More Space Collisions Could Turn Low Earth Orbit Into A Shooting Gallery Hazardous To Spacecraft
Issues of liability and fault are unresolved at this point in the collision of an Iridium Satellite LLC spacecraft and a defunct Russian satellite.
Iridium indicated the collision took it by surprise, adding that it has completed initial moves to avert a major loss of service to customers on Earth that the annihilation of its satellite otherwise would have caused.
Longer-term, “The company … is taking the necessary steps to replace the lost satellite with one of its in-orbit spares, and the operational planning stage is underway,” an Iridium statement said. “In addition, Iridium is continuing to work with the appropriate government agencies to gather additional information about the collision.”
While the catastrophic space collision may have cause “brief, occasional outages” for Iridium customers, and there will be but “limited” further outages, the company stated.
Apparently, there was no warning of the impending collision by the U.S. military, which tracks objects in space.
Issues of liability, insurance coverage and the like still are hazy.
What is clear, however, is that the collision — while statistically improbable in the vast void of space — has created hundreds of pieces of space junk moving at roughly 4.86 miles per second, meaning even a tiny object such as a shard of metal, a bolt or ball bearing can have a devastating impact if it collides with a spacecraft.
At a higher altitude, a Chinese anti-satellite test (using a ground-based interceptor missile to smash to smithereens an old Chinese weather satellite) also created a vast cloud of space debris, devastatingly high-speed shrapnel.
A fear now is that each successive collision greatly increases the amount of space debris whizzing through the blackness, increasing the likelihood of still more collisions, in an accelerating spiral of rising risk to spacecraft and astronauts.
In some limited areas of space, at certain altitudes, that fear already may have been realized, at least partially.
For example, the huge debris field from the collision may create a large danger-filled zone where no spacecraft can enter safely, a space threat that could last for years, according to Marine Corps Gen. James E. Cartwright, vice chairman of the Joint Chiefs of Staff.
Cartwright spoke before a space symposium of the Marshall Institute, a Washington think tank, and the U.S. Chamber of Commerce, at the Chamber headquarters in Washington.
It will be a month or two before the myriad pieces of debris from the collision (Cartwright termed it a “conjunction”) settle down and experts can determine how those pieces of shrapnel, each moving about 17,500 miles an hour, will affect spacecraft.
If the hazardous debris pieces deny spacecraft safe passage through a large area of space, that will be a significant problem, Cartwright said.
He declined to discuss who might be liable or responsible for the collision. “I’m not going to get into the legal side of this,” he said.
But for the future, he ventured some thoughts. Cartwright said that in the half-century since the Russian Sputnik satellite launched the space age, space has become “crowded,” and spotting potential problems before they occur would require space situational awareness.
A multi-national approach, with some global cooperation, would be well, he indicated.
But he stressed that attempting to track all objects in space and determining which pose a collision danger would be a monumental undertaking, and he was cautious about any conclusion that the Department of Defense should take on the task, especially where it would involve, say, determining whether a civilian or NASA asset was in danger of being hit.
If the department were to take responsibility for issuing warnings of potential collisions, it would have to “frame our relationship with the commercial sector,” on a global scale, with issues including indemnity to be resolved, he said. “This is an international problem” he said.
Iridium said in an earlier statement that it “lost” a satellite, but that other satellites in the 66-spacecraft-plus-spares constellation are filling in for work that the demolished bird performed, in a quick, initial fix.
The latest debris problem came after China in 2007 created a gigantic debris cloud by launching a ground-based interceptor to demolish one of its own orbiting weather satellites.
That widely condemned act, along with China using a ground-based laser to disable a U.S. military satellite, showed China has the ability to place critical American military satellites at risk.
The Iridium and Russian satellites splintered into about 600 pieces of space debris, though no precise estimate is yet available, according to Stratfor, a civilian intelligence-gathering organization.
Those 600 pieces add to roughly 18,000 objects that are catalogued and tracked, though many more smaller pieces of junk are whizzing along in the dark to pose potentially lethal hazards.
Stratfor, in a paper entitled “U.S, Russia: The Implications of a Collision in Space” that was published Thursday, said if more collisions occur, each creating hundreds of pieces of shrapnel moving at stupendous speeds, could create a major hazard to spacecraft.
The paper also questions how such an unlikely event could occur, given the enormous void of space, asking whether it is possible the Russian satellite might have been directed into the path of the Iridium 33 bird that was launched in 1997, though Stratfor quickly notes there is no evidence of such an anti-satellite attack.
The Russian satellite, launched in 1993, carried a nuclear reactor.
Russians are saying that Iridium should have spotted the collision danger, according to Xinhua, the Chinese news agency.
The debris poses a serious threat to spacecraft, because an altitude of about 500 miles is commonly used by many communications and other satellites, according to a Russian mission control official, RIA Novosti, the Russian news agency, reported.