Read Packing For Mars Online

Authors: Mary Roach

Tags: #Non-Fiction, #Humor, #Historical, #Science

Packing For Mars (19 page)

I was looking at the Columbia patch. The seven crew members’ last names were stitched around the perimeter: MCCOOL RAMON ANDERSON HUSBAND BROWN CLARK CHAWLA. Clark. Something clicked in my head. When I had first arrived on Devon Island, I’d heard that the spouse of one of the Columbia astronauts would be here. Laurel Clark was Jon Clark’s wife, I now realized. I didn’t know whether to say something, or what that something would or should be. The moment passed, and Clark kept talking.

The atmosphere at 40 miles up is too thin for blast waves, but not for shock waves. The investigation team concluded, mostly through a process of elimination, that that’s what killed the Columbia astronauts. Clark explained that in breakups at speeds greater than Mach 5—five times the speed of sound, or about 3,400 miles per hour—an obscure shock-wave phenomenon called shock-shock interaction comes into play. When a reentering spacecraft breaks apart, hundreds of pieces—none with the carefully planned aerodynamics of the intact craft—are flying at hypersonic speeds, creating a chaotic web of shock waves. Clark likened them to the bow waves behind a water-skier’s boat. At the nodes of these shock waves—the places where they intersect—the forces add together with savage, otherworldly intensity.

“It basically fragmented them,” Clark said. “But not everyone. It was very location-specific. We had things that were recovered completely intact.” He said one of the searchers who combed the Columbia’s 400-mile debris path in Texas found a tonometer, a device that measures intraocular pressure. “It worked.”

The wind outside the medical tent had picked up. The turbine made a tortured sound. It was a strange evening. We sat side by side, staring at the slides on Clark’s laptop, him narrating and me listening. Occasionally I’d interrupt with a question, but not the ones on my mind. I wanted to ask him how he had coped with learning the details of his wife’s death. I wondered why he had chosen to join the investigation. It seemed insensitive to ask. I imagine he got involved for the same reason he’s involved in the Red Bull Stratos Mission. He wants to learn everything he can about the things that happen to human bodies when the vehicle in which they are traveling breaks apart at high altitudes and crazy speeds. He wants to apply what he learns to design technologies that can be put in place to protect those bodies, to keep astronauts and space tourists alive, to keep families intact.

It is an extremely complicated challenge. Any spacecraft escape system works for a limited range of altitude and speed. Ejection seats, for instance, will work for the first eight to ten seconds of launch, before Q force—as the interplay of air density and speed-generated wind force is known—builds to a lethal level. An ejection system needs to quickly blast the astronauts far enough away from the craft to keep them from smashing into its appendages or getting caught in the fireball of a catastrophic explosion. The most recent Space Shuttle escape system employed a long pole that crew members would hook onto to slide out away from the craft and clear its wing. Retired aerospace engineer and space historian Terry Sunday points out that this would only work well if the shuttle were flying in stable, straight-and-level flight. “And in that case,” says Sunday, “why would you want to leave it?”

To survive the extreme speed and heat of reentry is yet more problematic. The Russian space agency has tested prototypes of an inflatable crew escape pod called a ballute (an amalgam of balloon and parachute). Heat shielding on the broad forward face of the pod protects the terrified occupant, and the large surface area creates the drag needed to slow the pod to a speed where a multistage parachute system could, if all goes well, lower it safely to Earth. It has never flown all the way from space to the ground. Alternatively, a parachute system could lower an entire capsule or crew cabin to the ground. (Current plans call for NASA’s new Orion capsule to be used initially as an ISS escape pod.) The chute would be heavy and costly to launch—and in the case of the Space Shuttle, the process of separating the crew compartment from the rest of the craft presented serious technical challenges. Also, the parachute would need its own heat shielding to keep it from melting during reentry, and this would make deployment trickier.

What about airplane passengers? Is there a way to bail out safely from a jet that’s about to crash? Why, other than the weight and expense, don’t airlines outfit every seat with a portable oxygen supply and a seat-back parachute? Many reasons. Time for a short primer on windblast and hypoxia.

 

AT THE HALFWAY POINT of the Beaufort Wind Force Scale, air is traveling 25 to 31 miles per hour. “Umbrella use becomes difficult,” states the Beaufort, a tad overdramatically. The scale tops out at 73 to 190 miles per hour—hurricane-force wind. That is all the blow nature can muster. Where the Beaufort leaves off is where windblast studies begin. Windblast isn’t weather. The air isn’t rushing into you; you are rushing into it—having bailed out or ejected from an imperiled craft.

At the speed of a typical private plane—135 to 180 miles per hour—the effects of windblast are mainly cosmetic. The cheeks are pressed flat against the skull, bestowing a taut, over-face-lifted appearance. I know this both from hideous photographs of me in the SkyVenture wind tunnel and from a 1949 Aviation Medicine paper on the effects of high-velocity windblast. In the latter, a man identified as J.L., handsome at 0 miles per hour, appears in a 275-miles-per-hour windblast with his lips blown agape, gums in full view like an agitated, braying camel.

At 350 miles per hour, the cartilage of the nose deforms and the skin of the face starts to flutter. “The waves begin at the corners of the mouth…and progress across the face at the rate of about 300 per second to the ear, where they break, causing the ear to wave.” Umbrella use is out of the question. At faster speeds this Q force causes deformations that can, as the Aviation Medicine paper gingerly phrases it, “exceed the strength of tissue.”

Cruising speed for a transcontinental passenger jet is between 500 and 600 miles per hour. Do not bail out. “Fatality,” to quote Dan Fulgham, “is pretty much indicated.” A windblast of 250 miles per hour will blow an oxygen mask off your face. At 400 miles per hour, windblast will remove a helmet—as it did to Bill Weaver’s SR-71 copilot. His visor was blown open and acted like a sail, snapping his head back against the neck ring of his suit and breaking his neck. At 500 miles per hour, “ram air” blasts down your windpipe with enough force to rupture various elements of your pulmonary system. An unnamed test pilot mentioned in a paper by John Paul Stapp ejected at more than 600 miles per hour. The windblast pried open his epiglottis and inflated his stomach like a pool toy. (This worked to his advantage, as he had ejected over water. “The estimated three liters of air in the stomach substituted as flotation gear, which he was in no condition to inflate,” wrote Stapp.)

At supersonic speeds, your body would be coping with the kind of Q force that used to regularly shake experimental jets to pieces. Dan Fulgham has heard about pilots who ejected at 600-plus miles per hour. “Ejection seats back then had metal wings on each side of the head to keep it from flopping around,” he told me. “When they did autopsies they found the brains had just been emulsified because of the tremendous vibration of the head between those steel plates.” Whenever they can, fighter pilots stay with a crippled jet until they can slow it down, reducing the Q load and raising their odds of survival. Red Bull has cause to be nervous about Baumgartner. He could be vibrated to death inside his suit as he approaches or surpasses the speed of sound.

The immediate and dire consequence of plunging into thin air is lack of oxygen. At 35,000 feet, a human being has 30 to 60 seconds of “useful consciousness.” You’d definitely want to be first in line at the emergency exit. I can tell you what it’s like to wander out to the edges of useful consciousness. As a prerequisite for the weightless flight I undertook in chapter 5, the engineering students and I took a NASA aerospace physiology seminar that included a hypoxia (not enough oxygen) demonstration inside the Johnson Space Center altitude chamber. By pumping air out of a sealed chamber, technicians can simulate the atmosphere at any altitude, all the way to near-total vacuum—a big box of outer space. Space agency personnel use these chambers to test spacesuits and other equipment that will be exposed to the vacuum of space.

After about a minute with our oxygen masks off at 25,000 feet—where one has two to five minutes of useful consciousness—we were asked to complete a list of mental tasks. One question read, “Subtract 20 from the year you were born.” I felt fine, but I remember puzzling over it, feeling utterly stumped, and moving on. One of the last questions was: “What does NASA stand for?” I obviously know this, but my answer reads, “N.”

More than useful consciousness you would need luck, given that 400 other panicked passengers are bailing out with you, creating a significant danger of tangled parachute lines and canopies. But it would be possible to survive, provided you stay with the plane until it slows to a more survivable speed. You might experience pain, but nothing major. At higher altitudes, as air pressure drops, air inside the body’s own chambers tries to unbutton its shorts and expand. A pocket of gas inside an unfilled tooth cavity may press painfully on nerves. Same sort of thing happens to air in the sinus cavities—particularly if they’re congested. Even gas dissolved in the cerebrospinal fluid inside the brain’s ventricles tries to expand. If I’d had a hole in my skull, my fellow students in the altitude chamber could have watched my brain bulge out of it.* The gas expansion you are most likely to notice is in your digestive tract. At 25,000 feet, air in the stomach, for example, expands threefold. “Go ahead and fire it off,” our instructor told us, as if eleven male college students needed an invitation.

 

BAUMGARTNER IS TAKING a break. He’s slumped in a chair with his helmet in his lap, sipping water. (Perris SkyVenture doesn’t stock Red Bull.) Art Thompson, the project technical director, is in a good mood. The suit is working well, and Baumgartner feels comfortable in it. (As comfortable as anyone ever feels in a spacesuit. As spacesuit historian Harold McMann put it, “It’s not a nice place to be. It’s not even a nice place to visit.”)

As you read this, there’s a good chance Felix Baumgartner will have completed his history-making jump. As I write this, I don’t how it turns out. I am cautiously optimistic. Skydiving from extremely high altitude is risky, but probably not as risky as Baumgartner’s more typical occupation—jumping from extremely low altitude. If something starts to go wrong during a space dive, you have five minutes to figure out how to remedy it. On a BASE jump, you don’t have five seconds. BASE jumpers don’t carry reserve chutes, as there’s no time to deploy them. “That’s why they don’t tend to have a long…” Thompson searches for the right word.

“Life span?” I offer.

“Career.”

Thompson says he isn’t worried. “Eventually, most BASE jumpers get complacent, but Felix is really anal about what he does. That’s what keeps him alive.”

Brave and anal: the ideal space explorer. Though you don’t find “anal” on any of those lists of recommended astronaut attributes. NASA doesn’t really use words like anal. Unless they have to.

Packing for Mars
SEPARATION ANXIETY

The Continuing Saga of Zero-Gravity Elimination

 

It is probably not the first time that a bunch of guys got together and installed a closed-circuit video camera in a toilet bowl at a government agency. It is surely the first time it has happened with the blessings and financial backing of the agency. And that the monitor has been mounted right there in the bathroom, angled for the viewing ease of the person on the toilet.

On the wall to the sitter’s left is a small plastic sign:

Positional Trainer

Sit Down on Trainer Seat and Spread Buttocks

The Johnson Space Center “potty cam,” as it is more casually known, is an astronaut training aid. It provides a vivid, arresting perspective on something you’ve had intimate contact with all your life but never really seen. Perhaps not unlike viewing one’s home planet from space for the first time. Positioning is critical because the opening to a Space Shuttle toilet is 4 inches across, as opposed to the 18-inch maw we are accustomed to on Earth. Jim Broyan, a waste-water engineer who designs toilets and other amenities for NASA astronauts, is showing me around. Broyan has a reedy build and an angular face. He peers at his visitor over the top of a pair of wire-frame glasses. He possesses a stealthy deadpan wit and is, I imagine, tremendous fun to work with.

“The camera enables you to see if your butt, your…” Broyan pauses in search of a better word: not more polite, just more precise. “…anus lines up with the center.” Without gravity, you can’t reliably gauge your position by feel. You are not really sitting on the seat. You are hovering in close proximity. The tendency, says Broyan, is to touch down too far back. Then your angle of approach is off, and you sully the back of the transport tube and plug some of the air holes that encircle the rim. Bad, bad move. Space toilets operate like shop vacs; “contributions,” to use Broyan’s word, are guided along, or “entrained,” by flowing air rather than by water and gravity, two things in short-to-nonexistent supply in an orbiting spacecraft. Plugged air holes can disable the toilet. Additionally, if you gum up the holes, it is then your responsibility to clean them out—a task Broyan understates as “arduous.”

The room with the potty cam is a working bathroom, complete with sink and paper towel dispenser, but it functions primarily as a classroom. Every astronaut must be potty-trained by Scott Weinstein, who has just joined us. Weinstein is also in charge of galley training—how to eat in space. His is a one-of-a-kind teaching position: taking the most skilled, credentialed, highest-achieving individuals in the world and putting them back in nursery school. Everything these men and women learned as toddlers—how to cross a room, how to use a spoon, how to sit on a toilet—must be relearned for space.

Scott is a big guy, 6 feet 5 and not without some cushioning. He has young kids, and it is easy to picture him with them—on his lap, on his back, climbing him like a play structure. Though he has a background in waste management, he spent seven years elsewhere in NASA, plotting rocket trajectories. Eventually Weinstein realized he wanted to work with people. I imagine he’s very good at what he does. His genial, matter-of-fact nature makes it easy to sit down with him and have a talk about things one doesn’t routinely talk about.

That is more important than you think. Zero-gravity excretion is not entirely a joking matter. The simple act of urination can, without gravity, become a medical emergency requiring catheterization and embarrassing radio consults with flight surgeons. “The urge to go is different in space,” says Weinstein. There is no early warning system as there is on Earth. Gravity causes liquid waste to accumulate on the floor of the bladder. As the bladder fills, stretch receptors are stimulated, alerting the bladder’s owner to the growing volume and delivering an incrementally more insistent signal to go. In zero gravity, the urine doesn’t collect at the bottom of the bladder. Surface tension causes it to adhere to the walls all around the organ. Only when the bladder is almost completely full do the sides begin to stretch and trigger the urge. And by then the bladder may be so full that it’s pressing the urethra shut. Weinstein counsels astronauts to schedule regular toilet visits even if they don’t feel the urge. “And it’s the same with BMs,” he adds. “You don’t get that same sensation.”

Broyan and Weinstein have offered to let me try the Positional Trainer. Weinstein reaches over to the wall and flips a switch that illuminates the inside of the bowl. Because once you sit down, you are blocking the light from the ceiling fixtures. “So,” says Weinstein. “You’re going to try to align yourself, flip on the light, see how you did.”

I ask him whether the astronauts are observing while they go, or before they start.

Broyan appears quietly stricken. “You can’t defecate on that toilet.” He glances at Weinstein, the briefest of glances yet unmistakable in its message: Oh my god oh my god she was gonna crap on the camera.

I wasn’t, honestly.

Weinstein, ever genial: “Well, technically you can, but then Crew Systems has to come in and clean it up.”

“It’s not a working toilet, Mary,” says Broyan, just to be sure I’m clear.

It has happened just once, a hit-and-run. “It was before my time,” says Weinstein. “If I’d been here, I’d have been pulling security tapes.” He wishes me good luck. The two of them leave and shut the door.

Imagine stumbling upon an especially rank porno channel, and then realizing it’s you on screen. My brain elects to reinterpret the image: See the funny puppet? Watch his mouth. What’s he saying? He’s saying, “Ooooo-aaaah-oooooo.”

When Weinstein and Broyan return, Weinstein says he doubts that many of the astronauts use the potty cam. “I get the sense most of them don’t want to see themselves.” Weinstein provides an alternate positioning tactic, “the two-joint method.” The distance between the anus and the front of the seat should equal the distance between the tip of the middle finger and its big knuckle.

Along the same wall as the Positional Trainer is a fully appointed and functioning Space Shuttle commode. It looks less like a toilet than a high-tech, top-loading washing machine. Though the device itself is a high-fidelity version of the one on board the shuttle, the experience is not. There is gravity down here at Johnson Space Center, and that makes all the difference. Gravity facilitates what is known in aerospace waste collection circles as “separation.” In weightlessness, fecal matter never becomes heavy enough to break away and drop down and venture forth on its own. The space toilet’s air flow is more than an alternate flushing method. It facilitates the Holy Grail of zero-gravity elimination: good separation. Air drag serves to pull the material away from its source.

A separation strategy courtesy of Weinstein: spread the cheeks. That way, there is less contact between the body and the “bolus” (another in the waste engineer’s vast arsenal of euphemisms)—and therefore less surface tension to be broken. The newest seat is designed to function as a “cheek spreader” to facilitate a cleaner break.

A more sensible arrangement might be to adopt the posture favored by much of the rest of the world—and by the human excretory system itself. “The squat tends to spread the cheeks,” says Don Rethke, a senior engineer at Hamilton Sundstrand, the contractor on many of the NASA waste collection systems over the years. Rethke suggested to NASA that they add a set of foot restraints higher up, to accommodate those who wish to approximate the squatting posture in zero gravity. No go. When it comes to the astronauts’ creature comforts, familiarity wins out over practicality. A kitchen table makes little sense without gravity, but all long-duration spacecraft have them. Crews want to sit around the kitchen table at the end of the day to eat and talk and feel normal and forget for a moment that they’re hurtling utterly alone through the blackness of a deadly vacuum. In the aftermath of Apollo, where there were fecal bags rather than toilets, bathroom facilities became a charged topic. “When the astronauts came back, they physically and psychologically wanted a sit-down commode,” says Rethke.

Understandable. The fecal bag is a clear plastic sack, similar to a vomit bag in its size, holding capacity, and ability to inspire dread and revulsion.* A molded adhesive ring at the top of the bag was designed for the average curvature of an astronaut’s cheeks. It rarely fit. The adhesive pulled hairs. Worse, without gravity or air flow or anything else to foster separation, the astronaut was obliged to employ his finger. Each bag had a small inset pocket near the top, called a “finger cot.”

The fun didn’t stop there. Before he could roll up and seal the bag to trap the offending monster, the crew member was further burdened with tearing open a small packet of germicide, squeezing the contents into the bag, and manually kneading the germicide through the feces. Failure to do so would allow fecal bacteria to do their bacterial thing, digesting the waste and expelling the gas that, inside your gut, would become your own gas. Since a sealed plastic fecal bag cannot fart, it could, without the germicide, eventually burst. “The test of a good friend was to hand the bag to your crewmate and have him get that germicide completely mushed in with the fecal material,” Gemini and Apollo astronaut Jim Lovell told me. “I’d go, ‘Here, Frank, I’m busy.’”

Given the complexity of the chore, “escapees,” as free-floating fecal material is known in astronautical circles, plagued the crews. Below is an excerpt from the Apollo 10 mission transcript, starring Mission Commander Thomas Stafford, Lunar Module Pilot Gene Cernan, and Command Module Pilot John Young, orbiting the moon 200,000-plus miles from the nearest bathroom.

CERNAN:…You know once you get out of lunar orbit, you can do a lot of things. You can power down…And what’s happening is—

STAFFORD: Oh—who did it?

YOUNG: Who did what?

CERNAN: What?

STAFFORD: Who did it? [laughter]

CERNAN: Where did that come from?

STAFFORD: Give me a napkin quick. There’s a turd floating through the air.

YOUNG: I didn’t do it. It ain’t one of mine.

CERNAN: I don’t think it’s one of mine.

STAFFORD: Mine was a little more sticky than that. Throw that away.

YOUNG: God almighty.

[And again eight minutes later, while discussing the timing of a waste-water dump.]

YOUNG: Did they say we could do it anytime?

CERNAN: They said on 135. They told us that—Here’s another goddam turd. What’s the matter with you guys? Here, give me a—

YOUNG/STAFFORD: [laughter]…

STAFFORD: It was just floating around?

CERNAN: Yes.

STAFFORD: [laughter] Mine was stickier than that.

YOUNG: Mine was too. It hit that bag—

CERNAN: [laughter] I don’t know whose that is. I can neither claim it nor disclaim it. [laughter]

YOUNG: What the hell is going on here?

Broyan showed me a circa-1970 photograph of a NASA employee demonstrating the Apollo fecal bag. The man is dressed in plaid trousers and a mustard-hued shirt with cufflinked sleeves. Like so many photographs from the 1970s, it has surely caused its subject lasting embarrassment. This one more so than most. The man is bending over, his rear protruding toward the camera. A fecal bag adheres to the seat of the trousers. The first two fingers of his right hand are inside the finger cot, poised like open scissors. The last finger is adorned with a wide silver pinkie ring. Though his face is hidden, there is, says Broyan, “speculation” as to his identity. Broyan included the photograph in the history section of the first draft of a recent engineering journal paper he wrote. His superiors asked him to take it out. The feeling was that it was “not the best view of NASA.”

Here is Broyan’s summary of the astronauts’ feedback on the Gemini-Apollo fecal bag system, as presented in that same paper. Clearly not all crew members embraced the scenario with the jollity of Young, Stafford, and Cernan.

The fecal bag system was marginally functional and was described as very “distasteful” by the crew. The bag was considered difficult to position. Defecation was difficult to perform without the crew soiling themselves, clothing, and the cabin. The bags provided no odor control in the small capsule and the odor was prominent. Due to the difficulty of use, up to 45 minutes per defecation was required by each crew member,* causing fecal odors to be present for substantial portions of the crew’s day. Dislike of the fecal bags was so great that some crew continued to use…medication to minimize defecation during the mission.

The Gemini-Apollo urine bags were less odious, but not very much so. Especially when they burst, as Jim Lovell’s did during Gemini VII. Lovell, quoted in astronaut Gene Cernan’s memoir, described the mission as “like spending two weeks in a latrine.” Hamilton Sundstrand suit and toilet engineer Tom Chase neatly summed up the sentiment among engineers and NASA brass at the end of Apollo: “We have to do better.”

NASA’s first zero-gravity toilet was a hands-on load-and-remove-your-own-bag model designed to facilitate specimen collection* during the medical fact-gathering missions of Skylab. It was built into the wall. In the years that followed, to accommodate the psychological and vestibular needs of the crews, NASA engineers and designers began building rooms and labs with a more consistent Earth-gravity-based orientation: tables on “floors” and lighting on “ceilings.”

Space Shuttle toilets have always been mounted on the floor, but you would not call them normal. The original shuttle toilet bowl featured a set of 1,200 rpm Waring blender blades positioned a brief 6 inches below the sitter’s anatomy. The macerator would pulp the feces and tissue—meaning, if all went well, the paper, not the scrotal, variety—and fling it to the sides of a holding tank. “It was kind of pasted there like papier-mâché,” says Rethke. Problems developed when the material in the holding tank was exposed to the cold, dry vacuum of space. (Freeze-drying was a way to sterilize it.) Now it didn’t stick together as well. The papier had lost its mâché. When the next astronaut switched on the macerator, tiny bits of fecal wasp nest that lined the walls of the tank would break off and get batted around by the blades, turning to dust that escaped into the cabin of the spacecraft.

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