Exploded Rocket Fragments Could Endanger ISS and Future Missions

The International Space Station will have to look out for new debris from an exploded Russian rocket (NASA image)

Traveling through low-Earth orbit just got a little more dangerous; a drifting Russian Breeze M (Briz-M) rocket stage that failed to execute its final burns back on August 6 has recently exploded, sending hundreds of shattered fragments out into orbit.

Russia and the U.S. Defense Department (JFCC-Space) have stated that they are currently tracking 500 pieces of debris from the disintegrated Breeze M, although some sources are saying there are likely much more than that.

After a successful liftoff via Proton rocket on August 6 from the Baikonur Cosmodrome, the Breeze M upper stage’s engines shut off after only 7 seconds as opposed to the normal 18 minutes, leaving its fuel tanks filled with 10 to 15 tons of hydrazine and nitrogen tetroxide propellants. Its payloads, the Indonesian Telkom 3 and the Russian Express-MD2 communications satellites, were subsequently deployed into the wrong orbits as the Breeze M computer continued functioning.

Although originally expected to remain intact for at least another year, the rocket stage “violently disintegrated” on October 16. Evidence of the explosion was first observed by astronomer Robert McNaught at Australia’s Siding Springs Observatory, who counted 70 fragments visible within the narrow field-of-view telescope he was using for near-Earth asteroid observations.

The exact cause of the explosion isn’t known — it may have been sparked by an impact with another piece of space junk or the result of stresses caused by the Breeze M’s eccentric orbit, which varied in altitude from 265 to 5,015 kilometers (165 miles to 3,118 miles) with an inclination of 49.9 degrees.

This was the third such breakup of a partially-full Breeze M upper stage in orbit, the previous events having occurred in 2007 and 2010, and yet another Breeze M still remains in orbit after a failed burn in August 2011.

Most of the latest fragments are still in orbit at altitudes ranging from 250 to 5,000 km (155 to 3,100 miles), where they are expected to remain.

“Although some of the pieces have begun to re-enter, most of the debris will remain in orbit for an extended period of time.”

– Jamie Mannina, US State Department spokesperson

According to NASA the debris currently poses no immediate threat to the Space Station although the cloud is “believed not to be insignificant.” Still, according to a post on Zarya.com the Station’s course will periodically take it within the Breeze M debris cloud, and “will sometimes spend several days at a time with a large part of its orbit within the cloud.”

Source: RT.com and SpaceflightNow.com.  Inset image: the Breeze M (Briz-M) upper stage which disintegrated on Oct. 16. (Khrunichev)