The four stage Taurus launch vehicle uses the same Orion solid motor combination used by its smaller cousin, the Pegasus, stacked on top of a larger Castor 120 solid motor.  The vehicle, which is 90 feet tall and weights between 152,000 lb and 223,000 lb at ignition, is designed to be easily transportable and launched from "austere" launch sites.  The vehicle has been flown a total of three times, beginning with its maiden launch in 1994, and was designed to extend Orbital's ability to launch small and Med-Lite satellites.

Four variants of the Taurus launch vehicle exist.  The smallest version, known as the ARPA Taurus, uses a Peace Keeper first stage instead of a Castor 120 motor.  Of the three Taurus launches, two have been ARPA Taurus configurations.  The standard Taurus, which has flown once, uses a Castor 120 first stage and a slightly larger Orion 50S-G second stage.  The Taurus XL uses the Pegasus XL rocket motors (Orion 50S-XL and Orion 50XL) and is considered a development stage launch vehicle.  The largest Taurus variant, the Taurus XLS, is a study phase vehicle that adds two Castor IVB solid rocket boosters to the Taurus XL to improve payload by 40% over the standard Taurus.  For all Taurus configurations, satellite delivery to a GTO orbit can be achieved with the addition of a Star 37FM perigee kick motor.