Dear colleagues!

The post-flight reconstruction of the INTERBALL Auroral probe (Interball 2) orbit has been recently finished in the Ballistic Center of the Keldysh Institute of Applied Mathematics (KIAM) of Russian Academy of Sciences. This work was based on the statistical processing of the complete information related to the trajectory measurements summarised with the information concerning the spacecraft (SC) reorientation moments. The non-gravitational accelerations generated by the work of the attitude control system were taken into consideration.

The six-component state vectors were obtained for every time intervals between the reorientation moments. These vectors were "connected" with the initial moment of the mentioned intervals. The components of the state vector are as follows: 3 components of the SC vector-radii and 3 components of its velocity in the inertial frame J2000.

The root-mean-square (RMS) error of the SC position determination inside the intervals is about 2-3 km (till 20 km on some sections of the orbit).

For the SC position calculation inside the corresponding intervals we recommend to use the integration of the differential equations of SC motion taking into account Moony-Solar perturbations and 8 terms of the Earth's gravitation field's potential. Such method will guarantee the accuracy mentioned above.

We shall name these new orbital elements as "Version 3" contrary to the former orbital elements "Version 1" and "Version 2" distributed earlier.

All orbital elements are presented in the IKI WEB server in the F1 format.

See various versions of the orbital element collections in the files as follows.