Rosetta and Philae Go for separation

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 upwards 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, a 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. “We’ll need some luck not to land on a boulder or a steep slope.” “There were various problems with the preparation activities overnight but we have decided to ‘go’. Rosetta is lined up for separation,” says Paolo Ferri, ESA’s head of mission operations. Thus despite the potential problem concerning the moment of touchdown, separation will proceed on the planned timeline. Separation will occur in space at 08:35 GMT / 09:35 CET, but it will take the radio signals from the transmitter on Rosetta 28 minutes and 20 seconds to reach Earth and be transferred to the Rosetta Mission Control Centre at ESA’s Space Operations Centre in Darmstadt, Germany. That means we must wait until about 09:03 GMT / 10:03 CET for confirmation the separation has happened correctly. The Go/No-Go decisions leading up to this milestone began last night at 19:00 GMT / 20:00 CET, with the first confirming that Rosetta is in […]



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