A recent #CometLanding tweet from Science magazine journalist Eric Hand states that no sample was obtained for analysis by the Philae lander's drill before the batteries were depleted:
COSAC PI: Drill tried to deliver sample. Ovens heated up. But data show no actual delivery. "There’s nothing in it." #CometLanding
The failure to deliver comet material to the ovens means that the data received from the isotope abundance experiment Ptolemy and from the complex organic chemicals experiment COSAC will not tell us anything useful about the comet's composition.
ESA has released preliminary analysis of the MUPUS (Multi-Purpose Sensors for Surface and Subsurface Science) experiment on the Philae lander.
http://blogs.esa.int/...
Because part of the MUPUS package was contained in the harpoons, some temperature and accelerometer data could not be gathered. However, the MUPUS thermal mapper, located on the body of the lander, worked throughout the descent and during all three touchdowns.
At Philae’s final landing spot, the MUPUS probe recorded a temperature of –153°C close to the floor of the lander’s balcony before it was deployed. Then, after deployment, the sensors near the tip cooled by about 10°C over a period of roughly half an hour.
“We think this is either due to radiative transfer of heat to the cold nearby wall seen in the CIVA images or because the probe had been pushed into a cold dust pile,” says Jörg Knollenberg, instrument scientist for MUPUS at DLR.
The probe then started to hammer itself into the subsurface, but was unable to make more than a few millimetres of progress even at the highest power level of the hammer motor.
“If we compare the data with laboratory measurements, we think that the probe encountered a hard surface with strength comparable to that of solid ice,” says Tilman Spohn, principal investigator for MUPUS.
Looking at the results of the thermal mapper and the probe together, the team have made the preliminary assessment that the upper layers of the comet’s surface consist of dust of 10–20 cm thickness, overlaying mechanically strong ice or ice and dust mixtures.
At greater depths, the ice likely becomes more porous, as the overall low density of the nucleus – determined by instruments on the Rosetta orbiter – suggests.
There is a small hope that later in 2015 when Comet 67P/C-G is closer to the sun the Philae lander may get enough sunlight to come out of hibernation.