Satellites travel to low-Earth orbit, geostationary orbit and deep into interplanetary space, orbiting the Sun, Mars and other celestial bodies. ESOC controls the Agency's ESTRACK network, a global system of tracking stations that transmit commands and receive valuable scientific data. ESOC is also responsible for tracking space debris, a growing threat to commercial and scientific exploitation of near-Earth orbits, and for developing new techniques and tools for mission operations.