ONERA accelerometers for future gravity mission

ONERA (the French Aerospace Lab) is developing, manufacturing and testing ultra-sensitive electrostatic accelerometer for space application. ONERA has procured the accelerometer for all the previous gravity missions (GRACE, GOCE, GRACE-FO) and works to improve the scientific return of the instruments.

One way is to propose an accelerometer with 3 sensitive linear acceleration measurements as well as 3 angular acceleration measurements for the attitude control or reconstruction. Two different configurations are proposed: CubSTAR, a miniaturized version with low accuracy but adapted for constellation or nanosat; and MicroSTAR, a high accuracy accelerometer.

CubSTAR accelerometer is a small volume instrument with the same performance on the 3 axes, the baseline being 20x20x20mm proof-mass in a 15x15x20cm volume envelope. A prototype was manufactured and tested during a drop-tower test. Moreover this prototype will be tested in vibration environment to check its good mechanical behavior.

MicroSTAR accelerometer is designed with a disruptive mechanical concept allowing using a 30x30x30mm proof-mass, with the same high-performance on the 3 axes. Modal and dynamic analyses have been performed and a prototype is under manufacturing.