2004: On 5 February 2004, ESA announced that the Rosetta mission's lander would be named “Philae”.
Philae is the island in the river Nile on which an obelisk was found that had a bilingual inscription including the names of Cleopatra and Ptolemy in Egyptian hieroglyphs. This provided the French historian Jean-François Champollion with the final clues that enabled him to decipher the hieroglyphs of the Rosetta Stone and unlock the secrets of the civilisation of ancient Egypt.
Just as the Philae Obelisk and the Rosetta Stone provided the keys to an ancient civilisation, the Philae lander and the Rosetta orbiter aim to unlock the mysteries of the oldest building blocks of our Solar System - comets.
Rosetta's study of Comet Churyumov-Gerasimenko will allow scientists to look back 4600 million years to an epoch when no planets existed and only a vast swarm of asteroids and comets surrounded the Sun. On arrival at the comet in 2014, Philae will be commanded to self-eject from the orbiter and unfold its three legs, ready for a gentle touchdown. Immediately after touchdown, a harpoon will be fired to anchor Philae to the ground and prevent it escaping from the comet's extremely weak gravity. The legs can rotate, lift or tilt to return Philae to an upright position.
Philae will determine the physical properties of the comet's surface and subsurface and their chemical, mineralogical and isotopic composition. This will complement the orbiter's studies of the overall characterisation of the comet's dynamic properties and surface morphology. Philae may provide the final clues enabling the Rosetta mission to unlock the secrets of how life began on Earth.