The Defense Satellite Communications Systems (DSCS) is an important part of the comprehensive plan to support globally distributed military users.
Currently, two Phase II and eight Phase III DSCS satellites orbit the earth at an altitude of more than 23,000 miles.
ST. LOUIS, July 8, 1997 -- Performing flawlessly, the tailless X-36 prototype fighter built by McDonnell Douglas (NYSE: MD) completed Phase 1 flight testing June 30 at NASA's Dryden Flight Research Center in Edwards, Calif.
"The aircraft is performing so well that we not only completed Phase 1 on schedule and within budget, but were also able to conduct flights on a daily basis and expand the Phase 1 flight envelope," said McDonnell Douglas' X-36 program manager Gary Jennings.
Phase 1 testing of the subscale, remotely piloted aircraft began May 17. In a series of eight test flights, a NASA/McDonnell Douglas team verified the aircraft's control software, ground station, data system and air data calibrations.
"We're delighted with the results of Phase 1 testing," Jennings said. "The aircraft is performing flawlessly, and its handling qualities and stability margins prove to be better than predicted. As a result, we were able to complete the last four flights in four consecutive working days -- which is quite a feat in the flight test world."
According to Jennings, two new software programs proved to be very effective during Phase 1 testing. Parameter Identification, produced by McDonnell Douglas, was used to determine individual flight control surface effectiveness. Real-Time Stability Margin, developed by NASA, was used to monitor the aircraft's phase and gain margins for the flight control system in real-time.
"The Real-time Stability Margin program was a key element in successfully completing Phase 1 in record time and on budget," said Rod Bailey, X-36 program manager for NASA. It worked so well, he said, that it allowed the X-36 team to expand the aircraft's maximum angle-of-attack from 15 degrees to 20 degrees in Phase 1.
The results of Phase 1 will be used to expand the flight envelope of the X-36 during Phase 2 flight testing, scheduled to begin in late July. Objectives include expanding the angle-of-attack envelope to 35 degrees and demonstrating agility that is equal to or better than that of current fighter aircraft at these elevated angles of attack.
McDonnell Douglas has fabricated two 28 percent scale aircraft for the X-36 program -- each measuring 18 feet long, 3 feet high, with a 10-foot wing span and weighing 1,250 pounds. Each is also powered by a Williams Research F112 turbofan engine that produces 700 pounds of thrust.
The tailless design of the X-36 greatly enhances the stealth characteristics of the airplane and promises to provide greater agility than current fighter aircraft have. The design also reduces weight and drag and explores new flight control technologies, such as split ailerons and thrust vectoring.
The X-36 is remotely controlled by a pilot in a ground station cockpit that receives an "out the window" view from a camera in the aircraft, complete with an overlay of a head-up display. This pilot-in-the-loop approach eliminates the need for expensive and complex autonomous flight control systems and allows for a quick-paced, aggressive flight test program.
NASA's Ames Research Center leads the X-36 program, which is funded under a roughly 50/50 cost sharing arrangement with McDonnell Douglas. The combined program cost for development, fabrication and flight testing is about $20 million.
NASA's Dryden Flight Research Center is hosting the X-36 program and providing range support
This is still my favorite
