The EZ-Rocket is XCOR's first demonstrator rocket-powered vehicle. We modified a "Long-EZ" homebuilt airplane, adding twin 400 lb thrust regeneratively cooled rocket engines. The engines are fueled with isopropyl alcohol and liquid oxygen. The alcohol is stored in an external composite fuel tank, and the LOX is contained in an insulated internal aluminum liquid oxygen tank.
All of these modifications and flight tests were performed at XCOR's facility at the Mojave Spaceport in Mojave, California. We have also flown the EZ-Rocket in front of the crowds at EAA AirVenture Oshkosh 2002, the largest airshow in the world, held in Oshkosh, Wisconsin, and The Countdown to the X-Prize Cup in Las Cruces, New Mexico in October, 2005.
Purpose of the program
We built the EZ-Rocket to show that we can design and build a rocket propulsion vehicle that is simple, cost effective, reliable, and above all operable. We chose the Long-EZ as an airframe based on its pusher configuration and an excellent power-off glide capability. Since the engines are easily restartable, our pilots, Dick Rutan and Rick Searfoss, have had the choice of extending the glide. Civilian astronaut Mike Melvil has also flown the EZ-Rocket, his first rocket vehicle experience. We have been able to re-start the engines in mid-flight and perform touch-and-goes, both of which had never been done before in a rocket powered aircraft.
With both engines running (800 lb thrust total) and maximum propellant load, takeoff roll is 500m (1650 ft) in 20 seconds. After pulling up, climb is established at constant airspeed at Vy (best climb speed), or 145 knots. Burnout occurs after a maximum of two and one-half minutes, still at 145 knots indicated, which equals Mach 0.4. The maximum altitude that has been attained is 11,500 ft. The maximum climb rate is 31 m/sec (6,000 ft/min). While the engines can quickly accelerate the aircraft to its never-exceed speed (Vne) of 195 knots, climb performance suffers at that high speed due to aerodynamic drag and the pilots typically use lower speeds for better overall performance.
At the plane's first public rollout, the EZ-Rocket flew to an altitude of 9,000 feet for a flight duration of approximately ten minutes. Since then a total of twenty-six test flights have demonstrated routine operation of a rocket-powered vehicle within the weight and volume constraints of an aircraft, with an austere hands-on ground crew of 5 people. Perimeter security, crowd control, and official observers have often outnumbered the operational crew! Specific impulse of the engines is higher than the engines in the Bell X-1 or the Redstone, which also used LOX/alcohol.
The first 13 flights were conducted at our base of operations at the Mojave Civilian Flight Test Center in Mojave, CA. Flights 14 and 15 were performed in front of very large crowds of airshow attendees at the EAA AirVenture Air Show in Wisconsin. Following that success, flights 22 through 24 enthralled the large gathering at The Countdown to the X-Prize Cup Event in New Mexico in 2005.
The target for the EZ-Rocket was to drive costs below $2,000 per flight. The actual number beat this estimate handily at approximately $900 per flight. A major portion of this price is helium used as a fuel pressurant. Our next generation vehicles have XCOR's rocket propellant piston pump technology on board, greatly reducing that particular per-flight expense.
A Record Breaker
In December 2005, the EZ-Rocket's 25th flight set the world record for Distance without Landing for its class by flying 9.94 miles from Mojave to California City, CA. The National Aeronautic Association (NAA) certified the EZ-Rocket as setting the long distance world record for any ground-launched Rocket-Powered Aircraft. EZ-Rocket pilot Dick Rutan exclaimed, "That was the shortest long-distance record flight ever!" (Dick previously held the record for flying around the world nonstop unrefuelled in the Voyager aircraft.)
At the end of 2001, Time Magazine named the EZ-Rocket as a "Transportation Invention of the Year". Scientific American honored the EZ-Rocket in it's annual "Scientific American 50" awards. The Space Frontier Foundation lauded the EZ-Rocket with it's Space Frontier Award, and the Aero News Network made the EZ-Rocket and it's team one of the first recipients of its "Annie" awards. For more information about these accolades, please visit our 'Awards and Recognition' page.
Since flying and testing the EZ-Rocket, we have successfully demonstrated low-cost and low-maintenance rocket-powered flight. We have gained valuable experience that has been applied to our follow-on engines. The EZ-Rocket was retired after its return flight from California City, but is currently in flying condition.
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