HDEV_Team

The goal is to quantitatively measure the pixel damage to the sensors over time. During night passes, when the video is black, we use a custom software program to analyze the video and count dead pixels.

The delay in our video distribution varies depending on certain circumstances, including the time it takes to downlink, process, and distribute the video. Typically, HDEV video is delayed by about 20 seconds. Interestingly, the downlink signal delay is only a couple of seconds. The biggest delay occurs during distribution across the Internet.

Each of the cameras do have the ability to take images in low light scenarios such as cities at night or auroras. However, each camera has fixed settings which were optimized on the ground for daylight imagery.

If you would like to see cities at night, you can view some of the time lapse sequences created by the Earth Science and Remote Sensing Group at the Johnson Space Center: http://eol.jsc.nasa.gov/BeyondThePhotography/CrewEarthObservationsVideos/. These are created using sequences of still images stitched together to create videos.

We developed HDEV with given resources and an aggressive timeline. We can apply the lessons we've learned to future space systems. The sun's reflection in the windows is greater than we anticipated; so it would have been good to use a coating on the glass to help reduce the reflections.

For our payload, we used commercially available cameras. The cameras are identical to the cameras that you can buy in the store, so there is no difference in the actual hardware. We removed the baseplate on one of the cameras in order to help it fit inside the HDEV enclosure. In addition, we also removed the internal camera batteries and physically locked the focus on the lenses.