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