PROJECT BACKGROUND
ESA is developing the third generation of weather forecast satellites, METEOSAT THIRD GENERATION (MTG).
Leonardo is in charge of the design, manufacture, and testing of the Lightning Imager (LI), an instrument that allows to “see” lightings from 36,000 km above Earth’s atmosphere.
CUSTOMER REQUEST
To test and calibrate the Lightning Imager (LI) optical instrument, Leonardo needs a high-precision positioning system. The system is integrated into a thermal vacuum chamber (TVC), thus it must be compatible with a clean and vacuum environment.
The system positions the instrument with respect to the Optical Ground System Equipment (“OGSE”) located outside of the TVC with a high travel range:
■ Cone rotation scan (Rxy ±5.1 deg) over 4 different optical channels
■ Large cone rotation scan (Rxy ±16 deg) with a COR 1,000 mm away in Z
THE SOLUTION
To meet the high travel range requirements, specifically over X & Y axis, as well as the distant center of rotation, SYMETRIE has developed and integrated a 2 axes module. This solution allows performing high amplitude motions without the constraint of designing a too big hexapod.
This table is integrated onto a ZONDA hexapod which meets the need for high precision, payload, and travel range:
■ The XY table allows to change the optical channel and making an important cone with a distant CoR.
■ The ZONDA hexapod allows to position the instrument and then performs an angular scan.
Furthermore, thermal braids and temperature sensors are integrated to guarantee optimal stability.
SPACE IMAGER TESTING PROJECT SPECIFICITIES
■ 10 -6 mbar vacuum
■ Cleanroom compatibility
■ 8 axes
■ Stability and angular precision (Stability < 2 µrad/15 min and Accuracy <15 µrad/deg)
■ Payload 150 kg
