Structure

 

Fig. 1 - Model of ANDE Sphere

 

Preliminary Design - Tolerances and Requirements

 

l                        Two hemispheres lathed from Al 7075-T4

l                        Diameter = 0.4826 m

                       lThickness = 1.32 cm

                        lCross-sectional area = 0.1829 m2

                        lMass = 25 kg passive, 50 kg active

l                        15-31 optical retro-reflectors

                        lWell characterized radar cross-section

                        lSpherical to better than 0.1%

l                        Cross-sectional area should not vary more than 0.1% from all orientations

                        lMasses must be known to within 0.1%

                        lRelative area-mass ratio of passive and active spacecraft should be known to better than 0.1%

l                        Accelerometer with dynamic range from 0-2E10-6 m/s2 (ANDE II)

                        lAccelerometer with precision of 10-5, with coriollis terms smaller than 10-10 m/s2
                                             (ANDE II)

                        lSurface must be smooth overall, with no gaps greater than 0.5 mm permissible

Fig. 2 - Preliminary sketch of ANDE sphere