Two NASA engineers have released a series of unique images that show the flames of the last space shuttle launch in a way the human eye can't see.
Using a custom camera mount holding seven cameras 1,250 feet from the space shuttle Atlantis on the launch pad, Louise Walker and J.T. Heineck set up equipment to capture more than 20,000 images during the spectacular 13 seconds of NASA's final shuttle launch at Kennedy Space Center in Florida.
"All five visible cameras record to internal memory and we communicate to them through Ethernet connections," said Heineck. "Each camera goes to a network hub, and we talk to the hub from miles away through the fiber optic connection."
Each taking 250 shots per second, Walker and Heineck's cameras snapped photos at different exposures. After shooting, software digitally removes saturated pure black (underexposed) or pure white (overexposed) pixels from one image and replaces them with the most properly exposed, and thus detailed, pixels in the set.
The resulting image is called a high dynamic range image, referring to the different dynamic ranges, or exposure and brightness, in each image, with a final product that captures the launch from a perspective the human eye can't see naturally.
This first image in the sequence was taken with the thermal infrared camera as the two solid rocket boosters (left) ignite followed by the main engine.
This is just one of the images used in the resulting composite, which compiled a series of different exposures into a final image with a greater dynamic range, showing greater detail throughout the image. This one shows some of the subtlety that would be lost in a properly exposed image.
If you were to take one normally exposed photo of the launch, you would be able to see the shuttle itself just fine, but the bright and powerful emission from the engines would appear white and blown out, with no detail visible in the image.
The variation in the exposures needed for the launch, from the brightness of the engine ignition to the varying tones of the exhaust emissions, is illustrated in this image.
Some of this mid tones of the exhaust plume and launch pad are more well exposed in this frame, but the highlights are blown out and the underexposed dark spots also lack detail.
This exposure shows a more properly exposed overall image, showing detail in the shuttle and the darker portions of the exhaust. However, the overexposed main engine exhaust lacks any detail, and thus will be discarded in the final, fused image and replaced with an exposure better suited for the brightness of that part of the image.
Using software to choose the best exposed parts of each of the thousands of images, the final fusion image gives a very detailed view of the last launch of NASA's space shuttle program.
The camera setup for STS-135 included seven cameras
The camera setup for the launch of the STS-135 mission included seven cameras, five visible spectrum black-and-white, high speed, high resolution; and two thermal infrared cameras to capture temperature data, which is visible on the bottom left of this image.
One infrared camera did not function during the launch, so only six images were used in the final fused photos and videos.
