While many people assembled to watch NASA’s Space Launch System (SLS), which recently concluded a full-scale booster test, only a few knew about the other groundbreaking test which was taking place at the same time.
This test was recorded by NASA’s HiDyRS-X (High Dynamic Range Stereo X) project, an innovative, high-speed, high dynamic range camera that captured detailed propulsion video data for the first time.
The HiDyRS-X project was developed in response to an issue that occurred while attempting to record the rocket motor tests. In addition being very loud, the rocket motor plumes were very bright, which made it hard to record without actually reducing the exposure settings on the camera.However, doing so tends to darken the remaining part of the image, blocking the other critical parts of the motor.
Video cameras typically record using a single exposure at a time; however, HiDyRS-X records many slow motion video exposures immediately and integrates these video exposures in a high dynamic range video that impeccably exposes all parts of the video image.
The HiDyRS-X project was started as part of the Early Career Initiative (ECI) of NASA Space Technology Mission Directorate. The aim of the ECI initiative was to provide a platform to young engineers who can work with innovative industry partners to head projects and develop hardware. One such ECI grant was awarded to Howard Conyers, a structural dynamist at NASA’s Stennis Space Center, in 2015.
Video Credit: NASA.gov Video/Youtube.com
Following a preliminary design review and an initial proof of concept, the HiDyRS-X project was deployed within NASA’s Game Changing Development program to execute its first prototype. The project, launched in association with Innovative Imaging and Research Corporation, was experimented on tiny rocket nozzle plumes at Stennis.
The full-scale booster test provided a unique opportunity to test the HiDyRS-X hardware in a complete setting. The Qualification Motor 2 (QM-2) test happened to be the second and last booster test prior to SLS’s initial test flight in late 2018.
QM-2 was conducted at Orbital ATK’s test facility located in Promontory, Utah. SLS is predicted to be the world’s most powerful rocket, and will take astronauts beyond deep space mission than ever before.
Conyers informed that while transitioning from the smaller-scale tests to the QM-2 test, offsetting the brightness of the booster plume seemed to be the most challenging. The plume was much brighter than what had been tested before.
Another challenging aspect was transporting and assembling the system at the QM-2 test site based in the Utah desert, a distant environment that required the HiDyRS-X group to be self-sufficient, methodical, and deliberate in its set up and preparation.
Boosters are very powerful, unlike the smaller scale rocket engine tests at Stennis, and once they are ignited they cannot be restarted or turned off. The team had a single shot to obtain good footage.
Conyers added that in the days before the QM-2 test, the HiDyRS-X team meticulously checked the connections and start processes, so that the camera can record the maximum amount of footage. On the actual day of the QM-2 test, the team used the camera to carry out more dry runs, making sure that everything was working properly.
When thousands gathered over a mile away to view the blazing plume of the rocket booster, Conyers and the HiDyRS-X team tracked the camera from a safe place, prepared to act if anything goes wrong.
As the countdown began to reach zero, the SRB ignited but the automatic timer of the camera failed to go off. Fortunately, the HiDyRS-X team were able to press the manual override, which enabled the camera to turn on instantly following ignition.
The camera, once engaged, was able to capture a few seconds of the two-minute test before the power source was disconnected suddenly. Then, in an unexpected sequence of events, the entire power of the solid rocket booster shook the ground, allowing the power cable to be disconnected from the power box.
With two unanticipated camera outages occurring during the QM-2 test, Conyers felt disappointed. “I was bummed,” Conyers says. “Especially because we did not experience any failures during the dry runs.”
On assessing the camera footage, the team observed a level of detail similar to the other successful HiDyRS-X tests. The HiDyRS-X team also observed a number of elements that were never captured on a film during an engine test.
“I was amazed to see the ground support mirror bracket tumbling and the vortices shedding in the plume,” Conyers says.
The HiDyRS-X team collected interesting information from the slow motion footage, while Conyers found something else by accelerating the playback.
I was able to clearly see the exhaust plume, nozzle and the nozzle fabric go through its gimbaling patterns, which is an expected condition, but usually unobservable in slow motion or normal playback rates.
Howard Conyers, Structural Dynamist, NASA’s Stennis Space Center
Although Conyers and the HiDyRS-X team were initially disappointed with the camera anomalies, they came out of the QM-2 with sufficient evidence that the technology not only worked efficiently, but can also provide unparalleled views of high exposure rocket motor tests.
The latest test experience also taught two important lessons to Conyers for the future: to start the camera a full 10 seconds prior to ignition to allow the ground team with the required time to manually initiate the camera in case of a timer failure, and to understand the power of the engine tests so that the electronics hardware can be properly secured and protected from disconnection or damage.
“Failure during testing of the camera is the opportunity to get smarter,” Conyers says. “Without failure, technology and innovation is not possible.”
The evaluation of HiDyRS-X will continue at Stennis while a second HiDyRS-X prototype is developed with sophisticated high dynamic range capabilities based on the information collected from the extensive experimentation conducted over the past few years. The second prototype will be built with a better manufacturing process to improve the alignment capabilities of multiple exposure settings, a key challenge addressed in the first prototype.
HiDyRS-X is not only considered as a game-changing technology that could transform propulsion video analysis, but also stands as a demonstration to ECI and the potential of committed young engineers in NASA.
Experienced NASA staff and recent hires equally have the capacity to make a significant contribution to the research and development goals of the agency. ECI’s importance on pairing young engineers with leading industry partners allows technological breakthroughs that would otherwise be not possible.
The Stennis HiDyRS-X ECI project continues to be an exciting and challenging public-private collaboration of which we are proud to be a part. It’s giving us the chance to mentor early career technologists and advance the way we image and assess rocket motor firings.
Mary Pagnutti, President, Innovative Imaging and Research Corporation