Early proposals
The first published mathematical study of the possibility of an artificial satellite was Newton's cannonball, a thought experiment by See more

Orbit and altitude control
Most satellites use chemical or ion propulsion to adjust or maintain their orbit, coupled with reaction wheels to control their See more

The environmental impact of satellites is not currently well understood as they were previously assumed to be benign due to the rarity of satellite launches. However, the exponential increase and projected growth of satellite launches are bringing the issue into … See more

• High-altitude platform station
• Solar aircraft
• Satellite refuelling See more

Earth observation
Earth observation satellites are designed to monitor and survey the Earth, called remote sensing. … See more

Issues like space debris, radio and light pollution are increasing in magnitude and at the same time lack progress in national or international regulation. Space debris pose dangers to the spacecraft (including satellites) in or crossing geocentric orbits and have the … See more

• EO Portal directory Archived 23 September 2013 at the Wayback Machine See more