Lockheed L-301 (sometimes called the X-24C, though this designation was never officially assigned) was an experimental air-breathing

hypersonic aircraft Hypersonic flight is flight through the atmosphere below altitudes of about 90 km at speeds greater than Mach 5, a speed where dissociation of air begins to become significant and high heat loads exist. Speeds of Mach 25+ have been achiev ...

project. It was developed by the

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...

and

United States Air Force The United States Air Force (USAF) is the Aerial warfare, air military branch, service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part ...

(USAF) organization National Hypersonic Flight Research Facilityhttps://books.google.com/books?id=DUkl5bH6k6EC&pg=PA98&lpg=PA98&dq=National+Hypersonic+Research+Facility+x-15+x-24c&source=bl&ots=Ubvm4kazo1&sig=16Y5rv1y8HLZX8fy8mHZGmDBev4&hl=en&ei=7exrSujtNpLWM4a5tPkG&sa=X&oi=book_result&ct=result&resnum=3 ockheed Secret Projects by Dennis R. Jenkins/ref> (NHFRF or NHRF), with

Skunk Works Skunk Works is an official pseudonym for Lockheed Martin's Advanced Development Programs (ADP), formerly called Lockheed Advanced Development Projects. It is responsible for a number of aircraft designs, beginning with the P-38 Lightning in 1 ...

as the prime contractor. In January 1977, the program was "tentatively scheduled to operate two vehicles for eight years and to conduct 100 flights per vehicle." ONFIGURATION DEVELOPMENT STUDY OF THE X-24C HYPERSONIC RESEARCH AIRPLANE - PHASE II/ref> NASA discontinued work on L-301 and NHRF in September 1977 due to budget constraints and lack of need.

Development

The L-301 HGV was intended to be a follow-on to the

X-15 The North American X-15 is a hypersonic rocket-powered aircraft. It was operated by the United States Air Force and the National Aeronautics and Space Administration as part of the X-plane series of experimental aircraft. The X-15 set spee ...

and X-24 (specifically the X-24B) programs, to take lessons learned from both and integrate them into an airframe capable of at least reaching Mach 8 and engaging in hypersonic skip-glide maneuvers for long range missions. While the NASA program, one of several to use the tentative X-24C designator, was ostensibly canceled in 1977, it was only canceled at the time because of USAF disclosures of duplicate black programs with the same contractors for similar vehicles. The vehicle used both air breathing ram or

scramjet A scramjet (supersonic combustion ramjet) is a variant of a ramjet airbreathing jet engine in which combustion takes place in supersonic airflow. As in ramjets, a scramjet relies on high vehicle speed to compress the incoming air forcefully ...

propulsion as well as a rocket engine, carrying both

RP-1 RP-1 (alternatively, Rocket Propellant-1 or Refined Petroleum-1) is a highly refined form of kerosene outwardly similar to jet fuel, used as rocket fuel. RP-1 provides a lower specific impulse than liquid hydrogen (LH2), but is cheaper, is s ...

and LH2 propellant as well as on-board stores of LOX. Drawings and mission profiles are available from the NASA website.

Design

Propulsion

Originally intended to carry the same XLR-99 engine used by the X-15, the primary engine was changed to the LR-105, which was the sustainer engine used on the Atlas launcher. This rocket engine, burning

and

LOX Liquid oxygen—abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries—is the liquid form of molecular oxygen. It was used as the oxidizer in the first liquid-fueled rocket invented in 1926 by Robert H. Goddard, an appli ...

, was intended to accelerate the X-24C to hypersonic speeds in order to ignite the hydrogen fueled, air breathing ram/

mounted in the belly of the airframe with which it would attain cruise speeds of at least Mach 6 and peak velocities of Mach 8+ at altitudes of or more. As such, this vehicle was plainly not intended to reach orbit.

Airframe

Design of the aircraft in various wind tunnel models and contractor drawings seems to follow variations of the FDL-5 and FDL-8 lifting body shapes originally developed by the USAF Flight Dynamics Laboratory in the 1950s, which were used in the earlier

X-23 Laura Kinney (born X-23; Pseudonym, codename Wolverine (character), Wolverine) is a fictional superhero appearing in media (communication), media published by Marvel Entertainment, most commonly in association with the X-Men. The character was cr ...

and X-24A/B programs. With a radically swept delta wing, and 2, 3, or 4 vertical stabilizers, as well as several body flaps (depending on the model), the vehicle did not lack for control surfaces. The vehicle measured long, wingspan, and height. Various drawings show a payload bay long and perhaps diameter.NASA.gov
/ref>

References

External links

* Operators’ reference drawin

Encyclopedia Astronautica

Nasa Archives- X-24C Phase 3
{{US experimental aircraft Cancelled military aircraft projects of the United States Lifting bodies L-0301 Crewed spacecraft Hypersonic aircraft Parasite aircraft Rocket-powered aircraft Scramjet-powered aircraft Spaceplanes Cancelled spacecraft