Martin-Marietta X-24

infobox Aircraft
name = X-24
type = Lifting body
manufacturer = Martin Marietta

---

caption = The X-24B, the only "racehorse" lifting body to be flown.
designer =
first flight = 17 April 1969
introduced =
retired = 26 November 1975
produced =
number built = 1
status = Out of service
unit cost =
primary user = U.S.Air Force
NASA
more users =
developed from = X-23 PRIME
variants with their own articles =The X-24 was an experimental US aircraft developed from a joint USAF-NASA program named PILOT (1963-1975). It was designed and built to test lifting body concepts, experimenting with the concept of unpowered reentry and landing, later used by the Space Shuttle.cite book|last=Reed|first=R. Dale|coauthors=Darlene Lister|year=2002|title=Wingless Flight: The Lifting Body Story|edition=|publisher=University Press of Kentucky|location=|id=ISBN 0813190266 " [http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980169231_1998082126.pdf also available as a PDF file] .]

X-24A Development

The X-24 was one of a group of lifting bodies flown by the NASA Flight Research Center (now Dryden Flight Research Center) in a joint program with the U.S. Air Force at Edwards Air Force Base in California from 1963 to 1975. The lifting bodies were used to demonstrate the ability of pilots to maneuver and safely land wingless vehicles designed to fly back to Earth from space and be landed like an airplane at a predetermined site.

Lifting bodies’ aerodynamic lift, essential to flight in the atmosphere, was obtained from their shape. The addition of fins and control surfaces allowed the pilots to stabilize and control the vehicles and regulate their flight paths.

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 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 Operational History

The X-24A was flown 28 times in the program that, like the HL-10, validated the concept that a Space Shuttle vehicle could be landed unpowered. The fastest speed achieved by the X-24A was 1,036 miles per hour (1667 km/h or Mach 1.6). Its maximum altitude was 71,400 feet (21.8 km) . It was powered by an XLR-11 rocket engine with a maximum theoretical vacuum thrust of 8,480 pounds force (37.7 kN).

The X-24A was modified into the more stable X-24B with an entirely different shape in 1972. The bulbous shape of the X-24A was converted into a "flying flatiron" shape with a rounded top, flat bottom, and double delta platform that ended in a pointed nose. It was the basis for the Martin SV-5J. The X-24A shape was later borrowed for the X-38 Crew Return Vehicle (CRV) technology demonstrator for the International Space Station.

; X-24A pilots
* Jerauld R. Gentry - 13 flights
* John A. Manke - 12 flights
* Cecil W. Powell - 3 flights

X-24B Development

The X-24B's design evolved from a family of potential reentry shapes, each with higher lift-to-drag ratios, proposed by the Air Force Flight Dynamics Laboratory. To reduce the costs of constructing a research vehicle, the Air Force returned the X-24A to the Martin Marietta Corporation (as Martin Aircraft Company became after a merger) for modifications that converted its bulbous shape into one resembling a "flying flatiron" -- rounded top, flat bottom, and a double delta planform that ended in a pointed nose.

First to fly the X-24B was John Manke, a glide flight on 1 August 1973. He was also the pilot on the first powered mission 15 November 1973.

X-24B Operational History

The X-24B demonstrated that accurate unpowered reentry vehicle landings were operationally feasible. Top speed achieved by the X-24B was 1,164 mph (1873 km/h) and the highest altitude it reached was 74,130 feet (22.59 km). The pilot on the last powered flight of the X-24B was Bill Dana, who also flew the last X-15 flight about seven years earlier.

Among the final flights with the X-24B were two precise landings on the main concrete runway at Edwards which showed that accurate unpowered reentry vehicle landings were operationally feasible. These missions were flown by Manke and Air Force Maj. Mike Love, and represented the final milestone in a program that helped write the flight plan for today's Space Shuttle program.

The X-24B was the last aircraft to fly in Dryden's Lifting Body program. The X-24B was flown 36 times.

The X-24B is on public display at the National Museum of the United States Air Force, Wright-Patterson AFB, Ohio.

;X-24B pilots
* John A. Manke - 16 flights
* Michael V. Love - 12 flights
* William H. Dana - 2 flights
* Einar K. Enevoldson - 2 flights
* Thomas C. McMurtry - 2 flights
* Francis Scobee - 2 flights

X-24C

There were a variety of "X-24C" proposals floated between 1972 and 1978. Perhaps the most notable was a Lockheed Skunk Works design, which would use scramjets to reach a top speed of Mach 8.cite book|last=Jenkins|first=Dennis R.|coauthors=|year=2001|title=Space Shuttle: The History of the National Space Transportation System|edition=3rd edition|publisher=Voyageur Press|location=|id=ISBN 0-9633974-5-1]

V-5J

Martin (-Marietta) SV-5 (X-23{SV-5D} PRIME, X-24{SV-5P} PILOT, SV-5J)

The Martin SV-5 was the model number, derived from the designation given to the shape of the lifting body, for the X-23 & X-24 Lifting Body research programmes.

The SV-5D was the Model number of the X-23A Prime approx. 1/3 Scale X-24 re-entry vehicle. q.v.

The SV-5P was the model number for the X-24A rocket powered lifting body research aircraft. q.v.

On their own initiative, Martin designed and built two examples of the SV-5J. The SV-5J was a jet-powered version of the Rocket powered X-24A. Martin also manufactured a full-scale, unfly-able, mock-up of the SV-5J. (Confusion over number built may be due to the mock-up being included in the production list).

The SV-5J had Identical dimensions to the X-24 A, but was powered by a single Pratt and Whitney J60-PW-1 jet engine of 1360 kgf, in place of the X-24A's Reaction Motors XLR-11-RM-13 rocket engine.

Martin were unable to convince Milt Thompson to fly the SV-5J, even after offering a 20,000$ bonus. Both examples remained unflown.

One of the SV-5J's was converted to represent the X-24A, for display at the U.S. Air Force Museum at the National Museum of the United States Air Force, Wright-Patterson AFB, Ohio.q.v.

The unfly-able mock-up ended up in Hollywood and was used for several movies as a space-ship prop.

Some verification can be had from this source:-

Ref: 1. Wingless Flight By R. Dale Reed, Darlene Lister, Chuck Yeager.

erial number

* 66-13551
** X-24A, 28 free flights; 10 unpowered, 18 powered
** X-24B, 36 free flights; 12 unpowered, 24 powered

pecifications

X-24A

aircraft specifications
plane or copter?=plane
jet or prop?=jet
ref=
crew= one pilot
capacity=
payload main=
payload alt=
length main= 24 ft 6 in
length alt= 7.47 m
span main= 11 ft 6 in
span alt= 3.51 m
height main= 9 ft 7 in
height alt= 2.92 m
area main= 195 ft²
area alt= 18.1 m²
airfoil=
empty weight main= 6,360 lb
empty weight alt= 2,885 kg
loaded weight main= 10,700 lb
loaded weight alt= 4,853 kg
useful load main=
useful load alt=
max takeoff weight main= 11,447 lb
max takeoff weight alt= 5,192 kg
more general=
engine (jet)= Reaction Motors
type of jet=Upgraded XLR-11 four-chamber rocket engine
number of jets=1
thrust main= 8,480 lbf
thrust alt= 37.7 kN
thrust original=
afterburning thrust main=
afterburning thrust alt=
max speed main=1,036 mph
max speed alt= 1,667 km/h
cruise speed main=
cruise speed alt=
stall speed main=
stall speed alt=
never exceed speed main=
never exceed speed alt=
range main= 45 miles
range alt=72 km
ceiling main= 71,407 ft
ceiling alt= 21,763 m
climb rate main=
climb rate alt=
loading main=59 lb/ft²
loading alt=288 kg/m²
thrust/weight=0.70
power/mass main=
power/mass alt=
more performance=
armament=
avionics=

X-24B

aircraft specifications
plane or copter?=plane
jet or prop?=jet
ref=
crew= one pilot
capacity=
payload main=
payload alt=
length main= 37 ft 6 in
length alt= 11.43 m
span main= 19 ft 0 in
span alt= 5.79 m
height main= 9 ft 7 in
height alt= 2.92 m
area main= 330 ft²
area alt= 30.7 m²
airfoil=
empty weight main= 8,500 lb
empty weight alt= 3,855 kg
loaded weight main= 11,800 lb
loaded weight alt= 5,350 kg
useful load main=
useful load alt=
max takeoff weight main= 13,800 lb
max takeoff weight alt= 6,260 kg
more general=
engine (jet)=Reaction Motors
type of jet=Upgraded XLR-11 four-chamber rocket engine
number of jets=1
thrust main= 8,480 lbf
thrust alt= 37.7 KN
thrust original=
afterburning thrust main=
afterburning thrust alt=
max speed main=1,164 mph
max speed alt= 1,873 km/h
cruise speed main=
cruise speed alt=
stall speed main=
stall speed alt=
never exceed speed main=
never exceed speed alt=
range main= 45 miles
range alt=72 km
ceiling main= 74,130 ft
ceiling alt= 22.59 km
climb rate main=
climb rate alt= 42 lb/ft²
loading main=205 kg/m²
loading alt=
thrust/weight= 0.71
power/mass main=
power/mass alt=
more performance=
armament=
avionics=

ee also

aircontent
related=
* X-23 PRIME
similar aircraft=
* M2-F1
* M2-F2
* M2-F3
* HL-10
* Space Shuttle
sequence=
X-21 -
X-22 -
X-23 -X-24 -
X-25 -
X-26 -
X-27
lists=
* List of experimental aircraft
see also=

References

External links

* [http://www.dfrc.nasa.gov/gallery/photo/X-24/ NASA Dryden X-24 Photo Collection]