Every now and then, due to the unique capabilities of our aircraft and our personnel, NASA gets called upon to assist the Air Force in one of its missions. In this instance we were asked to help by providing video documentation and airborne safety chase for a high-altitude first release of the X-51 hypersonic test vehicle. You can read more about this test flight on the Edwards Air Force Base Web site here: http://www.edwards.af.mil/news/story.asp?id=123206547 .
Normally, the Air Force would use its own chase F-16 aircraft. However, launch conditions were too slow for an F-16 at the planned altitude of 50,000 feet. NASA Dryden operates a fleet of four chase and support F/A-18 aircraft, and the high altitude and slow speed is something our aircraft could handle. NASA Dryden also has a unique cadre of truly talented airborne videographers and photographers. Taking videos and pictures requires a skill only learned through years of experience and this is routinely demonstrated in the NASA photo/video team’s superb products.
For this mission we conducted numerous briefings and several dress rehearsals so all participants, both in the air and on the ground, would be ready for their roles. The flight included the U.S. Air Force B-52, with the test vehicle tucked under the port wing and inboard of the engines, and two NASA F/A-18s. One F/A-18 was a single-seat aircraft with a primary mission of safety chase. It was there to allow the pilot to watch the takeoff and climb to altitude, ensuring the vehicle remained intact with no leaks or apparent anomalies in condition. The second F/A-18, a 2-seater I was flying, had the videographer in the aft seat. Our mission was to capture the X-51 as it separated from the B-52 and the rocket booster ignited, accelerating it into the record books. We took off about 15 minutes after the bomber and chase. We climbed to altitude in trail but were flying faster so as to catch them en route. We needed to be in position close to the B-52’s left wing when the flight reached the test area off the California coast.
After a trial run down the launch path, the flight circled back to point west again. This time the X-51 launch system was readied and clearance was received. The range was “green,” meaning the X-51 could be safely released.
As we got close to the desired launch point the appropriate calls were made: “30 seconds to release,” then “10 seconds,” followed by a tense delay until the hypersonic aircraft dropped free of the bomber.
In the video chase F/A-18, I was striving to be in exactly the right position, not too close but never too far away. At this high altitude the aircraft is not nearly as responsive as it would be down lower. Also, we were flying much slower for this launch, making the flight controls even more sluggish. One false flight control or throttle input, and we could easily fall way below or way behind the B-52 and then be unable to catch it in time to capture the video. The camera operator needed a clear view of the release but also needed to have it in sight as it dropped away before the rocket motor ignited. The X-51 was going to drop up to 1,000 feet below the B-52, so we had to be ready to go lower with it. This sequence all went without a single hitch and the X-51 booster rocket motor ignited in a beautiful, sharp plume. The vehicle rapidly accelerated away before climbing smoothly into the planned trajectory.
It was visually as flawless a launch as I have ever witnessed and truly an awesome sight. After the X-51 disappeared from view, which took about 45 seconds after being dropped from the bomber, we turned toward home. Now we could see the white contrail the X-51 had left in the sky. It was no longer arrow-straight, but wavy and kinked by the high-altitude winds. The flight home would take another 25 minutes, but it was a relaxing 25 minutes borne by the exhilaration of success.
To view the amazing video, follow this link. https://www.nasa.gov/multimedia/videogallery/index.html?media_id=14470278
The Air Force Research Lab’s X-51 project office said they were absolutely thrilled by NASA’s “superb safety and video chase support.” It was a privilege to participate with the team to help capture this video and make it available to a global audience.
Dick Ewers
NASA Research Test Pilot
