Suited for Space
Washington Post Staff Writer
Wednesday, October 14, 1998; Page H01
In 1903, Orville Wright made his short, history-making flight into the chill December wind of Kill Devil Hills, N.C., in an ordinary two-piece business suit. Today, having gained some altitude as the century progressed, the highest flyers among us require as many as 20,000 pieces in their suits.
More than 36 years have passed since John Glenn became the first American to orbit the earth, wearing a flight suit inspired by a car tire. Now 77, as he prepares for a second launch on Oct. 29, he has found that putting on that "second skin" is still a big hassle. And the demands of space fashion will be even tougher for construction workers who plan to begin assembling an international space station in orbit later this year.
In order to comprehend fully, viscerally, why astronauts are so darned concerned about what they wear, so willing to take the time and trouble to wriggle and contort and squeeze themselves into layer upon layer until they are encased in bulky pressure suits, consider the tale of Marine Lt. Col. William H. Rankin and his 1959 brush with the phenomenon of explosive decompression.
Forced to bail out of his F8U Crusader jet at 50,000 feet in summer-weight flight clothes, Rankin experienced an instant temperature drop from a balmy 70 degrees Fahrenheit to minus 70 degrees.
Rankin felt his body become "a freezing, expanding mass of pain," Lillian D. Kozloski, a Smithsonian Institution historian, writes in U.S. Space Gear. "His abdomen stretched and bloated suddenly and violently from expanding gas. His eyes felt as if they were tearing out of their sockets. Air exploded through his ears. Cramps struck like knives over his body." He bled from his eyes, ears, nose and mouth.
Serious research on such high-altitude effects had begun in the 1870s, with the first balloon flights by French scientists. Over the decades came various attempts to adapt deep-sea diving suits for use at high altitudes, often resulting in contraptions that left their wearers resembling Egyptian mummies; medieval knights; the Tin Man of Oz; or Hannibal Lecter, Hollywood's fictional serial killer in his travel cage.
Nineteenth century novelists had set the pace with creative space tales describing the traumatic but fanciful effects of space flight and creating their own spacesuit designs. Edgar Allan Poe sent a character named Mr. Pfaal to the moon in a balloon as early as 1835, and the fantasies of Jules Verne and H.G. Wells were credited with inspiring real-life space scientists.
By 1929, Buck Rogers had appeared as a comic strip character, and by 1934, his flexible metal outfit, with helmet and rocket gun, was for sale to fans. But, of course, they were only toys.
Progress was more difficult for the real articles. British physiologist John Scott Haldane conducted the first important spacesuit work of this century, developing an oxygen pressure suit for deep-sea divers and modifying it in 1933 for flight.
Effects of high-altitude flight obviously were similar in some respects to those of dives. Ascending from the deep, a diver goes from high to low pressure, causing gaseous nitrogen bubbles to be released from solution in body tissues, much as carbonated beverages fizz when the top is popped. Armored suits for divers had been designed as early as 1838 to prevent the "bends."
Pilots always wanted to push higher. In April 1934, Wiley Post, a stunt flyer and commercial pilot eager to rise above the weather, contacted the B.F. Goodrich Co. to request "a rubber suit which will enable me to operate and live" at altitudes between 34,000 and 50,000 feet, where he could take advantage of air currents in the jet stream.
What material could hold the required pressure without expanding so much that it burst? It occurred to a researcher named Russell S. Colley that a tire would be just the thing. So he developed for Post, in effect, a tire, with an inner tube shaped to encase the human form.
Colley had watched a tomato worm, an inhabitant of his wife's garden, make a 90-degree turn without discernible pressure changes anywhere along its length. In 1943, his team adapted the worm's natural design to produce the first major breakthrough in pressure-suit construction -- a system of segmented bellows for the arms and legs. At last, the wearer could actually bend.
This was the Navy's XH-5 pressure suit, also known as the tomato-worm suit. Among its innovations were a full-length, self-sealing zipper, a detachable neck ring that could pass over the head and ball-bearing shoulder joints for upper-arm rotation.
But mobility and visibility remained problems. If you've ever taken a rubber kitchen glove and blown into it, watching the fingers pop out and grow fat with air, you know the main problem with pressurized flight suits. They're stiff.
So by mid-century, a person dressed for space travel essentially underwent a clumsy metamorphosis into a different creature, bigger and more massive, with a pumpkin-like head and stiff joints that moved differently from the ones he or she was born with.
The trouble was that the pesky human also wanted to be able to punch buttons, pull levers, reach a stick and throttle, operate a bombsight, hold a socket wrench, turn bolts, move massive objects around and otherwise get things done. Designing a pressure suit tough enough to protect but supple and limber enough for a range of human shenanigans -- ah, there was the rub.
In 1952, the Colley team resolved many of these problems with invention of a swivel joint of airtight rotating bearings and fluted joints, producing a suit that looked like a series of small tires glued together and was known as the Mark IV. The team also developed a way to maintain suit pressure automatically, instead of relying on manual control.
Dissatisfied with the Navy's version, the Air Force developed its first practical full-pressure suit in 1956. The design by David Clark Co. and the Air Research and Development Command (now the Air Force Systems Command) incorporated a soft, fishnet-like nylon layer constructed to form a restraint that kept the inflated garment from ballooning shapelessly.
Known affectionately as the A/P22S-2, the suit was covered with an aluminized layer to reflect heat and ultraviolet rays. It would be worn by Neil Armstrong in 1961 when he made seven successful flights of the X-15 experimental aircraft to altitudes as high as 200,000 feet.
The spacecraft was, of course, designed to provide the necessary life support; but in case it failed, the flight suit was to provide emergency protection.
The Mercury "life-support garment" was a modified version of the Mark IV, made of aluminum-coated nylon-rubber. It incorporated oxygen-cooling and breathing systems, automatic warning gauges, connections for medical telemetering systems to record temperature and respiration and electrocardiographs for recording heart action.
Weighing 22 pounds, each suit was equipped with 13 zippers to ensure a good fit. In advance of the sewing and cutting, astronaut candidates wearing long underwear were covered head to toe with wet strips of brown paper tape, according to Kozloski. When the wrapping dried, both tape and underwear were carefully cut away. The resulting mold was used to make the suit. Each astronaut was provided with one for training, one for flight and a backup.
Half of the suit's cost was in the customized helmet of fiberglass, which had a clear Plexiglas visor. The helmets were equipped with molded liners, electrical cable containing wiring leading to earphones and dual adjustable microphones.
When the suit was plugged into the spacecraft support system, a ventilation stream provided fresh oxygen and cooling, and it carried body odor, perspiration, carbon dioxide, water, bits of loose hair and other debris out of the suit at a point near the right ear, where it was captured by a specialized system in the spacecraft.
On May 5, 1961, when Alan Shepard was launched as America's first man in space on a 15-minute suborbital flight to an altitude of 116 miles, the era of spacesuit improvement began along with him.
By the time of the third Mercury mission, on which Glenn made the first U.S. manned orbital flight, the changes included better wrist seals, modified glove zippers, a urine-collection device and tiny flashlights for seeing the instruments during night passes.
On his planned return to space aboard the shuttle Discovery this month, Glenn is to wear one of NASA's modern bright orange flight suits that, unlike the older numbers, can be donned in as little as five minutes, once you get the hang of it.
But because of the suit's multilayered complexity, rigid parts and snug fit in places, getting the hang of it took effort.
Earlier this summer at Johnson Space Center in Houston, several attendants helped Glenn to struggle into the flight suit as he sat in a pilot's chair, his legs in the bottom of the suit and body bent forward at the waist, trying to tug the top part over his head.
"Go to the daylight!" a technician urged. "Stay leaning forward," another said. "Now try to lay back."
The real challenge is getting through the metal neck ring and lining designed to form a watertight seal in case of an emergency bailout into the sea. "That's by far the most difficult part," astronaut Carl Walz says. "Whenever I get out of one, I have a sore back and a sore neck from pushing my head through that darn thing."
Just as children learn to grab the sleeves of their undergarments to keep them from riding up when they squeeze into a coat, astronauts must grab the sleeves of their long underwear "so it doesn't end up bunched at your elbow," Walz says.
Whereas astronauts once got wringing wet and smelly with sweat in flight suits cooled by forced air, they now enjoy an "active thermal system" of circulating chilled water inside a set of odd-looking long johns. This advance may even be responsible for a reduction in the incidence of space sickness, Walz says.
On the other hand, during periods of prolonged inactivity, such as lying in reclining chairs awaiting launch, the suits can become too cold. Also, some movements, such as reaching a certain switch, remain difficult while wearing the bulky backpack containing the required emergency parachute.
Donning the suit at the end of a flight produces another striking physical sensation. As the spacecraft burns back into the atmosphere and gravity builds up again, astronauts report, the helmets suddenly feel like elephants sitting atop their shoulders, straining neck muscles that grew accustomed to zero gravity.
But the flight suit is small potatoes compared to its bigger, fatter gadabout cousin. Early in the space program, in addition to the traditional flight pressure suit, astronauts needed something a little more versatile, something to wear when they went "out."
In March 1965, Russian cosmonaut Alexei Leonov took the world's first spacewalk, but his spacesuit was so unexpectedly plump with pressure that, as he tried to reenter his spacecraft, he couldn't bend, as required, to seal the airlock behind him, according to spacesuit experts. Leonov had to lower his pressure beyond what was considered safe in order to close the hatch.
A few months later, Gemini astronaut Ed White became the first American to walk in space, or, as NASA calls it, EVA (Extra Vehicular Activity). He wore a modified version of a flight suit, with an umbilical connection to the spacecraft that supplied oxygen and other life support.
Not until the Apollo flights began in the late 1960s were specialized, free-roaming spacewalk suits developed, eliminating the umbilical in favor of self-contained "backpacks" good for more than six hours, according to engineers at Hamilton Standard of Windsor Locks, Conn., which has managed NASA's spacesuit program since the early 1960s.
The Apollo lunar suit, complete with life-support equipment, weighed a whopping 180 pounds on Earth but only 30 pounds in the moon's gravity. The suits had to protect astronauts during prolonged excursions on the lunar surface, with its tropical 250- degree days, cosmic radiation, high-speed meteoroid bombardments and generally harsh environment.
In the shuttle era, suits have had to become more practical and versatile to accommodate the changing astronaut corps as it expanded to include women and also to assuage intensifying concern about costs.
Now, the shuttle spacesuit is being modified for its most daunting task -- construction, in orbit, of the U.S.-led international space station. The first component is scheduled for launch in late November. The job calls for an unprecedented 161 EVAs, totaling 1,700 crew hours over the next five years.
Today's NASA spacewalking spacesuit, called an EMU (Extravehicular Mobility Unit), costs about $10.4 million. The agency has just 12 EMU suits in its entire inventory for flight plus one used for testing and another flight model nearing completion. But the suits can be adjusted to fit many different sizes and shapes, to take more wear and tear and provide longer periods of life support at a time.
Bill Higgins, EMU engineering manager for Hamilton Standard, the manufacturer, says, "It's the smallest spacecraft in the world." It's a wearable spacecraft.
For the planned orbital laboratory, NASA plans to keep two primary suits and a spare onboard. The suits are to be certified for 25 spacewalks, instead of the previous maximum of eight, between costly trips to the ground for routine cleaning and refurbishing. A life-support cartridge previously good for just one spacewalk has been redesigned for 40.
NASA officials expect the suits to have an operating life of 25 years. Fabrics wear out first, along with the aluminized Mylar insulation, especially at joints in gloves and arms. In contrast to children's jeans, spacesuit knees get little abuse.
As crews rotate on and off the space station, they can act as their own spacesuit tailors, lengthening sleeves, shortening legs and the like. This will be done by means of interlocking rings, threaded at certain connection points on the lower leg, upper leg, upper arm, etc. For example, a crew member may select a "number three elbow."
"It's possible to put the suit on by yourself," astronaut Jerry Ross said as he trained for the first space station construction flight in December. "But it's not easy."
In a recent demonstration of how to don the suit in Earth gravity, NASA's Phil West, a specialist in space station tools, slithered into the bulky legs while lying prone on the floor, as if in a reverse molt. Next, he wriggled up into the hard upper torso, fixed to a floor-standing frame.
"The suit size is determined by your bone structure, more than your mass," he explains. The human body stretches as much as three inches in weightlessness. "You don't want the suit compressing your spinal column, so we size them long."
The term "spacewalk" is a misnomer, West says. It's more of a "float." At full pressure, you can't move your legs much. "The suit is just a big balloon shaped like a person," he says. "You're like a kid dressed warmly for a winter day, too bundled up to play."
Outside their spacecraft, depending on the sun's position, astronauts are exposed to temperatures ranging from plus to minus 250 degrees, but air conditioning inside their suits keeps them within a more liveable range between 50 degrees and 110 degrees, according to Hamilton Standard engineers.
For the spacewalking laborer, perhaps the most critical component of the spacesuit "skin," as opposed to life-support systems, is the glove because human hands do most of the EVA work. Opening the hand, closing the hand, gripping equipment and otherwise working for long periods in a spacesuit glove can be so rough on hand and arm muscles that spacewalking astronauts routinely use squeeze balls and other devices to strengthen their hands before a flight.
To ease the problem, glove design has undergone a series of improvements expected to be complete by December. These include improved wrist mobility, fingertip fabric that allows for greater sensitivity, better grip and heaters for jobs in prolonged cold. Astronauts have complained about cold hands.
The "waste management system" in both the launch and entry flight suit and the EVA suit, Walz says, is basically "Pampers." Although the orbiting shuttle is a dry environment, requiring astronauts to sip a lot of water, he said, they might cut back a bit before a spacewalk.
An irritating requirement that suit engineers are struggling to minimize is the need for hours of "prebreathing" (breathing under reduced pressure) to rid the blood of a lot of nitrogen and replace it with pure oxygen before a spacewalk.
U.S. spacesuits operate at a relatively low pressure in order to make movement of arms easier and lower the overall workload on the astronaut. But lower pressure requires a longer prebreathing period.
Aboard the shuttle, internal cabin pressure is reduced to facilitate the process, giving spacewalkers a head start the night before. But on the orbiting research laboratory, that will not be possible. So spacewalkers will have to "camp out" overnight inside an air lock.
For the international program, crew members are learning to use four different suits: American and Russian versions of the flight suit and the EVA suit.
According to those who have used both, the U.S. EVA suit is much more difficult to don. But once on, they say, it provides more freedom of movement, and its lower operating pressure enables hands to work longer in the stiff gloves without tiring.
The Russian suits fit a much smaller range of body types but can be entered much more easily, almost like a tiny spacecraft, through a door in the rear. And they operate at higher pressures, reducing time required for prebreathing.
It is a richness of choice that the explosively decompressing Col. Rankin no doubt would have appreciated after bailing out.