To be launched in 2010/2011, Keo will fly through space for 50000 years before returning to Earth.
KEO is the name of a proposed space time capsule which was to have been launched in 2003 carrying messages from the citizens of present Earth to humanity 50,000 years from now, when it would reenter Earth's atmosphere. Source
Every person living on Earth, small, weak, powerful or rich is provided with 4 pages of liberty and equality to pen down his message destined for his faraway great grandchildren. All the messages received, without undergoing any censorship, will be embarked aboard KEO. Read more