Philae (spacecraft)

Philae

Illustration of Philae
Mission type	Comet lander
Operator	European Space Agency / DLR
COSPAR ID	2004-006C
Website	www.esa.int/rosetta
Mission duration	Planned: 1-6 weeks Hibernation: 15 November 2014 – 13 June 2015
Spacecraft properties
Manufacturer	DLR / MPS / CNES / ASI
Launch mass	100 kg (220 lb)
Payload mass	21 kg (46 lb)
Dimensions	1 × 1 × 0.8 m (3.3 × 3.3 × 2.6 ft)
Power	32 watts at 3 AU
Start of mission
Launch date	2 March 2004, 07:17 (2004-03-02UTC07:17) UTC
Rocket	Ariane 5G+ V-158
Launch site	Kourou ELA-3
Contractor	Arianespace
End of mission
Last contact	9 July 2015, 18:07 (2015-07-09UTC18:08) UTC
67P/Churyumov–Gerasimenko lander
Landing date	12 November 2014, 17:32 UTC
Landing site	Abydos
Instruments APXS Alpha particle x-ray spectrometer CIVA Comet nucleus Infrared and Visible Analyser CONSERT Comet Nucleus Sounding Experiment by Radiowave Transmission COSAC Cometary Sampling and Composition MUPUS Multi-purpose Sensors for Surface and Subsurface Science PTOLEMY Gas chromatograph and medium resolution mass spectrometer ROLIS Rosetta Lander Imaging System ROMAP Rosetta lander Magnetometer and Plasma monitor SD2 Sampling, Drilling and Distribution SESAME Surface Electric Sounding and Acoustic Monitoring Experiment CASSE Comet Acoustic Surface Sounding Experiment DIM Dust Impact Monitor PP Permittivity Probe

Philae (/ˈfaɪliː/ or /ˈfiːleɪ/) is a robotic European Space Agency lander that accompanied the Rosetta spacecraft until it separated to land on comet 67P/Churyumov–Gerasimenko, ten years and eight months after departing Earth. On 12 November 2014, Philae touched down on the comet, but it bounced when its anchoring harpoons failed to deploy and a thruster designed to hold the probe to the surface did not fire. After bouncing off the surface twice, Philae achieved the first-ever "soft" (nondestructive) landing on a comet nucleus, although the lander's final, uncontrolled touchdown left it in a non-optimal location and orientation.

Despite the landing problems, the probe's instruments obtained the first images from a comet's surface. Several of the instruments on Philae made the first direct analysis of a comet, sending back data that will be analysed to determine the composition of the surface.

On 15 November 2014 Philae entered safe mode, or hibernation, after its batteries ran down due to reduced sunlight and an off-nominal spacecraft orientation at its unplanned landing site. Mission controllers hoped that additional sunlight on the solar panels might be sufficient to reboot the lander.Philae communicated sporadically with Rosetta from 13 June to 9 July 2015, but contact was then lost. The lander's location was identified to within a few tens of metres, but it was not seen. Philae, though silent, was finally identified unambiguously, lying on its side in a deep crack in the shadow of a cliff, in photographs taken by Rosetta on 2 September 2016 as the orbiter was sent on orbits closer to the comet. Knowledge of its precise location will help in interpretation of the images it had sent. On 30 September 2016, the Rosetta spacecraft ended its mission by landing in the comet's Ma'at region.