Help Shape the Future of Space Exploration

Join The Planetary Society Now  arrow.png

Join our eNewsletter for updates & action alerts

    Please leave this field empty

Headshot of Emily Lakdawalla

Diagram of on-orbit satellite collision

Posted by Emily Lakdawalla

12-02-2009 8:17 CST


Via comes this diagram showing the orbits of the two satellites that collided on the 10th. They were in nearly perpendicular polar orbits. Space around Earth may be "crowded" but still this was a low-probability event by any measure -- a few seconds' difference in timing, a meter or two difference in orbital altitude, and the collision wouldn't have happened. (Thanks to Gordan Ugarkovic for the tip.)

On-orbit spacecraft collision

Dan Deak, courtesy of

On-orbit spacecraft collision
On February 10, 2009 at 16:56 UTC, a functioning Iridium satellite and a defunct Russian satellite collided over northern Siberia. The two satellites were in nearly perpendicular polar orbits.

See other posts from February 2009


Or read more blog entries about:


Leave a Comment:

You must be logged in to submit a comment. Log in now.
Facebook Twitter Email RSS AddThis

Blog Search


Advocate for Space!

Fifteen years ago, Society members and passionate space advocates like you helped save the Pluto mission. Now we can do the same for missions to Europa and Mars.

Join over 27,600 people who have completed their petition and consider a donation to support advocacy efforts.

Sign Our Petition

Featured Images

The Magnificent Neptunian System
Pluto's blue skies
51 Eridani b
51 Eridani b (artist's conception)
More Images

Featured Video

A Perfect, Clear Day: LightSail's Launch

Watch Now

Fly to an Asteroid!

Send your name and message on Hayabusa-2.

Send your name

Selfies to Space!

Take flight with a selfie on LightSail™ in 2016!

Send a Selfie Now

Connect With Us

Facebook! Twitter! Google+ and more…
Continue the conversation with our online community!