Space crash: Iridium 'fixes' problem, but scientists worried

Iridium Satellite LLC, the US-based company whose satellite crashed with a defunct Russian military satellite last Tuesday, says it has done a quick-fix that will save its customers from communication outages, even as experts warned that the debris from the collision would be a threat in outer space for the next 10,000 years.

The fix in the satellite "addresses a significant portion of outages that customers otherwise might have experienced," said Liz DeCastro, a spokeswoman for the closely held company.

Iridium, based in Bethesda, Maryland, said it was preparing to activate one of its orbiting spares to restore the network fully. However, no further details were disclosed.

The company's 66-satellite constellation provides voice and data services for areas not covered by ground-based communications. It counts about 300,000 clients worldwide, including the US Department of Defense, maritime users and scientists at the South Pole.

Iridium declined to say if it was considering action against Russia for any negligence. Operators are expected to bring dying spacecraft back to Earth or park then in orbits out of the way of operational satellites.

"Of course, we're still looking at the matter," DeCastro said, adding that the company had no advance warning of the impending collision.

Russian mission control leader Vladimir Solovyov said the accident occurred in the busiest part of near-earth space. "This is a very popular orbit which is used by earth-tracking and communications satellites," Solovyov told reporters. "The clouds of debris pose a serious danger to them."

Other space traffic experts say that the potentially dangerous debris from the collision highlights risks that should be discussed immediately. (See: The great junkyard in outer space).

James Oberg, an aerospace engineer who worked on NASA's space shuttle programme and is now a space consultant, described the crash over northern Siberia as "catastrophic event." NASA said it was the first-ever high-speed impact between two intact spacecraft - with the Iridium craft weighing 560 kg and the Russian craft nearly a ton.

"At physical contact at orbital speeds, a hypersonic shock wave bursts outwards through the structures," Oberg said. "It literally shreds the material into confetti and detonates any fuels."

David Wright at the Union of Concerned Scientists' Global Security said the collision had possibly generated tens of thousands of particles larger than 1 cm, any of which could significantly damage or even destroy a satellite.

"The collision offers a literally heaven-sent opportunity for the Obama administration to take forceful, visible and long-overdue measures to address a long-ignored issue of 'space debris,'" Oberg said.

NASA acknowledged that the debris could pose a slight risk to the space station, which could be moved in an attempt to avoid any debris that may move in its direction. The topic also came up at the 46th session of the scientific and technical subcommittee of the UN committee on the peaceful uses of outer space in Vienna this week. 

"Since space is becoming an increasingly congested environment, heightened space situational awareness as well as international cooperation between governments and industry is critical in the future," the committee said statement.