Agena
[uh-jee-nuh]
noun Rocketry.
a U.S. upper stage, with a restartable liquid-propellant engine, used with various booster stages to launch satellites into orbit around the earth and send probes to the moon and planets: also used as a docking target in the Gemini program.
Dictionary.com Unabridged
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019