The 4AXL version, extended by 2.44 mm, was first tested May 1992. Its 30% performance increase would improve performance of vehicles, such as Atlas and Conestoga. 4AXL was combined with 4B's TVC system to create the stage 1 motor for CTA's ORBEX small launcher.. Length: 12.279 m with nose-cone adapter, 13.711 m with nose-cone. Diameter: 1.0185 m. Propellant Type: TP-H8299 HTPB Polymer, 20% Al, and 68% AP. Propellant Shape: forward cylindrical perforate with seven aft longitudinal slots. Propellant Mass Fraction: 0.884 ground ignited strap-on. Burn Time: 60.1 sec. Thrust (kN, vac): 599.81 average with 700.5 maximum. Isp: 269.2 sec vacuum. Itotal: 34.679 Mns vacuum. Pressure: 41.70 atm average with a maximum of 54.42 atm MEOP. Nozzle Throat Diameter: 318.8 mm. Nozzle Length: 1216.8 mm. Nozzle Exit Diameter: 937.3 mm. Nozzle Materials: 4130 steel with graphite phenolic throat insert, and a carbon phenolic exit cone. Casing Material: AISI 4130 steel 0.28 mm thick. Igniter Type: TX544 (>500 units flown successfully) forward internal pyrogen, with 2.45 kg TP-H8027 propellant that is cartridge loaded. Specific impulse with 15:1 nozzle 382.4 seconds.
Chamber Pressure: 42.30 bar. Area Ratio: 8.64. Propellant Formulation: HTPB.
AKA: Castor 4AXL; TX-780XL.
Status: In production.
Gross mass: 14,851 kg (32,740 lb).
Unfuelled mass: 1,723 kg (3,798 lb).
Height: 12.28 m (40.29 ft).
Diameter: 1.02 m (3.34 ft).
Thrust: 599.80 kN (134,840 lbf).
Specific impulse: 269 s.
Burn time: 60 s.
Number: 40 .