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Graphic courtesy Lockheed Martin
The Lockheed Martin Skunk Works sub-scale X-33 technology demonstrator shown in this computerized concept drawing represents the next generation Reusable Launch Vehicle. Incorporating proven technology, the X-33 is designed to deliver commercial or military payloads to low Earth orbit. 
Space plane
ventures closer
By 1st Lt. Chris Hemrick
Air Force Flight Test Center
Public Affairs

Imagine a future where a space plane lifts off from Edwards Air Force Base, Calif., and flies to Malmstrom Air Force Base, Mont. - about 950 miles - in about 20 minutes. Now, imagine that future is within two years.

Base organizations at the Air Force Flight Test Center at Edwards have teamed up with Lockheed Martin Skunk Works to develop and test the X-33, a 53 percent scale model of the future Reusable Launch Vehicle, called Venture Star.

Through flight and ground demonstrations, the X-33 will provide information necessary to allow the Lockheed Martin Corporation to make a decision on whether to proceed in the development of the full-scale, commercial, single-stage-to-orbit RLV. If created, the Venture Star would eventually replace the space shuttle as the next generation space transportation system.

"The goal is to lower costs from approximately $10,000 per pound down to around $1,000 per pound to get into orbit," said Chuck Rogers, Air Force Flight Test Center X-33 launch integration engineer/manager of the 412th Test Wing's Access to Space Office.

Members of Team Edwards who are assisting the Skunk Works, and the NASA Marshall Space Flight Center (the program head) with this program include the AFFTC, Air Force Research Laboratory Propulsion Directorate and NASA, Dryden Flight Research Center.

"It's a real paradigm shift that the industry pays the government for products, services and facilities, as a subcontractor to the contractor," said Rogers. The team prepared and presented proposals in competition with White Sands, N.M., and Kennedy Space Center, Fla., to be the X-33 launch site.

"Edwards was selected to be the X-33 launch site because of the excellent launch corridor available for launches toward the northeast, and our extensive flight test infrastructure and experience, which makes this an ideal place to test experimental vehicles, said Rogers. "Between Edwards and Utah, and Edwards and Montana are some of the most sparsely populated areas in the United States. That's very advantageous for launching a vehicle like this, since we want the program to be as safe as possible."

Fifteen-flight program

The X-33 will blast off from the site near Haystack Butte, located at the eastern edge of Edwards. A 15-flight program is planned for the X-33 from the launch site now under construction. The X-33 team already has defined the first seven flights that will, if successful, produce the data needed to provide the confidence for a decision to proceed with the full scale Venture Star.

Graphic courtesy Lockheed Martin
Construction began in November to prepare a 25-acre site at Edwards Air Force Base, Calif., to become the sub-scale X-33 technology demonstrator launch site. 

Construction has already begun on the X-33 and major components are already taking shape. The large tank that will contain the liquid oxygen has been completed, and the final assembly jigs are already in place at the Skunk Works facility at Palmdale.

An unmanned, autonomous vehicle, the X-33 uses differential Global Positioning System with a radar altimeter for navigation and landing.

"The differential GPS will guide it through its flight and down the runway for landing," said Rogers. "Some commands can be sent up to the X-33 from the ground, but the X-33 will operate as an autonomous vehicle during normal operations. The uplink to the X-33 would only be used if the vehicle deviates significantly from its planned flight path."

Rogers said the X-33 preflight and flight operations will be monitored and controlled from a refurbished operations control center located at Haystack Butte. There also will be range safety officers at the downrange sites.

Mach 15, 55 miles up

The X-33 is designed to travel at a top speed of Mach 15 (15 times the speed of sound), which is about three miles a second. The prototype will not achieve orbit, which would require a speed of more than Mach 25.

Once the X-33 is readied for flight, the engines will be fired two times on the launch pad, with the second firing having a duration of 20 seconds. The longest flight will be about 20 minutes at an altitude of about 55 miles. The plan is to demonstrate a two-day turnaround for the vehicle, said Rogers.

On Nov. 14, ground was broken for the launch site near Haystack Butte. Maj. Gen. Richard L. Engel, Edwards Air Force Base commander, predicted the X-33 would be a world-class vehicle researchers will use to learn incredibly important lessons.

If the venture is a success, a permanent launch facility could be built in the Edwards area. From here, vehicles could be launched in nearly any direction except south, with some launches going to equatorial orbits and some to polar orbits, returning to the central site (Edwards) to be launched again. This would allow a fleet of RLVs to be based at one site, according to Rogers.

The X-33 is expected to affirm new technology, such as the linear aerospace engine, a large composite liquid hydrogen tank and the spacecraft's lifting body design.

The engines compensate for altitude and are believed to be more efficient and a better fit for the wedged-shaped aircraft than conventional bell nozzle rocket engines, according to NASA officials.

Landing sites include Michael Army Air Field at Dugway Proving Ground in Utah, and at Malmstrom, near Great Falls, Mont. One of NASA's 747s will be used to carry the X-33 from its landing destinations back to Edwards, said Rogers.

Projected rollout, flight in '99

The projected date for the X-33 rollout is May 1999, with its first flight planned for that July. The program is scheduled to be completed by 2000. Once the X-33 demonstrates the technology, the contractor will solicit private investors for the RLV, Rogers said.

"If the X-33 program proves successful, there's going to be a competition for the RLV launch site. The Edwards area will definitely be a competitor," said Rogers.

"The selection of Edwards for the X-33 launch site is a win-win for both the program and Edwards, as well as the Antelope Valley," said Johnny Armstrong, acting chief of the AFFTC Access to Space Office.

"AFFTC participation in the X-33 program provides the opportunity for our personnel to hone their skills toward support of space-related programs that could provide valuable payoffs in the future, as the Air Force transitions into a Space and Air Force."


February '98 Issue -- Leading Edge

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