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Thirty-six years ago, John Glenn piloted the Mercury-Atlas 6 ``Friendship 7'' spacecraft on the first U.S. manned orbital mission. Launched from Cape Canaveral in Florida on Feb. 20, 1962, he completed a successful three-orbit mission around the Earth, reaching a maximum altitude of approximately 162 statute miles and an orbital velocity of approximately 17,500 miles per hour. Mission duration from launch to impact was 4 hours, 55 minutes, and 23 seconds.
As the Oct. 29 Shuttle launch has approached, there has been a revival of the kind of cultural optimism among the American people last seen with the Mars Pathfinder mission which began July 4, 1997, when millions of people around the world watched with tremendous interest and excitement as, once again, NASA proved all the naysayers wrong.
Among those cheering the loudest for John Glenn are the men and women of his generation, for whom the Kennedy-era space program is a living memory, and a touchstone for a time--not so long ago--in our nation's history, when things, and people, were better.
At the Kansas Cosmodrome in Hutchinson, seniors are taking Space Shuttle training and participating in mission simulations, to see if they would be up to snuff for a flight into space. The American Federation for Aging Research is airing 30- and 60-second spots on television, featuring John Glenn discussing the importance of space research to help keep seniors healthy and productive.
Even the media has dropped its sniping about political payoffs by the Clinton Administration to Glenn for his role on the Senate Judiciary Committee, and similar nonsense. The ``Style'' section of the Oct. 8 Washington Post features an article by reporter Kathy Sawyer, titled, ``John Glenn: Time Traveler.'' She reports that media criticism was ``drowned out,'' and that, in fact, at the press conference last January announcing his flight, ``tears glinted in the eyes of crusty network correspondents in the packed auditorium.'' Sawyer describes Glenn as an ``authentic, untarnished hero.'' The effect of his going back into space has been a kind of ``reverse Rip van Winkle,'' she says, since ``it is as if his astonishing return to space had reawakened a whole segment of society.''
A recent issue of Life magazine features Glenn in Shuttle training photos taken by the same photographer--now 80 years old--who took the pictures for the magazine's cover story on Glenn in 1962. Walter Cronkite, who covered space launches even before there was a NASA, is coming out of retirement to anchor the launch next week for CNN. In an article in Newsweek, Cronkite says, ``I think it's great that John Glenn is going up one last time. He's a true American hero at a time when heroes are in short supply.'' The White House announced today that President Clinton will be going to Cape Canaveral for the Oct. 29 launch, as will most of the Congress.
Glenn, himself, in an interview aried on Maryland Public Television's Health Week Oct. 11, began by saying ``I never thought I'd be able to go [into space] again. And who had ever thought age would be an advantage, instead of a disadvantage!''
Glenn recalled that he had always had an interest in medicine, and that if World War II had not intervened, and he had not gone into flying, he would have been a doctor. He stated, ``When I got here [to the Senate] 24 years ago, I asked to be on the Special Committee on Aging, because I wanted to look into some of these things.... We have about ten different areas in the human body that change with aging, and also occur to astronauts up there. They return to normal, when they return to Earth. The aging process here on Earth does not let you return to `normal,' so what the National Institute on Aging and NASA want to look at is if we can eventually find out what within the human body turns these systems on and off.''
Asked what he thought of the statement that had been made, that it is too risky to send a 77-year-old man into space, Glenn replied, ``I'm not interested in making this a suicide mission. I'm as interested in coming back as anybody else.'' That is why he underwent the same rigorous physical tests as all of the astronauts, he explained.
``I'm very concerned about doing a good job on this flight, because I think we have a sort of toe in the door to open up a whole new area of research that I think has the potential to be enormously valuable,'' Glenn declared.
Nonetheless, Glenn has discouraged efforts by the media to place his role at the center of this mission. At a news conference Oct. 8 at Cape Canaveral, Glenn chastised the press for focussing on the ``personal aspects'' of the mission, meaning his participation, and ignoring the scientific work that will be done aboard the shuttle, In fact, over 80 experiments are scheduled for the nine-day mission, some of which relate to the parallels between the processes of aging and adaptation of microgravity, in which Glenn will be a key subject.
Glenn determined that there would be great value in sending an older person into the microgravity environment to observe differences in the way his body adapted as compared to the much younger astronauts who typically fly on the Space Shuttle. And since he had always wanted a return flight, it was obvious whom he would suggest be the guinea pig.
Researchers at the space agency and in the medical field had already realized the benefit to both communities of joint experiments in space. In 1992, NASA signed a series of Memoranda of Understanding with the National Institutes of Health for joint space-based experiments. To date, NASA has signed agreements with eight of the separate NIH Institutes.
The physiological changes that an astronaut experiences in microgravity have been described as ``aging in fast forward.'' In the space of a few days, a healthy crew member finds that his sense of balance has been disturbed, his bone is demineralizing, his heart muscle shrinks, his immune system is depressed, and he has trouble sleeping. These manifestations, resulting from the adaptation to the space environment over a period of days, parallel those suffered by people as they age, over a period of years.
One of the advantages of flying John Glenn on the Space Shuttle, rather than anyone else his age, is that the space agency has accumulated nearly 40 years of physiological data on him, from the time he was chosen to be a Mercury astronaut in 1959. How the aging process has proceeded until now, in John Glenn's case, is documented. How the space environment affects someone that age is what scientists hope to learn.
It is assumed that although many of the symptoms of space adpatation and of aging are similar or even the same, the causes are different, and the mechanisms that trigger them may be different, as well.
But if we learn more about each cause, we may be able to develop additional countermeasures to prevent astronauts from suffering the changes from space flight. Similarly, we may be able to develop ``countermeasures'' to some of the manifestations of aging, by studying how the astronaut's body reverses its simulated aging when he returns to Earth.
The international crew includes European Space Agency rookie astronaut Pedro Duque from Spain, and second-timer Chiaki Mukai, M.D., of Japan. The crew will spend nine days in space in one of the most intense and complex missions ever flown in the Shuttle.
In some of the critical areas where researchers are anxious to compare the functioning of a 77-year-old to a 40-year-old in space, measurements of physiological adaptation to microgravity are taken on most or all members of any Space Shuttle crew, so there will be a large existing amount of data for the sake of comparison. For example, it is customary to analyze urine samples to observe the rate of calcium excretion, indicating the rate of demineralization of bone.
For this flight, muscle development and loss will also be studied. Dr. Arny Ferrando, from the University of Texas Medical Branch, has designed an experiment which will require Glenn and Pedro Duque to swallow pills containing the amino acid N-15 alamine. Ferrando will compare the amount of amino acid absorbed by the body and the amount passed out in the urine, to calculate how quickly proteins needed for muscle formation are built up, and broken down. He will also measure the amounts of cortisol and insulin in the blood samples the astronauts will contribute, to see if stress plays a part in muscle loss, as these hormones are evidence of stress.
Dr. Ferrando believes that the world's oldest astronaut will experience a more severe process of muscle loss in space, or longer recovery time when he returns to Earth.
One of the experiments that scientists are anxious to conduct, both for the benefit of astronauts and the elderly, concerns sleep. During a briefing at the Johnson Space Center on October 15, Dr. David Williams, an astronaut and Director of Space and Life Sciences, reported that on his mission, ``I found I slept six and a half to seven hours, and still felt that I had to toss and turn'' even though there was no pressure on his body. Many astronauts report their sleep is disturbed in space.
To try to help determine why astronauts do not sleep well, scientists will be monitoring the brain wave activity, eye movements, respiration patterns, and body temperature of Chiaki Mukai and John Glenn. They will swallow miniature thermometers with transmitters to report their temperature. Doctors will be interested to see if there are differences that are perhaps attributable to age.
In addition, Mukai will participate in the experiment, ``Clinical Trial of Melatonin as a Hypnotic for Space Crew.'' On designated nights she will take the hormone melatonin before bed, and her sleep and alterness upon waking will be observed. Although John Glenn was initially slated to also be a subject in this experiment, NASA recently announced, without elaboration, that he did not meet the criteria for that experiment,
Some naysayers have criticized the value of the data gathered on Glenn, complaining that his will be only one data point on an older person in space. Explaining the import of the experiments, Dr. Williams said it was not a matter of this mission finding answers. ``We'll just be making an observation. But observations lead to hypotheses, which lead to experiments, which lead to increased knowledge.''
In addition to the experiments in which John Glenn will be a subject, he will be ``another pair of hands'' to help with many of the 35 experiments that will be carried in the Spacehab laboratory inside the Shuttle's payload bay.
The subjects in the Vestibular Function Experiment are two marine Toadfish that will be electronically monitored to determine the effects of gravitational change on the inner ear. The balance problems afflicting astronauts upon return to Earth's gravity are also common among the elderly, and those suffering diseases affecting the vestibular system.
The effect of microgravity on cartilage growth will be studied in an experiment being flown in the National Institute of Health's Cell Culture Module. Previous experiments of cartilage grown in microgravity have shown distinct variations from those grown on Earth. The cell cycle of cartilage will be studied to observe how alterations due to microgravity effect cell growth and differentiation.
STS-95 includes a commercial bioreactor to grow cells and tissue in three dimensions which cannot be done as well on Earth. The BioDyn Bioreactor is entirely automated, and combines a rotating culture vessel where the tissue is grown, with the ability to collect samples during operation, without involving a crew member.
An experiment by Synthecon Inc. will use the bioreactor to grow a recombinant protein that can decrease the rejection of transplanted tissue. The cells that produce this protein must attach to something to grow, and will be cultured in a medium that contains polymer microbeads for this purpose.
Microencapsulation holds great promise for the ability to place treatments exactly where they are needed and improve the treatment of a number of diseases. One commercial experiment on STS-95 will focus on improving microencapsulating material for cells that produce insulin, to lead to an implantable treatment for diabetes, replacing insulin injections.
Another experiment is an investigation into the engineering of synthetic bone that can be used to treat diseases and replace damaged bones. Tissue engineering will also be carried out to grow ``heart patches'' or pieces of cardiac tissue, that can be used to replaced damaged heart muscle. The goal is to grow patches up to a half inch in size.
Crystal growth experiments have been described as the ``frequent flyers'' of the Space Shuttle program, as they have flown on over 35 Shuttle missions. Crystals grown in microgravity obtain a size, purity, and clarity that can not be duplicated on Earth. Studying the crystaline structure of proteins holds great promise for understanding disease and developing treatments and cures.
On this Shuttle flight, there will be three crystal growth techniques used, growing crystals of 26 different proteins, yielding 1,500 specimens for study. Crystals grown will include HIV-1 protease inhibitor as a target for treatment, an enzyme that could help in the development of antibacterial drugs, human insulin, and Chagas disease.
Also along for the ride will be cockroaches in three different stages of development, to observe the effect of microgravity on their life cycle. This experiment was designed by students at DuVal High School in Maryland.
Another student experiment will study the effect of microgravity on the weight and mass of common objects like soap, chewing gum, bubble wrap, crayons, and popcorn. (The experiments were chosen by elementary school children in Marietta Georgia).
Numerous additional life sciences experiments will study areas such as plant growth, responses of an artifical heart to space, embryogenesis in orchard grass, the effect of radiation on plans, and others.
A major payload on this Shuttle mission concentrates on outer, rather than ``inner'' space, and this is the SPARTAN spacecraft. It is a free-flying payload, that will be released from the Space Shuttle the second day of the flight, fly on its own, and be retrieved about 44 hours later.
While it is flying free of the Shuttle, about 70-100 miles away, it will be focussing its instruments on the corona of the Sun. The corona is the thin upper layer of the Sun's atmosphere, where the temperature is hotter than anywhere else in the Sun, and from where the solar wind originates.
The Sun has just begun the active phase of what is described as its sunspot cycle, so named because the visible ``sunspots,'' which are actually concentrations of magnetic fields, form and migrate from the equatorial region to the poles. The culmination of this solar activity that is spawned during the active cycle is the flipping of the magnetic poles of the Sun.
Aboard the SPARTAN spacecraft are two telescopes. The white light coronograph will measure the density of the electrons in the coronal white light, which is too dim to be viewed from Earth except during a solar eclipse. The ultraviolet coronal spectrometer will measure the velocities, temperatures, and densities of the coronal plasmas.
Data from these telescopes will be combined with those from the Ulysses spacecraft, which crossed the poles of the Sun, and the Solar Heliospheric Observatory, (SOHO), which has had some mishaps but is being reactivated. Scientists hope to use this suite of spacecraft and instruments to track the changes in the morphology and physical conditions of the corona during the solar cycle.
Asked at an Oct. 15 briefing how many major solar events he was expecting the SPARTAN instruments would encounter during its mission, Mission Manager Craig Tooley said, ``it could be as high as four or five a day at this level of solar activity.'' Scientists are hoping they will be treated to an event such as a dramatic coronal mass ejection during the two days SPARTAN is on duty.
The Solar Extreme Ultraviolet experiment on the Hitchhiker payload will be studying the response throughout the Solar System to the extreme ultraviolet emissions from the Sun, including the impact on the Earth's atmosphere. And the Hubble Space Telescope Optical Systems Test included on this mission, will test equipment that will be used next year on the next Hubble Space Telescope servicing mission, to up-grade the capabilities of world's premier optical telescope.
As Shuttle Commander Curt Brown said during the pre-flight crew press briefing on Oct. 15, regarding the breadth of science experiments on board, ``There is something for everyone on this flight. You name it, and we have it.''
And even though this will deservedly be known as ``John Glenn's mission,'' as impressive to the world as was Glenn's dogged determination to be able to fly in space again even at the age of 77, the scientific return will be as impressive, and long lasting.
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