The Apollo Chronicles
Page 6
Many Langley women faced similar dichotomies. NASA would eventually send Cathy Osgood to Cape Canaveral in preparation for launches—a woman traveling on her own for business. But she had to use her husband’s credit card to book tickets, as wives were not allowed to have their own. As her NASA career bloomed in the years that followed, she found her nerdy husband to be a new kind of American man. “He was great. He’s never one to say, ‘That’s a woman’s job,’ or anything of that sort.” She recalled intense deadlines for orbital computations—“I did bring in my sleeping bag and sleep in the ladies’ room”—where her husband would take care of the kids, groceries, and the cooking. (To be sure, Mr. Osgood’s attitude fell well outside norms at Langley and in America. But the outlook was making its debut.)
In the end, nothing was more groundbreaking than NASA’s absurd-sounding aims. In 1960, many Americans enjoyed dreaming of space, but many others wondered why the government would start spending all this money on such an esoteric project, Sputnik or no. “A man in space,” a former boss said to Osgood, after hearing of NASA’s first goal. “Doesn’t that give you the creeps?”16
The one-time submariner Max Faget had taken on the role of spacecraft designer for the nation’s first phase of space exploration, dubbed “Mercury,” aiming to put an American in orbit around Earth, hopefully before the Russians. By 1960, he’d finished the basic design and it was full of surprises. This early spaceship shared much with a submarine—not only was it absurdly cramped, with no corner wasted, but it also had a periscope instead of a window. Faget and his colleagues even argued over the size and weight of the human pilots. Given the available rockets’ ongoing struggles to lift much weight, it seemed absurd to send up, say, a six-foot, 180-pound test pilot when a much smaller person would do just as well. One engineer, a veteran who’d survived bombing missions over Germany, deadpanned that they should find legless astronauts to save forty percent on body weight.17
Faget seemed to have solved several basic problems for keeping a live astronaut rocketing into space and back to Earth in one unbroken piece, though the proof would await a real, nail-biting test. Not only would the tiny new capsule, sitting atop a rocket, have to protect a human body from harm in the violent acceleration toward space, it would later have to protect the human from an arguably more violent return to Earth, as the capsule would somehow slow from thousands of miles per hour, not burn up from the scalding friction of our atmosphere, and find a survivable impact speed.
The intense heating of re-entry was not a new problem. Early ballistic missile tests had measured tips of returning missiles surpassing ten thousand degrees Fahrenheit, well above the temperature of the sun’s surface. Even von Braun’s V-2 program had grappled with this issue. He and his team had considered all sorts of ways to cool a missile as it re-entered the thickest part of the atmosphere. He had even entertained a system with forced coolant near the nose cone, but introducing extra pumps, with fuel for those pumps, simply added too much extra weight.18
The surprising key to NASA’s safe re-entry was having a dumpy, blunt shaped craft instead of a sleek, pointy one.i Returning from space, a more pointy craft will zoom into Earth’s atmosphere and penetrate more deeply before slowing appreciably. Moving that quickly through the thicker air leads to the hotter-than-the-sun temperatures. Meanwhile, a craft shaped like a laboratory flask flying fat-side down slows more gradually. It also allows heat to dissipate into the surrounding air instead of building up in the vehicle itself.
To further outsource the incredible heat of re-entry, the engineers opted for a scary-sounding technology on the capsule’s bottom: an “ablator,” or a substance that literally burns away, sloughing off material as the spacecraft descends. As long as the capsule had a thick enough layer, the hot gas byproduct leaving the heat shield would actually carry a lot of the extra heat with it. And, as a small bonus, the capsule would literally become lighter as it re-entered; every ounce it could shed would make its journey just a tiny bit more gentle, moment to moment. But calculations and tests would have to be precise: too much ablator could make a capsule too heavy to launch, but too little meant the fires of atmospheric friction would consume the ablator and then roast the astronaut inside. “I did it on a slide rule,” said Aleck Bond, a colleague of Faget’s. “All my analytical work was done on a ten- to twelve-inch slide rule.” The thermal analysis suggested that just one inch of ablator should work. But for early tests, Bond says they doubled it, just to make sure.19
By 1960, these tests looked promising. And, true to the slide rules, using just an inch-thick fiberglass laminate proved good enough. It would lose a few pounds of material during re-entry, but only a fraction of its thickness overall, while temperatures inside the capsule remained moderate. (For the eventual Apollo capsule, much larger than the early man-in-space capsules, engineers fashioned a steel honeycomb lattice on the capsule’s bottom. Technicians then used caulking guns to inject each of 400,000 cells with a special new ablator that had been developed for nuclear warheads. This laborious attention to detail paid off; considering all of Apollo’s myriad components, the heat shield was among the least troublesome.)20
Temperature was far from the only concern when considering human beings lofted to space and back. The incredible thrust during launch and braking during re-entry would challenge the structure of the human body. The efficient genius of Faget’s capsule design had its fat bottom directed Earthward both during its launch atop a rocket and also for its solo return to the surface. At launch, the astronaut would be pushed against the capsule’s fat-bottomed side, as the rocket underneath pushed him up and into space. (Consider your car accelerating very quickly and your seat back pushing against you.) Then, upon return, when the capsule needed to lose tens of thousands of miles per hour, Faget and his team had the capsule plummet backwards, fat end first, and the astronaut would again be thrown against his seat back. (In this case, imagine if, with your car moving at one hundred miles per hour, you could deftly spin it around backward, and as you slowed to a stop your body would feel the strongest pressure again in the padded seat instead of straining against the seatbelt straps.) For the incredible accelerations of a space mission, this method gave engineers the best odds for protecting an astronaut’s ribcage and organs.
An automotive seat wouldn’t do for a space voyage. Faget and his fellow engineers came up with the “survival couch,” custom-molded to each astronaut’s back, including the backs of arms and legs. Engineers recall early trials of the survival couch idea, using an unlucky set of farm animals. According to one account, a couple of the Yorkshire pigs died from their upside-down fall, and the engineers reworked the survival couch.21 The redesigns smoothed the kinks and bumps from the seating, and watching healthy pigs trot away from horrific-looking backward falls raised the engineers’ hopes. The pigs in their safety couches were now surviving accelerations many times what any astronaut would need to experience. Tests on humans followed. Test subjects could be accelerated to twelve and even twenty times the acceleration of free fall on Earth and walk away from the survival couch without injury. NASA molded a special version for each of the original seven astronauts, just like one might do for a mouthpiece or an orthotic shoe insert (see Figure 3.2).
figure 3.2 Test versions of custom-molded survival couches at Langley. The names here include those of Langley employees who volunteered as test subjects. (NASA photograph.)
The capsule’s progress encouraged NASA, but their ability to pitch it safely into Earth orbit was another matter. In 1960, young Marlowe Cassetti became the chief reviewer for a series of disturbing silent films. “Somehow I was tagged as the launch guy,” he says. “I would get on average one per week . . . they were shooting up a lot of rockets. . . . I would get an express pouch from either Florida or California, hand delivered to me. I think they may have been classified. Our probability of getting into orbit had to be classified too.” A technician would lead Marlowe to a conference room, help set up a reel-to-reel pr
ojector, and then leave him with that week’s film, usually a compilation that played like a grim blooper reel. “If I recall correctly, they were nearly all failures. . . . [The rocket] would go up a few feet, fall back down, and there would be a tremendous explosion.” Marlowe quietly watched the debris settle before a rough splice brought on the next launch.
Reflecting on those early times, Henry Pohl summarized the situation: “The criteria for the launch to be successful was that it got out of sight before it blew up.” And as von Braun preached to Henry and his other Huntsville troops circa 1960, the initial goal for their rockets was to “make the target area more dangerous than the launch area.” Calling progress in rocket engines from 1958 to 1962 “phenomenal,” Pohl says it’s easy to forget just how bad things were. “In the late fifties, I believe one year we had fifteen Thors blow up. . . . They must have built about sixteen Titan I’s, and I am not sure that any of those ever got away from the pad. Maybe one.”22
What kind of notes did Marlowe Cassetti take during his grim private screenings? Mainly he kept track of successes versus failures and scribbled abbreviated observations for his bosses. One success, three failures, one abort (with no explosion). And Cassetti thought to himself, “We’re going to put guys on top of this? It’s really crazy.”
But Faget and his team had a plan for the worst-case scenario as well. They designed an “escape tower.” Photos of some of these rockets, including the eventual Apollo missions, show a skinny extension from the rocket’s highest tip, as if the designer were just trying to provide another few feet of height. In the event that a rocket blew up, the ingenuous escape tower, perched atop the astronaut’s capsule, would fire its own little cluster of rocket engines and pull the capsule away from the exploding rocket and deliver the astronaut to safety. Timing would be everything, but the engineers were confident the system could work. (As the program evolved, the tower was never needed, but by copying this system, the Soviet Union did later save the lives of two cosmonauts. They flew to Houston many years later to thank Max Faget in person.) (See Figure 3.3.)
figure 3.3 Artist’s rendition of the one-seater Mercury capsule with the escape tower attached (top). The pack strapped to the heat shield in this drawing (bottom) helped the capsule maneuver when in space, but like the escape tower, the pack was (usually) discarded before the capsule returned to Earth. (NASA image.)
Fundamental designs marched rapidly forward, thanks in part to a key set of engineering immigrants. Canadian aerospace engineers had first unveiled an advanced jet fighter, the Arrow, on the ill-fated day of October 4, 1957. “We rolled [it] out of the hanger for the press to see,” recalled engineer Owen Maynard, “and hardly anybody showed up at the stands.” Everyone covering aerospace for the media had been consumed by the news of Sputnik. That was the beginning of the end for the Arrow. After the Canadian government canceled the jet in 1959, NASA invited about twenty-five of the engineers to bring their expertise to Virginia. This was no simple move for the Canadians. “You have to understand,” one of Maynard’s colleagues said later. “There’s considerable prejudice north of the border about coming south of the border.”23 But the interesting work, at this point, pulled them across. Maynard, a structural engineer, specialized in craft that moved at extreme speeds under great stress, and he had helped design escape systems for jet pilots. “We were very quickly accepted royally into the community at the Space Task Group,” Maynard said.
Before America’s television habit, the engineers embraced old-world evenings. “We took ballroom dancing lessons with them,” Maynard said. Once a week, the class would retire to one of their homes. “We would continue with playing records and doing this different kind of ballroom dancing, including the Twist.” Aside from the dancing, however, his family suffered what so many did in NASA’s decade to come. His wife would ask him, “Why is it that you spend so much time at work when you’ve got these three wonderful kids and you love your kids so much?” She was right, Owen thought, and he adored his children, but, “I never could answer her that.” A great many of the engineers have expressed a similar wistful regret.
In the summer of 1960, Maynard witnessed the first test toward lifting a man into space. It aimed to use an air force “Atlas” rocket, just like those Cassetti had been watching, and lift a test capsule, sans astronaut, into space. Given the amount of work Maynard had already put in, NASA rewarded him with a trip to Florida to watch the launch. Maynard told an interviewer later about the strong emotions of those around him. “This thing was getting ready to fly, and it was like the baby that’s grown up and he’s going off to college, maybe going off to war or something. It was that kind of emotional.” One of the engineers cornered him. He confessed to Owen that he was worried sick about how the rocket coupled to the test capsule above it, saying the connection presented a definite weak point.
Despite heavy cloud cover in Florida, NASA went ahead with the launch, and the Atlas came apart about one minute after leaving the pad. Because of the weather, the team had no clue by eye or on film as to what happened. From that point forward, NASA set a rule against launching into overly cloudy skies.
After the rocket came apart, the project engineers scrambled about, sifting what little data they had. Bob Gilruth came striding out of the control room, found the off-duty Owen Maynard, and put his hands on Maynard’s shoulders. “Go find that thing,” Gilruth told him. “Find out what happened.” Maynard and some colleagues rented a couple of fishing boats and found the rocket’s debris field at sea. When a scuba team struggled to find a couple of key parts, Maynard took a deep breath and jumped in, free diving to a depth of thirty feet. His familiarity with the shape and design of the parts helped him locate the rogue pieces. They hauled everything back to an airplane hangar at the Cape and began a painstaking reconstruction, trying to diagnose the failure.
A subsequent meeting brought together engineers from the air force (the parents of the Atlas rocket) and representatives from various contractor companies who had built pieces of the Atlas and the capsule. During a coffee break, Maynard had an idea. He took out his slide rule and started scribbling mathematical notes on, yes, the back of an envelope. According to his calculations, the thin skin of the Atlas rocket could crumple and fail at the most stressful moments of the rocket’s ascent toward space—for instance, when the rocket broke the sound barrier about a minute into its flight. He handed his results to his boss, the only other NASA representative at the meeting. After coffee, his boss stood up and thanked everyone for their presentations, but he announced that Maynard had solved the puzzle and then abruptly adjourned the meeting. His scribbles, computing strain on the rocket at “Max Q,” the most violent acceleration, showed an alarming chance that the rocket’s thin skin would just crumple like so much paper. The others in the meeting “were livid,” according to Maynard, but the answer was undeniable.24
When engineers describe the Atlas as a metal balloon full of rocket fuel, that is no exaggeration. Without the pressure of fuel puffing its thin skin outward, a thumb’s pressure easily indents the side of a preserved Atlas today. Why build such a flimsy rocket? It goes back to needing to lift the least possible weight. The lighter a rocket, the less energy it needs to climb skyward. And indeed, when the Atlas was full of fuel, the skin was rigid enough, or almost rigid enough, for its workload.
The best solution for the rocket’s thin skin bordered on humiliating for the rocket’s military designers: a metal girdle for Atlas. “I made the mistake of calling it a ‘belly band’,” Gilruth recalled. “This was very, very unpopular with the air force.” But it worked.25
Approaching Thanksgiving of 1960, NASA prepared for another unmanned test. After the failed summer launch, NASA had suffered another beating in the press, and political pressure on the young agency redoubled. Now, with one of von Braun’s rockets, NASA would try again to lift a capsule into space, to see if it would leak, to see if it could function, to see if its interior temperatures would support a fragile hum
an being, and to see if it could return to Earth in one piece. As anxious NASA administrators, their political patrons, and scores of journalists tapped their fingers, the launch team waited through an unbroken month of hard Florida rain.
Around midnight on November 21, when the countdown finally reached zero, the excitement hit a crescendo. As the engines fired, one of von Braun’s German colleagues fell to shouting in German over the main communications channel, drawing English rebukes from engineers monitoring crucial systems. But the tremendous roar suddenly hushed, and as clouds of exhaust drifted away from the rocket, everyone could see it still sitting there. It had lifted about four feet from the pad and decided it felt like sitting back down; the rocket apparently couldn’t be bothered with a launch today.
As network television rolled, the little capsule, atop the now dormant rocket, sprung to life. It thought it must be landing already, so out popped its automatic parachutes, which draped downward over the rocket, as if protecting embarrassed modesty. And then, completing the sad display, a canister of green dye burst forth, intending to mark an aquatic landing spot to aid recovery teams. An engineer muttered something about the similarity to a clown car at the circus.26
While the engineers could only wish the malfunction had somehow stopped the TV cameras recording this feeble display, they had bigger problems. They had a rocket packed full of kerosene and liquid oxygen sitting upright with nowhere to go. And the wind might yank the entire tipsy thing over by its misguided parachutes. NASA did not know of the Soviets’ Nedelin disaster, but the possibilities of an unhappy ending were clear. One voice asked to get a gun, suggesting they shoot holes in the tanks to drain them. In the end, the engineers decided to keep everyone away from the rocket and let the returning Florida dawn eventually boil off the liquid oxygen; with that half of a potential disaster removed, crews then snuck out to drain the kerosene.