National Geographic : 2016 Nov
58 national geographic • november 2016 space with missions to the “Proving Ground,” he said, meaning around the moon and nearby points in space. That would lead in the 2030s to putting astronauts in orbit around Mars. “ When I look at challenges of getting a crew on the sur- face, it adds another order of magnitude of com- plexity to what we’re trying to do,” Gerstenmaier had told me earlier. “ That’s what drives me out of the 2030 time frame.” But that’s where SpaceX might help. Mars is a much harder place than the moon to land a spacecraft softly. Its gravity is stronger, and its atmosphere—while too thin to be much help in slowing a spacecraft or to sup- port life as we know it—is thick enough to cause overheating. Many unmanned probes have crashed on Mars. NASA has landed a one-ton rover, Curiosity, but a payload big enough to car- ry humans and keep them supplied would have to be the size of a house and weigh at least 20 tons. A parachute wouldn’t work—it would have to be as big as the Rose Bowl, and it would never open quickly enough. The most promising solution at the moment is the technology that SpaceX is developing: supersonic retropropulsion. When the Falcon 9 booster descends at supersonic speed through Earth’s thin upper atmosphere, it’s in Mars-like conditions. The success at Cape Canaveral last December, and subsequent landings on a ship offshore, are why so many people are now say- ing that sending humans to Mars is plausible—if far from a slam dunk. SpaceX has shared its data with NASA. At Kennedy Space Center, SpaceX has leased Launch Pad 39A, where the Apollo 11 astronauts blasted off for the moon. The company is young, nimble, and daring, as NASA was then; NASA has grown slow, bureaucratic, and cautious. But the two aren’t competitors, and they’re not in a race. They’re partners. SpaceX already delivers supplies to the space station in a Dragon capsule carried on a Falcon 9. In April, Musk announced Manhattan Project or the Apollo program: “We’re closer to Mars in terms of the technology re- quired to do it today than we were to the moon when President Kennedy set that goal in 1961. We are far closer.” We aren’t closer to paying for a Mars trip, though—and it’s the expense that killed the grand plans of the past. The Apollo moon land- ings cost about $140 billion in today’s dollars. Experts assume a realistic journey to Mars would cost at least that much; a fully loaded plan put forward under President George H. W. Bush had a price tag of $450 billion. But NASA’s annual budget for all human spaceflight is around nine billion dollars. To get to Mars before the 2040s would take a lot more money and a president with Kennedy-like commitment. During the moon race with the Soviet Union, NASA got more than 4 percent of the federal budget; now it gets about half a percent. If there were truly a “Mars race” with China, say, that might help, but the Chinese don’t appear in a rush to get there. When and whether we go to Mars doesn’t just depend on technology and money. It depends on what we consider an acceptable level of risk. Ad- vocates of an early landing say that NASA is too risk averse, that true explorers accept the possi- bility of failure or death, that the people who first tried to reach the poles or cross the oceans knew they might not make it—and often didn’t. NASA could send people to Mars a lot sooner if it didn’t worry so much about whether they’d arrive alive and eventually make it home. At the end of Gerstenmaier’s news conference in Utah, a local reporter stood up. He was 49 years old, he said, and he just wanted to know one thing: Would he live to see a man on Mars? “ Yes,” Gerstenmaier said. He hesitated for a moment and then added: “‘Man’ may be the wrong word. You will see a human being.” Then, after the applause and appreciative laughter had subsided, Gerstenmaier proceed- ed to explain why it was going to take until the 2040s. NASA needed to begin its return to deep When and whether we go to Mars depends on technology, money, and what we consider an acceptable risk.