US spacecraft debris ups risk for other missions

Debris from the US Defense Meteorological Satellite Program (DMSP) F13 satellite, which recently exploded in orbit, could pose a threat to other spacecraft and missions, warns a new research.

"Even though many of these objects will be no bigger than the ball in a ballpoint pen, they can disable a spacecraft in a collision because of their enormous speed," said one of the researchers Hugh Lewis from University of Southampton in Britain.

"In the case of the DMSP-F13 explosion, our work has shown that the introduction of a new cloud of small-sized debris into orbit will have increased the risks for other spacecraft in the vicinity, even if the risk from the larger fragments has been discounted," Lewis said.

On February 3, 2015, the DMSP F13 satellite exploded in orbit producing over an estimated 100 pieces of space debris that were detected using radar.

In assessing how debris created by the explosion might affect their spacecraft, the European Space Agency and other satellite operators concluded that it would pose little risk to their missions.

However, scientists from the Astronautics Research Group at the University of Southampton investigated the risks to a wide range of space missions, coming from smaller pieces of debris created by the explosion that cannot be detected using radar based on the ground.

In the case of the explosion of DMSP-F13, they detected 100 new catalogued objects, which suggest that more than 50,000 small fragments larger than 1mm were created.

The Southampton team developed a new technique called CiELO (debris Cloud Evolution in Low Orbits) to assess the collision risk to space missions from small-sized debris.

They produced a collision probability map showing a peak in the risk at altitudes just below the location of the DMSP-F13 explosion.

The map was created by treating the debris cloud produced by the explosion as a fluid, whose density changes under the effect of atmospheric drag.

The research was published in the Journal of Guidance, Control and Dynamics.