The XCOR EZ-Rocket was a test platform for the XCOR XR-4A3 rocket propulsion system. The airplane was a modified

Rutan Long-EZ The Rutan Model 61 Long-EZ is a tandem 2-seater homebuilt aircraft designed by Burt Rutan's Rutan Aircraft Factory. The Long-EZ has a canard layout, a swept wing with wingtip rudders, and a pusher engine and propeller. The tricycle landing ...

, with the propeller replaced by first one, then later a pair of pressure-fed regeneratively cooled liquid-fueled rocket engines and an underslung fuel tank. The engines were restartable in flight, and were contained within

Kevlar Kevlar (para-aramid) is a strong, heat-resistant synthetic fiber, related to other aramids such as Nomex and Technora. Developed by Stephanie Kwolek at DuPont in 1965, the high-strength material was first used commercially in the early 1970s a ...

armor shielding. The EZ-Rocket was registered as an experimental aircraft.

Development and history

The first flight took place on July 21, 2001, flown by

test pilot A test pilot is an aircraft pilot with additional training to fly and evaluate experimental, newly produced and modified aircraft with specific maneuvers, known as flight test techniques.Stinton, Darrol. ''Flying Qualities and Flight Testin ...

Dick Rutan Richard Glenn Rutan (born July 1, 1938) is a retired United States Air Force officer and fighter pilot, test pilot, and record-breaking aviator who in 1986 piloted the Voyager aircraft on the first non-stop, non-refueled around-the-world flight w ...

. On a typical flight, the EZ-Rocket took off on rockets, gained altitude for a minute or so, then switched off the rockets and glided to a dead stick landing. The vehicle actually flew better during dead stick landings than a standard Long-EZ due to lack of drag from a stationary pusher propeller — the vehicle's aerodynamics were cleaner in spite of its belly tank. It was also lighter due to the lack of a piston engine (the rocket propulsion system was significantly lighter), so enjoyed significantly lower

wing loading In aerodynamics, wing loading is the total mass of an aircraft or flying animal divided by the area of its wing. The stalling speed of an aircraft in straight, level flight is partly determined by its wing loading. An aircraft or animal with a ...

than a standard Long-EZ. When XCOR began flying its EZ-Rocket in 2001, the company decided to have it FAA certified as an experimental aircraft, avoiding the additional time required to seek a launch vehicle license from the

Office of Commercial Space Transportation The Office of Commercial Space Transportation (generally referred to as FAA/AST or simply AST) is the branch of the United States Federal Aviation Administration (FAA) that approves any commercial rocket launch operations — that is, any laun ...

(AST). Jeff Greason, a co-founder of XCOR, said on February 10, 2003 if they were starting out at that time they probably would seek an AST license due to the progress made in developing a regulatory regime for suborbitals.

Milestones and records

*October 8, 2000 - First firing of an

XCOR Aerospace XCOR Aerospace was an American private spaceflight and rocket engine development company based at the Mojave Air and Space Port in Mojave, California, Midland International Air and Space Port, Midland International Air and Spaceport in Midland, T ...

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 ...

-powered rocket engine. *July 21, 2001 - First flight, flown by

(single-engine configuration). *October 3, 2001 - First flight in twin-engine configuration. *January 24, 2002 - First rocketplane inflight engine relight. Piloted by Mike Melvill. *June 24, 2002 - First touch-and-go of a rocket-powered aircraft (world record). *Jul 11, 2002 - EZ-Rocket flies twice in one day. First same day rocketplane flights since 1945. *July 25, 2002 - EZ-Rocket first Oshkosh flight at the 2002

EAA AirVenture Oshkosh EAA AirVenture Oshkosh (formerly the EAA Annual Convention and Fly-In), or just Oshkosh, is an annual air show and gathering of aviation enthusiasts held each summer at Wittman Regional Airport and adjacent Pioneer Airport in Oshkosh, Wisconsi ...

air show. First rocketplane air show flight in the United States. *July 27, 2002 - EZ-Rocket second Oshkosh flight at the 2002

air show. Second rocketplane air show flight in the United States. *August 26, 2005 - EZ-Rocket requalification flight after three-year retirement. Piloted by Dick Rutan. *August 29, 2005 - Searfoss qualification flight. *September 1, 2005 - Altitude validation flight to 11,546 feet. Aircraft demonstrated sufficient range to fly from Mojave to California City and back without a relight, a prerequisite for the world record flight. *October 9, 2005 - EZ-Rocket second and third Las Cruces flights, at Countdown to X PRIZE Cup. Third and fourth rocketplane air show flights in the United States. *December 3, 2005 - Set the point-to-point distance record for a ground-launched, rocket-powered aircraft, flying 16 km from Mojave to

California City California City is a city located in northern Antelope Valley in Kern County, California, United States. It is north of the city of Los Angeles, and the population was 14,973 at the 2020 census. Covering , California City has the third-largest ...

in just under ten minutes, piloted by Dick Rutan. Also first official delivery of U.S. Mail by a rocket-powered aircraft. In recognition of this achievement, the FAI awarded Rutan the 2005 Louis Blériot Medal. *December 15, 2005 - First cross-country return flight of a rocket-powered aircraft in the United States, return flight from California City, piloted by Rick Searfoss.

Derivatives

The

Rocket Racing League The Rocket Racing League was a racing league that planned to use rocket-powered aircraft to race a closed-circuit air racetrack. Founded in 2005, the league made its first public flights in 2010 and was working to begin regular racing seasons. ...

aircraft currently in development, the Mark-III X-racer, is a design descendant of the EZ-Rocket aircraft. Although XCOR is not the developer of the rocket engine for the Mark-III, XCOR did develop the rocket engine for the Mark-I X-Racer, the first of the X-Racers to use a single rocket engine on a

Velocity SE The Velocity Model 173 SE (Standard Elite) is an entry level canard pusher aircraft from Velocity Aircraft.kerosene Kerosene, paraffin, or lamp oil is a combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in aviation as well as households. Its name derives from el, κηρός (''keros'') meaning "wax", and was regi ...

instead of

isopropyl alcohol Isopropyl alcohol (IUPAC name propan-2-ol and also called isopropanol or 2-propanol) is a colorless, flammable organic compound with a pungent alcoholic odor. As an isopropyl group linked to a hydroxyl group ( chemical formula ) it is the s ...

fuel. XCOR used both design and operational experience from the EZ-Rocket in the Mark-I rocket aircraft design.

Specifications

* Two XR-4A3 thrust rocket engines (non throttleable, restartable in flight) * 20 sec 500 m takeoff roll *

Vne In aviation, V-speeds are standard terms used to define airspeeds important or useful to the operation of all aircraft. These speeds are derived from data obtained by aircraft designers and manufacturers during flight testing for aircraft type- ...

= *

climb rate In aeronautics, the rate of climb (RoC) is an aircraft's vertical speed, that is the positive or negative rate of altitude change with respect to time. In most ICAO member countries, even in otherwise metric countries, this is usually expressed ...

= 52 m/s (10,000 ft/min) * maximum altitude = MSL * Fuel: isopropyl alcohol and liquid oxygen * Chamber pressure: ~ *

Specific impulse Specific impulse (usually abbreviated ) is a measure of how efficiently a reaction mass engine (a rocket using propellant or a jet engine using fuel) creates thrust. For engines whose reaction mass is only the fuel they carry, specific impulse is ...

: to * Noise: 128 dB at 10 meters

References

External links