Green flash: High-speed infrared helps reveal safer hypergolic propellant Note to journalists: A video about the hypergolics research is available on YouTube. For a copy of the paper, please contact Kayla Wiles, Purdue News Service, at wiles5@purdue.edu or 765-494-2432. Photos, video and other multimedia of the “green flash” experiments are available via Google Drive. Journalists visiting campus should follow visitor health guidelines. WEST LAFAYETTE, Ind. — When SpaceX’s Crew Dragon capsule splashed down off the Florida coast in August following its first crewed mission, the two astronauts inside could not exit the capsule immediately. Technicians outside had to confirm there were no airborne vapors from hydrazine, a highly toxic fuel used by the vehicle’s hypergolic thrusters.