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 at Hypersonic speed, speeds greater than Mach 5, a speed where Dissociation (chemistry), dissociation of air begins to become significant and high heat loads exist. Spe ...

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 federal government of the United States, US federal government responsible for the United States ...

and

United States Air Force The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its ori ...

(USAF) organization National Hypersonic Flight Research Facility (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, highly classified research and developme ...

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 X-24C-L301 was a scaled-up derivative of the Martin X-24C project that was to have been a hypersonic follow-on to the

X-15 The North American X-15 is a Hypersonic speed, hypersonic rocket-powered aircraft which was operated by the United States Air Force and the National Aeronautics and Space Administration (NASA) as part of the List of X-planes, X-plane series of ...

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 Non-ballistic atmospheric entry is a class of atmospheric entry trajectories that follow a non-ballistic trajectory by employing aerodynamic lift in the high upper atmosphere. It includes trajectories such as skip and glide. Skip is a flight tr ...

maneuvers for long range missions. The vehicle would have 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 b ...

propulsion as well as a rocket engine, carrying both

RP-1 RP-1 (Rocket Propellant-1 or Refined Petroleum-1) and similar fuels like RG-1 and T-1 are highly refined kerosene formulations used as rocket fuel. Liquid-fueled rockets that use RP-1 as fuel are known as kerolox rockets. In their engines, RP- ...

and LH2 propellant as well as on-board stores of LOX. The X-24C-L301 languished at the design phase when the X-24C project was shelved in September 1977 due a tight NASA budget.

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 Lox is a fillet of brined salmon, which may be smoked. Lox is frequently served on a bagel with cream cheese, and often garnished with tomato, onion, cucumber, and capers. Etymology The American English word ''lox'' is a borrowing of Yiddi ...

, 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 (designation X-23) is a fictional superheroine appearing in American comic books published by Marvel Comics, commonly in association with Wolverine (character), Wolverine, whose codename she has also used, and the X-Men. The characte ...

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 Aircraft with retractable tricycle landing gear