What is "castor-orbus"

The Castor-Orbus was a Castor 4 sounding rocket (research rocket designed to take measurements and perform scientific experiments during its flight) that was developed in 1992 by the Orbital Sciences Corporation (OSC) (United States). Launched three times in its five-year-long career from 1992 to 1997, the Castor-Orbus rocket launched successfully only once. It was first launched on October 16, 1992, while its final launch took place on October 4, 1997.

There were two Castor-Orbus models made, Castor-Orbus and Castor-Orbus 1.