Celestronaut: ISAP astronaut/cosmonaut/etc.
ISAP: International Space Administration Program, pronounced "Ee-sop."
Kookaburra IV: the spacecraft sent to rendezvous with the Sarterean spacecraft (as of yet unnamed) in Alpha Centauri A.
Sartereans: The intelligent species from the planet Sarter in contact with Earthlings, pronounced "Sar-ter-ray-ans."
TIC: Transgalactic Instantaneous Communicator, pronounced "tick."