Packing for Mars: The Curious Science of Life in the Void

by Mary Roach

  F endured a peak impact of 12 to 15 G’s—right on the cusp of injury. Gohmert explains that the extent of an accident victim’s injuries will depend not only on how many G’s of force there were, but on how long it takes the vehicle to come to rest. If a car stops short the instant it hits a wall, say, the driver may endure a split-second peak load of 100 G’s. If the car has a collapsing hood—a common safety feature these days—the energy of those same 100 G’s is released more gradually, reducing the peak force to maybe 10 G’s—highly survivable.

  The longer it takes the car to stop moving, the better—with one dangerous exception. To understand it, you need to understand what is happening to a body during a crash. Different types of tissue accelerate more quickly or slowly, depending on their mass. Bone accelerates faster than flesh. Your skull, in a lateral impact, leaves your cheeks and the tip of your nose behind. You can see this in a freeze-frame of a boxer’s face* as he’s punched in the side of the head. In a head-on, your frame gets moving first. It’s hurled forward until it’s stopped—by the shoulder belt or by the steering wheel—and then it rebounds backward. A fraction of a second later than your frame began moving forward, your heart and other organs depart. This means that as the heart is launched forward, it collides with the ribcage on its journey back the other way. Everything’s moving forward and back at different rates, colliding with the chest walls and rebounding. And all of this is happening within a few milliseconds. So fast that bouncing and rebounding are the wrong words. Things are vibrating in there.

  The big danger, Gohmert explains, is if one or more of those organs starts vibrating at its resonant frequency. This will serve to amplify the vibrations. When a singer hits a note that matches the resonant frequency of a wine glass, the glass starts to vibrate more and more energetically. If the note is sung loud enough and sustained for a long enough time, the glass will shake itself apart. Recall, if you are old like me, the Memorex ads with Ella Fitzgerald and the exploding wine glass. The same sort of thing can happen to an organ that hits its resonant frequency in a crash. It can shake itself off its moorings. And worse. “Essentially,” said Gohmert, after repeated wheedling for specifics, “you’re churned to death.”

  You may be wondering: Could Ella Fitzgerald explode your liver? She could not. Glass has a relatively high resonant frequency, up in the audible sound wave range. Body parts resonate down in the long, inaudible wavelength range called infrasound. A launching rocket, on the other hand, creates powerful infrasonic vibration. Could those sound waves shake apart your organs? NASA did testing on this back in the sixties, to be sure, as one infrasound expert told me, “that they didn’t deliver jam to the moon.”

  Bolte’s students are sliding F onto a stretcher and loading him into the back of a white van. He’s traveling to the OSU Medical Center where he’ll be scanned and X-rayed. The whole procedure will unfold exactly as it would with a live patient, right down to a forty-five-minute wait and a problem with the billing.

  Gohmert’s gaze rests on F. It is hard to read his look. Is he uncomfortable with having had to impact a human body? He turns to Bolte. This I didn’t see coming. “Do you ever put ’em in the front seat and take ’em through the HOV lane?”

  I RECALL AN IMAGE from early this morning. Two of Bolte’s students, Hannah and Mike, are standing beside F, talking and laughing as they untangle the long, fine wires that trail from the strain gauges mounted on F’s bones. Rather than seeming gruesome, the scene had a comfortable, familial feel, like a family stringing lights on the Christmas tree. I was struck by how at ease the students were. To them, the cadaver seemed to inhabit an in-between category of existence: less than a person, but more than a piece of tissue. F was still a “he,” but not someone you needed to worry about hurting. Hannah, in particular, had a lovely way with him. While F lay in the CT scanner late that night, an automated recording commanded, “Hold your breath.” “He’s really good at that,” she said. It was funny, but also a sideways acknowledgment of the unusual talents and abilities of the dead.

  Not quite so at ease were the NASA team. Outside the context of the testing (and the carpool lane bit), they made very few references to him, and usually with the pronoun it. Getting permission to be here entailed months of emailing with a NASA public affairs officer and culminated in a flurry of tense phone calls upon my arrival this morning. Dead people make NASA uncomfortable. They don’t use the word cadaver in their documents and publications, preferring the new euphemism postmortem human subject (or, yet more cagily, PMHS). In part, I’m guessing, it’s because of the associations. Corpses in spaceships take them to places they’d rather not revisit: Challenger, Columbia, the Apollo 1 fire. And partly, they are unaccustomed to it. I have come across only one project that made use of human cadavers in the past twenty-five years of aeromedical research. In 1990, a human skull rode Space Shuttle Atlantis, kitted out with dosimeters, to help researchers determine how much radiation penetrates astronauts’ heads in low Earth orbit. Worried that the astronauts would be unnerved by their decapitated crewmate, the researchers covered the bone with pinkish plastic molded to approximate a face. “The result was far more menacing than plain bone would have been,” noted astronaut Mike Mullane.*

  Back in the Apollo era, the agency’s discomfort over using dead people in capsule impact studies appeared to transcend any discomfort they felt about using live ones. In 1965, NASA collaborated with the Air Force on a series of tests very similar to today’s—but with human volunteers. Personnel from Holloman Air Force Base, seventy-nine in all, rode an ersatz Apollo space capsule seat on an impact sled while wearing helmets and other spacesuit components. The men endured 288 simulated splash-downs: upside down and right side up, backward, forward, sideways, at 45-degree angles. Peak forces were as high as 36 G’s, more than twice as powerful as the 12 to 15 G’s inflicted on Subject F today.

  Colonel John Paul Stapp, a pioneer in human impact tolerance research, breezily summed up the project in a press release: “It might be said that at the cost of a few stiff necks, kinked backs, bruised elbows, and occasional profanity, the Apollo capsule has been made safe for the three astronauts who will have perils enough left over in the unknown hazards of the first flight to the moon.”

  I spoke to a man who rode Holloman’s Daisy sled six times, in various positions, while wearing an Apollo helmet. Earl Cline is sixty-six now. His last ride was in 1966—25 G’s. I asked Cline whether he’d suffered any lasting damage. He replied that he hadn’t had any problems, but as the conversation went on, things began to emerge. To this day, he has pain in the shoulder that bore the brunt of a lateral impact. At the time of his discharge, he was found to have a torn heart valve and one eye that’s “off a little bit.”

  Cline reserves his sympathy for the guy whose eardrum ruptured and the one who rode the Apollo seat upside down “with his rear end up in the air” and wound up with a ruptured stomach.

  Cline expressed neither resentment nor regret, and has not pursued a disability claim. “I am very proud of the fact that I contributed. I like to think that when they went up in the Apollo missions their helmets didn’t shatter or anything because I tested them.” A subject named Tourville expressed a similar sentiment in a newspaper interview at the time of the Stapp “a few stiff necks” press release: “As long as I know this will save our Apollo astronauts from being hurt on their landings I don’t mind losing sleep with a stiff back for a few days.” Tourville took 25 G’s and suffered a compression injury of the soft tissue surrounding three vertebrae.

  Added motivation was provided by a generous hazardous-duty stipend. Bill Britz, a Holloman Air Force Base veterinarian, recalls being paid an extra $100 a month. Cline received $60 to $65 a month for riding the sleds a maximum of three times a week. Given that his base pay was $72 at that time, it was a significant amount. “I lived like an officer,” Cline told me, adding that there was a waiting list to become a Daisy sled volunteer. This was not the case over at Stanley Aviation, in
Denver, which NASA had contracted to do some landing impact studies. Capsule mock-ups were hoisted aloft and then dropped onto surfaces of differing compressibility to see what sorts of injuries an astronaut might have to cope with should the capsule go off course and land not on water, but on dirt or gravel or the Winn-Dixie parking lot. There, Britz told me, the pay was only $25. “They got derelicts from Skid Row!” You would think that a news scandal involving underpaid indigents would be a scarier prospect for NASA than one involving cadavers, but things were different back then. The homeless were “derelicts” and “bums,” and cadavers were people who rest on satin pillows.

  THE FIRST AMERICAN to live through a space capsule landing mishap endured 3 G’s more than the mission planners had anticipated. His capsule arced 42 miles higher than it was meant to and landed 442 miles off course. By the time rescue ships reached it, two and a half hours later, it had taken on 800 pounds of water and was partly submerged. With great trepidation, the hatch was opened. The space traveler was alive! Upon returning to base, he leapt into the waiting arms of Air Force Master Sergeant Ed Dittmer.

  The astronaut was the three-year-old chimpanzee called Ham. (Dittmer was Ham’s trainer.) Ham was more than just the first space capsule landing mishap, of course. He was the first American to ride a capsule into space and come back down alive. As such, he put a bit of a tarnish on the Mercury astronauts’ considerable shine. Ham’s much-publicized flight made it clear to all: The astronaut doesn’t fly the capsule; the capsule flies the astronaut. Along with fellow astrochimp Enos, who orbited Earth three months before John Glenn, Ham was the embodiment of a debate that persists to this day: Are astronauts necessary?

  ONE FURRY STEP FOR MANKIND

  The Strange Careers of Ham and Enos

  The John P. Stapp Air and Space Park is made entirely of things that can hurt you. Eleven historical missiles are displayed amid plantings of spiny desert succulents. You walk along the gravel pathways, reading the little signs: PRICKLY PEAR, LITTLE JOE, CRIMSON HEDGEHOG. From the names alone, it is sometimes hard to know which is which. Is TURKS HEAD a cactus or an exploding munition? A similar sort of confusion can be found 25 yards down the hill, at the base of the flagpoles that mark the entrance to the park and the adjoining New Mexico Museum of Space History and International Space Hall of Fame. Flush to the pavement is a bronze grave marker that says, WORLD’S FIRST ASTROCHIMP HAM.* The astrochimps were a knotty chimera. People weren’t sure how to think of them. Chimps or astronauts? Research animals or national heroes? They’re still not. Someone has left a basket of flowers on the grave, and someone else has left a plastic banana.

  You can’t blame people for being confused. The careers of Ham and Enos—the chimpanzees who, in 1961, flew the dress rehearsals for the first U.S. suborbital (January) and orbital (November) flights were in some respects not all that far off from the careers of Alan Shepard and John Glenn. The chimps and the two astronauts who followed them into space did not train together, but they could have. They spent time in the same altitude chambers and tried out weightlessness on board the same parabolic airplane flights, rode the same spinning centrifuges and vibration tables to get used to the noise and shudder and G’s of liftoff. Come the big day, astrochimp and astronaut would suit up and ride out to the gantry in the same Airstream trailer.

  For both species, piloting duties were light to nonexistent. Mercury capsules, as Ham’s veterinarian Bill Britz says, “were not flying machines, they were bullets.” Shoot them up, cue the parachutes, watch them come back down.* Speaking of both man and chimp, Britz said, “They were organisms placed on board.” The science of the Mercury program was an extension of the V-2 and Aerobee and parabolic flights that led up to it. Aerospace biologists had established that humans can function for a few seconds without gravity. But what about an hour, a day, a week? “People ask, Why?” says Britz of the era of the spacefaring chimp. “Mary, we just didn’t know.” What were the longer-term effects of space travel—not only of weightlessness, but of cosmic radiation? (High-energy atomic particles have been zinging through space at ferocious speeds since the Big Bang. Earth’s magnetic field protects us by deflecting cosmic rays, but in space, these invisible bullets smash unimpeded through cells, causing mutations. It’s serious enough that astronauts are classified as radiation workers.)

  Just as the Alberts laid the groundwork for the Mercury fliers, Ham and Shepard and the rest would pave the way for the Gemini astronauts. And on it went. Gemini paving the way for Apollo. Six-month space station missions paving the way for the eventual long haul to Mars. Each space program along the way provides opportunities for planetary science, but in the grander scheme of space exploration, every program is fundamentally practice and prep for longer, farther trips to come.

  Zero gravity still had NASA spooked. “The big bugaboo was weightlessness,” said John Glenn in a 1967 Associated Press interview. “Many ophthalmologists thought the eye would change its shape and that this would change the vision, so that maybe the man in space would not be able to see at all.” That is why, if you’d looked inside Glenn’s capsule, you’d have seen a scaled-down version of the classic Snellen eye chart taped to the instrument panel. Glenn had been given instructions to read the chart every twenty minutes. A color blindness test and a device to measure astigmatism were also on board. I used to hear about Glenn’s historic flight and think, “Man, what was that like—being the first NASA astronaut to orbit the Earth?” Now I know. It was like visiting the eye doctor.

  An overabundance of gravity—the multiple G’s of launch and reentry—also had NASA concerned. An astronaut needed to be able to reach the instrument panel in case something went wrong. If his outstretched arm weighed 70 pounds instead of 9, would he have the strength to raise it? This is why Ham (and later Enos) spent weeks learning a routine that would have them reaching over to an instrument panel and pulling levers throughout their flights. The lever-pulling also let researchers keep track of any cognitive ebbs during the chimps’ flights. They wanted to be sure that zero gravity, combined with some yet-to-be-discovered X factor, wouldn’t disorient a space flyer or slow his reaction time.

  Given that the Mercury fliers were gold-standard, swinging-dick military test pilots, the concern did not sit well. These men hadn’t been in space, but they’d spent enough time on the doorstep to feel confident they’d be fine. As test pilots, they’d endured G forces during climbs and pullouts that were higher and more sustained than any they’d have to deal with on a Mercury flight. They didn’t worry about their abilities; they worried, if anything, about their ride. As of two months before launch, the guidance system of the Redstone rocket that would carry Shepard’s capsule into space had been misbehaving, and there were seven last-minute modifications to the hardware that hadn’t been tested in flight. That’s another reason NASA sent chimpanzees up first. (They would come to regret the caution. Three weeks before Alan Shepard launched, cosmonaut Yuri Gagarin became the first man in space.)

  Ham’s flight implied—in a widely publicized manner—that the astronaut, America’s hero, was no more than a glorified chimp. “To be preceded by a chimpanzee was just a blow to their ego,” Bill Britz told me. The astronauts would surely have preferred another quiet dummy launch. In the months prior to Ham’s flight, a capsule was launched carrying a “crewman simulator”* that “breathed,” consuming oxygen and producing carbon dioxide to test the cabin sensors. The same insinuations could be made about a man whose job could be done by a dummy, but the press didn’t cover dummy flights the way they covered chimp flights. The banana pellet dispenser was gone when Shepard and Glenn climbed on board, but the stigma remained. As fighter jock Chuck Yeager, the rightest of stuff, famously put it, “I wouldn’t want to have to sweep monkey shit off the seat before I climbed into the capsule.”

  Though Ham and Enos and their alternates lived and trained in trailers alongside the astronauts’ live-work quarters at Kennedy Space Center’s famous Hangar S, Britz says he can’t
recall talking to Alan Shepard more than once or twice. “We didn’t mingle much.” Enos’s veterinarian Jerry Fineg agrees: “They didn’t want to recognize the fact that we were there.” Chimp jokes were poorly received. Britz told me a story about a placard posted on the wall of the van that both astrochimp and astronaut rode to the launch pad. “They had Alan Shepard’s trajectory plotted on [it]. We very carefully plotted Ham’s trajectory higher and farther.” (Owing to a malfunction, Ham flew 42 miles higher than planned.) “I’m telling you, it really pissed some people off. That thing disappeared in a minute.” Mercury launch pad director Guenter Wendt once reprimanded Shepard by threatening to replace him with one of those guys who works for bananas. Shepard, the story goes, threw an ashtray at his head.

  Chimp humor was less nettlesome for John Glenn than it had been for Alan Shepard, because Enos wasn’t the media sensation Ham had been. At the time Ham flew, a pair of Soviet dogs, Belka and Strelka, had already returned alive from orbiting Earth, and the press was impatient for a U.S. milestone in space. When Ham splashed down alive, they presented him less as a research animal than as a sort of short, hairy astronaut. The chimp appeared on the cover of Life magazine in his mesh flight suit* beside the headline, “A Confident ‘Ham.’ Back from Space.” The public sopped it up. Letters and flowers and gifts addressed to Ham began arriving at the chimpanzee colony at Holloman Air Force Base, where Ham returned after his flight. People sent their copies of Life with requests for Ham’s “autograph.” Holloman staff gamely complied, the little hand pressed on inkpads over and over, so many times that a copy of Life “autographed” by Ham fetches just $4 on eBay. (And is possibly a fake: Fearing they’d “wear him out,” the staff, Britz told me, “just put any chimp’s hand on it after a while.”)