Rosetta Space Probe Lands on Comet with DC Motors
Exploring New Territory and Making History
At the end of May 2014, the Rosetta space probe moved into an orbit around the comet 67P/Churyumov-Gerasimenko in order to map its surface and prepare for the landing of lander unit, Philae. This ballistic lander, weighing 100 kg, landed successfully on the comet on November 12th, 2014. The probe is powered by FAULHABER DC motors to ensure a secure landing on the comet. After an adventurous journey of over 10 years through outer space, this is a first in the history of space travel. Landing on a comet – a maneuver which has never been performed before – is in many ways beset with difficulties. The search for a suitable place to land was carried out on the basis of high‐resolution images of the comet's surface. These only became available, however, after Rosetta was just a few kilometers of the comet. There is also little known about the exact composition of the surface of the comet. Ice and dust, fissures and craggy structures are factors that needed to also be considered for the landing.
Accordingly, the Philae lander unit was conceived to handle many challenges. One of the greatest challenges was the minimum gravity affecting 67P. There was indeed no risk that the probe could crash or break apart upon landing, as it only weighs a few grams on the comet's surface. Rather, the concern was preventing Philae from bouncing off the surface of the comet after landing. FAULHABER DC motors designed harpoon anchoring system that would help firmly anchor Philae on the comet upon landing. In order to find firm footing on the surface and ensure this secure placement throughout the entire duration of the mission, a special anchor system was developed. Immediately after contacting the ground upon landing, two harpoons were to be shot via propellant charge into the surface of the comet. To secure the lander, the lines are then drawn taut by means of two cable winches, each one also driven by a FAULHABER motor. Thanks to FAULHABER's expertise with regard to applications in outer space, the harpoons and a host of other systems of the lander are equipped with FAULHABER drives.
Although the harpooning systems were initially shown as triggered, further investigation reveals that the harpoons did not deploy as planned. However, the harpoon anchoring system was just one application of FAULHABER motors in the Philae landing; once the explorer unit landed on the surface, several DC motors were used to help provide support during touchdown by converting kinetic energy to much needed electrical and thermal energy.
Additional Drive Systems Still in Use
Beyond the securing the landing, and providing electrical and thermal energy, there are a total of 14 different FAULHABER drive systems being used for other important tasks during this mission; many of the instruments and analyses systems being used to collect samples from the comet are powered by FAULHABER dc motors. Because of the extreme, and varying ambiant conditions on the comet's surface the devices and systems used required DC motors that could withstand challenging conditions without risk of failure. As a result, valuable insights into the origin and evolution of our solar system will be achieved through the mission; samples are being sent from the lander to Rosetta, and then to Earth as the mission continues.
MICROMO is a proud member of the FAULHABER Group. The tradition of innovation continues, on Earth and throughout space.
Back in November, the battery of the lander drained after 60 hours of being on the comet's surface. However, according to the European Space Agency (ESA) blog, the Philae lander has awakened from hibernation! On June 13th, Philae made contact with Earth (via Rosetta) for 85 seconds. With the comet getting closer to the sun there is now sufficient solar power to allow Philae to continue its mission and regain contact with Rosetta and Earth. More details on the updated story can be found in an article on the ESA blog, and other news sources.
Over the weekend the twitter accounts created for the Rosetta Probe and the Philae lander, respectively, shared the news with the following tweets:
Hello Earth! Can you hear me? #WakeUpPhilae— Philae Lander (@Philae2014) June 14, 2015
Congratulations to everyone involved with the mission!
An Additional (and Final) Update on Rosetta
On September 30th, 2016 the Rosetta probe sent its last signal to Earth at 13:129pm Central European Time. The Rosetta probe had been orbiting the Churyumov-Gerasimenko comet since the Philae lander touched down on November 12th, 2014. The ESA mission ended with Rosetta's impact on the comet Churyumov-Gerasimenko.
On the collision course to the comet, however, seven sensors and instruments were able to record data and send it to earth. "The mission of Rosetta can be described as a milestone in space travel. The achievements of the scientists and engineers have given us an incredible insight into the history of our planetary system," says Professor Pascale Ehrenfreund, Chairman of the Board of DLR. "The data and images that Rosetta and Lander Philae have transmitted to us will form the basis for planning and scientific questions for future missions in our solar system."