The Philae instrumentation and the importance of anticipated measurements

While Philae's landing attempts are still under progress, a set of 10 high end instruments will significantly contribute to the understanding of the comet's composition, in a way that was never possible before.

In total, Philae carries a science payload of ten instruments, weighting 26.7 kilograms (59lb), summing up to over one-fourth of the mass of the lander. One of the main systems, also referred to as SD2, is capable of drilling up to nine inches, obtaining soil samples and distributing them to other systems for analysis. SD2 consists of four subsystems: a drill, carousel, numerous ovens and a volume checker. In total, 26 platinum ovens will be used to preserve constant sample temperature as well as one oven for clearing the drill bit for reuse. 

Soil samples will be analyzed by a combined gas chromatograph and time-of-flight mass spectrometer, named COSAC, in order to determine the content of volatile components. In the same way, Ptolemy will be employed to measure stable isotope ratios of key volatiles on the comet's nucleus, while information on the composition, texture and reflectivity of the soil samples will be extracted from ÇIVA, a group of six identical micro-cameras, also equipped with spectrometers. CONSERT, another instrument mounted on Philae, based on electromagnetic wave propagation, will aid in the determination the comet's internal structure. It will emit radio waves that will travel through the comet's center and then will get picked up by the orbiting Rosetta. 

Additionally, information on the comet's surface density, thermal and mechanical properties will be collected through MUPUS, MUlti-PUrpose Sensors for Surface and Sub-Surface Science, while the nucleus' magnetic field and its interactions with solar wind will be studied with ROMAP, The Rosetta Lander Magnetometer and Plasma Monitor, a magnetometer and plasma sensor. The comet's outer layers will be studied with SESAME, The Surface Electric Sounding and Acoustic Monitoring Experiments, that will employ three different instruments (Cometary Acoustic Sounding Surface Experiment, Permittivity Probe and Dust Impact Monitor) to measure different sound aspects, such as its electrical characteristics and the way it travels through the comet's surface. 

All the obtained data are expected to significantly help in the better understanding and modeling of the solar system formation, given the belief that the comet was formed from leftover material, as the Earth and the other planets of the solar system were coalescing. Furthermore, it is widely believed that in that particular period, comets and asteroids were responsible for bringing water and potentially other organic molecules to Earth. In the case that water ice is located on the comet, Philae's measurements may help verify this hypothesis.