X-24A rocketplane

USA

Description:

The X-24A/SV-5P represented the low-speed end of the test spectrum for the START program that had also tested the X-23A. The X-24A was used in project PILOT (piloted low-speed tests, 1963-1975). The rocket-powered X-24A was specifically designed to explore the low-speed flight characteristics of a maneuverable lifting-body design. The design was essentially identical to the SV-5D used in project PRIME as the X-23A, allowing both ends of the flight spectrum to be tested on the same shape. The X-24A decisively demonstrated that lifting-bodies could consistently make precision landings on to a hard runway, proving the concept for the future Space Shuttle.
Only a single X-24A was manufactured, but two extremely similar jet-powered SV-5Js were also built. The SV-5Js were to be powered by a single J60 turbojet engine and used as trainers to introduce pilots to the low-speed handling characteristics of lifting-bodies, but in the end neither aircraft ever flew. One of the SV-5Js is on display at the Air Force Academy near Colorado Springs, Colorado, while the other has been superficially modified into an X-24A and is on display at the Air Force Museum. The X-24A itself was heavily modified to become the X-24B.
The X-24 was drop launched from a modified B-52 Stratofortress at high altitudes before igniting its rocket engine; after expending its rocket fuel, the pilot would glide the X-24 to an unpowered landing.
The X-24 (Model SV-5P) was built by Martin Marietta and flown from Edwards AFB, California. The X-24A was the fourth lifting body design to fly; it followed the NASA M2-F1 in 1964, the Northrop HL-10 in (1966), the Northrop M2-F2 in 1968 and preceded the Northrop M2-F3 (1970).
The X-24A was a fat, short teardrop shape with vertical fins for control. It made its first, unpowered, glide flight on April 17, 1969 with Air Force Maj. Jerauld R. Gentry at the controls. Gentry also piloted its first powered flight on March 19, 1970. The craft was taken to around 45,000 feet (13.7 km) by a modified B-52 and then drop launched, then either glided down or used its rocket engine to ascend to higher altitudes before gliding down. The X-24A was flown 28 times at speeds up to 1,036 mph (1,667 km/h) and altitudes up to 71,400 feet (21.8 km).
X-24A pilots:
- Jerauld R. Gentry – 13 flights
- John A. Manke – 12 flights
- Cecil W. Powell – 3 flights
Serial number: 66-13551
28 free flights: 10 umpowered, 18 powered.

Martin Marietta X-24A

Technical Data:

Manufacturer:	Martin Marietta Corporation
Operator:	USAF, NASA
Length :	24 ft 6 in (7.47 m)
Wingspan:	11 ft 6 in (3.51 m)
Heigh:	9 ft 7 in (2.92 m)
Wing area:	195 ft² (18.1 m²)
Empty weight:	6,360 lb (2,885 kg)
Loaded weight:	10,700 lb (4,853 kg)
Max takeoff weight:	11,447 lb (5,192 kg)
Crew:	one pilot

Power:	1 × Reaction Motors XLR-11rs four-chamber rocket engine, 8,480 lbf (37.7 kN)
Thrust:
Max speedt:	Mach 1.35 (1,667 km/h or 1,036 mph)
Range:	45 miles (72 km)
Service ceiling:	71,407 ft (21,763 m)
Wing loading:	59 lb/ft² (288 kg/m²)
First Flight	17 April 1969
Last Flight	4 June 1971
Total Flights	28
Fastest Flight	Mach 1.60 (1,036 mph)
Highest Flight	71,400 feet