The Philae platform is constituted of 8 sub-systems:
- The structure
- The thermal control system
- The power management system
- The flight electronics (main memory, main clock, Telemetry/Telecommand management (TM/TC), etc.)
- The Band S telecommunication system (two patch antennas on the upper face)
- The inertial wheel
- The cold gas propulsion system
- The landing gear (three legs, three feet with rigging screws, telescopic tube to cushion)
In total, a mass of 98 kg including 22 kg of instruments.
Energy/power from piles (1300 W.h), batteries (140 W.h) et photopiles (9 W).
On board memory: 2 x 16 Mb.
Communication with the orbiter: 16 kB/s.
Designed, developed, tested and operated by a European consortium.
Two other systems are located on the Orbiter but are functionally dependent of the Lander:
- The Orbiter/Lander interface for the TM/TC management (which includes 2 patch antennas identical to the Lander's ones)
- The Lander separation system (an endless screw that can accelerate Philae up to 50 cm/s, and a spring as safeguard)
Connected to the Orbiter, the power and communication can pass through wired connections called umbilicus. The three legs of the landing gear are folded along the solar panels.
The commands for the instruments and the data from the instruments are managed by the main flight electronics which apply the priorities and dating decided from the Earth.
The Rosetta Lander got a name: PHILAE
Like the Philae obelisk which proved essential to the Rosetta Stone to help deciphering the Egyptian hieroglyphs, the Philae Lander will help the Rosetta Orbiter unlock the mysteries of the comets.