Chemistry of Fire Page 22
An explosion rocks the superstructure, and sheets of flame pass across the windshield as the solid rockets separate. Day transforms to night as you leave the scattered light of the atmosphere, then comes a big kick when the shuttle separates from the massive external fuel tank. Astronauts say that it feels as if the ship has exploded. “You just can’t help thinking about Challenger,” Ross said. “I never go up without thinking about Challenger.” On January 28, 1986, Challenger blew up seventy-three seconds into its flight, killing the crew of seven, including a civilian schoolteacher named Christa McAuliffe. She was thirty-seven.
When Cabana finally looked up from his instruments on that first flight into space, he realized that they were already in orbit. Seeing the earth below, the universe beyond, he knew that life would never be the same again. Each astronaut I’ve met has said the same thing. As Cabana and Ross talked about it, there was a look of pity in their eyes. For this was the pinnacle of experience, and they were looking at someone who would never have it.
For months before Cabana’s mission, I went down to Houston to watch the guys train in the Neutral Buoyancy Lab, a swimming pool large enough to submerge elements of the space station. It’s eighty feet from the roof of the building to the bottom of the blue water. Suspended above the surface are yellow cranes that can move up to ten tons of hardware at a time. It was nine in the morning, and the water was swarming with divers there to assist the astronauts.
Ross and another astronaut, James Newman, were hanging in their space suits, suspended from racks—it’s the only way to get into them. They wore headphones and skullcaps, which made them look like monks. A woman fitted shoes onto Ross’s feet, then a crane picked him and Newman up and dumped them into the water.
Under the surface, Newman and Ross practiced attaching communications antennas to the outside of a model of part of the space station. Walking around in space is one of the most dangerous parts of the job—holding on to those golden handholds, using torque tools that can spin you around like a top and kick you off into the void, as I’d seen in the Virtual Reality Lab. There’s nothing virtual about it in space. It is reality. And while the astronauts are usually tethered for safety, they have to move around, clipping on and unclipping and then clipping again as they go. This is just the sort of repetitive behavior that can become automatic, leading to one unconsciously doing the wrong thing or doing things in the wrong order. NASA considers the risk of an accident due to the failure of a tether or while an astronaut is temporarily untethered to be significant.
In space, Newman and Ross can zoom from one place to another, but today, the divers must move them. Ross says, “Guys, will you beam me over to the other site now?” And the divers pick him up and move him to the next location. I hear him grumbling when he discovers that the elements he needs for the job are not there. It takes half an hour just to get this far—sitting underwater, trussed up in the suit—and he has nothing to do. He barks through the communications loop, “Four months from flight, and we’ve been working for over a year. We ought to have this stuff down by now. I’m starting to get ticked. We’ve got to get beyond this.”
No one ventures a response. They know they’ve messed up. Indeed, there are a few problems with the space station that are still being worked out. For example, if the station flies at an altitude that points the solar arrays at the sun for maximum electrical power, then, as the astronauts’ space station handbook says, this “results in the same side of the Station facing the Sun, while the other side faces the darkness of deep space. While [pieces of equipment] on one side of the Station may overheat, those on the other side may freeze.”
I was told that the problem was “being worked.” That’s NASAspeak for “We have no idea what to do about this.”
The procedures for assembling the space station can be drilled to perfection in the pool, but there are some problems and risks that no one can fully control. One of the most significant issues is orbital debris. A lot of junk has accumulated in space. As satellites and old fuel tanks age and disintegrate, this adds even more debris. A new rocket is launched every four days, on average. Then there are meteoroids. NASA has a whole department, the Orbital Debris Program Office, devoted to space junk. Jeff Theall does the computer modeling there. “We had to determine what the threat was, what the most likely particles you’re going to be hit with are, and what the probabilities of being hit with specific sizes are,” he explained. There’s so much junk up there from decades of shooting off rockets that the air force has a radar system for tracking the roughly nine thousand objects it can detect. But smaller objects cause trouble, too. The space shuttles’ windows are so damaged by small particles of space debris that they have to be replaced after most flights. Debris is such a nuisance that the shuttle flies backward whenever it can.
If an object larger than ten centimeters were to hit the space station, the results would likely be catastrophic. But the probability of that is low, because the radar system can detect those objects. If something that large is on a collision course with the station, a docked Russian Progress spacecraft can fire its jets to lift the station two miles higher to evade the object. In addition, NASA has developed shields that protect occupied areas of the station from objects smaller than one centimeter, which are the majority of the particles in orbit.
“The primary danger,” Theall told me, “is in objects that are too small to track and too large to shield against. Between two and ten centimeters, there is a danger.” And there are more than a hundred thousand objects in that range.
The toughest shielding is made of Kevlar and Nextel blanket placed between two layers of aluminum. If, in a worst-case scenario, a particle of metal, for example, were to penetrate that shielding, the effects would be disastrous. The closing velocity between the space station and the object would be about ten kilometers a second. Upon impact, the object would turn to molten metal. As it exploded into the interior of the space station, the observers inside would be blinded instantly by a brilliant flash of light, rendering them helpless. Next, they would be burned by the tremendous heat generated by the molten material—the severity depending on the amount of splatter. And finally, the station would begin venting.
“If you take a hit in the back of a manned module,” Theall said, “the air coming out could cause a thrust vector to spin the station like a top. It may spin it so fast that you’d break joints. Or so fast that docking mechanisms would release. Even if the crew were safe, they couldn’t get out. More likely, crew members might suffocate because the module they are in gets hit and the air escapes before they can move and close the door. In talking about them, you start to visualize them. It makes your blood run cold.”
At first glance, this dire scenario doesn’t seem too likely. Theall calculates something called the assessed probability of no penetration (PNP), the chance that the station will not be pierced by some type of orbital debris over a ten-year period. NASA’s sections of ISS have a 0.99 PNP rating, based on the American standard of shielding. Everyone in the sixteen-nation ISS coalition is adhering to a similar standard—except the Russians, who are going considerably lighter. Their service module in particular could be pierced by a speck as small as three millimeters. This makes being on the ISS like living in apartment building where only half the people have smoke detectors. Once the Russian vulnerability is incorporated into the calculations, the entire station’s PNP suffers considerably. The chance of being penetrated jumps from one in a hundred to one in five. And that’s factoring in Russia’s plans to upgrade their level of protection, both before launch and with additional shielding to be added after the ISS has been in orbit for a few years. NASA has urged them to do this and will probably transport the extra protection in the shuttle. Before the improvements are made, the odds will be more than one in three that the station will be penetrated. And the best guess is that between one in three and one in four penetrations would be catastrophic—you’d lose either a member of the crew or the station itsel
f.
“Their approach to risk is far different from ours,” Theall said of the Russians. “They don’t place as much importance on orbital debris as we do. They point to Mir and say it’s flown thirteen years and has not been hit.” Mir has been hit, at least by objects large enough to make dents that are visible on the inside walls of the quarters where the crew lives.
Theall nonetheless attempted to reassure me about the risks posed by orbital debris. While the odds of penetration seem high, particularly before the Russians improve their shielding, the station’s overall safety rating seems good. He estimates that there is only a 5 percent chance of losing a member of the crew or the station. And NASA is working toward an even safer standard—a 2 percent chance of catastrophic failure.
Theall said that there are greater dangers than space junk: ionizing radiation, for one. “If there’s a big solar flare—and odds are there will be while the ISS is up there—it could make the astronauts very sick,” he said. He believes that the loss of human life during EVAs—the “lost in space” scenario—is the number-one hazard. And EVAs will make up the bulk of the work as the station is built.
The idea for a space station began before the Russians launched Sputnik in 1957. Back then, many engineers thought that the best way to explore space would be to establish a station and work outward from there. But President Kennedy needed a big public relations coup, and going to the moon seemed more heroic.
Just before Neil Armstrong’s landing, NASA was working on a concept for a space station that would house a hundred people, a plan that was gradually whittled down to Skylab, an experiment involving three astronauts at a time. They occupied Skylab for six months during 1973 and 1974. Under Nixon, the idea of a space station was revived, and he approved the shuttle as a service vehicle for it. Under Reagan, development of a US space station (Freedom) was at last approved with a budget of $8 billion, and before long, the figure had swollen to $31 billion. By the time Bill Clinton became president, the space station employed twenty thousand people, and that first $8 billion was gone without a single, nut, bolt, antenna, or toilet having been launched.
One of the main reasons for drawing the Russians into the ISS program was that NASA had little experience with space stations, while the Russians had kept Mir occupied almost continuously since 1986. Our astronauts measure their experience by counting the hours they’ve spent in space. Cabana has about a thousand hours. Ross has about eleven hundred. Yuri Gidzenko, who will be among the first three people to live on the station, has nearly two hundred days in space. Sergei Krikalev, who went up with Cabana and Ross and who will join Gidzenko living on the station, measures his experience in years—one and a quarter and counting. (I got a look at him at a press conference, and he has a really far-out stare. His face barely moves when he talks.)
But experienced or not, the Russians didn’t have the money for their piece of the station. By the time Cabana and crew took off in December of 1998, their launch was more than a year behind schedule because the US had had to bail the Russians out. Russia was warning NASA that while the rest of the station was being assembled, additional delays might occur in delivering its second component, the service module, which was to provide propulsion, communications, the distribution of power, and even living quarters. Air & Space/Smithsonian magazine reported that Russia’s “delays have already brought the largest international space project in history to the brink of political disaster,” predicting that the partnership “might not survive” and “was already unraveling as the station’s first pieces moved to the launchpad.” More recently, the Russians announced that they would not be able to supply the six Progress spacecraft per year that would be required to prop up the station’s orbit, which decays over time. (The word “orbit” at such a low altitude simply describes an object falling over a very long period of time.)
And those weren’t the only troubles with Russia. On the night of February 23, 1997, a chemical oxygen generator aboard Mir burst into flames, threatening the lives of everyone on board. The fire even cut the crew off from one of the two Soyuz craft, their lifeboats for escape. Mir filled with smoke, and the sickening stench of the fire lingered for months afterward.
In June that same year, Vasily Tsibliyev was flying the Progress resupply vehicle by remote, attempting to dock it with Mir, when it slammed into the station, tearing a hole in its thin aluminum skin. As the station depressurized, Mike Foale, an American astronaut, rushed to the Soyuz to evacuate, only to find that the Russian cosmonauts wouldn’t abandon ship. Foale found himself all alone, waiting for the Russians, knowing that the rule book called for immediate evacuation. The realization slowly sank in that they simply weren’t going to do it. Here was the crux of the cultural gulf between the two nations: The cosmonauts would die heroes and be celebrated back home, bringing honor to their families. But for American astronauts, not only was dying bad form, but it could put an end to the whole program, not to mention their own careers. Astronauts didn’t go for that dead-hero stuff. They much preferred success to failure.
After a mad scramble, in which the punctured module was sealed off, the crew realized that the collision had damaged one set of the solar arrays that supply electrical power. Mir slipped into a free drift, the remaining panels couldn’t track the sun, and the batteries ran down, plunging them into darkness. Nothing worked. Even the toilet was electric.
That was not the end of their troubles. When the Progress clipped Mir, it had sent the Russian craft into a slow roll. Russia’s mission control had no Apollo 13–style solution to the mounting vexations. In the end, it was the American astronaut who thought of using the Soyuz’s rocket engines to stop the spin and reorient Mir toward the sun to restore power. The events gave NASA an unsettling preview of the difficulties that lay ahead when working with the Russians on the ISS. Indeed, the long-delayed Russian service module, a key element of the ISS, is closely modeled on Mir’s core block.
Congress has tried to kill the space station more than once, but it just won’t die. It mutates and reinvents itself—much like NASA. Today, the agency has redefined itself once more, with the International Space Station as its cornerstone. And NASA is hitting hard on the idea that the ISS is the future of mankind—in science, in exploration, in every way imaginable.
The reason that the space station (i.e., NASA) won’t go away is its potent combination of bureaucratic might and missionary zeal. Because people of passion have their own kind of power, too: the power to persuade. The outward manifestation of this passion is their stuff. No one can deny it: NASA makes the coolest stuff. NASA is a cult of hardware, the great garage of America’s homegrown tinkerers, those jack-of-all-trades types who knock together gadgets with the cast-off junk of others, forming the dream of the moment in cascading iterations and stillborn, crackpot trials and errors, until they come up with stuff so cool that the rest of the world simply can’t ignore it any longer (as the Wright brothers, the ultimate crackpots, did).
One day at Kennedy Space Center, I met up with a retired engineer who had volunteered to escort journalists around. We went out to the launchpads on Merritt Island to see the rare sight of two birds at once: Endeavour, which Cabana would take up to start building the space station, on Pad A, and John Glenn’s bird, Discovery, just to the north on Pad B. Because people had lost interest in the space station, NASA and others involved hoped that John Glenn’s flight would attract public attention to Endeavour.
We made our way along the brackish bayous that cut through Kennedy like a spider web, through mangrove and pampas grass and yucca. Up close, the whole contraption that would launch the space station seemed old and dirty and far too complex to make any sense—as if some artist-cum-engineer had gone mad up there. But as I studied it, I perceived that within the seeming chaos was the small bird—the shuttle orbiter itself, in which Cabana, Ross, and Kirkalev would rise with the nucleus of the ISS—and all at once it appeared to me as a fetus in an iron placenta with Teflon blood vessels, gray, whit
e, and yellow, running in a crazy pattern around it, and there seemed to dwell within that lunatic tangle a deep and inscrutable intelligence. No, the artist, the engineer—they weren’t crazy at all. They had simply been driven by an incomprehensible passion to this godly vision.
One such visionary was Roy Tharpe, who grew up on Merritt Island in the shadow of rocketry and has worked at NASA ever since he got out of college. One day he was on a survey crew on Complex 34 when a Titan rocket was taking from Complex 20. Tharpe thought he was safe several miles away, twenty feet up on a scaffolding. But the rocket took off, lost its gimbals, “and suddenly I found myself nose to nose with a Titan missile,” Tharpe told me. He jumped from the scaffolding, and the rocket thundered over his head and destroyed itself somewhere out in the salt marsh.
Energetic and curious, Tharpe was a tall man with bright blue eyes, a gentle smile, and a shock of white hair. On the shelf behind him in his office was a bust of Kennedy. Tharpe was now launch site manager for the ISS. The components of the station were assembled in this building—his building. They were assembled, tested, and proved. Then they were brought out to the launchpad. The station had given Tharpe (and NASA) a new lease on life. For the first time in more than twenty years, he said, it was “every bit as exciting” to work here as it had been during Apollo. “I was rode hard and put up wet in Apollo,” he said with a misty smile. “We partied hard, too. Apollo launch parties were a sign of the times.”
In describing his work, Tharpe immediately fixed on passion as the driving force. “That burning fire has got to be in your gut,” he said. And now more than ever he believed in the space station. “We didn’t find diamonds on the moon, but we’re going to make diamonds on the space station,” he told me. “We’re going to do unbelievable things in microgravity.”