Pyrios is an advanced Liquid rocket booster concept proposed in 2012 by Dynetics for use on NASA's Space Launch System heavy-lift launch vehicle.
Pyrios was intended to use the RP-1/LOX F-1B, a modernized version of the F-1A engine built by Aerojet Rocketdyne.
Dynetics is now performing tests on engine components pulled from storage.
Pyrios was intended to use the same attachment points as the five-segment SRBs[1] The name is derived from Greek mythology.
Pyrois was a horse that pulled sun god Helios’ chariot.