The High Definition Earth Viewing (HDEV) experiment went live on April 30, 2014.
Several HD video cameras are mounted to the External Payload Facility of the European Space Agency's Columbus module.
Each of these cameras look back at Earth with views changing from camera to camera on the live stream.
When the camera switches a gray then black color slate will briefly appear before the new live look pops up on the live stream.
NASA also says the picture may appear black at times.
"Since the ISS is in darkness during part of each orbit, the images will be dark at those times. During periods of loss of signal with the ground or when HDEV is not operating, a gray color slate or previously recorded video may be seen." says NASA.
According to NASA "Analysis of this experiment will be conducted to assess the effects of the space environment on the equipment and video quality which may help decisions about cameras for future missions."
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