Rosetta blog: Reconstructing Philae’s moody opposite a comet

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Data from both a Philae lander and Rosetta orbiter experiments, as good as make-believe formula formed on Philae’s automatic pattern have been used to refurbish a lander’s opinion and suit during a skirmish and touchdowns on Comet 67P/Churyumov-Gerasimenko on 12 Nov 2014.  A new animation was presented today, one year after Philae overwhelmed down on a comet, focusing on Philae’s thespian two-hour moody from Agilkia to Abydos – in this blog post we hear from some of a people behind a production.

Over a final year, some-more and some-more sum about accurately what happened have been gleaned from a minute analysis of information from several instruments and sensors. These have supposing an endless comment of a events from a impulse Philae distant from Rosetta, by a seven-hour descent, and a successive two-hour moody opposite a aspect that enclosed 3 touchdowns and a collision.

A numerical make-believe of Philae, calibrated and accurate with exam information from a image of a lander, was used to indication a communication with a aspect during Agilkia. The successive giveaway moody and after rebound dynamics were reconstructed from a arena in and with opinion information successive from a ROMAP instrument.

Together, these efforts done it probable to establish Philae’s poise on 12 Nov 2014 with sufficient correctness to make this new visualisation.

Philae’s initial touchdown on a comet (TD1) during 15:35 UT is compelled by a unequivocally accurate believe of a alighting position and course formed on ROLIS images, a times during that a 3 feet contacted a aspect as totalled by SESAME, a straight dynamics from a damping tube housekeeping data, lander dynamics simulations explaining a footprints imaged after by OSIRIS, outbound opinion reconstructed from ROMAP and RPC-MAG data, and a outbound quickness matrix formed on a arena reconstruction.

Felix Finke of DLR, one of a scientists obliged for a prolongation of a animation said, “By animating Philae’s spaceflight, we are gaining an impossibly singular discernment into what unequivocally happened during Philae’s touchdowns final year.”

“This animation and a information it relies on is providing a basement of a still persisting contention about Philae’s predestine on a comet,” combined Philip Heinisch from TU Braunschweig.

Immediately after a initial touchdown, Philae’s on-board stabilising flywheel was incited off and a residual bony movement eliminated to a lander itself. This caused a lander to spin up, reaching a revolution duration of about 13 seconds. This elementary revolution unkempt into a acrobatics nutation after a collision of one leg with a edge of a Hatmehit void during 16:20 UTC.

The animation provides an considerable painting of a successive pell-mell moody poise adult to a second touchdown (TD2) during 17:25 UT. The acrobatics motions of a lander during this proviso have been reconstructed regulating captivating margin measurements done by a ROMAP experiment. Even in a low ambient captivating margin of a cometary environment, both revolution and nutation could clearly be identified.

Hans-Ulrich Auster, PI of a ROMAP magnetometer during TU Braunschweig explained: “The successive hit of a acrobatics Philae with a aspect during a second touchdown was a many vicious one. The lander done hit with a aspect and Philae left a comet again, tranquil by a dual legs to a left and to a right of a patio and achieved a final rotation, a back roll, about a lander Y-axis.”


Welcome to a comet! Philae’s initial images from Abydos. ESA/Rosetta/Philae/CIVA

Fortunately, a movement was still vast adequate to right a lander adult onto a legs again and eventually into a final resting position during Abydos during 17:31 UT. The magnetometer group also reconstructed a back loop between a second and third touchdowns, along with a final opinion during a resting place, in front of a landscape seen in a CIVA images.

“With hindsight, one year later, and examination a movie, we am dismayed how propitious we were!” says Jens Biele, a lead author of a initial systematic paper relating lander impacts to aspect properties. “But we schooled a lot about a aspect automatic properties from these bounces, and Philae finally landed in an engaging turf where we would have never dared to land in a initial place!”

Detailed systematic and engineering analyses of a underlying information will be published in an arriving special emanate of Acta Astronautica.

More about Philae’s skirmish and trajectory:
Reconstructing Philae’s trajectory
Did Philae graze a void edge during a initial bounce?
OSIRIS perspective of Philae flapping opposite a comet

Also see: Biele et al., The landing(s) of Philae and inferences about comet aspect automatic properties 


Source: Rosetta blog