Voice coil actuator on-board NASA's spacecraft to Bennu

The OSIRIS-Rex launched on 8^th September2016 from Cape Canaveral Air Force Station in its mission to rendezvous with the Asteroid Bennu in 2018 and return samples to Earth in 2023.

For this space mission, a customised BEI Kimco moving magnet VCA was attached to, and will position the moving mirror assembly of the OSIRIS-Rex Thermal Emission Spectrometer (OTES). As the spacecraft approaches Bennu, the spectrometer scans the surface so that the material can be analysed for different parameters. 

OSIRIS-REx will spend two years surveying the asteroid in unprecedented detail. Then, in a robotic first, the spacecraft will reach out its mechanical arm and take a sample from the asteroid. Though the sample will be small, only a couple of pounds at most, it will be a time capsule of sorts recording our solar system's creation. With the sample stored safely, the spacecraft will speed away from the asteroid on a path back to Earth.

The BEI Kimco VCA was uniquely manufactured to custom requirements for high reliability and fail safe operation. Redundant technology, low-outgassing and high precision for exact motion control positioning were all key requirements to the actuator design. It was also critical to stay within the specific size, weight and power limits. 

This was achieved in a housing measuring approximately 2x3”. To meet the requirements for near zero emissions, BEI Kimco developed the actuator minimising the use of adhesives or inks and using only approved materials. This design primarily uses mechanical assembly methods within a clean manufacturing process, thereby eliminating substances that could cause outgassing. High energy Neodymium Iron Boron (NeFeB) magnets were incorporated to provide superior operating efficiencies.

In recognition of the team that worked on the OTES project, a signature plaque including individuals as well as BEI Kimco and other other suppliers, was attached to OTES before it left earth. An identical plaque was presented to BEI Kimco and each company or person included on the plaque. 

"The Astroid Bennu sampling mission was another exciting opportunity for us to meet unique customer demands," said Jim McNamara, Senior Applications Engineer. "In this case, a customised low outgassing design with high reliability, built-in redundancies, strict quality control, and cleanliness were all needed.

McNamara added: “It will be interesting to see the results of the mission in 2023 when the samples are brought to earth."