Japan Tsubame, Super Low Altitude Test Satellite, is a JAXA satellite intended to demonstrate operations in very low Earth orbit (below 200 km), using ion engines to cancel out aerodynamic drag and equipped with sensors to determine atomic oxygen density, an exposure facility to measure material degradation in the 200 km orbit, and a small camera.
Initial designs had conventional, though slightly canted, solar panels (compare to the aerodynamic shape and on-body solar panels of GOCE, which flew in a 255 km orbit).
Low Earth Orbit” (LEO), where many satellites live, goes from 160km (100 miles, 525,000 feet) to 2,000km (1,240 miles, 6.5 million feet). In LEO, we have some sample objects to look at.
Our own Project Calliope satellite will be 230km up (143 miles, 755,000 feet). The International Space Station (ISS) cruises higher up, from 278km (173 miles, 912,000 feet) to 460km (286 miles, 1.5 million feet).
Starting above the ‘space’ limit but a bit before LEO, the inner Van Allen Belts, which magnetically shield the Earth’s surface from high energy particles, extend from 100km (62 miles, 33,000 feet) up to 10,000km (6,200 mil, 3.3 million feet).
If there was more powerful propulsion it could be possible to sustain orbit at about 140 kilometers.
A constant 0.2 Newtons of thrust could allow a satellite to operate at 146 kilometers of altitude.

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