Urge President Obama to Move Us Toward a World Free of Nuclear Weapons
The world has changed dramatically since the end of the Cold War. In the 21st century, nuclear weapons are a global security liability, not an asset. Tell the president to reduce the threat from nuclear weapons.
Has anyone ever been hit by a piece of falling piece of space debris? Find the answer to this question and other interesting facts about space debris re-entry in our Space Age Trivia section.
Featured Satellites: Galileo
Four Galileo In-Orbit Validation satellites in orbit. (Copyright ESA—P. Carril)
Galileo is Europe’s satellite navigation system, designed to provide an accurate global positioning service under civilian control. It is inter-operable with GPS and Glonass, the US and Russian global satellite navigation systems. In October 2011, the first two of four operational satellites were launched, with two more following in October 2012. The four satellites, the minimum number for satellite navigation in principle, are serving to validate and test the Galileo system’s concept. The fully deployed Galileo system is designed to have 30 satellites, positioned in three circular Medium Earth Orbit (MEO) planes with inclinations of 56 degrees to the equator.