The name "Jet Propulsion Laboratory" dates to 1943. They do rockets. At least 2 years prior to that name change they had worked on JATO, which is "jet-assisted takeoff". The company Aerojet was founded in 1942, making solid-fuel rockets.
https://en.wikipedia.org/wiki/Jet_engine#Other_types_of_jet_...
The name "Jet Propulsion Laboratory" dates to 1943. They do rockets. At least 2 years prior to that name change they had worked on JATO, which is "jet-assisted takeoff". The company Aerojet was founded in 1942, making solid-fuel rockets.