After Glenn spoke with his wife Annie, and their two children via satellite, the family said he looks happier than they have ever seen him and that he has the effervescence of an excited child.
"He is really like a kid," Mrs. Glenn, 78, said of her husband of 55 years. "He looks like a young man, you know what I mean? He looks great. He's not 77."
Dr. David Glenn, 52, who initially opposed his father returning to space, said he hasn't worried about him since last Thursday's launch which by comparison, was "really scary."
However, David added: "I'll feel a whole lot better when he's back on Earth."
His mother and sister, Lyn, 51, couldn't agree more.
"All I can tell you is I feel 100 percent better than I did one week ago at this time. I was scared. I was really excited for John," Mrs. Glenn said. "But now I can say day after tomorrow I'm going to be able to touch him. That's very, very special to me."
In a news conference with the rest of the crew a few hours later, Glenn acknowledged that he misses his wife and the rest of the family, but wouldn't mind another week in orbit. The last time Glenn flew, as the first American to orbit the Earth on Feb. 20, 1962, he spent a scant five hours aloft.
After the news conference, Glenn spoke with Vice President Al Gore, who lauded the astronaut's work on Discovery. Glenn, in turn, joked about space as the ideal retirement home, where weightlessness guards against some of the usual inconveniences of aging.
"You spill food, it doesn't go on your necktie; it just floats out away from you...You don't need a walker up here...because you just float across the room...If you have trouble sleeping at night, why it's no problem, because you have another night coming up in not more than 45 minutes."
With the landing of the Discovery less than a day and a half away, NASA prepared Thursday for an unlikely -- but possible -- landing problem stemming from a missing drag parachute door on the space shuttle. CBS News Correspondent Sharyl Attkisson reports.
NASA's camera captured the door falling off when Discovery launched, but no one knows whether the parachute also fell out as the shuttle went into orbit. It could still be tucked, or even melted, inside the hatch.
A previous space shuttle landing using the parachute.(CBS)
"We're going to get the final word probably tomorrow on what we're really going to do and what we're going to plan for," Mission Cmdr. Curt Brown said Thursday.
The shuttle doesn't need the parachute to safely stop. The device was a post-Challenger improvement added to make front wheel touchdown softer, and prevent wear-and-tear on the brakes and landing gear. However, a problem could arise if the chute spontaneously deploys before the rear wheels hit the ground.
"When the shuttle's close to the ground, it is a glider of course, and if you pop that parachute inadvertently, it really acts like putting the brakes on hard," explains CBS News Space Consultant Bill Harwood.
NASA doesn't want to jettison the chute before landing, in the zero gravity of space, because it wouldn't float away and could pose trouble on re-entry. If the chute does pop out while Discovery is coming down, the commander and pilot will be ready to cut it loose to prevent what nasa terms a "crit 1 failure" -- a crash in which no one survives.
The mission's entry flight director told CBS News Thursday that NASA believes "nothing will happen" upon landing, but they're preparing for all possibilities. Why the door fell off in the firts place is now under investigation.
In between all the calls from well-wishers, Glenn and his crewmates continued their studies comparing space travel with aging.
Dave Williams, director of NASA's space and sciences division, said the mission is "going very, very well."
Williams told CBS News that Glenn has adapted very well to the space environment.
NASA also reported that a computer and two Hubble Space Telescope components flying aboard Discovery have held up well against cosmic radiation. The equipment is being tested 350 miles up to ensure it will work when installed by spacewalking astronauts in 2000.
Besides the computer, the shuttle is test-flying a data recorder for Hubble and a turbine-driven cooler needed to keep infrared camera sensors at minus-330 degrees. The camera's evaporating supply of nitrogen ice will be gone by the end of December, halting observations by the camera until the cooler is installed.
Experiments must be wrapped up by late Friday, Williams said. Friday night's work will involve getting the orbiter cleaned and the equipment stowed away for the Saturday morning re-entry and landing at Kennedy Space Center.