Date November 14, 2014. After achieving touchdown on a Comet for the first time in history, Scientists and Engineers are busy analyzing this new world and the nature of the landing. They discovered that the lander did not just touch down on Comet 76P/Churyumov-Gerasimenko once, but three times.

 

This image from Rosetta's OSIRIS narrow-angle camera is marked to show the location of the first touchdown point of the Philae Lander. It is thought that Philea bounced twice before settling on the surface of Comet 67P/Churyumov-Gerasimenko. The OSIRIS image was taken from a distance of 50km on 2nd September 2014, prior to landing.

 

After achieving touchdown on a Comet for the first time in history, scientists and engineers are busy analysing this new world and the nature of the landing.

 

Touchdown was confirmed at ESA's Space Operations Centre in Darmstadt, Germany at 16:03 GMT/17:03 CET on 12 November.

 

Since then, scientists, flight dynamics specialists and engineers from ESA, the lander Control Centre in Cologne, Germany and the Philae Science, Operations and Navigation Centre in Toulouse, France have been studying the first data returned from the Lander.

 

These revealed the astonishing conclusions that the Lander did not just touch down on Comet 67P/Churyumov-Gerasimenko once, but three times.

 

The harpoons did not fire and Philae appeared to be rotating after the first touchdown, which indicated that it had lifted from the surface again. Stephen Ulamec, Philae manager at the DLR German Aerospace Centre, reported that it touched the surface at 15:34, 17:25 and 17:32 GMT (Comet time -- it takes over 28 minutes for the signal to reach Earth, via Rosetta).

 

This information was provided by several of the scientific Instruments, including the ROMAP Magnet Field analyser, the MUPUS thermal mapper, and the sensors in the landing gear that were pushed in on the first impact.

 

The first touchdown was inside the predicted landing Eclipse, confirming using the lander's downward-looking ROLIS decent camera in combination with the Obiter's OSIRIS images to match features.

 

But then the lander lifted from the suface again -- for 1 hour 50 minutes. During that time, it travelled about 1km at a speed of 38cm/s, and landing in it's final resting place place seven minutes later.

 

The touchdown signal generated on the first touchdown induced the instruments to "think" that Philea has landed, triggering the next sequence of experiments. Now those data are being used to interpret the bounces. Preliminary data from the CONSERT experiment suggest that Philea could have travelled closer to the large depression known as Site B, perhaps sitting on its rim. High-Resolution orbiter images, some of which are still stored on Rosetta, have yet to confirm the location.

 

The Lander remains unanchored to the surface at an as yet undetermined orientation. The science instruments are running and are delivering images and data, helping the team to learn more about the final landing site.

 

The descent camera revealed that the surface is covered by dust and debris ranging from millimetre to metre sizes. Meanwhile, Philae's CIVA camera returned a panoramic image that on first impressions suggests the Lander is close to a rocky wall, and perhaps has one of its three feet in open space.

 

After discussions as to whether to activate those science instruments that may cause the position of Philea to shift, MUPUS and APXS have both been deployed.

 

The primary battery enabling the core science goals of the Lander may run out some time in the next 24 hours. As for the secondary battery, charged by solar panels on Philea, with only 1.5 hours of sunlight available to the lander each day, there is an impact on the energy budget to conduct science for a longer period of time. The original landing site offered nearly seven hours of illumination per 12.4 hour Comet day.