The modern era of low-flying satellites may begin this week
The idea of flying satellites in "very" low-Earth orbit is not new. Dating back to the dawn of the space age in the late 1950s, the first US spy satellites, as part of the Corona program, orbited the planet as low as 120 to 160 km (75 to 100 miles) above the Earth.
This low vantage point allowed the Kodak cameras on board the Corona satellites to capture the highest-resolution images of Earth during the height of the Cold War. However, flying so close to the planet brought a number of challenges, most notably that of atmospheric drag.
For much of the space age, therefore, satellites have flown much higher orbits. Most satellites today fly at an altitude of between 400 and 800 km (250 and 500 miles), which is high enough to avoid the vast majority of atmospheric drag while still being close enough to offer good communications and a clear view of the planet.
© Albedo
