Beyond: Our Future in Space (16 page)

BOOK: Beyond: Our Future in Space
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Living in Space

Being weightless is unnatural and uncomfortable. The airplane that gives people a taste of zero g is called the Vomit Comet. About half of all visitors to space experience motion sickness, which may consist of nausea, vomiting, dizziness, headaches, and general malaise. It usually wears off after two or three days, but 10 percent of all astronauts suffer a long-term and debilitating form of space sickness that interferes with their ability to function normally.
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This has been known since the early days, but astronauts expected to have the “right stuff” were reluctant to report it, and often they were grounded if they did. US Senator Jake Garn became the poster child for puking when he flew on the Shuttle in 1985, and astronauts since then have referred to the “Garn scale” to rate their own symptoms. Garn was essentially incapacitated during his entire flight. Oceanographer and NASA researcher Robert Stevenson said, “Jake Garn . . . made a mark in the Astronaut Corps because he represents the maximum level of space sickness that anyone can ever attain, so the mark of being totally sick and totally incompetent is one Garn. Most guys will get maybe to a tenth Garn, if that high.”
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A Dutch researcher did experiments where people were subjected to human centrifuges (often used for astronaut training) and observed that they suffered similar symptoms after leaving the centrifuge.
23
So the trigger for space sickness is adapting to a different gravitational force, rather than the absence of gravity. Technically, astronauts are never subject to zero gravity—gravity is everywhere in the universe. But in Earth orbit, astronauts and their “container” freefall at the same rate as their forward motion, so they “float” inside the container.
Microgravity
is a more accurate term.

Thanks to their Mir Space Station, Russians hold the records for the longest time in zero g. Valeri Polyakov spent 438 days on Mir in the mid-1980s and three other cosmonauts spent more than a year. By going up six times, Sergei Krikalev racked up 803 days in space. How these cosmonauts fared is providing vital insights into what to look for when we send humans to Mars.

The full set of physiological effects would give any potential spacefarer pause. A lack of gravity causes body shape to morph. Astronauts get 2 or 2.5 inches taller, but that extension (and subsequent compression when they return) is quite painful. Internal organs drift upward, faces get puffy, waists and legs shrink, and the result is a cartoonish image of a strongman. But this is an illusion; without gravity to fight against, muscles atrophy and bones get thin and brittle. Astronauts work out for two or three hours a day to combat these effects. The heart also weakens, and blood pressure may lower to the point where a person occasionally can pass out. Immune systems weaken in space, and the upward migration of body fluid leads to congestion and headaches. Glucose tolerance and insulin sensitivity vary wildly in space.

Since they’re not shielded by the Earth’s atmosphere, cosmic rays cause low-level brain damage, and they may accelerate the onset of Alzheimer’s disease. Eyes suffer, too; Russian cosmonaut Valentin Lebedev suffered progressive cataracts and went blind after spending eight months in orbit. The cosmic rays also create brilliant flashes of light in the eyeball, creating a kind of private disco ball.
24

Decent food combats physical discomfort, or at least boosts morale. Early astronauts had a fairly grim diet of flavored paste from a tube or bite-size, freeze-dried snacks. Floating crumbs and drops of liquid cause havoc with sensitive electronics, so they were avoided at all costs. Now the choice is much better. Astronauts can feast on pouches of shrimp cocktail, beef stroganoff, and cherries jubilee. Many of the technologies that NASA developed for preparing, sealing, sterilizing, and heating meals have been adopted by the food-service industry and are enjoyed by couch potatoes the world over. The Space Shuttle’s fuel cells generated water, providing the side benefit that water to reconstitute the food was made in orbit, saving launch weight.

On the orbiting space stations, the scene is quite familiar. Skylab astronauts gathered around a table where they could “sit” using foot straps, and they each had a knife, a fork, and a spoon, plus a pair of scissors to cut plastic seals. The International Space Station uses an eight-day rotation of meals, which could become monotonous if you were up there a year. Half the meals are American and half are Russian, with crews getting to taste and vet the food of the other country in their training sessions. The diet of burgers and borscht has broadened as people from other countries have started to fly aboard the station.
25

Astronauts get three meals and occasional snacks. Those having the midnight munchies must dip into the reserve supplies, which are brought in case landing is delayed for any reason. Raiding someone else’s food is a major transgression; every astronaut’s meals are customized according to their preferences and marked with a colored dot. Voyages have unraveled over less—the
Caine
mutiny over Captain Queeg’s missing strawberries comes to mind. Getting balanced nutrition is tricky due to the limited range of food available. Vitamin D is cranked up, since there’s no sunlight to help produce it and a deficiency would lead to excessive bone loss. Iron is dialed down because astronauts don’t make enough red blood cells to absorb the usual amount. Calories stay about the same as on Earth.

What goes in must come out. Containing and processing waste is a real problem in the close confines of a spacecraft or space station. NASA makes astronauts use a “positional trainer” that teaches them how to guide their feces into a two-inch-diameter opening, all while watching a video shot from underneath looking up. Diapers are a thing of the past, but when the space toilet has a problem, astronauts must resort to even more primitive collection methods. In 2008, the International Space Station’s lone toilet broke. TV satirist Stephen Colbert mocked NASA on his show for resorting to what they called “a bag-like collection system.” When NASA held a write-in naming contest for its next-generation toilet, Colbert rallied his viewers to inundate the NASA website. He won. But NASA wimped out and declined to name the commode the “Colbert,” dubbing it instead “Tranquility.”
26

For the few hundred who’ve been up, the experience transcends any physical discomfort. What a sublime experience it must be—to traverse in ninety minutes what took Jules Verne’s Phileas Fogg eighty days, to view the curved limb where sky shades into night, to glimpse beyond the horizon. And that’s just the edge of space. Beyond that, a vast array of fascinating worlds beckons.

7

A Plethora of Planets

_______________________

The Pale Blue Dot

As the difficulties of astronauts make clear, we’re perfectly adapted to our environment. The Earth fits us like a glove. The gravity, the length of day and night, the composition of the air, the climate—we survived and spread around this planet for tens of thousands of years without any assistance from technology.

So what does the Earth have to teach us about leaving home?

It shows us that we can adapt and survive in places where the physical environment is challenging. As we’ve seen early in this book, humans spread out of Africa and adapted to many inhospitable climates, such as the arid deserts of the Middle East and the frozen tundra of Siberia. Even today, descendants of these early voyagers make their homes in inclement places. Consider, for example, the durability of the people who live at the hottest, highest, driest, and coldest places on Earth.

The Timbisha tribe of Native Americans has lived near Furnace Creek in the Mojave Desert for more than a thousand years. Prospectors on their way to the California Gold Rush in the 1840s named this place Death Valley; in the summer, it can reach a scorching 134°F (57°C). The land is harsh, but until the traditional way of life was encroached upon in the last century, it provided the Timbisha with all they needed. The tribe traveled seasonally to harvest wild fruit and seeds. Piñon pine nuts and mesquite beans were major parts of their diet, augmented by lizards and rabbits.
1

Thousands of miles to the south, in the Peruvian Andes, indigenous people still live at an altitude of 18,000 feet (5,100 meters), high enough to give anyone who is unacclimated headaches and other symptoms of altitude sickness. Their nomadic lifestyle has been lost, replaced by backbreaking work in gold mines. At La Rinconada, miners live next to the mine and suffer mercury poisoning as a result. They receive no wages, but on the last day of every month they’re allowed to take as much ore from the mine as they can carry on their shoulders. As usual, man’s biggest indignities come from man and not from the land.

Continuing down the spine of the Andes, inhabitants of Chile’s Atacama Desert live where some places have never recorded rainfall. Some riverbeds have been dry for more than 100,000 years, and scientists come to this stark landscape to test instruments for future missions to Mars. The oldest mummified remains predate analogous Egyptian relics by thousands of years. About 20,000 Atacameños still live here, although their Kunza language is now extinct. They herd llamas and they grow maize to eat and ferment it into moonshine. They use the chañar berry for syrup, jam, and a medicinal remedy. Some families still climb the side of the dramatically sited Licancabur volcano to make an animal sacrifice on June 21, the southern winter solstice. In this ceremony, a knife is plunged into the chest of a sheep or goat and its still-beating heart is pulled out and held up as the Sun rises.
2

Oymyakon in Siberia is the coldest permanently inhabited place on Earth. Pen ink freezes here, metal sticks to skin, spit freezes before it hits the ground, birds fall from the sky in midflight, and coffins rise from the ground as the permafrost thaws and refreezes. The Evenki people eschew the town and prefer their nomadic lifestyle, herding reindeer. They set up and break camp every day to follow the herd and work their sleds 20 miles or more through rugged terrain and snowdrifts. Lard is a staple of their diet. When a reindeer dies, they eat every part. The night shift consists of protecting the herd from marauding wolves while armed only with a spear carved from a birch branch. Ancient ancestors of the Evenki traveled over the Bering Strait when it was a land bridge to become the first Americans.
3

We humans have adapted physically and genetically to harsh environments over thousands of years. Populations who have lived for many generations in arctic or subarctic climates have larger bodies than those in warm or tropical climates; the large mass means a lot of heat is generated, but the smaller surface area relative to the mass means it’s radiated away inefficiently. This principle explains the difference between the Masai of East Africa, who are tall and slender with long limbs, and the Inuit of the far north, who are short and squat. The populations have analogous differences in body-fat storage and basal metabolic rate. At high altitudes, mechanisms for adaptation include raised hemoglobin production (natives of high mountain valleys in Peru and Bolivia) and increased oxygen delivery to muscles via wider arteries and capillaries (natives of Nepal and Tibet).

Without technology, the highest and lowest parts of the Earth are uninhabitable. Just 160 Western climbers have ascended the six vertical miles of Mount Everest without oxygen (compared to more than 4,000 who have had an assist from oxygen), and the depth limit for unassisted diving is 410 feet. With technology, these limits stretch to Alan Eustace and his supersonic free fall in the pressurized suit from 135,890 feet, and film director James Cameron’s dive 35,790 feet to the bottom of the Mariana Trench in the DeepSea Challenger sub. These are transient experiences, putting the adventurers in mortal danger, but only for a brief time.

“All of humanity’s problems stem from man’s inability to sit quietly in a room alone,” wrote Blaise Pascal in his treatise
Pens
ées
in 1669. We’re wanderers. We need social interaction. We crave stimulation. All these requirements will be difficult to meet when we leave the sanctuary of the Earth. When humans go into space, they’re confined, in a limited sensory environment, and cut off from normal interactions with the majority of the “tribe.”

Figure 27. The Earth from a distance of four billion miles. The “Pale Blue Dot” was named by Carl Sagan after the Voyager spacecraft looked back at the Earth in 1990. If we travel in space, we may have to venture a great distance before we find a planet as habitable as ours. (The streaks are artifacts from the camera optics.)

In 1990, the Voyager 1 spacecraft paused at the edge of the Solar System, twelve years after its launch and six billion miles from Earth, and took a picture looking back. The iconic image of our planet as a pale mote suspended in an ocean of black space was called the Pale Blue Dot (
Figure 27
).

Carl Sagan requested the image and reflected on it in his 1994 book,
Pale Blue Dot
:

BOOK: Beyond: Our Future in Space
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