Mary Roach - Packing for Mars

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.

CU [CLOSE-UP]: …Several scenes of little monkey being prepared for flight in V-2, being placed in box with head sticking out, given hypodermic…

Night shot, launching of V-2.

CU: Parachute rolled up into ball on ground.

CU: Smashed instruments and equipment in warhead.

CU: Remains of the section containing the monkey.

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 [13] Using—how cool is this?—a gravity meter. Walk over an area of very dense rock while holding one of these meters, and you can watch the pull of gravity increase. (Fluctuations in Earth’s density change its gravity enough to pull missiles off their trajectory by as much as a mile or so; gravity maps of Earth were once top-secret Cold War possessions.) This effect is lessened if the dense rock is a tall mountain and you’re four or five miles above the mean surface of Earth. If you carry a bathroom scale to the top of Mt. Everest, you may see that you actually weigh a tiny bit less, not counting the marbles you have obviously lost. 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 [14] Or a space station garbage bag or a NASA spatula. When astronauts let go of objects, they become satellites for the few weeks or months it takes them to lose speed and fall out of orbit. The term “satellite” applies to any object orbiting the earth. The “spat sat,” as the orbiting spatula was known, had been used to test a spackling technique to fix dings in the exterior of the Space Shuttle caused by, ironically, orbiting debris. You don’t have to worry about being killed by falling spatulas or LSD gurus, because these things burn up when they reenter the Earth’s atmosphere. (Dr. Leary was recremated sometime in 2003.) 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.