9:00 AM - 9:15 AM
[S19-3-02] The InSight VBB seismometer: status and perspective for future missions
invited
SEIS is the primary payload of the NASA InSight mission due for launch on 5/2018. The instrument includes notably a Very Broad Band (VBB) 3 axis seismometer developed by the IPGP under CNES funding and subcontracted to EADS-SODERN for fabrication of the Flight Units.
Oblique VBB axis are inverted pendulum, with a 190 g mobile mass and natural frequency in the range of 0.4-0.5 Hz. A Displacement Capacitive Sensor detect the mobile mass movement with a resolution better than 5 pm/Hz^(1/2) at 1 Hz and drives the Feedback electronics. A ‘Balance Mechanism' allows adjusting very precisely pendulum balance position and correct leveling errors, gravity value uncertainty and instrument ageing. A ‘Thermal Compensation Mechanism' allows minimizing VBB thermal sensitivity passively with less than 10-5 m/s^2/K. Each axis power is smaller than 60mW and the performances requirement is 10^(-9) m/s^2/Hz^(1/2) between 0.01Hz and 1 Hz. Space qualification benefited from expertise from several CNES, JPL and SODERN experts.
By mid-February 2017, six VBBs had successfully completed their ProtoFlight Test program and one additional will be delivered before the end of the first 2017 trimester. These sensors will be integrated either in the FM Sphere (SEIS-SPH) or in its spare.
Performances in accordance with noise models have been demonstrated with previous prototypes and additional tests in 2017 will be made in BFO seismic observatory. The SEIS experiment will therefore provide high-quality seismic signal acquisition and associated seismic information during one Martian year, i.e. the nominal mission duration.
Future VBBs will be candidate for seismic missions requesting low noise sensors, such as those planed to the Moon in the 2020-2030 decade. Expected performances for a Moon VBBs will be at least one order of magnitude better than Apollo, and even larger improvement can be envisaged with an optical version, presently in development through IPGP-APC partnership
Oblique VBB axis are inverted pendulum, with a 190 g mobile mass and natural frequency in the range of 0.4-0.5 Hz. A Displacement Capacitive Sensor detect the mobile mass movement with a resolution better than 5 pm/Hz^(1/2) at 1 Hz and drives the Feedback electronics. A ‘Balance Mechanism' allows adjusting very precisely pendulum balance position and correct leveling errors, gravity value uncertainty and instrument ageing. A ‘Thermal Compensation Mechanism' allows minimizing VBB thermal sensitivity passively with less than 10-5 m/s^2/K. Each axis power is smaller than 60mW and the performances requirement is 10^(-9) m/s^2/Hz^(1/2) between 0.01Hz and 1 Hz. Space qualification benefited from expertise from several CNES, JPL and SODERN experts.
By mid-February 2017, six VBBs had successfully completed their ProtoFlight Test program and one additional will be delivered before the end of the first 2017 trimester. These sensors will be integrated either in the FM Sphere (SEIS-SPH) or in its spare.
Performances in accordance with noise models have been demonstrated with previous prototypes and additional tests in 2017 will be made in BFO seismic observatory. The SEIS experiment will therefore provide high-quality seismic signal acquisition and associated seismic information during one Martian year, i.e. the nominal mission duration.
Future VBBs will be candidate for seismic missions requesting low noise sensors, such as those planed to the Moon in the 2020-2030 decade. Expected performances for a Moon VBBs will be at least one order of magnitude better than Apollo, and even larger improvement can be envisaged with an optical version, presently in development through IPGP-APC partnership