37th COSPAR Scientific Assembly
Montreal, Canada , 13-20 July 2008

THE ISON INTERNATIONAL OBSERVATION NETWORK – LATEST SCIENTIFICACHIEVEMENTS AND THE FUTURE WORKS

• 18 scientific institutions in 9 states, including partners from ESOC, AIUB, astronomical organizations of Bolivia, Georgia, Moldova, Russia, Tajikistan, Ukraine, Uzbekistan
• 16 observatories and observation facilities
• 21 optical instruments
• more than 50 observers and researchers

• Selected objects observation across whole GEO-belt (360°)
• Near GEO-belt (± 2°) surveys for the arc 130.3W – 210.6E
• GEO region wide surveys for the arc 30W – 90E with the goal of discovery of all objects brighter than 16^m
• Uncatalogued GEO debris search (using different strategies, limiting magnitude 19^m) and tracking (limiting magnitude 21^m)
• GTO and other HEO objects observations including faint space debris
• Photometry of tracked objects
• High altitude space debris physical properties study
• Measurements, orbits and object properties database maintenance
• Close encounters analysis
• Improvement of the motion model using for data processing in part of non-gravity perturbations

• Global GEO coverage capability is achieved that is important for continuous studying of space debris situation in that region
• Since Jun 2007 wide GEO survey mode is implemented for longitudes 31.5W to 90E in a zone ±16° with respect to the “true” GEO ring. Partial GEO survey mode is implemented for other longitudes
• Overall number of obtained measurements exceeded 650000
• Number of continuously tracked objects in GEO and HEO - 1690, including 152 unknown bright GEO objects (brighter than 15^m) orbital data for which publishes annually in «ESOC Classification of Geosynchronous Objects» (the last one – Issue 10, Feb 2008) and 120 unknown bright HEO objects
• 439 faint (fainter than 15^m) GEO and GTO objects are discovered in GEO region surveys during the last 3 years, including objects with high AMR. Of this number 192 GEO objects are tracked continuously.
• Thus population of tracked objects in GEO region is increased more than 35 per cent. New discoveries continues to happen in every survey.
• Results are publishing monthly by KIAM in High Geocentric Orbit Space Debris Circular.
• Unexpected changes in orbital motion of old GEO objects are revealed. Cause of those changes is not yet understood but in any case they can not be explained by natural forces like gravity or solar radiation pressure.

• for debris on libration orbits → separation with small relative velocity from the “parent” object (possible scenario – low velocity collision, deterioration of outer surface under influence of the environment or low velocity operational fragment separation)

• for debris on drifting orbits → high velocity separation from any object in GEO region (possible scenario – fragmentation in explosion) or low velocity separation from objects moved to the graveyard orbit (possible scenario – low velocity collision or deterioration of outer surface under influence of the environment)

• Analysis of orbital motion for each tracked object and discovering events resulting in non-evolutionary changes of orbit (manoeuvres etc.)
• New classification of orbits for GEO operational satellites is proposed based on analysis of obtained data. Following classes of satellites are observed:
  
  • C1 – maintaining longitude and near-zero inclination
  
  • C2 – maintaining longitude only
  
  • C3 – maintaining longitude and non-zero inclination
  
  • C4 – maintaining non 'true GEO' period and near-zero inclination while remaining in GEO region
  
  • C5 – making manoeuvers on non 'true GEO' period orbit while remaining in GEO region
  Each class can be divided into two subclasses: 
  • - orbits with eccentricity less than 0.001
  
  • - orbits with eccentricity between 0.001 and 0.15
• Strange non-evolutionary changes are discovered for several old GEO objects
• Object 1997-070A (old spacecraft «Koupon») unexpectedly changed the direction of the drift on Jun 11, 2007 when it was near 90.82°E (drift rate changed on 0.16 °/day). Surprisingly it remained on libration orbit
• Object 1993-013A (old spacecraft Raduga) showed minor non-evolutionary changes in it's drift rate in Apr and Sep 2007. The reason of the changes is unclear.

• Successful experiments on independent discovery and tracking of debris created in fragmentations of Briz-M upper stage (object #28944), Block of ullage motor (#25054) and Fengyun 1C (#25730) are carried out. Small aperture (22 cm) optical instrument is used.
• 120 earlier unknown bright and more than 150 faint objects are observed on HEO orbits (mostly GTO and Molniya-type). All discovered bright objects are continuously tracking at present.

• > 30 telescopes with aperture from 15 cm to 2,6 m
• Independent continuous tracking of all objects larger than 1 m in size and more than 90% of objects larger than 0.5 m in size along all GEO arc
• Improved capability to detect and to track faint GEO and HEO objects with magnitude down to 21^m
• Monitoring of GTO, Molniya and other types of HEO and continuous tracking of more than 80% HEO objects larger than 1 m in size
• Capability to carry out regular optical surveys of LEO
• Publication of special information bulletin
• Maintenance of the special public Internet-resource with updated orbital information on all tracked high altitude objects

• New level of quality of GEO region research is achieved: full GEO arc coverage is established, regular wide surveys are carried out, for the first time our knowledge of true GEO population of objects brighter than 15^m is complete and presented for public
• Several hundreds of earlier unknown objects discovered in GEO region and on HEO orbits are presented a clear indication of lack of our knowledge of true high orbits population. Number of discovered new high altitude fragments continues to grow so the research should be expanded in order to obtain as complete information as possible on potentially dangerous objects crossing orbits of operational GEO and HEO spacecrafts.

• The regular process of discovering and continuous tracking of high orbit fragments is established (to the date more than 130000 obtained for nearly 450 such fragments)
• Obtained information is publishing on a regular basis
• The ISON network is developing intensively and will be capable soon to independently track all GEO and HEO objects brighter than 15^th-16^th magnitude as well as to accurately monitor LEO dangerous objects
• The ISON is an open scientific structure and all nations are welcome to participate