1. Istituto Nazionale Di Astrofisica - Istituto di Fisica dello Spazio Interplanetario ISA TeamISA Progress MeetingRome, 26 May 2009 ISA operations in cruise RSE support In-cruise calibration Periodical checkouts Long-term stability tests ISA cruise science RSE support In-cruise calibration Periodical checkouts Long-term stability tests ISA cruise science

2. Istituto Nazionale Di Astrofisica - Istituto di Fisica dello Spazio Interplanetario ISA TeamISA Progress MeetingRome, 26 May 2009 ISA operations in cruise Superior Conjunction Experiment (SCE) Quiet dynamical environment (no thrust) High-precision tracking ISA on ISA support of POD

3. Istituto Nazionale Di Astrofisica - Istituto di Fisica dello Spazio Interplanetario ISA TeamISA Progress MeetingRome, 26 May 2009 ISA operations in cruise The direct solar radiation pressure signal is above ISA sensitivity (possibly inside ISA band if MCS is rotating) Possibility of instrument calibration by comparison with tracking

4. Istituto Nazionale Di Astrofisica - Istituto di Fisica dello Spazio Interplanetario ISA TeamISA Progress MeetingRome, 26 May 2009 ISA operations in cruise Required information for in-cruise calibration tracking accuracy during SCEEstimation of tracking accuracy during SCE, and therefore of the accuracy in recovering the MCS acceleration expected acceleration signal acting on the MCSEstimation of the expected acceleration signal acting on the MCS, to be confronted with the tracking accuracy and accelerometer sensitivity expected signals acting on the sensing elementsRe-assessment of expected signals acting on the sensing elements, taking into account the different positioning of ISA with respect to MCS COM (instead of MPO COM) tracking accuracy during SCEEstimation of tracking accuracy during SCE, and therefore of the accuracy in recovering the MCS acceleration expected acceleration signal acting on the MCSEstimation of the expected acceleration signal acting on the MCS, to be confronted with the tracking accuracy and accelerometer sensitivity expected signals acting on the sensing elementsRe-assessment of expected signals acting on the sensing elements, taking into account the different positioning of ISA with respect to MCS COM (instead of MPO COM) Transducer factor

5. Istituto Nazionale Di Astrofisica - Istituto di Fisica dello Spazio Interplanetario ISA TeamISA Progress MeetingRome, 26 May 2009 ISA operations in cruise Periodical checkouts Long-term stability tests Zero position of the sensing massesZero position of the sensing masses: potential drifts in the working positions of the sensing masses will be detectable by a continuous read-out Noise levelNoise level: the (nearly constant) solar radiation pressure and the residual vibrations on MCS being the only source of vibration noise, it will be possible to test the instrument intrinsic noise with high accuracy

6. Istituto Nazionale Di Astrofisica - Istituto di Fisica dello Spazio Interplanetario ISA TeamISA Progress MeetingRome, 26 May 2009 ISA operations in cruise Cruise science Direct measurement of solar radiation pressure Flybys (anomalies, gradiometric measurements) Direct measurement of solar radiation pressure Flybys (anomalies, gradiometric measurements) An accelerometer disentangles gravitational and non-gravitational effects Out of the spacecraft center of mass, an accelerometer measures also gravity gradients

7. Istituto Nazionale Di Astrofisica - Istituto di Fisica dello Spazio Interplanetario ISA TeamISA Progress MeetingRome, 26 May 2009 ISA operations in cruise RSE-RD 50 ASD TN 35 page 11 ISA operation requirements for SCE