21 December 2021
Time to say goodbye to MetOp-A
After Performing 1.2 billion cycles during its operational lifetime, it is time to say a final goodbye to CSEM’s Corner Cube Mechanism (CCM) aboard the IASI instrument....
CSEM has developed a new micro-vibration test bench, which is capable of accurately characterizing the vibrations generated within space apparatus while researching the use of magnetic bearings for satellite attitude control. Smoothing the ride for sensitive space components is of critical importance. Over time low-level vibrations and small disturbances can lead to the degradation of high-precision optical space instruments, ultimately affecting their performance.
Using a custom-made dynamometer developed in-house using piezoelectric force sensors from Kistler , CSEM engineers have been able to precisely capture the micro-vibrations generated by a novel type of magnetic bearing reaction wheel. Taking accurate micro-vibration measurements, they were then able to characterize the effectiveness of a control algorithm that actively suppresses synchronous vibrations over the full speed range (Ref 1) – allowing higher rotational speeds thanks to reduced disturbances and power consumption.
For many years, CSEM has been a partner of the European Space Agency ( ESA ). Part of their joint research focuses on eliminating vibrations that originate from within the components found onboard satellites. Micro-vibrations can cause a whole host of issues, from higher energy consumption, deteriorated image quality (in the case of imaging missions), and limiting the satellite attitude control performance.
“To give an idea of scale, when we mention micro-vibrations, we mean within the millinewton range, we needed to have a highly sensitive measuring chain with very low noise. Kistler’s sensors and charge amplifier were perfect for this job and provided us with the high-quality results we needed,” remarks Guzmán Borque Gallego from CSEM. “We were really impressed by the way Kistler’s technology could cope with conditions that were beyond its given constraints, it’s incredibly robust,” adds Leopoldo Rossini , the previous head of CSEM’s micro-vibration facility.
With the support of Kistler’s measurement technology, CSEM’s engineers were able to comprehensively study a prototype reaction wheel with a magnetic bearing from the Swiss company, Celeroton . Their cutting-edge wheel technology is friction-free, meaning it has a virtually infinite lifetime. It can also actively suppress unwanted vibrations by control, allowing it to achieve higher performances at higher speeds. It is also incredibly compact in size and weight. In the future, it is hoped that this kind of wheel bearing will be used within satellites, stabilizing their attitude control to an even greater extent.
More info on CSEM’s and Kistler’s can be found HERE .
Refer to our Micro-vibration Characterization Facility flyer for further information.
Ref 1: Novel Generalized Notch Filter for Harmonic Vibration Suppression in Magnetic Bearing Systems, https://ieeexplore.ieee.org/document/9364732