Click on Picture to enlarge The New X-23

 

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The PRIME (Precision Recovery Including Maneuvering Entry) project ws the second part of the START (Spacecraft Technology and Advanced Reentry Test) program. It had the dual objective of testing advances in space hardware and further exploring the development of manned and unmanned lifting body vehicles. Four XV-5D [ed. note: also known as the X-23] vehicles were built by the Martin Company to fulfill the objectives of the PRIME program. Outside earth's atmosphere the SV-5D was maneuvered by the release of high pressure nitrogen through jet thrusters. When the craft re-entered the atmosphere its control system automatically swithced to airplane-type flaps for pitch and roll control.

On a typical flight, the unmanned XV-5D was launched by an Atlas booster from Vandenburg AFB, California. At the high point in its flight path, the Atlas pitched downward while its rocket continued accelerating it to speeds nearly as great as those of the spacecraft re-entering the earth's atmosphere. The lifting body's inertial guidance system directed it to a preselected recover point. Three PRIME test flights were made, the first on December 21, 1966, and the last on April 19, 1967. A scheduled fourth flight was cancelled due to the successes of the previous tests.

 

The X-24A

 

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The X-24A

The X-24A was the Martin Corporation's subsonic test version of the US Air Force's preferred manned lifting body configuration. This was flat-bellied with canted vertical stabilizers at the end of the rounded upper body. It was of the same configuration as the subscale X-23 Prime vehicle tested on suborbital flights in 1966 - 1967. Martin and the USAF hoped it would lead to a larger Titan III-launched manned orbital ferry vehicle (cinematically embodies in the 'XRV' spacecraft in the 1969 film version of Martin Caidin's novel 'Marooned').

The X-24A was air-launched from an NB-52 carrier aircraft and reached a maximum speed of Mach 1.6 and a maximum altitude of 21,800 m during its flight test. The X-24A handled well as a glider, but in powered flight it exhibited a nose-up trim change that prevented it from flying at low angles of attack. Air Force interest then focused on 'high fineness lifting body' configurations and the X-24A airframe was converted to the X-24B configuration. The X-24A was also known as the SV-5P configuration. Two nearly identical SV-5J's, equipped with a Pratt and Whitney J60-PW-1 jet engine of 1360 kgf, were built but never flown.

Total Length: 7.5 m. Maximum Diameter: 4.2 m. Total Mass: 5,192 kg. Total Propellants: 2,480 kg. Primary Engine Thrust: 3,845 kgf. Main Engine Propellants: LOX/Alcohol. Main Engine Isp: 225 sec. Total spacecraft delta v: 1,300 m/s. Electrical System: Batteries.

 

The X-23 Prime

 

Type	Lifting body
Manufacturer	Martin Marietta
Maiden flight	21 December 1966
Retired	19 April 1967
Status	Out of service
Primary user	United States Air Force
Number built	3
Variants	Martin X-24

 

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Preserved X-23 PRIME at USAF Museum, Dayton, Ohio

The Martin Marietta X-23A PRIME (Precision Reentry Including Maneuvering Reentry) was a small lifting body re-entry vehicle tested by the United States Air Force in the mid-1960s. Unlike ASSET, primarily used for structural and heating research, the X-23 PRIME was developed to study the effects of maneuvering re-entry, including cross-range maneuvers up to 710 statute miles (1143 km) off the ballistic track.

 

The X-23 Design

Each X-23 was constructed from titanium, beryllium, stainless steel, and aluminum "where appropriate". The craft consisted of two sections—the aft main structure and a removable forward "glove section". The structure was completely covered with a Martin-developed ablative heat shield 20 to 70 mm (¾ to 2¾ inches) thick, though the nose cap was constructed of carbon-phenolic.

Aerodynamic control was provided by a pair of 12-inch (30 cm) square lower flaps, and fixed upper flaps and rudders. A nitrogen gas reaction control system was used outside the atmosphere. At Mach 2 a drogue bal lute deployed and slowed the vehicle's descent. As it deployed, its cable sliced the upper structure of the main equipment bay, allowing a 47-foot (16.4 m) recovery chute to deploy. It would then be recovered by a specially-equipped JC-130B Hercules.

 

Flight Testing

The first PRIME vehicle was launched from Vandenberg AFB on 21 December 1966 atop an Atlas launch vehicle. This mission simulated a low-earth orbit reentry with a zero cross-range. The ballute deployed at 99,850 feet (30.43 km), though the recovery parachute failed to completely deploy. The vehicle crashed into the Pacific.

The second was launched on 5 March 1967. This flight simulated a 654-mile (1053 km) cross range re-entry, and banking at hypersonic speeds. Several stringers on the main parachute failed to cut, preventing a successful recovery. It too was lost in the Pacific.

The final PRIME mission was flown on 19 April 1967, and simulated reentry from low-earth orbit with a 710 mile (1143 km) cross-range. This time, all systems performed perfectly, and the X-23 was successfully recovered. An inspection by a USAF-Martin team reported the craft "ready to fly again", although no later mission was carried out. The third X-23 is now on display at the National Museum of the United States Air Force at Wright-Patterson Ohio.

Specifications (X-23)

General characteristics

• Crew: None
• Length: 6 ft 9 in (2.07 m)
• Wingspan: 3 ft 10 in (1.16 m)
• Height: 2 ft 1 in (0.64 m)
• Loaded weight: 890 lb (405 kg)
• Powerplant: × Nitrogen-gas reaction control thrusters

Performance

• Maximum speed: Mach 25
• Range: 710 miles (1,143 km)
• Hypersonic L/D Ratio: 1:1

Wikipedia,

 

 

The X-23A PRIME

 Company- Martin Marietta
Type- Test ablative coatings, re-entry control surfaces, and lift body characteristics.
Goals- Test configurations, control systems, and ablative materials for hypersonic reentry vehicles.
Primary Testing Facility Research- Vandenberg AFB / Pacific Ocean
Dimensions- Span- 3 ft, 10 in; Length- 6 ft, 9 in; Height: 2 ft, 1 in
Max Speed- Mach 25 (16,500+ MPH)
Range- 710 miles
Max Altitude- 90 miles
Power Plant- Atlas ICBM and nitrogen-gas reaction control thrusters
Thrust- N/A
Weights- N/A
Payload- Loaded: 890 lbs
Flights- 3
Number of Prototypes Built- 4
Project Tenure- 1966-1967
Project Status- Cancelled

 

Information

 

Click on Picture to enlarge

X-23A PRIME

The Martin Marietta X-23A PRIME (Precision Reentry Including Maneuvering Reentry) was a small lifting body re-entry vehicle tested by the United States Air Force in the mid-1960s. Unlike ASSET, primarily used for structural and heating research, the X-23 PRIME was developed to study the effects of maneuvering re-entry, including cross range maneuvers up to 710 miles (1143 km) off the ballistic track.

Each X-23 was constructed from titanium, beryllium, stainless steel, and aluminum "where appropriate". The craft consisted of two sections - the aft main structure and a removable forward "glove section". The structure was completely covered with a Martin-developed ablative heat shield 20 to 70 mm (0.8 to 2.75 inches) thick, though the nose cap was constructed of Carbon-Phenolic.

Aerodynamic control was provided by a pair of 12-inch (30 cm) square lower flaps, and fixed upper flaps and rudders. A nitrogen gas reaction control system was used outside the atmosphere. At Mach 2 a drogue ballute deployed and slowed the vehicle's descent. As it deployed, its cable sliced the upper structure of the main equipment bay, allowing a 47-foot (16.4 m) recovery chute to deploy. It would then be recovered by a specially-equipped JC-130B Hercules.

The first PRIME vehicle was launched from Vandenberg AFB on 21 December 1966 atop an Atlas launch vehicle. This mission simulated a low-earth orbit reentry with a zero cross-range. The ballute deployed at 99,850 feet (30.43 km), though the recovery parachute failed to completely deploy. The vehicle crashed into the Pacific.

The second was launched on 5 March 1967. This flight simulated a 654-mile (1053 km) cross range re-entry, and banking at hypersonic speeds. Several stringers on the main parachute failed to cut, preventing a successful recovery. It too was lost in the Pacific.

The final PRIME mission was flown on 19 April 1967, and simulated reentry from low-earth orbit with a 710 mile (1143 km) cross-range. This time, all systems performed perfectly, and the X-23 was successfully recovered. An inspection by a USAF-Martin team reported the craft "ready to fly again", although no later mission was carried out. The third X-23 is now on display at the National Museum of the United States Air Force at Wright-Patterson Ohio.

 

 

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