The Japanese government is scheduled to launch a testing model of earth observation satellite that travels low over the ground within 2017. While most existing earth observation satellites travel at 600-800 km above the ground, the testing model can travel at 180-300 km above the ground. Because a satellite has 1,000 times more air resistance at a low altitude than it has in space, it goes down unless some measures are taken. The testing model keeps its altitude by emitting a highly efficient ion propulsion engine, and its airframe is modified to reduce air resistance.
The Japan Aerospace Exploration Agency is scheduled to launch the testing model using the H2A rocket within 2017. Because it travels low over the ground, it can take clear photos using a low performance sensor. It is nicknamed “Tsubame (Swallow).” In addition to the ability to take clear photos for conventional earth observation, it can hopefully be used for security.
Tsubame (Swallow) earth observation satellite