The first stage consists of two S200 solid motors, also known as Large Solid Boosters (LSB) attached to the core stage. Each booster is wide, long, and carries of propellant. The S200 booster uses an HTPB based propellant. It is the largest solid-fuel booster after the Space Shuttle SRBs and Ariane 5 SRBs. The flex nozzles can be vectored using electro-hydraulic actuators and are used for vehicle control during the initial ascent phase. These boosters burn for 130 seconds and produce an average thrust of and a peak thrust of each.