Philae (FEE-lay) is named after an island in the Nile River where archaeologists found an inscription confirming their understanding of ancient Egyptian hieroglyphs based on the Rosetta Stone.
Launch date: March 2, 2004
Launch mass (lander only): 100 kilograms (including 26.7 kg of scientific payload)
Lander Dimensions: 1 cubic metre
Distance travelled to comet (aboard the much larger Rosetta spacecraft): 6,550 million kilometres
Total cost of mission including lander and orbiter: €1.4-billion ($1.9-billion)
Touchdown on comet: Nov. 12, 2014
Last contact prior to loss of power: Nov. 15, 2014, 1:15 CET
Signal reacquired: June 13, 2015, 22:28 CET
Some of the the scientific instruments that may be used if the mission resumes:
CIVA: a system of seven cameras that can take panoramic pictures of Philae's landing site. The cameras could show physical changes to the landing site that may have occurred since last November and help engineers understand the lander's position and attitude on the surface
MUPUS: a suite of sensors that can measure the density and thermal and mechanical properties of the comet's surface
ROMAP: a device for studying the comet's magnetic field and interaction with charged particles from the sun
SD2: a drilling system designed to deliver a surface sample to other experiments that can analyze the comet's chemical composition. A single attempt to extract a sample failed last November. It will require battery power to operate the drill again.
APXS: a device that uses a radioactive source to measure the elemental composition of the comet's surface material. It was unable to make contact with the surface before the lander went silent last September.