GLENN'S RETURN TO SPACE A BLAST FOR OLDER PEOPLE.

Byline: Martin Merzer Knight Ridder Newspapers

John Glenn is a senior astronaut in every sense of the phrase, and his return to space this week - at the age of 77 - represents much more than just a step for one man.

It is a big step for older men and women everywhere.

``This is neat,'' said Dr. Carl Eisdorfer, 68, director of the University of Miami's Center for Adult Development and Aging. ``It opens up whole new vistas for older people. It's going to send a very powerful message to the public.''

Said Kurt Volker, 56, a former NASA technician now living in Dania, Fla.: ``It's terrific. It shows you that life doesn't stop at 60.''

Blastoff is scheduled for 2 p.m. Thursday. Glenn's presence aboard shuttle Discovery - a grandfather soaring into space with crew mates half his age - is rekindling interest in the space program, a phenomenon that bridges the generations.

America's most enduring space hero, Glenn insists that his work 345 miles above Earth could yield scientific advances for the elderly. During the nine-day mission, he will subject himself to a variety of medical tests, including studies of bone loss, sleep disorders, muscle deterioration and body temperature.

``All of a sudden,'' Glenn said, ``my age became an advantage instead of a disadvantage.''

Others believe the mission resonates more with sentiment than science, but there is wide agreement on this: Glenn's excellent new adventure thrills and heartens the rapidly growing corps of older Americans, and it is reminding all Americans that advancing age does not condemn people to society's sidelines.

George Hoggard, a safety expert at the Kennedy Space Center, trained Glenn in emergency escape procedures from the shuttle and launch pad. Hoggard is 61.

``I'm real proud to see him do this, and I admire him a heck of a lot for his efforts,'' Hoggard said. ``It sends this message: Don't discriminate against age, because you have real valuable people here.''

In 1962, Glenn became the first American to orbit Earth. His entire flight in Friendship 7 took only four hours, 55 minutes and 23 seconds.

Now, he will live in space for more than a week, in tight quarters with six other people and in an environment that often afflicts much younger people with persistent, profound cases of airsickness.

At 77, Glenn is nearly twice as old as the typical astronaut and 16 years older than the oldest human ever to fly in space - former astronaut Story Musgrave, grounded last year because he was deemed too old.

Doctors say Glenn is in excellent health and sailed through NASA's rigorous training program, though something - the details have not been released - compelled NASA to drop him from one element of the sleep disorder experiments.

``I feel great,'' Glenn said. ``I passed all the physicals. They literally checked me more than any astronaut that's ever flown, including the original seven. I've had every heart exam they know how to give.''

`An old man's game'

Some of his contemporaries agree that he should be fine, though they express a bit of envy and stick a needle of their own into their old friend.

``I don't have the political clout, but I'd love to fly in space again,'' said Al Worden, who flew to the moon aboard Apollo 15.

``It's a geriatric game anyway. Think about it - you sit around, you look out the window. It's an old man's game.''

Jokes aside, Glenn and his friends and his trainers know that this is a bold and risky endeavor.

``Yeah, John Glenn could get up there and have a heart attack,'' said Phil Engelauf, the mission's chief flight director. ``But even 40-year-olds drop dead.''

Glenn and his crew mates will conduct 83 experiments during their flight, many of them devoted to ailments of the elderly. Glenn will be poked and prodded with needles, wired to monitoring devices, constantly under scrutiny by two doctors aboard Discovery and countless experts back at Mission Control.

``There is a huge personal satisfaction in going up again,'' Glenn said. ``I don't deny that.

``But my main concern, truly, is to do as fine a job as I can so we bring back a lot of data to enable that kind of research to go forward. That's a real thrill, to be taking part in something like this.''

Scientists know that the physical effects of space flight, even on younger astronauts, are remarkably similar to the physical effects of old age.

Among other things, the weightlessness and microgravity of space almost always sap astronauts of some bone mass. Experiments planned for Glenn will study that medical oddity and its similarity to osteoporosis, the bone loss often suffered by old people.

``We spend $9 billion a year treating broken bones from osteoporosis,'' Glenn said. ``This study could benefit you, your grandmother, your wife, your husband, most of the elderly in this country who are subjected to that sort of thing.''

Important research

The need for such research is evident, and growing.

About 34 million Americans are now 65 or older. That number is expected to triple as baby boomers retire. By the year 2050, 800,000 Americans will be more than 100 years old.

Given that, the government and several health and senior citizens organizations already are taking advantage of Glenn's renewed celebrity.

``If you can only walk around the room or up and down the halls of the building or around the block once, do it,'' Glenn says in a public service announcement that asks older Americans to start exercising.

But something else also is at work here: Glenn's mission is stimulating a new sense of pride among older Americans, a sense of enhanced self-worth.

``While we've been changing life expectancy, we haven't done all that much to change attitudes about the potential of older people,'' said Eisdorfer, the University of Miami aging specialist. ``Society's whole attitude is that older people are dysfunctional. We need to change that.''