November 12, 2014

Philae (spacecraft)

Philae makes the first soft landing on a comet

Philae fell for seven hours with no engine and no steering, and the harpoons meant to pin it down never fired. One landing turned into three.

Released at 08:35, down at 15:34

Rosetta released the Philae lander at 08:35 GMT on 12 November 2014, 22.5 kilometres from the centre of Comet 67P/Churyumov–Gerasimenko; confirmation reached Earth at 09:03.

Philae descended for about seven hours without propulsion or guidance and first touched the comet at 15:34 GMT, at the chosen Agilkia site. The signal reached ESA's control centre at 16:03, because the one-way radio delay was 28 minutes 20 seconds.

It was the first soft landing on a comet — made by Philae, the detachable lander, not by Rosetta itself.

Three contacts, not one

The anchoring harpoons did not fire and the lander rebounded. Telemetry later showed three surface contacts: 15:34, 17:25 and 17:32 GMT.

After the first impact Philae stayed off the surface for about 1 hour 50 minutes and travelled roughly a kilometre, made a smaller second hop, and finally stopped at a poorly illuminated site later named Abydos.

ESA announced a single successful touchdown that afternoon; the three-contact trajectory was reconstructed from telemetry over the following days.

Working from a cliff shadow

Philae began its programmed experiments and sent images and scientific data to Earth through Rosetta while sitting unanchored in an uncertain orientation.

At its final site it received about 1.5 hours of sunlight during each 12.4-hour comet day; the site originally chosen would have given it nearly seven.

It completed most of its first science sequence and returned data for nearly 57 hours before entering hibernation as its battery depleted.

Sources

Researched 24 Aug 2026 9 sources not yet audited

How this was checked

Researched from the web into a fact sheet and rewritten from that sheet. This article has not yet had an independent model audit. How the pipeline works →

What the sources leave uncertain

The date and first-touchdown achievement are certain. “Successfully lands” needs qualification because Philae failed to anchor, bounced twice and stopped far from the intended site.
ESA initially announced a single successful touchdown; the three-contact trajectory was reconstructed from telemetry over the following days.
The first touchdown occurred at 15:34 GMT on the comet, while Earth received confirmation at 16:03 GMT because of the radio delay.