The International Year of Astronomy

 

Although space exploration is only half a century old, just ten years older than the Guiana Space Centre itself, more than 5,000 years were needed to send the first satellite into space … from the Chaldeans and the Mesopotamians to today’s space engineers, the route was a long one!

José Golitin, one of many CNES engineers at the Guiana Space Centre, buzzes with enthusiasm at the magic of astronomy, “a strange word that triggers something in the imagination.”  Nevertheless, he is an engineer first and foremost and goes on to say that “the precursor of all other sciences, astronomy is based on scientific methodology and hence demonstration, which infers the concept of operational constraints. At the heart of our activity and resources, I am lucky enough to have a very tangible awareness of our Universe.”

This is indeed true, as José is responsible for Telemetry.  Governed by Kepler’s laws, the telemetry from a launcher is essential to calculating the orbit parameters for the payloads of the European Ariane launcher.   José explains that “basically, everything begins for the passenger when our mission, that of the launcher, comes to an end.”  And for good reason; either the launcher is placing a satellite in orbit, or it is sending a probe into deep space.  The satellite’s trajectory depends on its velocity: coupled with the Earth’s gravitational force, a velocity of 8 km/s creates an equilibrium which enables an injected satellite to remain on its orbit.  If injected at a velocity of 11 km/s, the satellite becomes a probe which can escape from the Earth’s gravity and head straight out into space, drawn by the gravitational force of the other bodies in the Universe.