How the EZ-Rocket Works

by Craig Freudenrich, Ph.D.
Rocket Racers and Xerus
A poster for Leading Edge Rocket Racing, the first Rocket Racing League team
A poster for Leading Edge Rocket Racing, the first Rocket Racing League team
Image courtesy Rocket Racing League

The EZ-Rocket has made its last flights testing new rocket plane technologies. XCOR Aerospace is now moving on to two new projects: the development of rocket racers and a suborbital spacecraft.

Rocket Racers

Dr. Peter Diamandis, founder of the Ansari X-Prize, has established the Rocket Racing League (RRL) with Granger Whitelaw, a two-time Indianapolis 500 champion. Diamandis and Whitelaw envision wide television coverage and large audience turnouts like those of NASCAR. The Rocket Racers will race worldwide in independent events, on a 5000-feet high, two-mile long track. Fans will watch the planes fly through a virtual course created by Sportvision (the same company that created the "1st and 10" line on football fields). The season will culminate in a championship race for a $2 million purse at the X Prize Cup, an annual event held in Las Cruces, New Mexico.

The Rocket Racing League will spark the development of new technologies from private companies and inspire new generations of rocket scientists. Rocket racing test demonstrations were performed at the 2005 X-Prize Cup. In January 2006, the Rocket Racing League announced a contest for fans to name the first Mark-1 X-Racer. The prize includes e a one-year VIP pass to all Rocket Racing League events. The winner will be announced in October 2006, when the Mark-1 X-Racer is revealed to the public for the first time.

Artist's rendering of a Rocket Racing League venue
Image courtesy Rocket Racing League
The Mark-1 X-Racer Development Vehicle
Photo courtesy Rocket Racing League

Xerus: XCOR's Next Step

XCOR Aerospace's next project is the creation of a suborbital space plane, Xerus. They have identified three markets that could benefit from an inexpensive, reusable launch vehicle:

  • Space tourism - Many people would like to experience zero gravity and outer space, but cannot afford a $20 million ride into orbit. A suborbital flight would give passengers three minutes of weightlessness at an altitude of 60 miles (100 km).
  • Suborbital payloads - Currently, the space shuttle or sounding rockets carry many small-scale science experiments that do not necessarily need to be in orbit. Some of these experiments are secondary to the shuttle's mission and may be bumped from a flight. With the Xerus, they could have dedicated missions.
  • Launching microsatellites - The Xerus could serve as the first stage to deliver tiny satellites with small payloads. The launch vehicle would carry the satellite on a smaller rocket stage, release it, and let that rocket fire the microsatellite to orbit. This would be less expensive than using dedicated multi-stage rockets or the space shuttle.
Artist's rendering of the Xerus
Image courtesy XCOR Aerospace

Xerus will use several main engines to reach an altitude of 100 miles (about 65 km), then coast to 130 miles (about 100 km). It will reach a top speed of Mach 4, about 10 times faster than the EZ-Rocket, and will take off and land like a conventional airplane. Once outside the atmosphere, the craft will use 50-lb rocket thrusters for maneuvering (attitude controls). Xerus will use liquid-fueled rocket technology like that developed and tested on EZ-Rocket. It will also use piston pumps for both the fuel and the oxidizer (EZ-Rocket only uses one for the oxidizer). XCOR is developing this technology for NASA and the Defense Department.

Artist's rendering of the Xerus launching a small payload
Photo courtesy XCOR Aerospace

Once XCOR finishes the design for Xerus, it plans a program of 20 test flights.

For lots more information on the EZ-Rocket, the Rocket Racing League, Xerus and related topics, check out the links below.

Past Rocket Planes

The Germans developed rocket planes -- the Lippisch Ente and the Messerschmitt Me 163 Bs and Cs -- along with jet engines during World War II. These planes reached speeds of 600 miles per hour (966 km/h), just under the speed of sound. The Soviet Union also experimented with rocket planes, and the Japanese even developed a rocket-powered Kamikaze bomber.

After World War II, rocket planes were used experimentally to test the performance of aircraft at hypersonic speeds. On Oct. 14, 1947, Chuck Yeager was the first to break the sound barrier in the Bell X-1 rocket plane.

Perhaps the most famous rocket plane was NASA's X-15. The X-15 was built to research the aerodynamics, stability, flight controls, heating, and physiological effects of high-speed, high-altitude flight. It made 199 flights between June 1959 and October 1968 and set altitude (354,200 feet, or 67 miles) and speed (4520 mph, or Mach 6.7) records for piloted, hypersonic flight. Information from the program was useful in developing the Mercury, Gemini, Apollo and Space Shuttle programs.

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More Great Links

Sources

  • Belfiore, Michael. "X-Racers, Start Your Rockets!" Popular Science, February 2006. http://www.popsci.com/popsci/aviationspace/f1fd870c7a079010vgnvcm1000004eecbccdrcrd.html
  • "Rocket Plane Sets Record." Machine Design, February 23, 2006. http://www.machinedesign.com/ASP/viewSelectedArticle.asp?strArticleId=59966&strSite=MDSite&catId=0
  • XCOR Aerospace: EZ-Rocket http://xcor.com/ez.html
  • XCOR Aerospace: Going Suborbital http://xcor.com/suborbital.html
  • The X-Prize Cup http://www.xpcup.com/index.cfm

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