Accidental Collision of DMSP R/B and Chinese Debris on 17 January 2005

1
Accidental Collision of DMSP R/B and Chinese
Debrison 17 January 2005
7 February 2005 Summary
2
Executive Summary

• The second known accidental collision between two
  Earth satellites from different missions occurred
  on 17 January 2005, involving a 1974 US rocket
  body and debris from a Chinese rocket body which
  exploded in March 2000.
• Both objects were in similar retrograde orbits.
• The collision occurred at an altitude of 885 km.
• Only two debris from the US rocket body had been
  detected within three weeks of the event.
• The only other known accidental collision between
  two Earth satellites from different missions
  occurred on 24 July 1996, involving the 1995
  French CERISE spacecraft and debris from a French
  rocket body which exploded in November 1986.

3
Collision Summary

• Time and Location of Collision 0214 GMT, 17
  January 2005
• 80.6 S, 306.8 E
• Altitude of Collision 885 km
• Satellites Involved in Collision US DMSP 5B F5
  R/B (Thor-Burner 2A final stage)
• Sat. No. 07219, Int. Designator 1974-015B
• Launched 16 March 1974
• Orbit at time of collision 775 km by 885
  km
• Chinese CZ-4 Third Stage Debris
• Sat. No. 26207, Int. Designator 1999-057CV
• Created during Explosion on 11 March 2000
• Orbit at time of collision 700 km by 895
  km
• New Debris Created Two pieces from DMSP R/B
  tracked
• (Sat. No.s 81057 and 87876)

4
Location of Collision

• Groundtracks /- 30 minutes of 0214 GMT, 17
  January 2005

CZ-4 Debris
DMSP R/B
5
Location of Collision, Alternate View
DMSP R/B
CZ-4 Debris
700 km by 895 km 98.2 deg inclination
775 km by 885 km 99.1 deg inclination
Collision Altitude 885 km
6
Colliding Objects plus 2 Debris
Graphic by AFSPC/1SPCS
7
New Debris from DMSP R/B
Graphic by AFSPC/1SPCS
8
Perturbation of CZ-4 Debris Orbit
Graphic by AFSPC/1SPCS
9
Breakup of CZ-4 in March 2000(1999-057C, Sat.
No. 25942)

• CZ-4 third stage suffered a post-mission,
  propellant-induced breakup on 11 March 2000.
  More than 300 debris were officially cataloged.
  A total of 176 cataloged debris remained in orbit
  on 17 January 2005.