I am heavily invested in Rosetta and Philae, the orbiter/lander combo at Comet 67/P. It was the focus of my recent trip to NASA JPL and our recent show on Slooh.com. I did lots of show prep.
Everything went right with Philae until it didn’t. It’s ending will deprive science of much of the data they’d hoped for.
Philae was released by Rosetta and dropped toward the comet. The word ESA used was “ballistic.” With nearly zero gravity the 200’ish pound Philae weighed around a gram. The drop took seven hours.
It hit the comet’s surface at walking speed, but the ice screws didn’t grip and its harpoons didn’t deploy.
The harpoons did not fire and Philae appeared to be rotating after the first touchdown, which indicated that it had lifted from the surface again.
Stephan Ulamec, Philae manager at the DLR German Aerospace Center, reported that it touched the surface at 15:34, 17:25 and 17:32 GMT (comet time – it takes over 28 minutes for the signal to reach Earth, via Rosetta). The information was provided by several of the scientific instruments, including the ROMAP magnetic field analyser, the MUPUS thermal mapper, and the sensors in the landing gear that were pushed in on the first impact.
The first touchdown was inside the predicted landing ellipse, confirmed using the lander’s downwards-looking ROLIS descent camera in combination with the orbiter’s OSIRIS images to match features.
But then the lander lifted from the surface again – for 1 hour 50 minutes. During that time, it travelled about 1 km at a speed of 38 cm/s. It then made a smaller second hop, travelling at about 3 cm/s, and landing in its final resting place seven minutes later. ESA news release
The probe has come to rest alongside a large boulder. It is blocked from the Sun. Its solar cells, hoping for eight hours of daylight, only get one and a half.
Philae will work for a few days, then run out of juice. It’s a lander, not a rover.
In the meantime there’s concern deploying some of its instruments could bounce Philae again. No one knows where. At the moment even scientists aren’t even sure where on the comet Philae sits.
There will be good science from this mission, but not as much as hoped for. Space continues to be a supremely challenging pursuit. It is still much too dangerous and expensive to include humans. It always will be that way.