WASHINGTON -- In the Mercury days, John Glenn was known as the serious one among America's first seven astronauts.
As he prepares to return to space for the first time since 1962, the former senator from Ohio is smiling, loose, relaxed, even able to tell old-guy-in-space jokes.
"I think they're funny," Glenn said Wednesday.
He said he likes the one about Glenn's mission being the first flight on which an astronaut will be allowed to preboard. He laughed heartily at the gag that his will be the first flight in which the Tang is mixed with Metamusil.
And then there was the cartoon showing him on a space walk, aided by a nursing-home walker.
Indeed, almost every hour of Glenn's nine days in space already has been accounted for. It won't all be glamorous.
A drug will be injected into his arm in a test to examine the breakdown of muscle mass that happens to the elderly on Earth and to everybody in space.
He'll have brain-wave monitors hooked up to his head, eye-movement sensors affixed to his face, a respiration monitor and other wires, gizmos and gadgets.
"Four nights out of nine I'll have to get that whole rig on and try to sleep," Glenn said. "I'll be fully instrumented."
One of Glenn's tasks as junior member of the team will be bar-coding samples of the astronauts' blood and urine -- using a laptop computer for the first time -- then running the blood samples through the onboard centrifuge and storing the urine bags in the shuttle's freezer.
Is that the way Glenn imagined his days in space would be? He grins and shakes his head "no" but says nothing.
Glenn would rather talk about the mission's underlying science.
"I hope we get good enough data out of this, if we do it right -- if I do it right -- that NASA will see the value of doing this in the future," he said. "I'm really excited about the research."