Aerojet Rocketdyne is the latest company to become part of Stratolaunch Systems’ effort to develop a large air-launch system. The company announced Monday that it won a contract from Stratolaunch for six RL10C-1 engines, variants of the RL10 engines used on the upper stages of the Atlas V and Delta IV rocket. Those engines, which use liquid oxygen and liquid hydrogen propellants, will be used on the upper stage of Stratolauncher’s rocket, with two RL10’s per vehicle. The contract also includes an option for an additional six engines. Orbital Sciences is providing the lower stages of the rocket, using solid motors.
The announcement also includes some new nomenclature for Stratolaunch Systems’ vehicle, which typically has been called simply Stratolauncher. According to the Aerojet Rocketdyne press release, the overall launch system, both airplane and launch vehicle, is called the “Eagles Launch System,” while the rocket itself is called “Thunderbolt.” (The release does not indicate if the systems custom-built giant aircraft has its own distinct name.) Neither this nomenclature, nor the Aerojet Rocketdyne contract, is reflected on the Stratolaunch Systems website, where the latest press release is dated June 3, 2013.