Following a night of critical Go/NoGo decisions, Rosetta and Philae are cleared for separation, despite a problem onboard the lander.
During checks on the lander’s health, it was discovered that the active descent system, which provides a thrust to avoid rebound at the moment of touchdown, cannot be activated.
At touchdown, landing gear will absorb the forces of the landing while ice screws in each of the probe’s feet and a harpoon system will lock Philae to the surface. At the same time, the thruster on top of the lander is supposed to push it down to counteract the impulse of the harpoon imparted in the opposite direction.
“The cold gas thruster on top of the lander does not appear to be working so we will have to rely fully on the harpoons at touchdown,”says Stephan Ulamec, Philae Lander Manager at the DLR German Aerospace Center read more…