The world’s first rocket was built by Nazis to deliver bombs without leaving home. For all its fire-breathing bluster, a rocket is simply a means of delivering something—very fast and very far. The rocket was called the V-2. The first payload was the evil sleet of warheads that came down on London and other Allied cities during World War II.

The second was Albert.

Albert was a nine-pound rhesus monkey in a gauze diaper. In 1948, more than a decade before the world had heard of Yuri Gagarin or John Glenn or Ham the astrochimp, Albert became the first living creature to be launched on a rocket to space. As part of the spoils of war, the United States had taken possession of three hundred train carloads of V-2 rocket parts. They were by and large the playthings of generals, but the V-2s caught the imagination of a handful of scientists and dreamers, men more interested in the going-up than the coming-down.

One of them was David Simons. In his oral history, Simons describes a conversation with his boss, James Henry, at the Aeromedical Research Laboratory at Holloman Air Force Base, near White Sands Proving Ground in New Mexico. The conversation is classic 1940s, an era when people regularly began their sentences with “Why,…” and “Boy,…”

Dr. Henry starts it off. “Dave, do you think man will ever go to the moon?” I like to picture him in a lab coat, pensively poking his chin with the eraser end of a No. 2 pencil.

Simons replies without hesitating. “Why, of course. It’s just a matter of engineering design and time to work out the problems—”

Henry cuts him off. “Well, what would you think of having an opportunity to help us put a monkey in a captured V-2 rocket that would be exposed to about two minutes of weightlessness and measure the physiological responses to weightlessness?” It was a very long question.

“Oh! What a wonderful opportunity! When do we start?”

It is a moment that, to me anyway, signals the birth of American space exploration. It captures both the geeky excitement and the hand-wringing uncertainty over what might befall a human organism shot to the edges of the known world. Space was an environment in which no one and nothing on Earth had evolved, or, for all the scientists then knew, could survive.

Henry put Simons in charge of Project Albert. I’m looking at a book with photographs from the project. There is the V-2 poised for flight, 50-plus feet tall. There is Albert, with his rhesus monkey muttonchops and delicate eyelids cast down like a doll’s. Below this, a shot of Albert strapped to a tiny stretcher, being slid inside a makeshift aluminum capsule that will fit into the nose cone where warheads were meant to go. You can’t see the face of the enlisted man who holds him, just his midsection: the fly of his khaki pants and the cuff of a too-short shirtsleeve. His nails are dirty. There is his wedding ring. What does his wife think? What does he think? Does it strike him as odd: launching this towering rocket, the world’s first ballistic missile, with nothing on board but a doped-up monkey?

Probably not. Aerospace professionals at the time were gripped with almost universal foreboding at the prospect of cutting loose from gravity’s hold. What if man’s organs depended on gravity to function? What if the pumping of his heart failed to push his blood through his veins, and instead merely churned it in place? What if his eyeballs changed shape and compromised his visual acuity? If he cut himself, would his blood still coagulate? They worried about pneumonia, heart failure, debilitating muscle cramps. Some fretted that without gravity, signals from floating inner-ear bones and other cues to the body’s position would be absent or contradictory—and that this might cause perturbations that would, to quote aerospace medicine pioneers Otto Gauer and Heinz Haber, “deeply affect the autonomic nervous functions and ultimately produce a very severe sensation of succumbence associated with an absolute incapacity to act.” I queried an online dictionary about succumbence. It said, “Did you mean succulents?”

The only way to know was to send a “simulated pilot” up there—to launch an animal in the nose of a thundering V-2 rocket. The last attempt at something similar took place in 1783. That time the experimenters were Joseph and Étienne de Montgolfier, the inventors of the hot-air balloon. It was like something from a children’s book. A duck, a sheep, and a rooster went for a ride beneath a beautiful balloon, in the skies over Versailles on a summer afternoon. On they sailed, over the king’s palace and the courtyard filled with waving, cheering men and women. In fact, it was an ingenious, controlled inquiry into the effects of “high” (1,500 feet) altitude on a living organism. The duck was the control. Since ducks are accustomed to such altitudes, the brothers could assume that any harm that befell one was likely to have been caused by something else. The balloon landed uneventfully after a two-mile voyage. “The animals were fine,” reads Étienne de Montgolfier’s report of the flight, “and the sheep had pissed in the cage.”

Gravity turned out to be the least of the Alberts’ concerns. There were six Alberts, told apart, like kings or movie sequels, by the Roman numeral after their name. It was Albert II who made history. (Albert I suffocated while awaiting liftoff.) The excellent volume Animals in Space reproduced the historic printout from the recorder that monitored Albert II’s heart beats and the breaths he took during the zero-gravity portion of the flight, 83 miles high. They did not stray far from normal. (He had, like all the Alberts, been anesthetized.) They were also among his last. The nose cone tore loose from its parachute and fell to the desert floor. At worst, a lethal scenario. At best, a very severe sensation of succulents. The National Archives has footage of Albert II’s launch and flight. I didn’t order a copy. The shot list was enough.

AT FIRST BLUSH, Project Albert is difficult to fathom. Here are men contemplating sending a human being into space atop a tank carload of explosive chemicals, and they’re worried he might be harmed by gravity?

To understand the Project Albert mind-set, you need to spend a few moments pondering the forces of gravitation. If you are like me, you have tended to think of gravity in terms of minor personal annoyances: broken glassware and sagging body parts. Until this week, I failed to appreciate the gravitas of gravity. Along with electromagnetism and strong and weak nuclear forces, gravity is one of the “fundamental forces” that power the universe. It was reasonable to assume that gravity might have something darker up its sleeve that mankind was yet unaware of.

A quick refresher: Gravity is the pull, measurable^* and predictable, that one mass exerts on another. The more mass involved, and the shorter the distance between the masses, the stronger the pull. The moon is more than 200,000 miles away, yet it is massive enough that without any conscious effort, without plugging anything in, it pulls the Earth’s water and even its tectonic plates moonward, causing ocean and (very, very small) land tides. (Earth exerts similar forces on the moon.)

Gravity is why there are suns and planets in the first place. It is practically God. In the beginning, the cosmos was nothing but empty space and vast clouds of gases. Eventually the gases cooled to the point where tiny grains coalesced. These grains would have spent eternity moving through space, ignoring each other, had gravitational attraction not brought them together. Gravitation is the lust of the cosmos. As more particles joined the orgy, these celestial blobs grew in size. The bigger they became, the bigger the pull they exerted. Soon (in a thousands-of-centuries sort of way) they could lure larger and more distant particles into the tar pit of their gravitational influence. Eventually stars were born, objects big enough to pull passing planets and asteroids into orbit. Hello, solar system.

Gravity is the prime reason there’s life on Earth. Yes, you need water for life, but without gravity, water wouldn’t hang around. Nor would air. It is Earth’s gravity that holds the gas molecules of our atmosphere—which we need not only to breathe but to be protected from solar radiation—in place around the planet. Without gravity, the molecules would fly off into space along with the water in the oceans and the cars on the roads and you and me and Larry King and the dumpster in the In-N-Out Burger parking lot.

The term “zero gravity” is misleading when applied to most rocket flights. Astronauts orbiting Earth remain well within the pull of the planet’s gravitational field. Spacecraft like the International Space Station orbit at an altitude of around 250 miles, where the Earth’s gravitational pull is only 10 percent weaker than it is on the planet’s surface. Here’s why they’re floating: When you launch something into orbit, whether it’s a spacecraft or a communications satellite or Timothy Leary’s remains, you have launched it, via rocket thrust, so powerfully fast and high and far that when gravity’s pull finally slows the object’s forward progress enough that it starts to fall back down, it misses the Earth. It keeps on falling around the Earth rather than to it. As it falls, the Earth’s gravity keeps up its tug, so it’s both constantly falling and constantly being pulled earthward. The resulting path is a repeating loop around the planet. (It is not endlessly repeating, though. In low Earth orbit, where spacecraft roam, there’s still a trace of atmosphere, enough air molecules to create a teeny amount of drag and—after a couple years—slow a spacecraft^* down enough that without a rocket engine blast it falls out of orbit.) In order to escape the Earth’s gravitational pull completely, an object must be hurtling at Earth’s escape velocity: 25,000 miles per hour. The more massive a celestial entity, the harder it is to break its hold. To escape the monstrous gravity of a black hole (a huge collapsed star), you’d need to travel faster than the speed of light (about 670 million miles per hour). In other words, even light can’t escape a black hole. That’s why it’s black.

Getting back to weightlessness. Weight is a bit of a mind-bender. I had always thought of my weight, on any given day, as a constant, a physical trait like my height or my eye color. It’s not. I weigh 127 pounds on Earth, but on the much smaller moon, whose gravitational pull is one sixth of Earth’s, I weigh about as much as a beagle. Neither weight is my real weight. There is no such thing as a real weight, only real mass. Weight is determined by gravity. It’s a measure of how fast you’ll accelerate if you happen to be dropping through the air like Newton’s apple. (Here on Earth, were there no atmospheric drag to slow you down, gravity would accelerate you at the rate of 22 miles per hour faster for each second that you fall.) If you’re standing on the ground, you obviously don’t speed up, but the pull is still there. You’re not falling, just pressing. The acceleration reads as weight on a bathroom scale. When there’s nothing to press against, as in the free fall of orbit, then you are weightless. The “zero gravity” that astronauts experience aboard an orbiting spacecraft is simply a continuous state of falling around the Earth.

If something provides a supplemental source of acceleration—something added to the acceleration prompted by Earth’s gravity—now your weight will change. Take your bathroom scale into an elevator and watch the readout as you take off. You will briefly gain weight, and perhaps a minor reputation around the building. The elevator’s acceleration has added an extra earthward pull to the earthward pull of gravity. Contrariwise, when the elevator approaches the top floor and slows down, the deceleration renders you briefly lighter; it has accelerated you skyward, counteracting some of the Earth’s downward pull.

Why is there this force, this pull between objects? Poking around on the Web for a suitably patient entity to ask, I came upon the Gravity Research Foundation, founded by multimillionaire businessman and fire alarm magnate Roger Babson. After gravity pulled Babson’s sister toward the bottom of a river and she drowned, he became history’s most voluble antigravity activist, publishing screeds like Gravity: Our Enemy No. 1. If I were Babson, I might have nominated water or currents for the number-one spot, but the man was unshakable in his ire.^*

Babson is dead, but the foundation lives on. It no longer characterizes its efforts as antigravity, a term that has come to connote “crackpot.” “We are neither ‘pro-gravity’ nor ‘anti-gravity,’” director George Rideout, Jr., told a journalist who profiled the organization in 2001. They are, he said, just trying to learn as much as possible about it. I contacted Rideout seeking an explanation of why gravity exists. He told me to go ask a physicist.

I did. I made a hobby of it. But why are two masses drawn together, I’d say. “Mary, Mary, Mary,” was the kind of response I tended to get. “Because space-time exists,” said one physicist. “What does ‘why’ mean?” said another. Perhaps gravity is a mystery even to those who understand it. I can well imagine that the prospect of messing with it must have been daunting to the pioneers of aerospace medicine out in the desert in 1948.

DISMAYED BUT UNDETERRED, Simons and his crew launched four more Alberts. Albert III’s rocket exploded. Alberts IV and V were, like Albert II, victims of malfunctioning parachute systems. Albert VI made it to the ground with his vital signs little changed, but died of heat prostration while rescuers searched for the nose cone. Eventually the Air Force—and you do wonder what took them so long—stopped naming their ill-fated gravity monkeys Albert. More importantly, they began to move away from the V-2s in favor of a smaller, less problematic^* rocket called the Aerobee.

Patricia and Michael, in 1952, were the first monkeys to survive a trip to Weightlessville. The macaques’ heart rate and breathing was monitored throughout the flight and appeared to be normal. Biomedical research from this era appears to have been fixated on pulse and respiration. Publicity images from that era invariably show a physician in a white coat and crewcut, holding a stethoscope to a monkey’s narrow chest. That’s all the Albert papers reported on. You couldn’t diagnose much from it—yep, still alive—but this was the limit, circa 1950, of the data you could transmit back from a rocket 30 or 50 or 80 miles up. To rule out any subtler effects of weightlessness, the Air Force would need a subject they could interview: a human. For that, they needed a safer way to go about it.

It was a team of brothers, Luftwaffe aerospace medicine pioneers Fritz and Heinz Haber, who, in 1950, dreamed up a technique known today as parabolic flight. The Habers theorized that if a pilot flies the same kind of parabolic arc as a suborbital rocket (or a baseball pop fly), then the passengers, for anywhere from 20 to 35 seconds at the top and the downward segments of the arc, will experience weightlessness, just as the monkeys had. If the pilot then pulls out of the downward dive and heads back up and repeats the process, over and over until his fuel runs low, science will have an accumulation of several minutes of weightlessness to work with—at a fraction of the cost of building and launching rockets. These roller-coaster zero-gravity flights are still flown today by space agencies to test equipment or train astronauts or humor authors who have pestered them ceaselessly for months (more on this shortly).

Here the scene shifts to South America. The Habers had a colleague named Harald von Beckh, who lived in Buenos Aires after the war. Von Beckh knew from the V-2 and Aerobee rocket flights that weightlessness posed no grave threat to survival, but he wondered whether it would disorient a pilot or otherwise compromise his ability to fly a craft. So naturally, von Beckh went out and got some snake-necked turtles. Hydromedusa tectifera are, like post-war Nazis, native to Argentina, Paraguay, and Brazil. These are turtles that hunt like snakes, coiling their overlong necks into an S and then unwinding in bullet-fast strikes that rarely miss. That is what von Beckh planned to test. Would weightlessness put them off their game? It did. The turtles moved “slowly and insecurely” and did not attack a piece of bait placed directly in front of them. Then again, the water in which they swam was repeatedly floating up out of the jar and forming an “ovoid cupola.” Who could eat?

Von Beckh quickly moved on from turtles to Argentinean pilots. Under the section heading “Experiments with Human Subjects”—a heading that, were I a doctor previously employed by Nazi Germany, I might have rephrased—von Beckh reports on the efforts of the pilots to mark X’s inside small boxes during regular and weightless flight. During weightlessness, many of the letters strayed from the boxes, indicating that pilots might experience difficulties maneuvering their planes and doing crossword puzzles during air battles.

The following year, von Beckh was recruited by the Aeromedical Research Laboratory at Holloman Air Force Base—home of Dave Simons and Project Albert. Simons was keen to continue his zero-gravity research using the newfangled parabolic flight technique. All he needed was a willing pilot. Only one man volunteered. Joe Kittinger “made a career” out of volunteering. “You can’t get any real fun things unless you volunteer,” says Kittinger in an oral history on file at the New Mexico Museum of Space History. (Kittinger has a unique sense of fun. In 1960, he volunteered to make a parachute jump into the near-airless void 19 miles above the Earth, to test survival equipment for extremely high-altitude bailouts. More on this in chapter 13.)

Kittinger would take the plane up at a 45-degree angle, and then arc it over and plunge back down, all the while watching a golf ball suspended on a string from the cockpit ceiling. “That was our instrumentation!” Kittinger told me. When the plane achieved zero gravity, the golf ball started floating. So did Kittinger, of course, but he was strapped in his seat. Meanwhile, back behind the cockpit, a Salvador Dali photo had come to life. Von Beckh and Simons were studying, among other things, cats’ ability to right themselves in zero gravity. “The guys would take them and just let them float,” recalled Kittinger. “Here would come a cat and I would push the cat back. A couple of times we had a monkey come floating up to the cockpit. And I would take the monkey and I would push it back.”

When it became clear that a few seconds of weightlessness was more entertaining than it was troublesome, the aerospace medicine crowd began to apply their boundless nervous energy to the scenario of longer-duration missions. Would an astronaut on a three-or four-day orbit of Earth or a trip to the moon be able to eat, or did he need gravity to help the food along? How would he drink water? Does a straw work in zero gravity? Late in 1958, three captains at the U.S. Air Force School of Aviation Medicine at Randolph Air Force Base in Texas commandeered an F-94C fighter plane and fifteen volunteers and undertook a project to answer these simple questions. Though they were phrased less simply for the journal paper, which came out under the title “Physiologic Response to Subgravity: Mechanics of Nourishment and Deglutition of Solids and Liquids.”

The captains were not reassured by what they found. New and never-before-encountered dangers presented themselves. Water in a cup became “an amoeboid mass” that would levitate from the cup and “envelop” the face. “The fluid flowed into the…sinuses as the subjects attempted to breathe. Choking—virtually a sense of drowning—was a common occurrence.” Eating was deemed equally perilous. “A number of subjects reported that pieces of food hung suspended in the oropharynx and several reported that bits of food floated up over the soft palate into the nasal passages.” Chewed food, they claimed, was drifting up the esophagus into the mouth, where it “caused the subjects to vomit and feel ill.” I would have assumed that the vomiting was due to the plane’s insane trajectory, or perhaps something having to do with zero gravity’s effect on the vestibular system, but the researchers stuck to their loopy guns and coined a new, utterly nonexistent phenomenon: Weightless Flight Regurgitation Phenomenon.

Fast-forward five months. The three captains are now majors. They commandeer yet another F-94C and begin “Physiologic Response to Subgravity: Initiation of Micturition.” The concern was legitimate. If you counteract the pull of gravity, will the bladder still empty correctly? Based on their zero-gravity experiences with glasses of water (“exceedingly messy”), the researchers knew better than to have the men urinate into an open container. Using scrap hosing from oxygen masks and small weather balloons, they fashioned enclosed urine receptacles. To make sure everyone needed to go, the subjects were, with characteristic Air Force zeal, told to drink eight glasses of water over the course of the two hours leading up to flight time. Severe discomfort resulted, such that several of the men had to visit the head well before the plane took off. In the end, everything worked fine, and the urine flowed normally.

Kittinger has a name for the researchers: weenies. “There were scientific papers put out all over the place by the experts that said that [zero gravity] was going to be the limit to putting man into space,” says Kittinger in his oral history. “And I just sat there and laughed my butt off, because I loved it! I thoroughly enjoyed it.”

You can’t really blame the weenies. You have to put their concerns in the context of the times. Space and zero gravity were uncharted territory where none of the familiar rules could be assumed to apply. Over the course of history, the same sort of anxiety has appeared every time a newer, faster form of transport has come along. “When technical perfection of the steam engine made the development of railways possible, scientists were afraid that the velocity of the trains would exert harmful effects upon the human body.” The quote comes from an aviation medicine text published in 1943. (Locomotives at that time could not exceed fifteen miles per hour.) In the early 1950s, as commercial flights became available, doctors feared that flying might harm the heart and adversely affect the circulation. When a Dr. John Marbarger showed that it did not, United Airlines gratefully awarded him its Arnold D. Tuttle Award.

Parabolic flights are still being flown by space agencies, but these days it’s not human beings they’re testing—it’s equipment. Every time NASA develops a new piece of hardware—be it a pump or a heating element or a toilet—someone has to haul it up on a plane out of Ellington Field near Houston to see what sort of problems might develop in zero gravity. Twice a year, something even more problematic gets hauled up there: college students and journalists.