Center For Space Standards & Innovation

Chinese ASAT Test

(2007 December 5) The official debris count from China's anti-satellite missile test has reached 2,317 pieces big enough to be tracked and NASA's Orbital Debris Program Office is estimating more than 35,000 pieces larger than 1 cm (see "China's Anti-Satellite Test: Worrisome Debris Cloud Circles Earth," Space.Com, Feb 2.) This makes the January 11 test the largest debris-generating event in history, far surpassing the previous record set in 1996, according to Dr. T.S. Kelso. Dr. Kelso serves as Senior Research Astrodynamicist in the Center for Space Standards & Innovation (CSSI) and webmaster of CelesTrak, a site dedicated to tracking space objects and monitoring them for in-orbit collisions.

A Technical Summary of this event—including information from NASA's Orbital Debris Program Office about the total number of large and small pieces, the increased number of conjunctions seen in SOCRATES reports, and analysis of the total number of satellites affected is available on CelesTrak. Resources from Dr. Kelso's April 19 webinar, Space Debris: Chinese ASAT Adds More to the Clutter, are also available.

Dr. Kelso has produced videos, high-resolution graphics, and interactive animations (VDFs) using AGI software to illustrate the ramifications of the test. The graphics and animations were derived from information cataloged by the North American Aerospace Defense Command (NORAD) and released to the public via Space Track, operated by Air Force Space Command. They were last updated on December 5, following a posting by NORAD of 2,317 trackable pieces of debris from the incident. The satellites and debris fragments are greatly magnified to illustrate the location of the orbits.

HIGH-RESOLUTION STK GRAPHICS: Download the high-resolution graphics by clicking on the images above. In all uses, please courtesy "STK-generated images courtesy of CSSI ("

Chinese ASAT Test
Chinese ASAT
All-Sats Scenario

STK-GENERATED VIDEOS: ASAT high-definition WMV download (39MB), ASAT high-definition ZIP download (39MB), or ASAT broadcast quality QuickTime MOV (515MB zipped with no audio). In all uses, please courtesy "STK-generated videos courtesy of CSSI ("

INTERACTIVE AGI VIEWER VDF FILES: Provide a comprehensive sense of the overall space environment by allowing you to zoom in and out and move around the Earth while watching all the satellites moving in their orbits. They require the free STK Viewer software and appropriate to run. Click the links below to access the VDF files. In all uses, please courtesy "STK-generated VDFs courtesy of CSSI ("


  • Chinese ASAT: The Chinese weather satellite as it is struck, causing a debris cloud
    • The files show the period from 2007 January 11 at 2228 UTC until January 12 at 0600 UTC. The FENGYUN 1C (pre-attack) orbit is shown in red. The Xichang Space Center location is also noted. The pieces of debris catalogued by NORAD and released to the public via Space Track are shown in green. The animation shows the spread of the resulting debris cloud for the first few orbits. Initial analysis shows pieces in the debris cloud ranging from below 200 km in altitude up to almost 4,000 km, posing a threat to many operational satellites, due to the polar orbit of the debris cloud.

  • ISS-ASAT DEBRIS: The ISS passing through the debris cloud
    • These files show how the ISS passes through the ring of debris at the southern part of its orbit.

  • LEO-ASAT DEBRIS: The larger population of satellite payloads in orbit that could be affected by the debris
    • These graphics depict the larger population of LEO satellite payloads (size exaggerated for visibility) that could be affected. A satellite payload is that portion of a launch vehicle that will conduct the operational mission of the satellite in orbit. Examples of payloads include sensors, transmitters/receivers, or other scientific or engineering experiments. Potential conjunctions with satellite payloads currently on orbit can be found by searching for "FENGYUN 1C DEB" using SOCRATES.

  • All-SATS: View of All Satellites including Debris Ring from Chinese ASAT Test Readily Visible
    • This debris event is so large that the debris can be easily seen without doing anything to emphasize the debris cloud.


"Orbital Litterbugs"
MSNBC Cosmiclog, 2007 Feb 2

“China’s Space-Weapon Test Could Endanger Astronauts and Satellites”
ABC News Technology & Science, 2007 Feb 1

“Space Junk”
ABC News Blogs. 2007 Feb 1

“Chinese A-SAT Test Called “One of the Worst Ever” Debris Incidents”
Space News Business Report, 2007 Jan 29

"A View to a Satellite Kill"
MSNBC Cosmiclog, 2007 Jan 25


STK Viewer is a free product that allows anyone with a Windows computer to view an STK-generated scenario. With AGI Viewer, you can animate a scenario forward or backward, pause the animation, and zoom or pan the view for a more complete understanding of the event. As with Adobe Acrobat, where the authoring software requires a license but the Adobe Reader is free, STK can produce AGI Viewer files—also known as VDFs—that can then be viewed by anyone with the AGI Viewer software. More on AGI Viewer can be found at