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Historical Fact Sheet
X-33 Flight Operations Center

Photo description: An aerial shot of the 30-acre X-33 Flight Operations Center, located on the northeast corner of Edwards Air Force Base, Calif., shows the 250-foot-tall water tower, moveable vehicle shelter and flame trench.
An aerial shot of the 30-acre X-33 Flight Operations Center, located on the northeast corner of Edwards Air Force Base, Calif., shows the 250-foot-tall water tower, moveable vehicle shelter and flame trench. (Air Force/J. Shrine)

Construction of the X-33 Flight Operations Center - where the NASA X-33 Technology Demonstrator will launch -- was completed in December 1998, just a little more than 12 months after groundbreaking and under budget. The center is located on the eastern portion of Edwards Air Force Base, Calif., approximately 40 miles northeast of the Lockheed Martin Skunk Works in Palmdale, Calif., where the X-33 is being assembled.

In March, the construction crew led by industry team member Sverdrup Corp., St. Louis, handed over the center to the operations team after completion of verification and performance testing.

This unique facility marks a dramatic departure from traditional launch sites. Designers took advantage of lessons learned over years of operating launch sites and aircraft facilities to create a flight center that exemplifies the overall program philosophy of building a reusable launch system that operates more like an airplane.

The flight operations center is a small-scale version of a future "spaceport," designed to minimize operational activities during X-33 flight tests and support the program's and the nation's goal of low-cost access to space. Taking full advantage of the X-33 architecture, the complex provides for maintenance of the vehicle in the horizontal position, rotation of the vehicle to the vertical position for pre-flight servicing, and vertical takeoff - all from the same location, eliminating movement of the vehicle on the ground between these operations. The center also supports the lean ground crew of less than 50 people who will service the X-33 between flights.

The $32 million flight operations center sits on 30 acres and was constructed using 4,000 cubic yards of concrete. The center includes:

  • a rotating vehicle mount and strong-back for lifting the vehicle from a horizontal servicing position to a vertical takeoff position for flight;
  • a preflight checkout position and flame trench;
  • a 9,500-square-foot moveable shelter positioned on rails;
  • liquid hydrogen and liquid oxygen tank farms capable of storing more than 250,000 gallons of cryogenic liquids;
  • a 250-foot-tall, 250,000-gallon water tower that will supply the water deluge system at launch; and
  • a small mission control room located inside a hill one mile from the pad

Sverdrup Corp. accomplished the design and construction of the site in record time, in keeping with the fast-paced nature of the X-33 program, and the X-33/VentureStar™ team's commitment to minimizing costs.

The X-33 Operations Control Center, located at Haystack Butte nearly a mile from the center of the preflight checkout position, will serve as mission control for the X-33 flight tests. The control room is linked to the flight operations center's data and communications systems through fiber optics and standard telephone cables. Locations at NASA Dryden Flight Research Center and Edwards Air Force Base also are connected to the systems.

A distinguishing feature of the flight operations center is the 90-foot-wide by 105-foot-long movable "translating shelter" that will serve as a hangar where the X-33 will be housed and serviced in the horizontal position. As the time for takeoff nears, the shelter will roll back from the X-33, allowing the vehicle to be rotated vertically on its liftoff mount before fueling and the eventual flight countdown.

This efficient preflight processing system will support the extremely short turn-around times X-33 will demonstrate. Plans call for the X-33 program to demonstrate two seven-day turnarounds and one two-day turnaround during the flight test series. Aircraft-like operations constitute one of the goals for both the X-33 and the VentureStar™ programs.

A new Vehicle Positioning System also will support the accelerated turn-around times for the X-33. NASA's Kennedy Space Center, Fla., developed and tested the system that utilizes a laser alignment system to precisely rotate the X-33 to vertical for flight. A weight simulator was attached to the liftoff mount in January to confirm the laser system's operation. Positioning traditional launch vehicles on their stands typically is a lengthy, labor-intensive effort. Total time for the X-33's laser preflight positioning operation is expected to be one hour.

A 35-foot-deep by 30-foot-wide flame trench with 3-foot-thick walls is an integral part of the center. The flame trench's curved bottom will divert the X-33's rocket engine exhaust away from the vehicle as it clears the pad. During construction, approximately 400 cubic yards of concrete were placed in just one day to form the flame trench.

At engine ignition, the 250-foot-tall water tank will drop 80,000 gallons of water per minute down a 42-inch underground pipeline to the flame trench. While water spray will cool the trench's concrete walls, the deluge system will serve as a sound suppression system to reduce the intensity of the engine's shock waves rebounding from the flame trench back toward the vehicle.

Storage tanks for liquid hydrogen, liquid oxygen, and liquid and gaseous helium and nitrogen are located at the flight operations center. The propellant storage and supply system has undergone verification testing using liquid nitrogen.

Several ground vibration tests and static aerospike engine flight readiness firings are scheduled for the X-33 while at the pre-flight checkout position. For the ground vibration testing, the X-33 will be attached to the rotating liftoff mount and raised into the vertical position. Specialized test equipment will be attached to the X-33 to simulate vehicle flight vibration conditions on the ground. This is to ensure that internal vibration-induced problems do not hamper the X-33 in flight.

Static firings of the X-33's aerospike engines will serve as final flight readiness verification for both engines. For the static firings, the vehicle will again be rotated into the vertical liftoff position while attached to the mount. Hold-down bolts will keep the X-33 earth-bound while the engines are throttled to maximum power. The static firings will last approximately 20 seconds each.

Within the 30-acre site, areas that were directly impacted by the construction were environmentally monitored and approved to minimize the impact on the environment. A paved road provides access to the flight operations center for site personnel as well as for vehicles delivering supplies such as propellants. The X-33 vehicle will be towed to the pre-flight checkout position along the same access road as well.

The X-33 is a half-scale, suborbital technology demonstrator of a reusable space plane Lockheed Martin calls the "VentureStarTM." Managed by NASA's Marshall Space Flight Center, Huntsville, Ala., the goal of the $1.2 billion program is to demonstrate advanced technologies that will dramatically increase reliability and lower the cost of putting a pound of payload into space from $10,000 to $1,000.

The X-33 is scheduled to conduct flight tests beginning in mid-2000. It eventually will fly at speeds faster than Mach 13 and at an altitude of 60 miles to prove its technologies and systems.

X-33 Specifications

Length: 69 ft
Width: 77 ft
Takeoff weight: 285,000 lbs
Fuel: LH2/LO2
Fuel weight: 210,000 lbs
Main Propulsion: 2 J-2S Linear Aerospikes
Take-off thrust: 410,000 lbs
Maximum speed: Mach 13+
Payload to Low Earth Orbit: N/A

More Information

For further information, contact: Carol Lane, Director X-33/VentureStar™ Business Development (408) 743-4933