ATK will provide the Castor 30XL, an upgraded second-stage motor for Orbital Science’s Taurus II commercial launch vehicle, under a $57m contract.

The Castor 30XL is a larger and higher-performance solid rocket motor with greater payload capability compared to the present Castor 30A, used on the current configuration of the Taurus II.

The Castor 30XL will be used after the first four flights of Taurus II are run on Castor 30A and Castor 30B.

Taurus II medium-class launch vehicle is due to conduct commercial cargo resupply missions to the International Space Station (ISS) for Nasa.