An Unhealthy Secret For Glenn?

While 77-year-old astronaut John Glenn had volunteered to be the subject of 80 experiments while on space shuttle Discovery this past week, there's one exercise that NASA doctors would not let him do, reports CBS News Correspondent Sharyl Attkisson.

Some might call it a story of how not to handle a national hero. It began last February when NASA assigned Glenn to a study on the natural sleep hormone, melatonin.

But putting Glenn on the melatonin study meant the requirements had to be changed to include people Glenn's age. A pre-flight safety test was taken, which included extensive cardiorespiratory monitoring.

During the physiological testing, the lead researcher on the sleep study said he detected an abnormality in Glenn. He notified NASA, but to his surprise, they already knew of the problem and hadn't told anyone about it, citing medical privacy.

No one will say what the abnormality is, but Glenn was dropped from the melatonin study, raising questions as to whether he was fit to fly.

"I don't remember that we probed anybody as much from the medical standpoint as Sen. Glenn, and he has a clean bill of health," said NASA physician Dr. Arnauld Nicocropolis.

Nevertheless, the whole thing set off a four-alarm public relations firestorm.

"Whether this means anything medically in the long term, I don't know," said CBS News Space Consultant Bill Harwood. "But it certainly is an embarrassment on a mission this high profile for one set of doctors to know there's something wrong and not to tell the other set who's considering him for an experiment."

Reported By Sharyl Attkisson