The gravimeter "B-grav" for in-situ gravity measurements at the surface of an asteroid

We investigate a miniaturized 3D compact gravimeter as part of geophysical instrument package dedicated to small bodies of solar system like Asteroids. The described prototype will be setup on a CubeSats assemblage which lands on the secondary object of the Didymos system. Specificities of selected solutions meet problematic to measure very tinny 50μm/sec² gravimetric field corresponding to 5 ppm of Earth gravity. The system will operate in a hash thermal environment without leveling, with strictly limited power, mass and signal treatment facilities. A system with three components mounted in an orthogonal geometry allows obtaining the gravity field in amplitude and in all angular positions without any requirement of levelling. We set-up the gravimeter in a vertical position to reject the Earth gravity field. We induce by tilt of the system μchanges of forces like the Asteroid one. B- Grav will use a in-situ calibration process to control the laboratory transfer function determination.