefully trained chimpanzee named Ham was suited up and blasted into space.
Mercury astronaut Scott Carpenter credits the chimps with being the first to conquer the final frontier.
"They paved the way for us. We could have done it without them but not nearly as quickly," Carpenter says.
Since then Ham's descendents have proved indispensable, through their involvement in seat ejection tests, sonic boom studies and gravity experiments.
But after years of service and contributions to dozens of human endeavors, the Air Force was forced to retire its chimps in 1997 in a process that has proven easier said than done.
After a two-year study, the Air Force recently announced it will split up the chimps. Most will not retire. They will spend the rest of their days involved in medical research tests at the Coulston Foundation.
The foundation, which declined CBS News' request for an on-camera interview, has been investigated many times by the U.S. Department of Agriculture on charges of animal neglect.
The Air Force decision has drawn dissent from renowned chimpanzee expert Jane Goodall. "It's not what they deserve," she says.
Goodall has lent her name to a lawsuit filed against the Air Force to win custody of the animals to prevent them from winding up at Coulston.
"People now aren't thinking in terms of the rights of the chimps," says Goodall. "It's much more convenient to keep that line between humans and animals separated."
A few lucky chimps, just a handful, have gone to a sanctuary near San Antonio, Texas, where they will peacefully spend their days in retirement.
"If the financial resources had been available, more, if not all, of the Air Force chimps would have been retired," says sanctuary director Wally Sweet.
"It's just that the money wasn't there. It's time for us to realize we [owe] them an honorable discharge," he says.
But Carpenter says it's not that simple. Chimps are not humans and to apply a human concept like retirement to them does not do them justice.
"I think these animals served a noble cause," says Carpenter. "They should, if necessary, be asked to continue to serve a noble cause...but they shouldn't be subjected to pain or discomfort."
"They are not tools. They think and feel. We owe them something," argues Swett.
At the very least, their advocates say, they are owed a little peace, fresh air and sunshine after helping us reach for the moon.
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