As some of you may remember, four years ago NASA kicked off a very cool space experiment dubbed High Definition Earth Viewing —HDEV, for short.
The project was meant as a two-year Earth observation study that continuously streamed views of our planet from the vantage point of the International Space Station (ISS) — and it’s still going strong today, ceaselessly broadcasting spectacular footage of our planet that you can watch online.
The HDEV initiative makes use of four HD cameras, enclosed in a pressurized and temperature-controlled housing which is mounted on the ISS. The four cameras are installed on the exterior of the Columbus module — a science laboratory made by the European Space Agency for the space station.
From their perch 250 miles above the surface of our planet, the cameras record stunning views of Earth that are simply awesome — in the very literal sense of the word.
As NASA explained back in 2014, when HDEV was first launched, the project was designed “to stream the first continuous, high definition video from the space station.”
The great thing about HDEV is that it “allows anyone with an internet connection to view our world from above,” stated officials from the space agency.
To see what Earth looks like from orbit right at this moment, follow the HDEV livestream below — courtesy of NASA — or go to the Earth Science & Remote Sensing Unit (ESRS) website.
Each of the four cameras that keep the project going is oriented in a different direction, to ensure that HDEV captures several viewing angles of our planet. More specifically, one camera is always facing forward, another one is constantly looking nearly straight down, while the remaining two are oriented toward the back.
If you should happen to come upon a black image, don’t fret; that only means that the space station is positioned on the night side of Earth. At the same time, a grey color slate will occasionally appear on the screen whenever the system switches from one camera to the other.
“The cameras are programmed to cycle from one camera to the next, and only one camera can work at a time. As they cycle, each camera must turn off and the next camera turn on before the HD video starts, taking about eight to 10 seconds to change,” notes the ESRS.
“While the HDEV collects beautiful images of the Earth from the ISS, the primary purpose of the experiment is an engineering one: monitoring the rate at which HD video camera image quality degrades when exposed to the space environment (mainly from cosmic ray damage),” points out the ESRS.
The main goal of the project is to help researchers find out what type of camera can better withstand the harsh conditions in outer space so that they know which one to choose for future missions, NASA explained.
For this purpose, HDEV is fitted with four distinct types of cameras, each of them demonstrating a different type of technology. Every week, images from each camera are analyzed to assess the level of deterioration, so that the project team can ultimately determine which technology works best in space.