In August of 1959, nearly 13 years after the V-2 flight captured the first sub-orbital images of Earth, Explorer 6 was launched into orbit. There, it sent back hundreds of hours of scientific data and, most importantly, our first orbital photograph of the planet we call home.
An important mission
First and foremost, Explorer 6’s job was to measure all things electromagnetic in the upper atmosphere, from radio propagation to cosmic rays. It also observed the actions of micrometeorites as they passed from the vacuum of space into our upper atmosphere, where they faced resistance and friction before burning up in the resulting heat. Also onboard was a scanning device that was being tested for use in photographic Earth’s cloud cover from above. That scanning device was responsible for capturing our first image of Earth from orbit.
While it may not look like much, that white smudge on a dark gray background is a photo of a portion of the central Pacific Ocean, illuminated by the sun, and its cloud cover. At the time the photo was taken, Explorer 6 was one week into its mission and roughly 17,000 miles above the surface, zooming through the skies over Mexico.
Explorer 6 remained in service for 60 days before its power level dropped too low, causing it to lose contact with ground control and gradually fall from orbit. It had been running at partial power after only three of its four solar panels deployed. Even after the satellite was declared “dead,” it remained in orbit for nearly two years, and during that time, scientists found a use for it. Explorer 6 became a target for an anti-satellite missile test using the Bold Orion rocket. About a week after NASA lost contact with the satellite, the US Air Force set their rocket’s sights on the tiny satellite and fired away. The test was a success, passing within three and a half miles of the craft.