March 27, 2007
In the 1940s, women started playing instrumental roles in missions at JPL. By the 1950s, well before the advent of the desktop computer, it wasn't unusual for young women around the United States to be hired out of high school to do calculations.
Barbara Paulson arrived at JPL in 1948. In those days, JPL designed rockets for the U.S. Army. Paulson calculated rocket paths, or trajectories. "One Corporal (rocket) trajectory took all day," she says. "The early Friden mechanical calculators we used couldn't do logarithms, so we used these big books of atmospheric densities as a function of altitude that had been calculated by Work Projects Administration people during the Great Depression."
Paulson also played a role in the historic launch of the JPL-built Explorer 1. On the night of Jan. 31, 1958, she was assigned to the operations center for Explorer 1. She plotted data coming in from the satellite and a network tracking station.
Over time, a group of about a dozen women was formed to perform trajectory calculations. Macie Roberts and, later, Helen Ling, both supervisors for the group, hired only women. Their attitude reflected a general cultural belief of the times that some kinds of jobs were more appropriate for women than for men. "Men back then always thought they knew more than you did," Ling remembers. "So if you hire them under you, they're uncomfortable, you're uncomfortable. So I just hired women just out of college. I thought that if you didn't give them a chance, they'll never get a chance."
Ling also liked to rehire women who left JPL. In the 1960s, before the Lab had a family leave policy, women who were having children had to quit. Paulson left to have her first daughter and returned in 1961. Many of the women took advantage of Ling's phone invitation to return.
The advent of electronic computers slowly changed what the all-female computations group did. The women were trained to program in FORTRAN, the primary computer language developed for scientific applications. Sue Finley, hired into the group in 1958, remembers that the male engineers largely didn't want to do the programming themselves in the 1960s. It was still considered "women's work," not part of an engineer's job description. So the group began to code and run programs for calculating trajectories to the planets, for various Earth orbits and other tasks assigned them by the Lab's engineers.
New computers didn't change the fact that data were still plotted by hand. Electronic computers couldn't plot data until the 1970s. "I worked on Ranger 3 telemetry by hand," recalls Finley. "The computer wasn't working that night. JPL's Al Hibbs read it to me over the phone and I plotted it. When everyone realized that Ranger 3 hadn't reached escape velocity and wouldn't reach the moon, I went home. I got there around six in the morning and my husband was watching the news. They had a little blackboard up with the numbers I had calculated on it. I said 'Those are my numbers!' Almost nobody in the outside world knew we women did that work."
As electronic computers grew in capability, demand for the group's services actually grew for awhile as engineers wanted more and more programs written. Once digital computers could be programmed to make plots, the women didn't have to do that task by hand any more. Instead, engineers started to want computer-animated movies to help promote missions. Animated movies could show the trajectories and views of the planets during spacecraft flybys. Linda Lee, a graduate of Univ. of California-Berkeley's computer science program, turned JPL's trajectory analysis of a mission to rendezvous with Halley's comet into one of the earliest mission animations. She now develops command and sequencing software.
Finley, who plotted Ranger trajectories by hand, is now a software testing engineer at JPL, and is involved in software development for the upcoming Mars Science Laboratory mission.
Ling developed software for many missions over the years, including the Infrared Astronomical Satellite, Magellan, Mars Observer and Topex/Poseidon. Her work was particularly favored by Charley Kohlhase, the Voyager mission designer, who didn't want anyone else to develop his software. Ling retired in 1994 but still keeps in touch with her former colleagues. She lives in South Pasadena, Calif., with her husband Art.
Paulson retired in 1993 after 42 years of service to JPL. Many of the other women left JPL over the years, and a few have passed away. A handful are still employed at JPL. The lifespan of the computing group and its evolution helps illustrate the changing roles of women at JPL.
Barbara Paulson, Helen Ling, Vickie Wang, Charles Kohlhase, Joan Jordan, Frank Jordan, Sue Finley, Linda Lee, Sylvia Miller and Kathy Thuleen all contributed their time and memories to this article.
Written by Erik Conway/JPL Historian