Lika Electronic, heading for space
Innovative solutions that make a difference to the world always come from ambitious challenges and creative synergies. Communication and interaction between advanced research and practical engineering experience are at the heart of any effort at developing intelligent products and cutting edge systems. This is the reason why, s ince its inception in 1982, Lika Electronic has been working in close cooperation with universities and research centres as well as key suppliers and customers from all over the world in order to build sophisticated, tailor-made motion control solutions and open up new opportunities. One of the major projects in recent years has brought about great technological advances and significant impacts on work and daily practice, providing huge benefits to the company. Relying on its high-tech skills and ingenuity as well as the in-depth expertise, Lika Electronic decided to take up the challenge together with leading technology partners to build a state-of-the-art, ultra-reliable motion control encoder in an unprecedented space endeavour. At present I38 SPACE optical encoder is heading for outer space and peering into farflung galaxies.
ROSETTA pioneering spacecraft: the final step Rosetta is the ESA European Space Agency's scientific project involving a consortium of more than 50 contractors (private companies, institutes and universities) in Europe and the United States. It is unique across all the space projects because it is the first mission planned to orbit and land on a comet. It will come to an end during the year 2016. Rosetta probe (Figure 1) was launched by an Ariane 5 rocket on 2 nd March, 2004, from Europe's Spaceport in Kourou, French Guiana on a journey of more than 10 years to the comet 67P/Churyumov-Gerasimenko, Figure 2. It entered the orbit around the comet's nucleus in first days of August 2014 after a series of gravity assist manoeuvres to gain enough orbital energy, with three swing- Figure 1 - Rosetta spacecraft (artist's rendering) Image courtesy: ESA Š J. Huart bys at Earth (March 2005, November 2007 and November 2009) and one at Mars (February 2007). En route to the comet, the star rover flew by the asteroids Steins (September 2008) and 21 Lutetia (July 2010). Rosetta spacecraft carries eleven science instruments to probe the comet's nucleus and map its surface in fine details. It also attempted to deploy a package of instruments (the Philae Lander, Figure 3) to the surface of the comet on November 12, 2014. Not everything has been fine, Figure 2 - The duck-shaped comet 67P by after few bounces Philae landed in a wrong position under some rocks. It lost Rosetta’s OSIRIS narrow-angle camera on 3 August 2014. Credit: ESA / Rosetta / MPS for power and lay dormant in the OSIRIS Team MPS / UPD / LAM / IAA / SSO / dark, and there is little hope that INTA / UPM / DASP / IDA it will become operational again. Some instruments did their duty anyway and the good job will allow to study some of the most primitive, unprocessed material in the Solar System. Thus the mission will provide clues to the physical and chemical processes at work during the formation of planets, beginning 4.6 billion years ago, and the prebiotic organic molecules that seem to be abundant on the icy comet's surface. The final step will be during the year 2016. The Rosetta probe may be sent Figure 3 - Touchdown! After a tense wait during the seven-hour descent to the surface of Comet crashing into the distant comet it has been orbiting at the end of its 67P/Churyumov-Gerasimenko, the signal confirming lifetime next September. But the spacecraft is expected to have a far softer the successful touchdown arrived on Earth on landing than its ill-fated Philae lander, which bounced uncontrollably across Wednesday November 12th at 16:03 GMT (17:03 the surface of the duck-shaped comet 67P. Instead it will approach the CET). The figure is an artist's concept.
comet slowly, beaming back as much information as possible to scientists on Earth in its dying moments. Among the instruments on board is the OSIRIS, the Optical, Spectroscopic and Infrared Remote Imaging System. OSIRIS is the eye and the imaging recorder of the comet chaser throughout its long journey to the 67P comet. It consists of a Wide Angle Camera (WAC, Figure 4) and a Narrow Angle Camera (NAC, Figure 5) and is intended to capture high-resolution images of both the flight and the comet's nucleus. Cooperation with CISAS (Centro Interdipartimentale di Studi e Attività Spaziali, an acronym which stands for Interdepartmental Centre for Studies and Space Activities) of the University of Padova has resulted in the development of an ultra-reliable and high-performance encoder for controlling the movement of the shutter motors in both WAC and NAC thermostated telescopes. Thanks to this Lika Electronic has been recognized as the first company in Italy and the second in Europe to manufacture an encoder intended for space applications.
Figure 5 - NAC Narrow Angle Camera Figure 4 - WAC Wide Angle Camera
The space encoder I38 SPACE incremental encoder is integrated into the brushless motors mounted on the shutter mechanism of both the WAC and NAC cameras (in Figure 6 two motor-encoder packages are visible in the bottom of the assembly). This very compact (Ø 38 mm, 36 mm depth, 55 g weight) and very low power consumption (200 mW max.) optical encoder has a resolution of 14,400 PPR and an accuracy better than ±10° el. As stated, it is designed to control the sophisticated movement of the shutter and is capable of monitoring exposure times shorter than 10 msec. and ensuring a lifespan longer than 500,000 cycles at least. Sure enough, malfunctions are not acceptable throughout the very long mission (over 12 years). Furthermore it is expected Figure 6 - Assembly of the OSIRIS shutter system. to operate under extreme The mechanism includes two shutters for exposure condition of low monitoring and protection of the cameras. temperatures and outer Image courtesy: CISAS University of Padova space vacuum (temperature range between 233[K] and 323[K] (-40°C +50°C / -40°F +122°F). Anyway I38 SPACE has been tested according to ESA standards in the temperature range +70 ± 2 °C / -50 ± 2 °C. Because of the wide temperature fluctuations and radiations, selected components have been fitted without using any glue. Besides technical success, also costs were a key factor: as CISAS states “Lika's encoders proved to be about 5 times cheaper than similar high-tech space encoders from specialist competitors”. This project means a great deal to Lika Electronic, to its new daily experiences and the future endeavours and can positively vouch for Figure 7 - I38 SPACE incremental encoder is made of the technical competence and the high-tech ingenuity of a forward Titanium with Kapton cables. The brushless motor is assembled on the front side. thinking innovative and global company.
What's happening now 2016? The ultimate goal After 12 years since launch, a deep space journey of approximately 3.7 billion miles (6 billion kilometres) thus far, three flybys of our planet, four overall gravity assist manoeuvres, 31-month hibernation, more than two years of trip along with the comet following the rendezvous in May 2014, the first controlled landing of the Philae lander in November 2014 and lots of scientific data and discoveries, Rosetta spacecraft is ready for the ultimate goal in September 2016. Rosetta and Philae - both solar-powered - will no longer receive enough sunlight to operate as the comet recedes from the Sun. The next step will be trying to land the Rosetta probe on the comet as softly as possible and from there it will send more unique, detailed and specific data about the changes to the comet's surface, composition, atmosphere and plasma environment at unprecedentedly close distances. Landing Rosetta on the comet will be a fitting ending to this incredible mission. Then the mission will necessarily draw to a close. By then, both the spacecraft and the comet will be on their way out of the Inner Solar System.
JOURNEY MILESTONES • 2 March 2004 Launch • April 2004 Instrument Checkout & Comet Linear • 4 March 2005 first Earth Gravity Assist • July 2005 Deep Impact Observation • 25 Feb 2007 Mars Gravity Assist • 13 Nov 2007 Second Earth Gravity Assist • 5 Sept 2008 Asteroid Steins flyby • 13 Nov 2009 Third Earth Gravity Assist • 10 July 2010 Asteroid Lutetia flyby • July 2011 Aphelion passage • 8 June 2011 Enter deep space hibernation • 20 Jan 2014 Exit deep space hibernation • 7 May 2014 Comet rendezvous manoeuvres begin • 6 August 2014 Arrive at comet • 10 September 2014 Start global mapping of comet • 12 November 2014 Philae Lander delivery • 13 August 2015 Perihelion passage • September 2016 Landing of the Rosetta probe on the comet's surface and mission end
Keep in touch for up-to-date information!
To learn more: http://www.esa.int/Our_Activities/Space_Science/Rosetta http://rosetta.jpl.nasa.gov/ https://www.facebook.com/RosettaMission @ESA_Rosetta @ESA Collection of documents about the mission from Lika's Issuu page https://issuu.com/lika_electronic/stacks/e1281c75bf864f9a80f615b461cbc591 Movies from Lika's YouTube channel https://www.youtube.com/watch?v=EqtPy21Hwp4 https://www.youtube.com/watch?v=1K7s4qqHxHI