Antares 2

Antares 2 (X-259) was an American solid rocket engine stage and engine built by Hercules/ABL / Thiokol.^[1][2][3] It was used from the mid-1960s to 1995, in the Scout and Strypi family of rockets,^[4][5] and on the Project FIRE Velocity Packages.^[6] It burned solid propellant – the stage was also the engine's fuel chamber - and was used about 96 times.^[1]

Antares X-259 rocket stage

Project FIRE Velocity Package diagram, with the Antares X-259 visible.

Details

Basic details of the X-259 engine:^[1]

• Thrust: 93.10 kN (20,930 lb_f)
• Gross mass: 1,400 kg (3,100 lb)
• Unfuelled mass: 300 kg (660 lb)
• Specific impulse: 293 s.
• Specific impulse sea level: 233 s.
• Burn time: 36 s.
• Height: 2.9 m (9.5 ft)
• Diameter: 0.78 m (2.6 ft)

Variants

There were various variants:^[1][4]

• Antares 2 was used on Scout X-2 1C, B 2A, B-1 F, D-1 F and D; Strypi Tomahawk, XI and IX; SPARTA and Athena H
• Antares 2A was used on Scout-X2, X2B, X2M, X3, X3A, X3C, X3M, X4, X4A, X5C, A, A1, B, B1, C, and D1; and Project FIRE;

• Antares 2B was used on Scout-A2, B2, E1 and Scout-F1.