Model: Leopard. Test vehicle. Family: Rook. Other Family: Retired. Country: UK. Status: Retired 1962.

Two stage aerodynamic test vehicle consisting of 1 x Rook + 1 x Gosling. Developed from the basic Rook vehicle for tests requiring higher velocities.

The Rook motor was 0.43 m in diameter and 5.28 m long. It contained a case-bonded charge of 846 kg of non-aluminized plastic propellant giving a total impulse of 1760 kN-seconds in 5.6 seconds; with a maximum thrust of 323 kN and a specific impulse of 213 seconds. The motor was capable of withstanding the 40g acceleration it provided during firing. It was employed as the first propulsion stage of the Leopard and Jaguar (Jabiru) supersonic test vehicles, and by itself in single-stage test applications.

Four Gosling motors with canted nozzles were used as boosters for the British Thunderbird ramjet surface-to-air missile. 664 Gosling IV motors were supplied for the Thunderbird, Bloodhound, and Seaslug Mark II missiles.

For sounding rocket applications, motors were supplied with in-line nozzles. The Gosling IV had an a all up mass of 256 kg, was 3.00 m long, and 0.254 m in diameter. It produced an average thrust of 124 kN over its 3.15 second burn time.

Manufacturer: RAE. Launches: 11. Failures: 3. Success Rate: 72.73%. First Launch Date: 1959-10-22. Last Launch Date: 1962-11-30. Launch data is: complete. Apogee: 20 km (12 mi). Liftoff Thrust: 0 N ( lbf). Total Mass: 1,500 kg (3,300 lb). Core Diameter: 0.44 m (1.44 ft). Total Length: 6.00 m (19.60 ft).

• Stage1: 1 x Rook. Gross Mass: 1,057 kg (2,330 lb). Empty Mass: 186 kg (410 lb). Motor: 1 x Rook. Thrust (vac): 300.000 kN (67,440 lbf). Burn time: 5.50 sec. Length: 5.40 m (17.70 ft). Diameter: 0.44 m (1.44 ft). Propellants: Solid.

• Stage2: 1 x Cockatoo-1. Gross Mass: 200 kg (440 lb). Motor: 1 x Gosling. Thrust (vac): 152.000 kN (34,170 lbf). Burn time: 2.50 sec. Length: 3.30 m (10.80 ft). Diameter: 0.26 m (0.85 ft). Propellants: Solid.

1959 October 22 - Aberporth -. Leopard L2B FAILURE: Failure. Test mission Agency: RAE. Apogee: 0 km ( mi).

1960 January 2 - Aberporth -. Leopard L1B FAILURE: Failure. Test mission Agency: RAE. Apogee: 0 km ( mi).

1960 January 7 - Aberporth -. Leopard L1C FAILURE: Failure. Test mission Agency: RAE. Apogee: 0 km ( mi).

1960 February 23 - Aberporth -. Leopard L1D Test mission Agency: RAE. Apogee: 20 km (12 mi).

1960 April 29 - Aberporth -. Leopard L1E Test mission Agency: RAE. Apogee: 20 km (12 mi).

1960 April 29 - Aberporth -. Leopard L1F Test mission Agency: RAE. Apogee: 20 km (12 mi).

1960 May 5 - Aberporth -. Leopard L1G Test mission Agency: RAE. Apogee: 20 km (12 mi).

1960 May 27 - Aberporth -. Leopard L3 Test mission Agency: RAE. Apogee: 20 km (12 mi).

1960 July 12 - Aberporth -. Leopard L4 Test mission Agency: RAE. Apogee: 20 km (12 mi).

1961 July 20 - Aberporth -. Leopard L5 Test mission Agency: RAE. Apogee: 20 km (12 mi).

1962 November 30 - Aberporth -. Leopard L6 Leopard 6 test Agency: RAE. Apogee: 20 km (12 mi).