Student Features

X-43A Being Readied for Flight
Picture of Hyper X Plane
In Phase I of the Hyper-X Program, Three 12-Foot-Long, Unpiloted Aircraft Designated X-43A, Will Fly Up to Ten Times the Speed of Sound to Demonstrate "Air-Breathing" Engine Technologies. Each High-Flying Experimental Aircraft Will Fly Once Within a Test Range Off the Southern California Coast.
The NASA multi-year experimental hypersonic ground and flight test program, called Hyper-X, will demonstrate "air-breathing" engine technologies that promise to increase payload capacity – or reduce vehicle size for the same payload – for future hypersonic aircraft and/or reusable space launch vehicles. Built around the program’s X-43 research vehicle, the first flight in this technology demonstration program took place on June 2, 2001. It was unsuccessful, due to a rocket booster failure. It was planned to be the first time a non-rocket, air-breathing scramjet (supersonic-combustion ramjet) engine has powered a vehicle in flight at hypersonic speeds – speeds above Mach 5 or five times the speed of sound. This is equivalent to about one mile per second or approximately 3,600 miles per hour at sea level and far faster than any air-breathing aircraft has ever flown.

As envisioned, payload capacity will be increased by discarding the heavy oxygen and associated tanks that rockets must carry by using a propulsion system that uses the oxygen in the atmosphere as the vehicle flies at many times the speed of sound. Hydrogen will fuel the program’s research vehicles, but it requires oxygen from the atmosphere to burn.

Langley & Dryden – A Joint Effort

The Hyper-X Phase I is a NASA Aeronautics and Space Technology Enterprise program being conducted jointly by the Langley Research Center, Hampton, Va., and the Dryden Flight Research Center, Edwards, Calif. Langley is the lead center and is responsible for hypersonic technology development. Dryden is responsible for flight research.

Phase I is a six-year, approximately $215 million program to flight-validate scramjet propulsion, hypersonic aerodynamics and design methods. Planning for follow-on Mach 5 through 7 flights of a slightly larger X-43 powered by an Air Force Research Laboratory developed hydrocarbon-fueled scramjet is underway. This activity, which is a project under the Marshall Space Flight Center Advanced Space Transportation Program (ASTP), started in October 2001, and plans to fly in 2007.

Research Flights from Mach 7 - 10

A team led by A2I2 (formerly MicroCraft, Inc.) built three unpiloted X-43A research aircraft in support of Phase I.

Illustration of Hyper X Configuration
Hyper-X Vehicle Configuration
Research began with conceptual design and wind tunnel work in early 1996. The three liftingbody X-43A aircraft are identical in appearance but are engineered with slight differences simulating engine inlet variable geometry, generally a function of Mach number. Each vehicle is designed to fly once. The first and second vehicles have been designed to fly at Mach 7 and the third at Mach 10. The second flight is planned for summer 2003.

At Mach 10 – or 10 times the speed of sound – the 12-foot-long, 5-foot-wide aircraft will be traveling at about two miles per second (approximately 7,200 miles per hour at sea level). Speeds over Mach 5 are defined as "hypersonic."

Each X-43A will ride on an Orbital Sciences Corp. booster rocket which will be launched by the Dryden B-52. For each flight, the role of the booster is to accelerate the Hyper-X research vehicle to the test conditions at approximately 100,000 feet, where it will separate from the booster and fly under its own power and preprogrammed control.

Illustration of Hyper X Simplified Flight Trajectory
Each of the Hyper-X Research Vehicles Will Achieve Test Speed and Altitude with the Help of the NASA Dryden B-52 Aircraft and an Expendable Booster Rocket, as Shown in this Simplified Flight Trajectory.
The Hyper-X research vehicle will be separated from the booster rocket by two small pistons. Shortly after separation, the Hyper-X scramjet engine will operate for ten-plus seconds to demonstrate forward thrust in flight. When the scramjet engine test is complete, the vehicle will go into a high-speed maneuvering glide to collect up to six minutes of hypersonic aerodynamic data while flying to a mission completion point in the Naval Air Warfare Center Weapons Division Sea Range off the southern coast of California.

Vehicle and engine ground tests and analyses are being performed prior to each flight in order to reduce technical risk and to compare with flight test results. This included a spare flight engine which was mounted on a wind tunnel model that accurately represents the size and shape of the full-scale vehicle. The model was tested in Langley’s 8-Foot High Temperature Wind Tunnel to verify the ramjet/scramjet propulsion system operability and performance at Mach 7 flight conditions.

Picture of Hyper X Wind Tunnel Test
Wind Tunnel Tests Show Good Aerodynamic and Propulsion Performance for the Hyper-X configuration. Shown Here is a Mach 7 Test of the Full-Scale Model with Spare Flight Engine in Langley’s 8-Foot High Temperature Wind Tunnel.
First Scramjet Demo Top Goal

This challenging ground and flight research program will significantly expand the boundaries of airbreathing flight by being the first to fly a "scramjet" powered aircraft at hypersonic speeds.

Demonstrating the airframe-integrated ramjet/scramjet engine tops the list of program technology goals, followed by development of hypersonic aerodynamics data and validation of design tools and methods for air-breathing hypersonic vehicles.

A ramjet operates by subsonic combustion of fuel in a stream of air compressed by the forward speed of the aircraft itself, as opposed to a normal jet engine, in which the compressor section (the fan blades) compresses the air. Ramjets operate from about Mach 3 to Mach 6.

A scramjet (supersonic-combustion ramjet) is a ramjet engine in which the airflow through the whole engine remains supersonic. Scramjet technology is challenging because only limited testing can be performed in ground facilities. Hyper-X will build knowledge, confidence and a technology bridge to very high Mach number flight.

Graphic Illustration of Hyper X and Booster
In this Artist's Concept, the Booster has Completed its Task of Carrying the Research Vehicle to the Test Altitude and Speed, and the Research Vehicle has Separated from the Booster Prior to Scramjet Ignition.
Currently, the world’s fastest air-breathing aircraft, the SR-71, cruises slightly above Mach 3. The highest speed attained by NASA’s rocket-powered X-15 was Mach 6.7. The Hyper-X aircraft will fly faster than any previous air-breathing aircraft.