Monica Jacinto

Monica Jacinto Reza (born December 30, 1964) is an American metallurgist and materials engineer. In the mid-1990s, she co-invented Mondaloy, a nickel-based superalloy used in rocket engines, while working at Rocketdyne.

On June 22, 2025, she disappeared while hiking in the Angeles National Forest. Her disappearance is under investigation as part of the White House probe into the missing scientists conspiracy theory.

Early life and education She earned a Bachelor of Science in metallurgical engineering from Columbia University. She later attended the University of California, Los Angeles (UCLA), earning a Master of Science in materials engineering in 1997. developed Mondaloy, a nickel-based superalloy that withstands high-pressure, high-temperature gaseous oxygen without combusting. The material does not require protective coatings and maintains structural strength at extreme operating conditions, allowing rocket engine components to be lighter and more reliable.

In 1999, Reza collaborated with the Air Force Research Laboratory (AFRL) as part of a cost-sharing program to scale up production and refine processing methods for Mondaloy. NASA also funded research into the alloy in the early 2000s for potential use in large oxygen-rich booster engines. The alloy was eventually used in approximately 12 components of Aerojet Rocketdyne's AR1 engine and the Hydrocarbon Boost Technology Demonstrator. In 2004, while working at Boeing as an associate technical fellow, Reza received the inaugural Luminary Award from the Hispanic Engineer National Achievement Awards Corporation (HENAAC), recognizing her contributions to the Hispanic technical community and her work "inspiring youth to pursue engineering and technical careers". In 2026, a House Oversight Committee press release cited unconfirmed public reporting that Reza had worked in a materials‑processing role at NASA’s Jet Propulsion Laboratory. +Patents application for Jacinto

Her disappearance is under investigation as part of a White House probe into people with high government clearance and scientists who have died or gone missing in recent years, including retired Air Force major general Neil McCasland, Caltech astronomer Carl Grillmair, and MIT fusion scientist Nuno Loureiro, among others.