The ODDStar Experiment

Introduction

The ODD (Orbiting Debris Device) –Star experiment was dedicated to track and identify orbiting space debris, and to perform quantitative measurements of their characteristics.

 

Products & Information

The ODD (Orbiting Debris Device) –Star experiment was launched during the second qualification flight of the Ariane-5 launcher on 30 October 1997 into a near GTO orbit. ODD-Star was performed as part of the TEAMSAT project.

The Maqsat-H cylindrical body, which was the upper payload for the Ariane 502 flight, was painted with a high contrast pattern (75% white and 25% black paint) to support testing and calibration of ground-based optical and radar stations in Europe. The painted Maqsat-H is shown in Figures 1-3.


 

Maqsat-H (only the white part is visible here)
Figure 1 - Maqsat-H (only the white part is visible here)
The painted Maqsat-H, together with TEAMSAT
Figure 2 - The painted Maqsat-H, together with TEAMSAT
Separation of YES satellite from Maqsat-H in orbit (artist impression)
Figure 3 - Separation of YES satellite from Maqsat-H in orbit (artist impression)

The ground stations are used to track and identify orbiting space debris. For quantitative measurements these instruments need to be calibrated using reference objects with well defined characteristics. The contrasting paint does also allow detection of the rotation or tumbling of Maqsat-H.

While Maqsat-H was the main object of the ODD-star experiment and the only one with a specific surface paint for this purpose, the other major objects released during the Ariane 502 flight (the Speltra, Maqsat-B with upper stage and the small YES satellite) were also used as test objects. Additionally, surface paint degradation will be observed and studied in the coming years.


 

Results

 

A few days after launch the ground-based optical and radar instruments of various institutes detected and tracked. The bright Maqsat-H (maximum optical magnitude about 8.4) was (and still is) even visible by a pair of binoculars. Thanks to their reflection pattern and total brightness, the Maqsat-H,/TEAMSAT, YES, A502 Speltra and the A502 upper stage with Maqsat-B could all be identified and their light curves be recorded. These calibration measurements will support the observation of other objects in space whose sizes and reflectivity are not known. The observations will be continued and also provide information on material and paint degradation under exposure to the harsh space environment.

 

Fig. 4, 5 and 6 were obtained by the 1 m Zimmerwald telescope of the University of Bern. The photograph 4 shows the Maqsat-H and the much fainter YES satellite together with 2 reference stars. This photo was taken from a distance of more than 20000 km on 3 November 1997 (22:30 UT). The two reference stars appear blurred because they moved relative to the tracked objects YES and Maqsat-H during the photograph exposure time. Figs. 5 and 6 show the measured light curves for YES and Maqsat-H, respectively.


 

 

Maqsat-H and the fainter YES satellite together with 2 reference stars
Figure 4 - Maqsat-H and the fainter YES satellite together with 2 reference stars
Measured light curves for YES
Figure 5 - Measured light curves for YES
Measured light curves for Maqsat-H
Figure 6 - Measured light curves for Maqsat-H

References

M. Bandecchi and W.J. Ockels, ‘The TEAMSAT Experience’, ESA Bulletin 95, pp132-143, August 1998.

 

Team

  • Kayser-Threde (D),
  • University of Bern, Zimmerwald observatory (CH),
  • ESA (several sections at ESTEC and ESOC, lead by TEC-EES, )

Contact point at ESA: G. Drolshagen