US satellite explodes and ESA assesses risk

A US Air Force weather satellite exploded in Earth orbit on February 3, scattering debris along its path. In a report by Space.com, Air Force and space officials indicated the breakup of Defense Meteorological Satellite Program Flight 13 (DMSP-F13) was due to a malfunction of its battery system rather than a collision with a foreign body. Meanwhile, The European Space Agency (ESA) has released an assessment of the hazard posed by the debris.

DMSP-F-13 is part of a program set up in the 1960s to provide real-time weather data relevant to US military operations. The program was declassified in 1972 and in 1998 control was transferred from the US Air Force to the National Oceanic and Atmospheric Administration (NOAA) to save costs. DMSP-F-13 was launched in 1995 into a sun-synchronous polar orbit at an altitude of about 500 mi (800 km). Due to its age, it had been relegated to the status of backup satellite as the DMSP constellation was updated.

According to Space.com, the loss of the satellite was due its batteries failing catastrophically because of old age. This is a major problem with older satellites. Newer ones are designed to prevent such an occurrence, but telemetry indicated that the temperature of the batteries on DMSP-F-13 spiked suddenly just before the explosion.

The blast caused the satellite to break into fragments, which at last count were estimated to number 46 pieces. ESA ran an assessment based on data shared by the US Joint Space Operations Center and determined that the remains of DMSP-F-13 pose no danger to its operations, and that the orbits of the fragments will eventually decay until they burn up in the Earth's atmosphere.

"The event is not considered major," says Holger Krag of ESA’s Space Debris Office. "Should the reported number of fragments stabilize at this level, we can consider it to be within the range of the past 250 on-orbit fragmentation events. For our missions – with CryoSat-2 being closest to the event altitude – we do not expect any meaningful risk due to the event."

The Air Force says that the loss of DMSP-F-13 will have no effect on its services. The US government has not indicated that the debris from last month's explosion poses any hazard to its space operations.

Source: ESA