Clarke is credited with the concept of communications satellites in 1945, decades before they became a reality. Geosynchronous orbits, which keep satellites in a fixed position relative to the ground, are called "Clarke orbits."
Several real-life space vessels have been named in honor of his fiction works, as a testament to how they helped scientists envision the future of humanity's place in the cosmos [video]. NASA named the command module for the Apollo 13 mission as well as a Martian orbiter after Clarke's 'Odyssey' [video].
Clarke was also honored by the United Kingdom, which had him knighted in 2000, and Sri Lanka, [video] which bestowed upon the author its highest civilian honor in 2005. Sir Arthur will be missed by the international space community. Ad Astra our friend!