How about a spaceship that travels as fast as Helios-B, the US–German solar probe that was the fastest-ever unmanned space probe? Launched in 1976, it was clocked at forty-two miles per second (more than 150,000 miles per hour) as it accelerated toward the Sun. (Note that this is only one-fiftieth of one percent of the speed of light.) Such a craft would cut the travel time to the nearest star down to a mere nineteen thousand years—nearly four times the length of recorded human history.
What we really want is a spaceship that can travel near the speed of light. How about 99 percent of light speed? All you would need is 700 million times the energy that thrust the Apollo astronauts on their way to the Moon. Actually, that’s what you would need if the universe were not described by Einstein’s special theory of relativity. But as Einstein correctly predicted, while your speed increases, so too does your mass, forcing you to spend even more energy to accelerate your spaceship to nearly the speed of light. A back-of-the-envelope calculation shows that you would need at least ten billion times the energy used for our Moon voyages.
No problem. Our engineers are the best. But now we learn that the closest star known to have planets is not Proxima Centauri but one that is about ten light-years away. Einstein’s theory of special relativity shows that while traveling at 99 percent of the speed of light, you will age at only 14 percent the pace of everybody back on Earth, and so the round trip for you will last not twenty years but about three. On Earth, however, twenty years actually do pass by, and when you return, everyone has forgotten about you.
The Moon’s distance from Earth is ten million times greater than the distance flown by the original Wright Flyer at Kitty Hawk, North Carolina. That aeroplane was designed and built by two brothers who ran a bicycle repair shop. Sixty-six years later, two Apollo 11 astronauts became the first moonwalkers. In their shop, unlike the Wright brothers’, you’d find thousands of scientists and engineers building a several-hundred-million-dollar spacecraft. These are not comparable achievements. The cost and effort of space travel derive not only from the vast distances to be traveled, but also from space’s supreme hostility to life.
Many will declare that early terrestrial explorers also had it bad. Consider Gonzalo Pizarro’s 1540 expedition from Quito across Peru in search of the fabled land of oriental spices. Oppressive terrain and hostile natives ultimately led to the death of half of Pizarro’s expedition party of more than four thousand. In his mid-nineteenth-century account of this ill-fated adventure, History of the Conquest of Peru, William H. Prescott describes the state of the expedition party a year into the journey:
At every step of their way, they were obliged to hew open a passage with their axes, while their garments, rotting from the effects of the drenching rains to which they had been exposed, caught in every bush and bramble, and hung about them in shreds. Their provisions spoiled by the weather, had long since failed, and the live stock which they had taken with them had either been consumed or made their escape in the woods and mountain passes. They had set out with nearly a thousand dogs, many of them of the ferocious breed used in hunting down the unfortunate natives. These they now gladly killed, but their miserable carcasses furnished a lean banquet for the famished travelers.
On the brink of abandoning all hope, Pizarro and his men built from scratch a boat large enough to take half the remaining men along the Napo River in search of food and supplies:
The forests furnished him with timber; the shoes of the horses which had died on the road or had been slaughtered for food, were converted into nails; gum distilled from the trees took the place of pitch; and the tattered garments of the soldiers supplied a substitute for oakum. . . . At the end of two months, a brigantine was completed, rudely put together, but strong and of sufficient burden to carry half the company.
Pizarro transferred command of the makeshift boat to Francisco de Orellana, a cavalier from Trujillo, and stayed behind to wait. After many weeks, Pizarro gave up on Orellana and returned to the town of Quito, taking yet another year to get there. Later Pizarro learned that Orellana had successfully navigated his boat down the Napo River to the Amazon and, with no intention of returning, had continued along the Amazon until he emerged in the Atlantic. Orellana and his men then sailed to Cuba, where they subsequently found safe transport back to Spain.
Does this story have any lessons for would-be star travelers? Suppose one of our spacecraft with a shipload of astronauts crash-lands on a distant, hostile planet. The astronauts survive, but the spacecraft is either totaled or broken. Problem is, hostile planets tend to be considerably more dangerous than hostile natives. The planet might not have air. And what air it does have may be toxic. If the air is not toxic, the atmospheric pressure may be a hundred times higher than on Earth. If the atmospheric pressure is tolerable, the air temperature may be 200° below zero—or 200° above zero. None of these possibilities bodes well for our astronaut explorers.
But perhaps they could survive for a while on their reserve life-support system. Meanwhile, all they would need to do is mine the planet for raw materials; build another spacecraft from scratch or repair the existing damage, which might mean having to rewire the controlling computers (using whatever spare parts can be mustered from the crash site); build a rocket-fuel factory; launch themselves into space; and then fly back home.
Delightfully delusional.
Perhaps what we should do is genetically engineer new forms of intelligent life that can survive the stress of space yet still conduct scientific experiments. Actually, such creatures have already been made in the lab. They’re called robots. You don’t have to feed them, they don’t need life support, and they won’t get upset if you don’t bring them back to Earth. People, on the other hand, generally want to breathe, eat, and eventually come home.
It’s probably true that no city has ever held a parade for a robot. But it’s probably also true that no city has ever held a parade for an astronaut who wasn’t the first (or last) to do something or go somewhere. Can you name the two Apollo 12 or Apollo 16 astronauts who walked on the Moon? Probably not. Apollo 12 was the second lunar mission. Apollo 16 was the second-to-last. But I’ll bet you have a favorite picture of the cosmos taken by the orbiting robot known as the Hubble Space Telescope. I’ll bet you can recall images from the rovers that have six-wheeled their way across the rocky Martian landscape. I’ll further bet that you’ve seen some jaw-dropping images of the Jovian planets—the gas giants of the outer solar system—and their zoo of moons, images taken over the decades by the Voyager, Galileo, and Cassini space probes.
In the absence of a few hundred billion dollars in travel money, and in the presence of hostile cosmic conditions, what we need is not wishful thinking and sci-fi rhetoric inspired by a cursory reading of the history of exploration. What we need—but must wait for, and indeed may never have—is a breakthrough in our scientific understanding of the structure of the universe, so that we might exploit shortcuts through the space-time continuum, perhaps through wormholes that connect one part of the cosmos to another. Then, once again, reality will become stranger than fiction.
• • • CHAPTER TWENTY-NINE
REACHING FOR THE STARS*
In the months that followed space shuttle Columbia’s fatal reentry through Earth’s atmosphere in February 2003, everybody became a NASA critic. After the initial shock and mourning, no end of journalists, politicians, scientists, engineers, policy analysts, and ordinary taxpayers began to debate the past, present, and future of America’s presence in space.
Although I have always been interested in this subject, my tour of duty with a presidential commission on the US aerospace industry has further sharpened my senses and sensitivities. Amid the occasional new arguments on the op-ed pages and TV talk shows, the same questions roll out with every new woe in the space program: Why send people instead of robots into space? Why spend money in space when we need it here on Earth? How can we get people excited about the space program again?
Yes,
excitement levels are low. But lack of enthusiasm is not apathy. In this case, the business-as-usual attitude shows that space exploration has passed seamlessly into everyday culture, so most Americans no longer even notice it. We pay attention only when something goes wrong.
In the 1960s, by contrast, space was an exotic frontier—traversed by the few, the brave, and the lucky. Every gesture NASA made toward the heavens caused a splash in the media—the surest evidence that space was still unfamiliar territory.
For many, particularly for NASA aficionados and everybody employed by the aerospace industry, the 1960s were the golden era of American space exploration. A series of space missions, each more ambitious than the one before, led to six lunar landings. We walked on the Moon, just as we said we would. Surely Mars was next. Those adventures sparked an unprecedented level of public interest in science and engineering, and inspired students at every level. What followed was a domestic boom in technology that would shape our lives for the rest of the century.
A beautiful story. But let’s not fool ourselves into thinking we went to the Moon because we’re pioneers or explorers or selfless discovers. We went to the Moon because Cold War politics made it the militarily expedient thing to do.
What about discovery for its own sake? Are the scientific returns on a manned mission to Mars inherently important enough to justify its costs? After all, any foreseeable mission to Mars will be long and immensely expensive. But the United States is a wealthy nation. It has the money. And the technology is imaginable. Those aren’t the issues.
Expensive projects are vulnerable because they take a long time and must be sustained across changeovers in political leadership as well as through downturns in the economy. Photographs of homeless children and unemployed factory workers juxtaposed with images of astronauts frolicking on Mars make a powerful case against the continued funding of space missions.
A review of history’s most ambitious projects demonstrates that only defense, the lure of economic return, and the praise of power can garner large fractions of a nation’s gross domestic product. In colloquial terms, that might read: You don’t want to die. You don’t want to die poor. And if you’re smart, you’ll honor those who wield authority over you. For expensive projects that fulfill more than one of these functions, money flows like beer from a freshly tapped keg. The 44,000 miles of US interstate highways offer a crisp example. Inspired by Germany’s autobahns, these roads were conceived in the Eisenhower era to move matériel and personnel for the defense of the nation. The network is also heavily used by commercial vehicles, which is why there’s always money for roads.
During the shuttle program the empirical risk of death was high. With two lost shuttles out of 135 launches, an astronaut’s chances of not coming home were 1.5 percent. If your chances of death were 1.5 percent every time you visited the Piggly Wiggly, you would never drive your car. To the Columbia crew, however, the return was worth that risk.
I’m proud to be part of a species whose members occasionally and willingly put their lives at risk to extend the boundaries of our collective existence. Such people were the first to see what was on the other side of the cliff face. They were the first to climb the mountain. They were the first to sail the ocean. They were the first to touch the sky. And they will be the first to land on Mars.
There may be a way to keep going places, but it involves a slight shift in what the government usually calls national defense. If science and technology can win wars, as the history of military conflict suggests, then instead of counting our smart bombs, perhaps we should be counting our smart scientists and engineers. And there is no shortage of seductive projects for them to work on:
• We should search Mars for fossils and find out why liquid water no longer runs on its surface.
• We should visit an asteroid or two, and learn how to deflect them. If one is discovered headed our way, how embarrassing it would be for us big-brained, opposable-thumbed humans to meet the same fate as T. rex.
• We should drill through the kilometers of ice on Jupiter’s moon Europa and explore the liquid ocean below for living organisms.
• We should explore Pluto and its family of icy bodies in the outer solar system, because they hold clues to our planetary origins.
• We should probe Venus’s thick atmosphere to understand why its greenhouse effect has gone awry, giving rise to a surface temperature of 900° Fahrenheit.
No part of the solar system should be beyond our reach. We should deploy both robots and people to get there, because, among other reasons, robots make poor field geologists. And no part of the universe should hide from our telescopes. We should launch them into orbit and give them the grandest vistas for looking back at Earth and at the rest of the solar system.
With missions and projects such as those, the United States can guarantee itself an academic pipeline bursting with the best and the brightest astrophysicists, biologists, chemists, engineers, geologists, and physicists. These people will collectively form a new kind of missile silo, filled with intellectual capital. They will be ready to come forward whenever they are called, just as the nation’s best and brightest have always come forward in times of need.
For the US space program to die along with the crew of the space shuttle Columbia—because nobody is willing to write the check to keep it going—would be to move backward just by standing still.
• • • CHAPTER THIRTY
AMERICA AND THE EMERGENT SPACE POWERS*
I was born the same week NASA was founded. A few other people were born that same year: Madonna (the second one, not the first), Michael Jackson, the artist formerly known as Prince, Michelle Pfeiffer, Sharon Stone. That was the year the Barbie doll was patented and the movie The Blob appeared. And it was the first year the Goddard Memorial Dinner was held: 1958.
I study the universe. It’s the second oldest profession. People have been looking up for a long time. But as an academic, it puts me a little bit outside the “club.” Yes, I’ve spent quality time in the aerospace community, with my service on two presidential commissions, but at heart I’m an academic. Being an academic means I don’t wield power over person, place, or thing. I don’t command armies; I don’t lead labor unions. All I have is the power of thought.
As I look around at our troubled world, I worry. Not enough people are putting thought into what they do. Allow me to provide a few examples.
One day I was reading the newspaper—a dangerous thing to do, always—and I saw a headline complaining, “HALF OF SCHOOLS IN DISTRICT SCORED BELOW AVERAGE.” Well, that’s kind of what an average is! You get about half below and half above.
Here’s another one. “EIGHTY PERCENT OF AIRPLANE CRASH SURVIVORS LOCATED EXIT DOORS BEFORE TAKE-OFF.” You might be thinking, Okay, that’s a good piece of information; from now on, I’m going to notice where the exit doors are. But here’s the problem with that datum: suppose 100 percent of the dead people noticed where the exit doors were. You would never know, because they’re dead. This is the kind of fuzzy thinking that goes on in the world today.
I’ve got another example. It’s often said that the state lottery is a tax on the poor, because people with low incomes spend a disproportionate amount of their money on lottery tickets. It is not a tax on the poor. It’s a tax on the people who never studied mathematics.
In 2002, having spent more than three years in one residence for the first time in my life, I got called for jury duty. I show up on time, ready to serve. When we get to the voir dire, the lawyer says to me, “I see you’re an astrophysicist. What’s that?” I answer, “Astrophysics is the laws of physics, applied to the universe—the Big Bang, black holes, that sort of thing.” Then he asks, “What do you teach at Princeton?” and I say, “I teach a class on the evaluation of evidence and the relative unreliability of eyewitness testimony.” Five minutes later, I’m on the street.
A few years later, jury duty again. The judge states that the defendant is charged with possession of 1,7
00 milligrams of cocaine. It was found on his body, he was arrested, and he is now on trial. This time, after the Q&A is over, the judge asks us whether there are any questions we’d like to ask the court, and I say, “Yes, Your Honor. Why did you say he was in possession of 1,700 milligrams of cocaine? That equals 1.7 grams. The ‘thousand’ cancels with the ‘milli-’ and you get 1.7 grams, which is less than the weight of a dime.” Again I’m out on the street.
Do we say, “I’ll see you in a billion nanoseconds”? Do we say, “I live just 63,360 inches up the road”? No, we don’t talk that way. That’s mathematically fuzzy thinking. In this case, it might even have been intentionally fuzzied.
Another area of fuzzy thinking out there is the movement called Intelligent Design. It asserts that some things are too marvelous or too intricate to explain. The contention is that these things defy common scientific accounts for cause and effect, and so they’re ascribed to an intelligent, purposeful designer. It’s a slippery slope.
So let’s start a movement called Stupid Design, and we’ll see where that takes us. For example, what’s going on with your appendix? It’s much better at killing you than it is at anything else. That’s definitely a stupid design. What about your pinky toenail? You can barely put nail polish on it; there’s no real estate there. How about bad breath, or the fact that you breathe and drink through the same hole in your body, causing some fraction of us to choke to death every year? And here’s my last one. Ready? Down there between our legs, it’s like an entertainment complex in the middle of a sewage system. Who designed that?
Some people want to put warning stickers on biology textbooks, saying that the theory of evolution is just one of many theories, take it or leave it. Now, religion long predates science; it’ll be here forever. That’s not the issue. The problem comes when religion enters the science classroom. There’s no tradition of scientists knocking down the Sunday school door, telling preachers what to teach. Scientists don’t picket churches. By and large—though it may not look this way today—science and religion have achieved peaceful coexistence for quite some time. In fact, the greatest conflicts in the world are not between religion and science; they’re between religion and religion.
Space Chronicles: Facing the Ultimate Frontier Page 21