Rise of the Rocket Girls

by Nathalia Holt

  While Barbara kept an eye on Viking, Helen was spending her evenings at the swimming pool. She loved sitting on the bleachers and watching her daughter, Eve, swim. Next to her was a big stack of work. As Eve practiced with her team, Helen worked out the kinks in her programs. She looked up every once in a while and watched her daughter’s powerful kick. Eve was strong and beautiful, and Helen was proud of her. Life wasn’t always easy for Helen’s children. Their mother’s work sometimes felt like another child who needed constant looking after. But though Helen’s attention was sometimes divided, her kids were always foremost in her life.

  Their home life was simpler now with kids in school, and now that Arthur was at JPL alongside his wife. He worked with the mechanics at the lab, and the couple shifted their schedules as needed around the kids’ activities. They especially wanted to support Eve’s exceptional ability in the water. Luckily, Helen could lug her printouts with her. Her programs ranged widely in scope, since she had her hand in just about every project. When she wasn’t writing the programs herself, she tried to spot her colleagues’ mistakes. She thrived on the details of the work, which made her an excellent supervisor.

  Kathy Thuleen was going to miss Helen. She was pregnant for a third time and leaving the lab. She loved being an engineer and had never enjoyed more responsibility than she had in the previous two years. Programming was precious to her. She had two young sons and wished she could come back after having this baby too, but her husband was being transferred to San Diego and they were moving. She knew she would never find another job like the one she was leaving. The group gathered for a teary farewell lunch, everyone wishing Kathy luck.

  While Kathy anticipated her baby’s arrival, the women looked ahead to Viking’s encounter with Mars. The ship reached the planet on June 19, 1976, and the orbiter began taking pictures as planned. Around 6 p.m., Helen and the team anxiously awaited the images, which they would use to select a landing spot. They came in slowly, line by line on the television screen, and everyone crowded around, desperate for a closer look. With the first photograph there was cheering and excitement. Unlike the paint-by-numbers pastel picture that had formed their first view of Mars, this image was clear and detailed. Soon, though, their excitement faded into shock. This wasn’t the Mars they knew. The pictures showed lava flows and deep craters stretching across the surface. It was far more cratered than the Mariner images had led them to expect. The rocky terrain was forbidding, hardly the spot to land a robot. “We need you,” one of Helen’s colleagues said, turning to her. Helen could see that a new computer program was going to be necessary if they were going to land safely. They wouldn’t have much time.

  They had originally planned to land Viking 1 on Mars on July 4, 1976. It would be a grand gesture in celebration of the United States bicentennial. Now they would have to push back the date. They couldn’t wait too long; once the second Viking arrived at Mars they would need to switch their attention, and the DSN, to the new spacecraft. Everyone was spending sixteen-to eighteen-hour days trying to understand the complex geology of Mars. The engineers and scientists had to work together closely to find a spot big enough for the lander but near enough to what they thought might be flowing water. Caltech students and interns were counting the craters one by one while they fed the raw numbers into new computer programs. The scientists reviewed the computer analysis and tried to make sense of it. Some of the students were surprised by how much of the operation required human interaction. They expected to see supercomputers instead of people doing all the work. Senior scientist Harold Masursky good-naturedly responded to one inquiry: “Computers are just like wearing shoes. You need them when you are walking on gravel, but they don’t get you across the gravel.”

  Nancy Key was trying to get across the gravel. She spent the country’s birthday working late in the lab. Viking needed the women computer programmers, as well as most of the JPL staff, and few employees could take the holiday off. As July Fourth fireworks went off, she heard distant thuds that proclaimed celebration. The black sky filled with color and smoke. Some of the women went to the windows to look, opening them wide so they could stick their heads out. Then they went back to work.

  A warm night’s breeze swept in through the open windows. Nancy noticed black ash dancing on the gusts of air and floating through the room. “What’s happening?” she asked. The women looked outside and saw the hillside ablaze. The fireworks had ignited the dry canyon shrubbery. They debated what to do. “Well, the fire doesn’t look too big,” one of the women said. Nancy agreed. With their Martian robot circling millions of miles away, they were too consumed with calculations to worry about fires. They stayed where they were, and luckily the fire was soon put out.

  Using the computers’ analysis, the scientists picked the safest spot they could find. On 5 a.m. on July 20, 1976, they sent down the lander. The mood was tense. The lander dropped, and its parachute opened. But with no live pictures, they had no idea if the robot was headed for a safe parking spot or a jagged rock that would destroy their work. There was nothing to do but wait while the robot slowly floated down to the surface. Then came the words they had been waiting for: “Touchdown, we have touchdown.” The room erupted in celebration. Nancy couldn’t believe they had made it. Amid a flurry of hugs and kisses, the first image ever taken from the surface of Mars came through at JPL. The view of the rocky surface confirmed the danger of the landing site. They wouldn’t find out until the next day, when the first color images of the planet came in, how lucky they had been. A huge boulder that stood only thirty feet away would have caused the lander to tumble and fall.

  The first color picture from the surface of Mars was rocky and red. The sky was a curious dusky-salmon color. The Red Planet was living up to its name. But the lander wasn’t there just to take photographs; it was looking for chemical evidence of life. Two months later a second lander would join in the search. What the Vikings found on the surface of Mars led to more questions than answers. While one set of experiments designed to detect metabolism from microbes living in Martian soil was positive, other tests were negative, igniting controversy. Conspicuously absent were organic compounds in the soil, suggesting that the planet harbored no life at all.

  While Barbara and her colleagues pondered the future of the Mars missions over lunch, a man with floppy dark hair sat down at a table nearby. They all knew who the visiting scientist was. Carl Sagan had taken part in the missions at JPL for years—Mariner, Pioneer, Viking—and he seemed to have a hand in everything they worked on. Everyone knew he was extremely bright and friendly. Barbara smiled across the room at him.

  Sue joined them at the lunch table. She was easing back into her routine. Coming back to work had been good for her—she loved her work and her friends. What was hard was going home. She adored her little boys but struggled with her husband. After fifteen years of marriage she couldn’t go on. As she wrestled with the decision, she kept thinking, I don’t want my boys to think this is what marriage is like. She no longer valued stability above all else; instead she wanted to give her sons a home without strife. The decision was painful, but she decided to go forward with a divorce and hope for the best.

  Far from her worries at home, Sue was working on computer programs for the Grand Tour. She and Barbara were using the Exec 8 operating system on the UNIVAC computer and programming in FORTRAN 5. It was the latest in computing technology. They were working with Charley Kohlhase, an engineer and Voyager’s Mission Design manager. He was an old friend from the early Mariner missions. Kohlhase and the project manager, John Casani, weren’t fans of the clunky moniker MJS 77, the working name of the Grand Tour mission, so they scribbled alternatives on a blackboard: Nomad, Pilgrim, Antares. None of them worked. Finally, the name Voyager, pulled from a defunct Mars mission, stuck. It felt right.

  The team analyzed thousands of possible trajectories to determine Voyager’s path through space. The engineers never seriously considered including little Pluto in the trajectory
. While their once-in-176-year alignment was perfect for exploring Jupiter, Saturn, Uranus, and Neptune, it would take a once-every-600-year alignment to travel to Pluto as well. Just getting past Saturn was going to be a challenge. In fact, they had to be careful not to mention their plans to visit Uranus and Neptune outside the lab. The engineers knew that Congress had barely approved this mission and that if they proposed extending the tour, the entire operation could be in jeopardy. Instead, they would proceed in secret and hope to get authorization after leaving Saturn.

  Voyager was such a massive effort that everyone had to pitch in. Overwhelmed with work, they fretted over possible mistakes. Gentry Lee, the section manager, stressed the importance of checking their work by introducing the term “proper paranoia.” While Barbara could still remember the rush of excitement in JPL’s early days, when the computers raced to get their calculations from their notebooks to the rockets firing in the test pits, nowadays they checked and rechecked their equations before passing them along to be implemented. So the women repeated the phrase to one another, the words becoming a mantra of mindfulness as they scrutinized their calculations.

  When there was a rush job and they needed to program quickly, Kohlhase would burst into the offices and ask for Helen. With the perfect combination of speed and precision, she was always his choice.

  While the women were reaching for the edges of the solar system, there was trouble in the space closer to home. Skylab, the first space station, was struggling. Two of its rocket thrusters sprang leaks, and due to unusually high solar activity, a rescue became impossible. After orbiting Earth for six years, the station had to be abandoned. Commander Jerry Carr, one of the last astronauts to leave Skylab, was saddened by the departure, later saying of the space station, “It had hung together beautifully for us, and we kind of hated to leave it.” On July 11, 1979, Skylab fell to its doom, the atmosphere breaking it up and scattering it over the Indian Ocean and Australia. However, before its untimely end, it had proved that humans could live and work in space. Skylab was an important stepping-stone in the development of the modern International Space Station.

  As expensive equipment fell from the sky, Sylvia, now armed with her master’s degree in engineering from West Coast University, was becoming a star at the lab. Plucked out of Helen’s group and working with Dick Wallace, she was building a reputation as an extremely talented engineer. Her programming on the Voyager mission was meticulous, producing elegant trajectories for the twin ships. Sylvia’s task was especially difficult; she needed to plot a path close enough to Jupiter’s moons and Saturn’s rings to use their gravity while still staying in the proper alignment to fling the spacecraft out to Uranus and Neptune. To hedge their bets, the team charted a course for Voyager 1 that would take a shortcut through the solar system, getting closer to Jupiter and Saturn, while Voyager 2 would wind its way around more slowly, flying by both Uranus and Neptune. To accommodate this plan, Voyager 2 would actually be launched first.

  At the end of May 1977, Sylvia and her date sat in a movie theater watching the blockbuster Star Wars. Sylvia was tired, and her mind kept drifting back to a computer program that wasn’t working properly. It was hard to let go of the code and relax; she went over the broken commands again and again. Suddenly a view of the stars filled the screen. It was the splendor of outer space, as imagined by George Lucas, and Sylvia was entranced. She giggled at R2-D2, amused at the difference between robots in movies and those in the lab, and reveled in the quirky characters in the bar scene. Along with everyone else in the theater, she became lost in the story. Later, as they left the dark movie theater for the bright light of day, she felt energized. It was as if she had a secret, shared only by those at JPL. She was about to see the real outer space, a view that needed no special effects from Hollywood.

  There was one NASA icon who would not live to see the majesty of Voyager. Wernher von Braun succumbed to pancreatic cancer on June 16, 1977, at the age of sixty-five. His legacy of mighty rockets would live on in the exploration of the solar system when, two months later, Voyager 2 sat atop a powerful Titan-Centaur rocket at the launchpad at Cape Canaveral. It was early morning, and those at JPL were full of nervous energy. The women knew this was their one shot at the Grand Tour. The planets wouldn’t align like this again for another three lifetimes.

  Almost immediately things began to go wrong. First the onboard computers failed on the launchpad. Thankfully, this was a quick fix, and they were ready to begin again. In four-foot-high digits, the iconic launch clock at Kennedy Space Center counted down to zero. A billow of white smoke appeared as the rocket set off, lifting slowly from the ground. As expected, the launchpad became consumed in clouds of exhaust that engulfed everything and everyone, almost as if the sky had descended upon the earth. A luminous white light, the result of aluminum oxide exhaust from the rocket boosters, blinded observers. In mere minutes the whole thing was out of sight.

  As the rocket carried the spacecraft up through the clear Florida sky, the ship began to get confused. Like humans who find themselves in the throes of a wild spinning sensation, Voyager was suffering from mechanical vertigo and unable to get its bearings. Bruce Murray, JPL’s new director, called it an anxiety attack. The engineers at JPL watched helplessly. If they rebooted the system it might never reorient itself. The entire mission would be a wash as the probe forever sought direction in the vastness of space. Instead, they waited, hoping the computer system would fix itself. Soon, its fault-protection programming kicked in and the ship righted. Yet only an hour later there was another hiccup. The semi-autonomous Voyager, dealing with another orientation failure, shut down communications with Earth. JPL mission control was nervous; the robot had a mind of its own. Then, seventy-nine minutes later, Voyager found its bearings, communications came back up, and the ship was finally on its way to Jupiter.

  The second Voyager launch was even more of a nail-biter. It took place on September 5, just sixteen days after Voyager 2’s liftoff. Although it was the second Voyager to be launched, it was named Voyager 1, since its arc through space would leapfrog the spacecraft past its twin, delivering it to Saturn first. The day started out promisingly. The sky was a clear, dark blue in Florida while dawn had yet to break in California. It didn’t matter to the team at JPL; they were huddled inside, waiting for the countdown. At 8:56 a.m. in Florida, in a fiery flash of light and exhaust, the rocket carrying the ship lifted off. Sluggishly at first, then rising steadily, it soon disappeared, a coil of smoke in the cloudless sky the only evidence of its path.

  Something was wrong. On both coasts they watched as the rocket rose slowly through the atmosphere, a little too slowly. At Cape Canaveral, two JPL staff members were particularly concerned. Charley Kohlhase turned to John Casani and said, “We may not be making it. We’re not getting enough velocity.” If the spacecraft couldn’t reach escape velocity, its tour of the solar system would be a short one. It would pop into Earth’s orbit, caught in the clutches of gravity and unable to travel any farther. They were running out of both propellant and time. The ship had already eaten through twelve hundred pounds of fuel it shouldn’t have needed. The culprit was a tiny fuel leak in the propellant line. In California, the mood was tense. They sat helplessly; there was absolutely nothing they could do. Then, with 3.4 seconds of propellant left, the rocket made it, breaking the chains of gravity before the first-stage Titan fuel tanks fell away. Relief washed over the entire team. Voyager 1 had reached a high enough orbit.

  Now the engineers and computers turned their attention to the second-stage Centaur rockets, which they knew contained extra fuel, enough, they hoped, to push the ship onto its path to Jupiter. Yet burning through all this fuel until the tanks were empty carried a risk. The walls of the fuel tanks were thin strips of stainless steel, no thicker than a dime. The tank was built like a balloon, kept inflated only by the presence of propellant. The design was ideal for keeping the weight of the rocket down. However, once the tank ran dry, the walls would collaps
e in on themselves, possibly ripping apart at the seams as they did so. If this happened, an explosion could be sparked that would destroy the ship.

  Flight controllers at mission control waited as the rocket coasted into the anticipated position and then fired the Centaur rockets again. For a second time, they got lucky. Within seconds before the tanks emptied completely, the ship sailed into the correct orbit to make it to Jupiter. The tanks, nearly empty, dropped away.

  The ultimate interstellar journey had begun. Equipped with scientific instruments, cameras, and a gold-plated copper record designed by Carl Sagan and his colleagues, Voyager was off. The record was a message in a bottle, containing such diverse sounds as crashing surf, birdsong, greetings in fifty-five languages, and an eclectic ninety minutes of music. Helen and her team wondered what mysteries the spacecraft might uncover as it set out to explore the universe.

  CHAPTER 12

  Look Like a Girl

  The size of the storm made them gasp. The red spot that represented the maelstrom was as big as three Earths and vivid in angry swirls. It looked like a giant eye, staring back at the crowd of JPL employees observing it. Among the bewildered spectators in the lab’s auditorium were Barbara Paulson, Helen Ling, and Sylvia Lundy. They couldn’t believe they were looking at Jupiter. The colors of the planet’s atmosphere resembled the light brushstrokes and blurred detail of an impressionist painting, with bands of soft blue and ivory cut by dark red stripes. It was hard to believe those bands were circling the giant planet at speeds of 400 miles per hour. The moons stood out in spectacular glory; on Io, never-before-seen volcanoes, ten times as powerful as those on Earth, erupted in plumes of sulfur. From March 5 to April 13, 1979, Voyager 1 swooped past the Jupiter system, gathering an immense amount of data and nearly nineteen thousand images; it was a decade of discovery condensed into one encounter.