Satellite space navigation relies on star trackers, optical systems that detect the position of fixed stars and provide it to the course control system. OHB Italy asked Loson to design and build the star tracker support structures for the NAOS satellite, a very high-resolution optical Earth observation satellite system built for the Luxembourg government. Inside the satellite it ensures the proper mounting and load distribution of the star trackers, which are the navigation tools for tracking stars and detecting the satellite’s position.
The supporting structure must have sufficient rigidity to ensure the absence of vibrations, which could affect the accuracy of the surveys, and be light so as not to reduce the satellite’s payload. It must also ensure resistance to a wide variety of loads, ranging from extremely heavy ones during launching to near-zero ones during orbital flight.
The most critical issue relates to the choice of materials (high-modulus M55J composite and cyanate ester resin) and the construction solution. Loson’s vast experience with superlight materials [link a TECHNOLOGIES] allowed us to make a composite honeycomb sandwich coupled with INVAR metal inserts to minimize thermal expansion. We were also responsible for making the tooling, which was particularly complex. Finite element analysis enabled us to identify vibration frequencies and optimize strength.
We also created the appropriate manufacturing process to fall within the minimum tolerances set by the specifications, creating special bonding yards and extremely precise machining. Tomography tests and dimensional measurements ensured the quality of the finished product.
