The sky: a part of divinity and life
We humans have always looked to the sky to find peace of mind or connect to something larger than ourselves. Crucial elements required to create life can be found inside the furnace of stars: we are stardust. Since life began on Earth, living creatures have evolved in relation to electro-magnetic fields emitted by the Sun, the Earth and lightning.
The atmosphere: our tiny habitat
The Earth’s atmosphere helps create the right temperature, pressure and chemical conditions for life. It also protects us from the sun’s harmful ultraviolet emissions. If Earth was the size of an apple, the atmosphere would be 1/20th of the apple’s skin. Space begins at the Kármán line, only 100 km (62 miles) above sea level. If you ever cross deserted land, the closest human beings might be astronauts in the International Space Station, passing 420 km above your head.
A satellite constellation uses multiple satellites to cover larger areas on the ground. The further from the Earth, the wider the area that the satellite can cover. Yet, most constellations use Low Earth Orbits (LEO, at altitudes of 160 km – 2,000 km); some use Medium Earth Orbits (MEO, at 2,000 km – 36,000 km). Geostationary Orbit (GEO) satellites keep a stationary position 36,000 km above the same spot on Earth. A TV satellite dish always points to the same GEO broadcasting satellite. The most recent Internet service constellations use LEO orbits.
