Chapter 1
When Women Reached for the Stars: The Untold Story of NASA's Human Computers
In the summer of 1957, a young woman sat at a desk in Pasadena, California, her pencil flying across graph paper as she calculated rocket trajectories that would soon make history. While the world knew the names of male scientists and astronauts, these women-known as "computers" before that term described machines-worked behind the scenes, their mathematical brilliance powering America's journey to space. Nathalia Holt's "Rise of the Rocket Girls" reveals this hidden history, documenting how a group of talented young women with math degrees became the backbone of NASA's Jet Propulsion Laboratory. These pioneers not only broke gender barriers in science but also transformed into the world's first computer programmers, their calculations guiding spacecraft to the moon, Venus, Mars, and beyond. The book has garnered praise from astronauts and historians alike, with former NASA Administrator Charles Bolden calling it "essential reading for anyone interested in understanding how women have shaped our technological journey to the stars."
Chapter 2
The Beginning: From Suicide Squad to Rocket Science
In March 1939, Barbara "Barby" Canright was crossing Caltech's campus when an explosion shattered the air. Looking up, she witnessed debris raining down from a failed rocket experiment by the notorious "Suicide Squad"-Frank Malina, Jack Parsons, and Ed Forman. These daredevil scientists were attempting to develop rocket technology in an era when such research was considered fringe science.
Despite their reckless reputation, the group had secured government funding and renamed themselves the Air Corps Jet Propulsion Research Project-the embryonic beginning of what would become the prestigious Jet Propulsion Laboratory (JPL). Frank approached Barby with a job offer that would double her typist salary if she would use her mathematical skills as a "computer"-the term then referring to a person who performs calculations.
As a human computer, Barby joined an exclusive tradition spanning centuries. These mathematical experts had previously calculated everything from Halley's Comet's return to artillery trajectories during World War I. Working in the isolated Arroyo Seco canyon above Pasadena, the team focused on developing rocket engines that could assist aircraft takeoff-technology known as JATO (jet-assisted takeoff).
By August 1941, they were testing these units on small aircraft. After early failures-including one that destroyed what was marketed as "the world's safest plane"-they achieved success. With six rockets attached to a small aircraft, they reduced takeoff distance by half. Later, with twelve units, they achieved the first American rocket-powered airplane flight-just months before such technology would become critically important to the war effort.
When Pearl Harbor thrust America into World War II in December 1941, JPL's work accelerated dramatically. The military urgently needed JATO units for heavy bombers taking off from short aircraft carrier runways. Barby's calculations became vital as she filled twenty notebooks with precise figures computing thrust-to-weight ratios that allowed the team to compare engine performance under different conditions.
As JPL expanded, they hired more computers-Freeman Kincaid, Melba Nead, Virginia Prettyman, and Macie Roberts-forming a close-knit calculation team. The computer room became a hub of activity with their prized Friden calculator, slide rules, and notebooks transforming raw data into meaningful insights that would eventually help America reach for the stars.
Chapter 3
Building the Computing Team: The Sisterhood Forms
By the early 1950s, Macie Roberts had been promoted to supervisor of the computing section and made a decision that would shape JPL's future: she would hire only women for her team. This wasn't merely personal preference-Macie believed women worked better together without male competition disrupting the group dynamic. She began carefully selecting bright young women with mathematical talents who would mesh well with her existing team.
Barbara Lewis, eager to escape limited career options for women, joined JPL after her sister Betty, who worked as a secretary there, mentioned seeing women working with calculations. During her interview for a position paying ninety cents an hour-more than double minimum wage-Barbara was immediately put at ease by Macie's warm presence.
Helen Chow, a Notre Dame graduate struggling to find work in window display design, was hired on the spot after impressing Macie with her mathematical background-something Macie rarely did with candidates. Sue Greene, who had excelled in advanced mathematics at Claremont men's college while modeling part-time, joined after working as a computer at Convair calculating complex equations for rocket tests.
In 1951, Marie Crowley arrived after graduating from Immaculate Heart College with degrees in chemistry and mathematics. During her interview, Macie asked if Marie minded working with "colored people," referring to Janez Lawson, with whom Marie would share a desk. Janez, a UCLA chemical engineering graduate with honors, represented a significant milestone as the first African American in a professional position at JPL, coming at a time when California remained largely segregated.
The intensity of their work-often twelve-hour days, five days a week-eroded the women's outside social lives but strengthened their bonds with each other. They frequently gathered for potluck dinners and parties, unable to get enough of each other's company. This "sisterhood" would prove crucial as they tackled increasingly complex challenges in the space race.
While working on the Sergeant missile project-JPL's most advanced weapons system with a self-contained inertial guidance system-the computers calculated Earth's gravitational effects using velocity and orientation data from new instruments. Though labs worldwide were working with gyroscopes, JPL needed to prove an all-inertial system was feasible to secure army funding.
By 1956, the Sergeant project was coming to fruition. Unlike the troubled Corporal missile that preceded it, testing went smoothly. The Sergeant became the finest missile they had created-and the last weapon the women would ever work on. Though bureaucratic delays meant JPL's weapons often became obsolete shortly after deployment, the team was already shifting focus toward a new frontier: space exploration.
Chapter 4
From Missiles to Satellites: America Enters the Space Race
The first hint of JPL's space ambitions came when Barbara and Macie spotted Wernher von Braun-the controversial former Nazi rocket scientist who had developed the V-2 rocket-sitting alone in the cafeteria. Despite his troubling past, von Braun had become America's preeminent rocket scientist and space visionary, writing articles about space stations and consulting for Walt Disney's "Man in Space" films.
Von Braun was at JPL for Project Orbiter-plans for America's first satellite. William Pickering, JPL's director, had advocated for an Earth satellite as the U.S. contribution to the International Geophysical Year (IGY), a worldwide science project scheduled for July 1957 through December 1958.
However, on August 9, 1955, JPL's confidence was shattered when the Department of Defense Committee on Special Capabilities chose the Navy's Project Vanguard over their Project Orbiter for the IGY satellite program. While Orbiter was designed to meet scientific minimums with tested rocket systems, Vanguard promised more ambitious scientific studies despite using the still-developing Viking rocket. The computers suspected political motives behind the rejection-the government wanted to keep the Army focused on missiles rather than satellites, and von Braun's Nazi past may have hindered their proposal.
Despite this official rejection, JPL cleverly continued their satellite work under the Jupiter ballistic-missile program. They designed the Jupiter-C rocket with four stages: the Redstone rocket at the base, followed by a spinning tub of eleven Baby Sergeants, then a second tub with three Baby Sergeants, and finally a fourth stage containing the payload-the forbidden satellite itself-with a lone Baby Sergeant providing the final push into space.
Helen Chow calculated precise spinning rates for the tubs-550 rpm before launch, gradually increasing to 650 rpm after 70 seconds, then to 750 rpm after 155 seconds-to prevent vibration that would tear the rocket apart. Meanwhile, Marie and the engineers developed Microlock, a new tracking system sensitive enough to detect tiny signals as small as a milliwatt from three thousand miles away.
On September 20, 1956, Jupiter-C made its first secret launch from Cape Canaveral. Despite Pentagon concerns that JPL might attempt an unauthorized satellite launch, officials had taken precautions-the fourth stage contained no fuel, just sandbags instead of a satellite. The rocket achieved a record-breaking Mach 18 velocity and climbed 3,335 miles, higher than any man-made object had gone before.
Then came the shock that changed everything. On October 4, 1957, the Soviet Union launched Sputnik, the world's first artificial satellite. At a Washington D.C. embassy reception, JPL Director Bill Pickering learned the news from a New York Times reporter and watched in stunned silence as vodka flowed freely while the satellite passed overhead every ninety-six minutes, beeping triumphantly.
Helen and her colleagues were devastated, knowing they could have been first with their hidden satellite design. Despite nationwide anxiety, President Eisenhower stubbornly refused to authorize JPL's launch, insisting on waiting for Project Vanguard to maintain separation between space exploration and military endeavors.
Public anxiety grew as Americans feared the Sputniks might be weapons or spy machines. On December 6, 1957, Project Vanguard's launch was broadcast live on television, only to end in spectacular failure as the rocket lifted just feet off the ground before tipping over and erupting in flames. Newspapers mockingly dubbed it "Flopsnik" and "Kaputnik."
Under intense pressure, the Eisenhower administration finally authorized Pickering and von Braun to pursue their satellite. The computers excitedly retrieved their hidden notebooks as engineers unveiled their secret satellite shell. The mission, dubbed Project Deal, would use the four-stage design from Jupiter-C to launch instrumentation developed by James Van Allen.
After two weather delays, launch day finally arrived on January 31, 1958-just 84 days after authorization. Barbara and Margie waited nervously in the dimly lit mission control room in Pasadena. At Cape Canaveral, with no media present to avoid another public failure, the rocket fired at 10:48 p.m. Richard Feynman, Al Hibbs, and Lee DuBridge watched over Barbara's shoulder as she calculated the satellite's velocity. When they detected the signal after its first 90-minute orbit, confirming success, America had finally entered the space race.
Chapter 5
Reaching for the Planets: From Explorer to Mariner
As America's space program made things official with the establishment of NASA on July 29, 1958, JPL eagerly anticipated transitioning from weapons development to planetary exploration. Engineers and computers dreamed beyond lunar missions to Mars and Venus-planets that captured the American imagination as potential harbors of alien life.
The team's first attempt at lunar exploration came with the Pioneer missions. Using calculations from their earlier Project Red Socks, they designed a spacecraft atop a Jupiter missile with the same spinning Baby Sergeants configuration as Explorer, its nose cone painted in black and white stripes that earned it the nickname "merry-go-round."
On December 6, 1958, Sue nervously entered the cramped control room for Pioneer 3's launch. When the Jupiter missile stopped firing prematurely, Sue calculated through the night that the spacecraft would rise only 63,500 miles before falling back to Earth. Despite this disappointment, JPL received good news: they had officially become part of NASA while maintaining their Caltech management, giving them independence to focus on scientific exploration rather than weapons development.
Pioneer 4 launched successfully on March 3, 1959, with the first-stage rocket performing perfectly. The Microlock tracking system that had occupied so many of the computers' hours worked flawlessly as Pioneer 4 joined Luna 1 in solar orbit. Despite this success, JPL felt they were still behind the Soviets and longed to explore the planets.
As JPL expanded with a doubled budget between 1950-1953, supervisor Macie Roberts carefully recruited qualified women who would fit with her team. Barbara, newly promoted to supervisor following Macie's retirement (despite engineer Bill Hoover's sexist objections), visited the Goldstone antenna in the Mojave Desert that would become central to JPL's Deep Space Network-a system of three giant radio antennas positioned around the world to maintain constant contact with distant spacecraft.
By 1960, Barbara had learned she was pregnant with a due date in October. Unlike other pregnant women who simply left the lab, Barbara's position was too critical-she and her boss devised a plan for her to work until she gave birth. However, seven months into her pregnancy, Barbara received a shocking phone call: "You have to stop working immediately, today. We can't have a pregnant employee." Citing "insurance purposes," JPL fired her after a decade of service.
As JPL reorganized under NASA, Helen Ling was appointed head of the newly named Mission Design department. Her team of women computers, known as "Helen's girls" or "the sisterhood," bristled when engineers called them "computresses." Meanwhile, new IBM computers using transistors instead of vacuum tubes began appearing alongside the human computers.
On April 12, 1961, Yuri Gagarin became the first human in space aboard Vostok 1, shocking Helen with another Soviet victory. America responded less than a month later when Alan Shepard briefly reached space in Freedom 7, though unlike Gagarin, he didn't orbit Earth.
When Barbara's daughter Karen was seven months old, Helen called offering her a position in her group. Barbara carefully considered the offer, knowing that working mothers were rare in 1960-only 25% of married mothers with children under eighteen were employed. Despite societal expectations, Barbara missed the lab and the flexible hours would accommodate family life. She accepted the position and began calling babysitters.
The women threw themselves into the Mariner program, JPL's favored project designed to send spacecraft to Mercury, Venus, and Mars. Using an Atlas-Agena launch vehicle, Mariner would construct ten spacecraft to explore Earth's closest planetary neighbors. The design featured solar panels facing the sun for continuous power and a large antenna pointing back to Earth.
On December 14, 1962, Mariner 2 made its closest approach to Venus. Despite glitches including overheating and a lost solar panel, the spacecraft successfully scanned Venus as Helen and Melba anxiously tracked its position from the control room. It was America's first win in the space race, celebrated with a Venus float in the Rose Parade displaying the words "Venus to Pasadena" in red roses.
Instead of the alien jungles many had imagined, Mariner 2 revealed Venus had temperatures and pressures far too high to sustain life. Unlike Earth, Venus rotates clockwise and extremely slowly-one Venusian day equals 243 Earth days.
Chapter 6
Programming the Future: From Human Computers to Software Engineers
While the computers took pride in their accomplishments, their jobs were increasingly threatened by digital computers eliminating human computer positions across NASA facilities. However, Helen fought against obsolescence by transforming her team into NASA's first computer programmers. Unlike other NASA centers where women's jobs were disappearing, JPL's women became more indispensable with their programming expertise, working closely with male engineers but developing specialized skills the engineers rarely possessed.
The women began learning FORTRAN (Formula Translation), a new programming language ideal for translating mathematical equations into code. Barbara and Helen found it easy to learn through Caltech classes sponsored by JPL. They wrote programs on paper using specific computer-recognizable commands, then transferred them to punch cards using keypunch machines.
In 1960, an IBM 1620 computer joined the team, taking up space in a nook adjoining the computer room. The women named her "Cora" after the "Core Storage" sign on her door and treated her as part of the group. Barbara even added a nameplate for Cora beneath the human team members' names.
Building on Mariner 2's success, JPL prepared for an even more ambitious mission to Mars-140 million miles away, four times the distance to Venus. Using a similar design but adding a camera, the Mars mission would launch twin spacecraft within a tight 27-day window. The computers calculated a complex trajectory that would take seven and a half months, carrying the spacecraft more than 180 degrees around the sun-the longest interplanetary mission ever attempted.
While NASA discussed lunar landing sites, preparations for the Mars missions intensified. The women watched from a glass balcony as men in white coats assembled the Mariner spacecraft. Despite distributing "good luck" peanuts, Mariner 3 failed when its fiberglass shroud didn't jettison properly. Working around the clock, the computers recalculated everything for Mariner 4 with its redesigned metal shroud.
On July 14, 1965, Mariner 4 reached Mars, transmitting real-time images that revealed an ancient planet with polar ice caps, strange "chaos terrain," and a thin atmosphere unsuitable for complex life. This scientific revelation contradicted popular culture's portrayal of Mars in works like H.G. Wells' "The War of the Worlds," though scientists still hoped simpler life forms might exist beneath the surface.
As women's liberation movements swept the nation in 1970, the computers at JPL were officially recognized as engineers-a breakthrough as significant as landing on the moon. Helen developed a plan to increase female representation in engineering by hiring women as programmers and encouraging them to pursue engineering degrees while mentoring them at JPL.
The computing landscape had transformed dramatically. Where Helen once programmed by inserting pins into a Burroughs E101 pinboard and teams competed for time on massive IBM machines, now each staff member had their own personal computer. This revolution came through microprocessors-Intel's 4004 chip contained 2,300 transistors on a tiny silicon wafer with computing power equal to the massive IBM 1620 that the women had once cherished.
Chapter 7
Legacy Among the Stars: From Viking to Voyager and Beyond
Barbara worked on trajectories for the Viking mission to Mars, designing a path for the spacecraft to travel 206 million miles while maintaining contact with Earth's Deep Space Network. Each Viking spacecraft would split into an orbiter and lander, with the lander searching for simple life forms using a robotic arm to collect and analyze soil samples.
When the first spacecraft reached Mars in June 1976, the images revealed unexpectedly rocky terrain with lava flows and deep craters. Helen was called upon to create new computer programs as the team worked 16-18 hour days to find a suitable landing site. The lander finally touched down on July 20, 1976, sending back the first images from Mars' surface-rocky and red with a dusky-salmon sky.
Sue and Barbara worked on the Grand Tour mission, later renamed Voyager, using the latest Exec 8 operating system and FORTRAN 5 programming. With Mission Design manager Charley Kohlhase, they analyzed thousands of possible trajectories, carefully planning paths that would use the gravity of Jupiter and Saturn to propel the spacecraft toward Uranus and Neptune.
The Voyager missions revealed Jupiter's massive storms and bands of atmosphere moving at 400 mph, with volcanoes erupting on its moon Io. When the spacecraft reached Saturn, they captured unprecedented images of intricate, intertwined rings with odd spokes. After NASA approved continuing the mission beyond Saturn, Voyager 1 headed toward the edge of the solar system while Voyager 2 continued to Uranus and Neptune.
The mission would eventually travel 13 billion miles, with both spacecraft entering interstellar space before their plutonium power sources run out around 2025. For the JPL team, Voyager represented their most beautiful and important accomplishment, revealing Earth's uniqueness while hinting at possibilities beyond our solar system.
After forty-five years at JPL, Barbara retired in April 1993, packing up mementos from countless missions. A year later, Helen retired with no regrets, her farewell celebration drawing engineers from across JPL's history. Younger than her friends, Sylvia attended their retirement parties with a heavy heart but was excited to step into her dream role as project manager in the Mars exploration program.
The proportion of female engineers at JPL increased from 9 percent in 1984 to 15 percent in 1994, making it the NASA center with the highest percentage of women-an achievement made possible by Macie and Helen's tireless fifty-year campaign to hire women. This stood in stark contrast to national trends, where female computer science graduates declined from 37 percent in 1984 to just 18 percent today.
When Helen retired, she was the last of the original "computers," replaced by a new generation of women with greater power and responsibility. Sylvia, bridging the gap between eras, left JPL in 2008 after forty years, while Sue remained, determined to see her Juno mission reach Jupiter in 2016.
The women's legacy extends into deep space-particularly with Voyager 1, which carries programs first handwritten by this extraordinary group of women on just forty kilobytes of memory. These programs, soaring amid space dust, are "the legacy of women written in the stars."
Chapter 8
The Invisible Pioneers: How Women Shaped Our Journey to Space
When we look up at the night sky and contemplate humanity's exploration of space, we typically think of astronauts in spacesuits and male scientists in white lab coats. Yet behind every successful space mission stood a team of brilliant women whose mathematical minds calculated the trajectories, orbital mechanics, and navigational parameters that made these journeys possible.
The story of JPL's human computers reveals how women have always been central to scientific and technological advancement, even when their contributions remained invisible to the public. These women didn't just perform calculations-they pioneered new computational methods, developed programming languages, and eventually transformed into the world's first software engineers.
Their story parallels the broader transformation of American society through the mid-20th century. From Barby Canright's groundbreaking work during World War II to Janez Lawson breaking racial barriers in the 1950s, from Barbara Paulson being fired for pregnancy to Sue Finley's six-decade career at NASA, these women navigated personal challenges while helping humanity reach for the stars.
What makes their accomplishments even more remarkable is the context in which they occurred. These women thrived in an era when society expected them to prioritize marriage and motherhood above all else. They balanced family responsibilities with demanding careers, often working overtime and weekends to meet mission deadlines while still rushing home to care for their children.
Today, as we send rovers to Mars and prepare for human missions to deep space, the legacy of these rocket women continues. Their calculations, converted into computer code, still guide spacecraft through the solar system. Their mentorship programs still shape NASA's hiring practices. And perhaps most importantly, their stories remind us that the journey to space was never just "one giant leap for mankind"-it was also countless small steps taken by women whose names we're only now beginning to recognize.
As we look toward the future of space exploration, we would do well to remember the lesson of JPL's computing team: innovation thrives when we tap into the full spectrum of human talent, regardless of gender, race, or background. The stars, after all, are for everyone.
