Fred Gregory is 39 and black, a native of Anacostia who served as a helicopter rescue pilot in Vietnam, flew forest fire forays in Idaho, switched over to jets for the experience and then back to helicopters as a test pilot. Four years ago, Fred Gregory decided he wanted more from life. He wanted to be an astronaut.

Forget the fact that there hadn't been any black astronauts -- Gregory had more serious wickets to jump through. He had reached the Air Force age limit of 35, and he tested helicopters, not 1,800-mile-an-hour jets. The Air Force didn't nominate helicopter pilots for astronaut service. The Air Force only nominated the pilots who flew and tested high-performance jets.

Sure enough, when the Air Force nominated 133 pilots four years ago for astronaut service, Fred Gregory's name was not on the list. Did Gregory salute and say 'Yessir'? No, sir. Gregory submitted his own civilian application and offered to resign from the Air Force if it would help his selection.

"I always think that if somebody puts that kind of limitation on you, that's the time to attack it," Gregory says today. "I never let things like that hold me up."

It's a determination like Gregory's that symbolized all breeds of astronaut, new and old. It's what helped win Gregory selection; it's what the people who select astronauts look for -- what sets a candidate apart from the rest of the crowd.

When he arrived at Houston's Johnson Space Center two years ago, Gregory came in with 34 others in the eighth class of astronauts -- the first new astronauts in 10 years. The reason for the renewed demand is the space shuttle, which will be carrying crews of up to six astronauts each time it flies. If the shuttle flies no fewer than 10 times a year as it now appears it will, that's 60 astronauts who get to fly every year. Since few astronauts expect to fly more than twice a year, there is a clear need for more.

The eighth class is different from the first seven. Of the 35 new astronauts, one is Oriental, three are black, six are women, and 13 are either doctors or scientists whose job will not be to pilot or even copilot the shuttle. They'll handle the precious satellite cargo the shuttle will bring home to Earth. The scientist will also be responsible for the conduct of experiments, like making pure forms of rare vaccine that can only be done in weightlessness. They'll operate telescopes, sample the atmosphere in low Earth orbit with super-sensitive instruments and conduct photographic surveys of the Earth's resources.

Age alone sets the new breed apart. When John Glenn flew Friendship 7 three times around the world to put America squarely into the Space Age, most of the new breed were in high school and a few were in elementary school. At 39, Fred Gregory is one of the oldest: He was in the Air Force Academy when John Glenn orbited Earth in 1962.

Many of the new breed made it to Houston because they showed the same determination Gregory did, that extra something that set them apart from the crowd.

Take Rhea (pronounced Ray) Seddon, born and raised in Murfreesboro, Tenn. Seddon is 32, blond and petite, a surgeon by training. Nicknamed "Cosmic Ray" by the doctors at City of Memphis Hospital where she did her surgical residency, Seddon was so determined to become an astronaut she took flying lessons before she applied, calculating correctly that a private pilot's license wouldn't hurt her chances of making it.

The oldest of the women astronauts is 37-year-old Shannon Lucid, who was born in a Japanese prison camp in Shanghai during World War II and is the only astronaut who is a mother. In her teens, Lucid already loved airplanes so much she paid for flying lessons babysitting and cleaning college dormitory rooms. She was so eager to bcome an astronaut her application was the first of 10,000 to reach the Johnson Space Center.

Then, there are Bill and Anna Fisher. Anna's 30; her husband Bill is 34. Both are doctors, both applied for the eighth astronaut class -- and only Anna made it. Bill wasn't even called for an interview by the Astronaut Selection Board.

So what did Bill Fisher do? Bill Fisher got his pilot's license and a master's degree in biomedical engineering and applied again this year. This time he was interviewed by the selection board and accepted with 18 other new astronauts who began training this month as the ninth class to enter the Johnson Space Center.

If Fisher symbolizes astronaut determination, Jeff Hoffman typifies the coolness under stress that is also an astronaut hallmark. When John Glenn orbited the Earth, Jeff Hoffman was in high school in a suburb of New York City. Now 35 and a Ph.D. astrophysicist from Harvard, Hoffman climbs mountains and is an avid sky diver. Once his parachute opened less than halfway and he began to spin like a top and fall like a stone. Hoffman calmly checked his stopwatch against his altimeter to figure how fast he was falling. Too fast. He figured he was a dead man or at least a badly injured man if he didn't do something fast. There's not much you can do in a situation like that so Hoffman cut the half-open chute from his back, hoping he'd stop spinning and his reserve chute would open. The reserve chute popped clear 800 feet off the ground.

Hoffman speaks for many of his colleagues as well as himself in describing the drive that makes people want to be astronauts: "I grew up on science fiction, and when people landed on the moon I was not surprised. I always figured sooner or later somebody would do it. Someday, we're going to have space stations; someday we're going to be living on other planets. It's something I've always felt . . . Moving out into space is so fundamental to the future of humanity that it's exciting being a part of it. My feeling is that the shuttle is the beginning of a permanent stage of activity in space we're never going to pull back from."

There are a few of the new breed who haven't longed to be astronauts since adolescene. One is Sally Ride, 29, a tennis nut who grew up affluent in the Los Angeles suburb of Encino. "I didn't even think about being an astronaut," Ride says now. "When I was growing up, I never considered it." a

Ride was an astrophysical Ph.D candidate when she saw an ad in the Stanford Daily that said NASA was taking astronaut applications from women."A light flashed," is the way Ride puts it. "As soon as I saw the ad, I knew that's what I wanted to do."

In turning to careers as astronauts, fledgling scientists like Sally Ride are giving up a lot. Ride is turning her back on the career she chose first for herself, a career in astrophysics in which she invested eight years of study at Stanford. As an astronaut, Ride will never do her own science. At best, she will ride into space carrying some other scientist's bags.

When she came to Houston two years ago, Ride tried to keep her hand in astrophysics and learn her job as an astronaut at the same time. She wrote two papers on work she'd already begun at Stanford, attended as many scientific conferences as she could and consulted by telephone with other astrophysicists. But about a year ago, the first phase of astronaut training stopped and a more demanding phase began. "The job here kept using more time, and physics kept getting further away, and my energy ebbed, and I guess I haven't done too much research in the last six months," Ride concedes. "I don't know if I should say this, but I think I'm really an astronuat now. I'm much more interested in doing the job here than I am in my own research."

Jeff Hoffman lost more than Ride. Hoffman had already built gamma ray telescopes he launched on balloons when he put it all behind him to become an astronaut. Hoffman was busily building telescopes for two satellites at the Massachusetts Institute of Technology when he answered the call for new astronauts.

"I never had any question that if they took me I was going to come," Hoffman says with just a twinge of regret. "I'll miss it, and I'll be doing somebody else's science for him, but I was prepared for it. Most of my scientist friends think this is a frivolous think I'm doing, but it's been my dream all my life, to go into space."

Rhea Seddon gave up a lucrative career as a surgeon for a job that paid a starting salary of $24,700 a year. Outside of the junior officer military pilots, just about all the new astronauts took pay cuts at $24,700 a year. None of them can ever hope to make more than $50,000 a year if they stay in astronaut service. The highest paid astronaut is Deke Slayton, whose 21 years of service as an astronaut earns him $50,100 a year.

"Some of my doctor friends will never get over it," Seddon says. "They think I'm crazy."

Like Ride, Seddon has tried to keep a strong contact with her first career. She reads as much of the medical literature as she can but feels the field changes too rapidly for her to keep pace. She schedules two shifts of 24 hours a month in a nearby hospital emergency room but acknowledges it's getting harder to maintain her surgical skills.

"I can see myself here for the next 10 years," Seddon says realistically, "and I think by that time I'll no longer be able to get back into medicine. I already feel myself slipping out of that world, but I've made the commitment to this and it's been worth it."

The commitment the new astronaut breed has made is to fly the space shuttle for at least the next 10 years, which is the planned operational lifetime for the shuttle. The shuttle's maiden flight is now scheduled for March of 1981. There are to be four shuttle test flights, each of them flown by two experienced pilots who are members of the old astronaut breed.

The first flight will last 54 hours. Basically, it will test three things: the shuttle's engines, the 30,922 glass tiles installed on the shuttle airframe to protect it from the heat of reentry and cargo bay doors. If the doors can't be opened automatically, the shuttle can't cool itself off on the daylit side of the Earth because the radiators that expel heat from the shuttle are right behind the cargo bay doors.

The second flight will last four days and the third and fourth flights seven days apiece. Each successive flight will demand a faster ascent, more maneuvers in orbit and a steeper entry path. The first flights will all begin at Cape Canaveral and end at California's Edwards Air Force Base, whose endless runways are surrounded by dry lake beds that can be used for emergencies if the shuttle overshoots a runway on landing.

If the space agency gets the first shuttle flight off next March and the first four test flights are successful, at least two of the new astronauts will get to fly on the fifth shuttle flight late in 1982. That's when the shuttle crew will grow from two to five to deploy the first of four relay satellites the space agency will put into orbit to replace its ground network of tracking antennas.

Delays in ground-testing the engines and in fabricating and installing the shuttle's tiles have delayed the first flight by two years. Shuttle managers figure they will have completed the last engine test this month and installed the last tile next month, which means the Columbia can move out of the Orbiter Processing Facility at Cape Canaversal and into the Vehicle Assembly Building in late August.

Once inside the VAB, the huge external fuel tank will be mated to the shuttle together with two solid rocket engines that will help boost it into orbit. Late in September, the Columbia, tis fuel tank and its solid rocket engines will be moved to the shuttle launch pad where it will be tested time and again to make sure everything fits and works.

Some time early next year the three liquid hydrogen-fueled engines, the most powerful engines ever built, will be fired for 20 seconds right on the pad while the shuttle is held down by constraining locks. It will be the first of the last three tests the shuttle will undergo before its first real voyage. The countdown to shuttle liftoff will have begun.

Liftoff can come none too soon to suit the new astronauts. By the time the first of them get to fly in 1982, they will have been in training for more than four years. That's more than they bargained for and longer than they thought they'd have to wait for a first flight. The new breed is a little restless.

"A couple of them have complained to me that they're just as far from flight as they were when they came aboard two years ago," says veteran astronaut Alan Bean, who flew to the moon on Apollo 12, commanded the second Skylab flight and was put in charge of training the new astronauts. "Well, I know some guys like Bob Crippen (copilot of the first shuttle flight) who've waited more than 10 years without a flight, so these new guys are going to have to learn a little patience."

New guys. That's what Bean called them. New guys. Astronauts are never called astronauts at the Johnson Space Center. Even the six women are "the guys." The T-shirt the class picked out for themselves, the eighth astronaut class in 20 years, says "TFGN" in big letters and shows 35 space-suited astronauts crawling out of a space shuttle, like circus clowns scrambling from a Volkswagen. The "TFNG" stands for "Thirty-Five New Guys."

The new guys are different in many ways. They're better educated and more at home with the computers that will help them fly the space shuttle. The test pilots among them have flown faster higher performance aircraft than the old test pilot astronauts ever flew. Nineteen of the 35 are veterans of Vietnam, having flown a combined total of more than 2,900 combat missions.

"Almost every one of these new guys has shown before they even got here that they could perform under stress," says veteran astronaut John Young, who will pilot the first shuttle flight next March, they've got a depth of experience that wasn't available 10 years ago."

They'll need all the experience they can muster. The winged space shuttle is, by John Young's own accounting, an "order of magnitude" more complex and difficult to fly than the Apollo 16 spacecraft he took to the moon and back in 1972.

The space shuttle is so complex it has four computers talking to each other 440 times a second to make sure none of the four has made any mistakes. If three computers decide a fourth has erred, they'll order the errant machine out of service. There is even a fifth computer on board that's kept in ready reserve, just in case the other fail in tandem.

Young points out that the space shuttle has 38 little jet engines that control it in flight, none of them pointing in a straight direction. Fire a down-pointed jet and the shuttle just doesn't pitch upward, it yaws to one side too.

"Only a computer could operate such a device," Young says. "A human being could never remember how to point 38 thrusters -- he just couldn't do it."

The shuttle is so complex that the new shuttle astronauts were divided into two groups right from the start: the pilots who will fly the shuttle and the mission specialists who will handle the cargo and scientific instruments. The requirements for both groups were liberalized. Mission specialists can wear glasses, the pilots and mission specialists can be as short as 5' and as tall as 6' 4".

"In the old days, I wouldn't be here" says Steve Nagel, 33, a 6' 2" Air Force test pilot who also flew in Vietnam. "I'm here now because the shuttle cockpit is bigger. The flight deck's the same size as an airliner."

The training has been different, too. None of the new astronauts has had to suffer a ride in a centrifuge machine. where humans are whirled at inhuman speeds to see how they handle the "G" forces of rapid ascent and descent. In fact, the centrifuge at Houston has been dismantled and a water tank the size of the shuttle cargo bay is being built in its place so astronauts can paddle about inside and get the feel of weightlessness.

It was good experience, but we don't need the centrifuge anymore," says Deke Slayton, who at 55 is still on the astronaut roster and is the only one of the original seven still here.

"The shuttle only pulls three Gs on launch and 1.5 Gs on entry. Hell, anybody can take that."

More than the centrifuge has disappeared from astronaut training. There is no more training for jungle and desert survival because there's no need for it. The water survival course stayed on because the ejection seats in the shuttle cockpit could drop the pilots in the ocean if their liftoff was aborted. Gone are the geology field trips. After all the shuttle isn't going to the moon. There's less flying time in the T-38 jet trainer because of zooming jet fuel costs. Astronauts are limited to 15 hours of flying time a month and use it to practice aerobatics and formation flying, which is a lot more demanding than cross-crountry flights.

The shuttle space suits are small to accommodate women. Cockpit chairs move up and down to make it easier for women to reach switches. The shuttle's cargo bay doors. are earier to open in case women have to suit up and go out in space to close them if they jam.

"Women are just not as strong as we are in the hands and arms," Al Bean says. "So we modified the space suit and made some changes in levers and things so their hand and arm strength can do the job."

The women have fit in faster than anticipated They've taken the same T-38 ejection seat training, the same parasailing instructions and the same water survival course the men have. The only difference is they fly in the back seats of T-38s, but so do many of the male mission specialists who are not former military pilots. The mission specialists are not expected to be qualified jet pilots and are not required to take the training that would qualify them.

A few of the older astronauts still bristle when they're asked why it took women so long to break the astronaut barrier. Says Deke Slayton: "I've always maintained since Day One there wasn't any reason to have women just because they were women.The only reason they weren't here before is that they didn't meet the qualifications we had. Now they do."

Al Bean speaks a little more softly when he talks about women astronauts. "Two years ago I thought they'd be women in space suits trying to act like men in space suits. Well, I was wrong. It's just as natural for a women to be in space suit as it is for a man."

When they began, the new astronauts were given nine months of indoctrination to instruct them on where they fit in. They were lectured by experts on everthing from astronomy to oceanography. Retired astronauts like Gene Cernan and Neil Armstrong came back and briefed them on past flights, emphasizing the peculiarities and pitfalls of space flight. Jack Schmitt took time off from his job as U.S. senator from New Mexico and Frank Borman left behind the presidency of Eastern Airlines for a while to do the same thing.

The 35 new guys were taken on a tour together of all NASA centers, the first time an entire astronaut class went anywhere together and the first time a group of astronauts were even at a few of the out-of-the-way centers. Giggling and shoving each other, carrying cameras and looking for all the world like vacationers, they were taken to the Kennedy Space Center where they'll lift off, Marshall Space Flight Center where the Large Space Telescope is being built for them to carry into space, Lewis Research Center where rocket engines are designed, and the Mississippi Test Facility (at Bay St. Louis) where they're tested.

They went from there to Goddard Space Flight Center in Maryland where unmanned satellites are directed in flight and to the Ames Research Center in Mountain View, Calif., where research aircraft are tested and planetary spacecraft are controlled. They ended up at Pasadena's Jet Propulsion Laboratory where to Voyager spacecraft were being directed to Jupiter and Saturn when they got there.

The trip to Pasadena's Jet Propulsion Laboratory was a surprise. The new astronauts were greeted by JPL Director Bruce Murray, a planetary geologist from the California Institute of Technology who's been wary of manned space flight because of the money it sucks from unmanned planetary flights. In effect, Murray told the astronauts they were a luxury he didn't know he could afford.

"We're not totally happy to see you here is more or less what he said," remembers Steve Nagel. "It was not what we expected.

Halfway through indoctrination, each new astronaut was given a specific shuttle assignment to carry out the rest of his or her career. Some of the women got harder assignments than the men. Sally Ride was told she'll specialize in the robot arm that will deploy and retrieve satellites in orbit. Anna Fisher's specialty is the pressurized space suit, which she wears and tests at least four hours a week to suggest improvements in the suit.

"It's inflated to about four pounds per square inch, so there are places in the suit near the joints where you have to manhandle it to move it," says John Young, who assigned Fisher the space suit. "Four pounds per square inch over your whole hand and pretty soon you can't move the hand."

There's been nothing easy about the last nine months of shuttle training. Classes start at 8 in the morning and end at 6 at night. There are classrooms on shuttle systems and systems changes. There are hours on end inside cockpit smulators, spread out over two shifts a day. There are trips to contractor factories to check on changes. Most of the shuttle astronauts find they bring work home.

Everybody's expected to fly 15 hours a month and stay in physical condition on their own. That means weekend flying and early morning exercise. The astronauts have their own gym, handball and racquetball court but nobody to remind them when to work out. Almost everybody plays raquetball and everybody rides a bicycle or runs a few miles a day.

Having spent so much time together, the eighth astronaut class is a tight-knit group. They gather together on Friday nights for "Happy Hour," have Texas-style barbecues at the homes of the married members and divide into "red" and "blue" teams for softball and touch football games. The married astronauts spend more time with each other than they spend with the single astronauts and vice versa. An exception to the rule is Shannon Lucid, the mother of three whose husband left his job and followed her to Houston when she was selected. "I don't have a lot of time to do things on the side," she says. "You can't do everything." And there's been at least one romance in the eighth class; by her own admission Rhea Seddon is "dating" one of the pilots. e

What do the shuttle astronauts expect of all this? Well, they became astronauts for one reason. "I expect to fly a lot," Lucid says succintly. "These guys see the astronaut job as a career, you know, 20 years with the space shuttle," Al Bean says of the new group. "Everybody here figures they'll fly two or three times and some of them probably figure they'll fly 20 times."

For the black astronauts, there's a special pressure beginning to build up as their days in space draw near. Everybody remembers the social and political pressure put on John Glenn after he became the first American in orbit. Everybody remembers the pressures on Neil Armstong, the first man on the moon, who's still something of a recluse 11 years later. It's not going to be much different for the first black in space.

It may be better to be second or third because then you can enjoy the experience a little more," says Guion S. Bluford Jr., 37 and a combat veteran from Vietnam. "It isn't something I'm running after." Fred Gregory agrees it's not something he's after either but add philosophically: "Let's get there first. I'm so glad I'm here, I wouldn't trade this for anything."

None of them would. They're all so glad to be here they can't wait for their first flight. On of their favorite pastimes is listening to the old astronauts tell tales about space flight. Like an evangelist, Bean tells them about his time on the moon and his time in Skylab and what it was like and the thrill of each new day and nigh in the black seas of space:

"I can remember one time I was cleaning off a Sky lens and I looked down and I could see Italy and Egypt and then Israel and then in darkness the fires off the arabian coast," Bean told a handful of them not long atgo. "Can you see yourselves passing over New York City at 17,000 miles an hour and you're outside assembling some solar panels? People are going to look up and see these things each night get bigger and bigger. You know what that's going to be like? It's going to be incredible, that's all."