By JARED SHELLY, senior editor/web editor, Risk & Insurance®
While space is commonly thought of as a vast, infinite frontier, mankind has managed to leave so much debris and discarded metal there that it's causing problems for satellites and spacecrafts.
So-called 'space junk' can range from defunct satellites and rockets weighing hundreds of tons, to smaller discarded tools, to salt-grain sized particles. All of that debris can wreak havoc on vessels in orbit.
In 2009, for example, a spent Russian satellite, Cosmos 2251, collided with a working U.S. satellite called Iridium 33, destroying it.
Space debris and ensuing collisions can also lead to scraps falling to Earth after they re-enter the atmosphere. In fact, a NASA satellite is expected to fall to Earth sometime in late September or early October, the organization announced last week. While much of it is expected to burn up as it enters the Earth's atmosphere, there is a one-in-3,200 chance that a piece will hit a person on the ground, NASA said.
Experts estimate that there are 22,000 objects in orbit, but that only counts pieces that are larger than a tennis ball. David Wade, a space underwriter with Atrium Space Insurance Consortium, said the total number is actually in the hundreds of thousands.
A new report from the National Research Council in Washington calls on NASA to develop a formal strategic plan to better allocate resources devoted to managing orbital debris.
NASA's budget for studying and fighting space pollution is not keeping up with the complexity of the problem, said Darren McKnight, technical director of Integrity Applications Inc. in Chantilly, Va. who was asked to serve on the National Research Council's Committee on the Assessment of NASA's Orbital Debris Programs.
"In the last 15 years, the budget has not gone up at all," said McKnight.
The report also said that the situation may have reached a "tipping point" where debris is regularly colliding, creating even more, smaller, pieces of debris.
The National Research Council also called on NASA to develop a database to track all debris-related issues?even relatively small incidents that can degrade a mission, such as tiny particles invading a satellite's thermal control system.
"We know there have been many satellites that have had degraded missions because of debris impact," said McKnight, "but we don't currently have instruments on board space craft to determine unequivocally why a subsystem failed."
The North American Aerospace Defense Command tracks larger pieces of debris and issues warnings to satellite operators so they can manoeuvre out of harm's way. The smaller stuff, though, still goes undetected.
Space junk proliferated in 2007 when China blew up an old weather satellite, creating 150,000 pieces of junk, according to some estimates.
Could the end of NASA's shuttle program bring more dollars to space pollution cleanup? McKnight has his doubts because of budgetary concerns, and instead said the effort will have to be led by worldwide governments.
Blanket space insurance policies could cover damage due to space debris, said Wade, but the damage would have to affect a satellite's imaging or communications capabilities to be admissible as a claim.
Few buyers purchase loss-of-revenue insurance for space missions because those policies require that the satellite be unusable for a period of time before the policies are triggered.
NASA and others have been attempting to mitigate the amount of space debris that's left during future missions by reducing batteries at the end of life so they don't explode and create small pieces of debris to be left in space.
"Over time, these efforts will reduce the growth of debris," said Wade, "although collisions between the existing debris will ensure that the debris population continues to grow for some time yet before the mitigation efforts start to have an effect."
Scientists have plenty of ideas for cleanup. Solutions include sending robotic spacecraft to snatch large pieces; firing a laser to evaporate some of the surface material; or generating a small jet to drive the debris into the atmosphere.
"None of these ideas have made it beyond a paper study so far," said Wade.
McKnight said the problem has to be dealt with either now, or else later it will be that much more difficult and expensive.
"You're going to do something about it," he said. "It's only a question of when and how much."
September 12, 2011
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