Written by: Jordan Beck 

Yvonne Madeline Claeys Brill was born on December 30, 1924 in St. Vital, Manitoba, now a suburb of Winnipeg, to parents who immigrated from Flanders, Belgium years earlier. All the children in the Claeys family were highly motivated and successful in school, so the desire for post-secondary education came naturally for Yvonne. At the young age of 10, riding the street cars through downtown Winnipeg and watching young university students walking to and from classes, she solidified her decision for post-secondary education. Her interest in the strict sciences developed in high school in her chemistry, physics, and mathematics classes. Her teachers were not particularly supportive of her ambitions for a career in STEM. Her high school principal suggested that she attend Norman School to obtain her teaching certificate, which was a focus for women in those days. She was not interested.

“I just felt I had more enterprise than that.”

She was awarded the Governors Medal for Academic Excellence upon graduation from high school.  She enrolled in science at the University of Manitoba focusing her courses in physics, chemistry, and mathematics. Her initial plans were to enroll in the Faculty of Engineering, although at the time, women were refused admission as there were no accommodations for women at the required outdoor engineering camp over the summer.

“You just have to be cheerful about it and not get upset when you get insulted.”

Throughout her time at the University of Manitoba, Yvonne was not only succeeding in her academic studies, she was a highly involved student. She was the Secretary (1943-44) and Editor in Chief of the Question Mark (1944-45) on the Science Students’ Council, and a member of both the Science Co-Ed Council and the University Speed Skating Team.

Yvonne went on to graduate at the top of her class with her Bachelors of Science (Chemistry and Mathematics) in 1945.

Following graduation, she was offered two jobs: one in New York and the other at Douglas Aircraft Company in California. Yvonne arrived in California just before the end of the war and was initially assigned to the research department at Douglas. She was later offered a one year contract in the Aerodynamics department. In 1946, Douglas won a contract for Project RAND, which was to launch an unmanned Earth orbiting satellite.

At that time Yvonne was working as a mathematician using the slide rule and Marchant, both types of old-fashioned calculating. The goal was to determine the trajectories for the sizing of the different stages on the rocket to get it to a 100 nautical mile orbit. Prior to the start of the RAND project, Yvonne had already begun her Master of Science in Chemistry at the University of Southern California, attending classes in the evening and working at Douglas during the day. One of the engineers spearheading the project, Dr. R. Kruger, told Yvonne that if she were to join the project, they would set up a propulsion or chemical group once the project funding came through, and she would be transferred over. Shortly thereafter, the chemical group was formed and Yvonne reviewed literature related to German rockets. Yvonne was charged with finding a lightweight rocket fuel to launch unmanned satellites. At RAND, Yvonne calculated and tabulated high-performance propellant temperature combinations, which became industry standard in the US for many years.

As Yvonne progressed in her Master’s degree, and the RAND project evolved into a purely theoretical project, she decided to move to Marquardt Corporation, a small company where she was the only women engineer working as the group leader for igniters and fuels. Her work at Marquardt was to design and develop ignition systems for a US supersonic ramjet missile.

Around this time, Yvonne met her future husband William (Bill) at the Linus Pauling lecture at UCLA and wed the following year in 1951.

“All of his opportunities were on the East Coast, and all of mine were on the West Coast. But, in thinking about it, my decision was that good jobs are easier to find than good husbands, so I married him and moved east.”

Yvonne and Bill moved to East Hartford, Connecticut in 1952 where Bill got a job at Olin-Matheson in the research department and Yvonne joined United Aircraft Corporation as a Principle Investigator in the research department working with turbojet engines. After three years in Connecticut, both Bill and Yvonne left their jobs and settled in Princeton, NJ where Bill worked at Petrotex and Yvonne worked at Curtiss Wright, in the Wright Aero Division as a Project Engineer. There, she was working on high-energy fuels for turbojets, turbofans, and ramjets. It was in 1958 that Yvonne left Curtiss Wright to care for growing family, Matthew, Joe, and Naomi, but kept in the field by working part-time at FMC Corporation as a consultant, advising over rocket engine fuels and oxidizers.

By 1962, she decided to go back to work full time and a job in RCA Astro-Electronics’ rocket division came up as a result of her consultation work with FMC Corporation. Yvonne’s expertise and previous work with rockets, ramjets, and turbojets for both commercial and military aircraft led her to be assigned to a project for the Director of Research at United Technologies. This project allowed her to come up with and eventually propose the hydrazine resistojet, in which she would later patent.

She was looking at the performance and what areas of the periodic table emphasis could be put on to get higher performance fuels. She determined that using the equation to calculate performance, and stripped out all the gamma-1 (heat capacity functions), the equation now consisted of two important factors, the square root of the chamber temperature divided by the molecular weight of the products. She then decided to graph the specific impulse (ISP) and it was evident that if the molecular weight of the exhaust gases do not change very much, increasing the chamber temperature of the exhaust coming out and get higher ISPs. This finding resonated with Yvonne.

When she interviewed for this position at RCA, they told her she would be an ideal employee because as a woman, she was mature, and had her family bearing years behind her. Her male colleagues were very disappointed during her first year at RCA working on spacecraft was quite different to what she has done before. Soon she went on to prove that she was more than capable in her work.

“If I were as smart as you think I should be, I’d be too smart to work here”.

Her confidence in her ability and her sharp whit, ended any remaining criticism colleagues at RCA had. Her first project at RCA (Voice Broadcast Study) was conducted out of NASA Lewis where she was tasked to study satellites used for communication, and as the only propulsion engineer at RCA, she had the sole responsibility of looking for the appropriate type of propulsion system required. Throughout her study of satellites, apogee motors were being used, which required good point accuracy and in those days was not the case. Yvonne explained that once the apogee motor has finished burning, the aircraft might begin off course. So a chemical propulsion system would be needed to stop the diversion quickly, while the satellite was still in ground vision, so that you can send the satellite back in the desired direction.

She had the idea of using hydrazine. Hydrazine coupled with a Shell 405 catalyst, where hydrazine exothermically gives off heat when it decomposes when you put it over a catalyst bed. She explained that this occurred instantaneously allowing the start and stop the engine as required, which controlled altitude. Once she had the idea of how the design for a new engine could work, she spent many late nights and weekends conducting a whole analysis. She proposed that two systems are required on board, a chemical propulsion system in addition to the already existing apogee motor.

Her discovery of the hydrazine resistojet won her international acclaim, leading to her securing a patent (U.S. Patent No. 3,807,657) in 1972.  By 1983, the first communication satellite using her propulsion system was used and later became industry standard.

“I just kept pushing, I didn’t care who shins I kicked, as long as… and the ideas got adopted.”

Yvonne left RCA as Manager of Propulsion on the NOVA spacecraft in 1981 and took up a managerial position of the solid rocket motor on the Space shuttle at the NASA Headquarters. The problematic bureaucracy she faced caused her to return to RCA in 1983, following a brief stint at a job in Italy. Her job at RCA evolved from the former monitoring of the construction of propulsion systems, design, and analysis work, to project proposals, which she did not find fulfilling. Yvonne’s impeccable spirit and adventure brought her to another successful opportunity in London, England. Yvonne thought that her husband would join her, but he was offered a position of visiting fellow at Princeton University in the Chemistry Department, which had too much prestige to leave behind.

During her time in London, she worked for the International Maritime Satellite Organization (INMARSAT) from 1986 to 1991, which had a charter from the United Nations to do communications from space to all mobile equipment. They got the first satellite off the ground in 1990, with following prototypes bring launched thereafter. Yvonne left full-time work at INMARSAT in 1991 and returned to the U.S. and worked as a consulting propulsion engineer at Telespace. Upon her return she was tapped with multiple projects from the National Research Council, one of which was a mandate from Congress to NASA to look at advanced solid rocket motors that were being proposed for the Shuttle. Her first consulting project with Telespace was to monitor the construction of two spacecraft at Hughes in Thailand, then a contract in Norway for a handover in orbit. The last spacecraft consulting project that Yvonne worked on was for Telenor in 2000, which was the space division of the Norwegian telecommunication company.

In 2005, Yvonne had been working on an 18-month project with the National Research Council for the Air force and Department of Defense to assess the status of air breathing of rocket propulsion in the United States. Yvonne worked tirelessly as an aerospace consultant since her departure from INMARSAT and worked on project specializing in satellite technology and space propulsion and was still working the week of her passing.

Yvonne’s legacy as a groundbreaking propulsion engineer and rocket scientist is celebrated through the many impressive awards and accolades she has received throughout her career, as well as being a lifelong inspiration and mentor for many women and girls to enter STEM careers.

Sadly, Yvonne Brill passed away in 2013. Following her death, the AIAA and the NAE Aerospace Engineering Section established the Yvonne C. Brill Lectureship in her honour, which “recognizes an individual who has made significant contributions in aerospace research or engineering”.

In 2020 the Faculty of Science at the University of Manitoba awarded Yvonne Brill, posthumously, with the inaugural Memorial Award in the category, “Applications that Changed the World”.

“It took one woman to invent a rocket thruster, and two men to invent Post-its” – the Washington Post, 2010.

Honours and Awards:

Faculty of Science Memorial Award for Applications that Changed the World, 2020

Kate Gleason Award from the American Society of Mechanical Engineers, 2011

National Inventors Hall of Fame, 2010

National Medal of Technology and Innovation, 2010

American Association of Engineering Societies (AAES) John Fritz Medal, 2009

New Jersey Inventors Hall of Fame, 2009

Honorary Fellow of the American Institute of Aeronautics and Astronautics (AIAA), 2008

AIAA Wyld Propulsion Medal – present for outstanding achievement in the development and application of rocket propulsion systems, July 2002

IEEE Judith A. Resnik Award to be presented at IGARSS-2002 IEEE International Geosciences & Remote Sensing Symposium, June 2002

NASA Public Service Medal: “in recognition for your agrent dedication and commitment to NASA as a member of the Aerospace Safety Advisory Panel. Your contributions towards the safety of NASA’s programs with particular focus on aerospace propulsion programs, with benefit of Nation for generations to come,” April 2001

U.S. Space Flag Recipient: “in appreciation for your outstanding leadership and continuing support to ensure astronaut flight crew safety” presented by NASA Astronaut Office, April 2001

Women in Technology International Hall of Fame, June 1999

NASA Group Achievement Award to Aerospace Safety Advisory Panel, June 1998

Dr. Harold W. Ritchey Distinguished Lecturer, April 1994

Society of Women Engineers (SWE)  Resnik Challenger Medal, Society for Women Engineers Annual Conference, June 1993

International Academy of Astronautics, April 1988

National Academy of Engineering, October 1987

Society of Women Engineers Achievement Award: “for Important Contributions in Advanced Auxiliary Propulsion of Spacecraft and Devoted Service to the Professionalism of Women in Engineering,” June 1986

AIAA Fellow, April 1986

Society of Women Engineers Fellow, June 1985

DeBeers Corporation Diamond Superwoman Award, February 1980

Engineer of the Year Award Central New Jersey Engineering Council, January 1979

NASA Order of the Big Dipper, awarded by NASA/GSFC, August 1974

RCA AstroElectronics Engineering Excellence Award, January 1970

Information collected from a 2005 interview conducted by Deborah Rice for the Society of Women Engineers.