Birth Date: 30 December 1924
Date of Death: 27 March 2013 (age 83)
Place of Birth: Winnipeg, Canada
Place of Death: Princeton, New Jersey


KEYWORDS: Yvonne Brill, Aerospace engineer, Space, Rocket scientist



Yvonne Madelaine Brill (née Claeys) was an extraordinary woman and the only female in her generation of aerospace engineers. She was an outstanding scientist, especially because of her determination and will to improve aerospace technology. She was the inventor of a system for a rocket engine called ‘hydrazine resistojet’.

At her times women were not accepted to study engineering thus she studied science and mathematics at her hometown university in Manitoba. Her attempt to explain the reason for women non-acceptance in the engineering field concerns the need of camping in the wilderness and the lack of interest in building adjusted facilities for women.

After completing her Master’s degree and working in several companies, she collaborated in many interesting projects. One was Project RAND, which later became the famous Rand Corporation, one of the first think tanks for the US Air Force. She got married with a colleague she met when working for a small company, the Marquardt Corporation, and she gave up her career when she had her first child.

The highlight of her career was the invention of the electrothermal hydrazine thruster (EHT), which was designed to keep communications satellites from deviating from their orbit. The hydrazine thruster makes it possible to control the satellites’ orbits and to keep them in the proper trajectories longer, proving much more efficient than all previously invented thrusters. In addition, in 1980’s she received a Diamond Superwoman award. Brills’ rocket propulsion system also allowed satellites to carry a smaller load of fuel and a larger load of instruments into space. Additionally, her measurements of performance of various rocket fuels were standardized for further scientific work in the rocket area.



Yvonne Madelaine Brill

Yvonne Madelaine Claeys Brill was born in Winnipeg, Canada on 30 December 1924. She was the daughter of uneducated parents who immigrated from Belgium to Canada. Her father was a carpenter. As a child she admired prominent female pilot Amelia Earhart, who was the first woman to fly solo across the Atlantic and Pacific oceans.⁴ After being denied admission to the men-only engineering department at the University of Manitoba, she completed a bachelor’s degree in chemistry and mathematics at the same university. She then moved to southern California and started working in the aerodynamics department of Douglas Aircraft in Santa Monica while at the same time studying for a Master’s degree in chemistry at the University of Southern California³. Although her major interest was in engineering, she was transferred to the chemistry department and got involved with rocket propellants, rocket engines and ramjets³ (p. 76). At that time, the company became the basis for RAND Corporation, where Brill helped design the first American satellite.⁶ Though she enjoyed working in the chemistry department with air-breathing jet engines, after having earned her master’s degree in chemistry she decided to pursue a career in engineering.³ At the time of the Cold War she was asked to calculate thermodynamic components for very high temperatures to ascertain the performance of oxidizers and rocket fuels. The data she assembled was used for the thermodynamic tables adopted for the first industry standards.³ She did not pursue her PhD in chemistry because she was more interested in the rocket engineering field and  because of the discrimination against women in chemistry-related workplaces.³

She met her future husband – who was a postdoctoral student in chemistry – while working for the Marquardt Corporation, where she ran various tests on the ramjets. Some conflict appeared between them when looking for job opportunities. She had found a potential employment in the West Coast and her husband on the East Coast. They followed his career path, moved to the East Coast, got married and had three children, two sons and a daughter.³ Later, they moved to Princeton New Jersey, and Yvonne occasionally worked as a consultant in propellants and research in advanced fuel combinations. She returned to work as in her forties  and became the first and only propulsion engineer on staff at the RCA Astro Electronics.³ In an interview with Magdolna Hargittai she illustrates how her innovation became patented:

Actually, when I went through the calculations of the performance, it gives you 30% more, which was very significant. I wrote a disclosure and eventually the company, RCA, applied for a patent and put it on their spacecrafts, there are quite a number of them that uses this thruster. I discovered last summer, checking with a company who builds hydrazine thrusters, that there are 120 spacecraft in orbit using their electrothermal hydrazine thrusters.³ (p.77)

Her innovation was called hydrazine resistojet and was much more efficient and suitable for controlling satellites’ orbits and communication. Hydrazine resistojet was used for the first time in 1983 but did not take long for Brill to devise another successful  propulsion system as program manager for the RCA/Navy Nova spacecraft project.³ Since 1983, companies such as RCA, GE, Lockheed Martin and Orbital Sciences have used EHTs in their communications satellites.⁵ Between 1981 and 1983, Brill worked for NASA and made contributions to the development of a space shuttle rocket engine.⁶  Her career path was varied since she changed working environment every few years, thus gaining valuable experience in chemistry and engineering. Yvonne Brill served as a role model for further generations of women engineers, including her daughter.⁷ In her remarkable career she expanded the horizons of space technology and innovation. During her lifetime, the number of women engineers increased noticeably despite the fact that engineering was still regarded as a male occupation. Yvonne Brill was very well aware of the importance of role models, and participated in the promotion of activities for women to be brave enough to stand out, go to work and make their mark in the fields of science and engineering. She was an active member of the Society of Women Engineers, whose main goal was to raise young women’s awareness of opportunities in engineering. Furthermore, she was awarded the Society of Women Engineers’ Achievement Award in 1986. Considering that she worked in a male-dominated area, it is surprising that she was not exposed to discrimination, except for a few comments. This was probably due to her attitude towards the everyday challenges she was facing at work and at home. One of the most attention-grabbing debate was after she passed away and the New York Times admired her cooking skills before mentioning that she was “also a brilliant rocket scientist³ (p. 79). However, they rewrote the article after an outbreak of protest by a number of readers.³

Brill received many awards, among which the AIAA Wyld Award in 2002 and the AAES John Fritz Medal in 2009. President Obama mentioned her special achievement in 2011 when giving a speech presenting nominees for the National Medal of Technology and Innovation, where she was awarded the National Medal of Technology and Innovation. She died in Princeton, New Jersey on 27 March 2013 of complications from breast cancer.²



Besides her husband, with whom she shared her family life and a passion for work in the aircraft industry, she was accompanied by peers such as John Northrop (company), Andrew Viterbi (school), Arthur Nobile (school), John Silliker (school), Rangaswamy Srinivasa (school), and others.⁵

After receiving the Society of Women Engineers’ Achievement award, she was recognized by her peer-group for her contributions to rocketry and space. She was elected fellow of the American Institution for Aeronautics and Astronautics.³.

In the words of Mike Griffin, she was an exceptional aerospace engineer who should be remembered as a pioneer, “She truly represented the best of what American aerospace engineering and system development should be – a pioneering spirit coupled with a clear vision of what the future of an entire area of systems should be, with the ingenuity and genius necessary to make that vision a reality”.²

National Inventors Hall of Fame: Yvonne Brill


I decided there were so few women engineers that they were not about to make a rule to discriminate against one person and that proved to be perfectly correct. As long as you showed that you were capable and willing to do the work and not to try to get by some flimsy excuse, you were respected.

Cited in Magdolna Hargittai, Women Scientists: Reflections, Challenges, and Breaking Boundaries, New York, Oxford University Press, p.78.

I always remember there was a very old-line person, typical stodgy old-line person in charge of personnel. And his argument was, ‘How could a woman with three children ever get to work on time?’ Years later … he apologized to me and said I really had worked out very well.

Cited in Gannon, Megan (1 Apr.2013), “Pioneering Rocket Scientist Yvonne Brill Dies at 88”. URL: <> (last accessed 24 Oct. 2017)> (last accessed November 2017).

I combat the problem at a different angle than, I think, a man would have. I think this is generally true. Or taking another example, manufacturing. My daughter, who has a degree in mechanical engineering, is in manufacturing and, in general, women just know, intuitively, an easier way to put things together and make them work. They may not have been encouraged in mechanical things when they were young, but it certainly shouldn’t prohibit them from being able to do that work well.

Cited in Magdolna Hargittai, Women Scientists: Reflections, Challenges, and Breaking Boundaries, New York, Oxford University Press, p. 78.



Each of these extraordinary scientists, engineers, and investors is guided by a passion for innovation, fearlessness even as they explore the very frontiers of human knowledge, and a desire to make the world a better place. Their ingenuity inspires us all to reach higher and try harder, no matter how difficult the challenges we face.

Cited by Magdolna Hargittai, Women Scientists: Reflections, Challenges, and Breaking Boundaries; President Barack Obama words when announcing the 2011 recipients of the National Medal of Science and the National Medal of Technology and Innovation.



1980: The Diamond Superwoman Award by Harper’s Bazaar
1985: An elected fellow of the American Institution for Aeronautics and Astronautics
1986: The Society of Women Engineers’ Achievement Award
1999: An inductee into the Women in Technology International Hall of Fame
2001: The NASA Distinguished Public Service Medal
2002: The AIAA Wyld Propulsion Award
2009: The American Association of Engineering Societies John Fritz Medal
2010: An inductee into the National Inventors Hall of Fame
2011: The National Medal of Technology and Innovation


  1. Blashfield, Jean F. (1996), Women inventors, 3, Minneapolis, Capstone Press.
  2. Gannon, Megan (1. Apr 2013), “Pioneering Rocket Scientist Yvonne Brill Dies at 88”. URL: <> (last accessed 24 Oct. 2017).
  3. Hargittai, Magdolna (2015), Women Scientists: Reflection, Challenges, and Breaking Boundaries, New York, Oxford University Press.
  4. Labrecque, Ellen (2017), Yvonne Brill and Satellite Propulsion, Ann Arbor, Michigan, Cherry Lake Publishing.
  5. National Inventors Hall of Fame: Yvonne Brill. URL: <> (last accessed 24 Oct. 2017).
  6. Schreiber A., Barbara (2013), ”Yvonne Brill, Canadian-born American aerospace engineerrocket scientist”, Britannica Book of the Year. URL:<> (last accessed 24 Oct. 2017).
  7. Tietjen, Jill S. (2017), Women in Engineering and Science: Engineering Women: Re-visioning Women’s Scientific Achievements and Impacts, Switzerland, Springer Nature.


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