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BBC MUNDO RADIO
(April 17) -- Imagine half a million marbles circling Earth -- a sort of celestial obstacle course for the International Space Station, shuttles and satellites.
That's the increasingly problematic issue of orbital debris. The objects can be as big as a defunct satellite, but -- traveling at speeds of 17,500 miles an hour or more -- even a paint flake can put a chink in a space shuttle window, as happened on one mission.
"It's almost like it's being sandblasted by these very small pieces of space debris," said Roderick Heelis, director of the Hanson Center for Space Sciences at the University of Texas at Dallas.
The amount of junk in low Earth orbit -- where the shuttle and the space station travel -- has increased 60 percent since 2006, according to NASA. Recent additions to the trash belt include 3,000 pieces of debris created last year when China destroyed a defunct satellite as a test of anti-satellite military capability, and 2,000 more bits that came from a collision this February between an Iridium commercial satellite and a dead Russian satellite.
William Jeffs, NASA spokesman for the Astromaterials Research and Exploration Science Directorate at the Johnson Space Center in Houston, said the millions of pieces of space junk include half a million pieces bigger than a marble and 20,000 bigger than a softball.
Although the shuttle will be retired later this year and the space station program will end in 2020, the problem will continue to pose a threat to satellites vital for communications, weather monitoring and the military. So it's little surprise the United States and other countries have begun to focus more on the issue of space junk, designing satellites that deorbit themselves after they finish their jobs and other techniques to reduce debris.
As for the space station itself, its trash is loaded into the Russian Progress vehicles, which ferry supplies up. After the Progress is filled with junk -- something NASA spokesman Kelly Humphries likened to "cramming your suitcase full of everything you want to take with you" -- it is sent hurtling toward Earth, where much of it burns up in the atmosphere.
Some of the trash that doesn't fit into the Progress, along with experiments and broken items NASA wants to inspect, comes back on the Leonardo Multi-Purpose Logistics Module in Discovery's payload bay. When Discovery returns to Earth on Sunday, it will be carting 20,000 pounds of trash and equipment.
It's all a sea change from the days when Russia's Mir space station dumped its trash into space -- 87 bags of it, said Jonathan McDowell of the Harvard-Smithsonian Center for Astrophysics. (That trash likely is long gone, since it was in low Earth orbit moving at a slow enough speed for Earth's gravitational pull to quickly bring it down to a fiery death.)
"Space is like the Wild West used to be," said David Wright, senior scientist at the Union of Concerned Scientists. The first explorers of the new frontier "didn't feel like they needed laws. They dumped their trash anywhere."
Now, new binding international agreements are needed to bar anti-satellite tests like the one China did and require that countries that launch satellites and other spacecraft be more careful about what gets left behind in space, Wright said. Otherwise, "all the great things you want to use space for beneficially could be much, much more difficult to use."
Meanwhile, the United States and other countries have an extensive system for tracking space debris, using telescopes and computer modeling. Bob Plemmons, professor of mathematics and computer science at Wake Forest University, does some of the tracking for the Air Force. The problem is getting worse as more and more countries put up satellites, he noted: "With technology today, it's essential to have good communications satellites."
And the end of the space shuttle program will mean some data collected on weather conditions and the positions of other satellites will need to be collected by new satellites, adding to the risk, he said.
In higher orbits, such as those for satellites, the debris is going even faster, Heelis pointed out. And it's farther from Earth, so it takes longer to be destroyed -- decades or centuries instead of years.
"Space is large, so the chances of [debris] hitting you are very small," Heelis said. "But if it does hit you, the consequences are very large."
That's the increasingly problematic issue of orbital debris. The objects can be as big as a defunct satellite, but -- traveling at speeds of 17,500 miles an hour or more -- even a paint flake can put a chink in a space shuttle window, as happened on one mission.
"It's almost like it's being sandblasted by these very small pieces of space debris," said Roderick Heelis, director of the Hanson Center for Space Sciences at the University of Texas at Dallas.
ESA / AP
A computer-generated image shows "space junk" circulating in low Earth orbit. "Space is like the Wild West used to be," said David Wright, senior scientist at the Union of Concerned Scientists.
The amount of junk in low Earth orbit -- where the shuttle and the space station travel -- has increased 60 percent since 2006, according to NASA. Recent additions to the trash belt include 3,000 pieces of debris created last year when China destroyed a defunct satellite as a test of anti-satellite military capability, and 2,000 more bits that came from a collision this February between an Iridium commercial satellite and a dead Russian satellite.
William Jeffs, NASA spokesman for the Astromaterials Research and Exploration Science Directorate at the Johnson Space Center in Houston, said the millions of pieces of space junk include half a million pieces bigger than a marble and 20,000 bigger than a softball.
Although the shuttle will be retired later this year and the space station program will end in 2020, the problem will continue to pose a threat to satellites vital for communications, weather monitoring and the military. So it's little surprise the United States and other countries have begun to focus more on the issue of space junk, designing satellites that deorbit themselves after they finish their jobs and other techniques to reduce debris.
As for the space station itself, its trash is loaded into the Russian Progress vehicles, which ferry supplies up. After the Progress is filled with junk -- something NASA spokesman Kelly Humphries likened to "cramming your suitcase full of everything you want to take with you" -- it is sent hurtling toward Earth, where much of it burns up in the atmosphere.
Some of the trash that doesn't fit into the Progress, along with experiments and broken items NASA wants to inspect, comes back on the Leonardo Multi-Purpose Logistics Module in Discovery's payload bay. When Discovery returns to Earth on Sunday, it will be carting 20,000 pounds of trash and equipment.
It's all a sea change from the days when Russia's Mir space station dumped its trash into space -- 87 bags of it, said Jonathan McDowell of the Harvard-Smithsonian Center for Astrophysics. (That trash likely is long gone, since it was in low Earth orbit moving at a slow enough speed for Earth's gravitational pull to quickly bring it down to a fiery death.)
"Space is like the Wild West used to be," said David Wright, senior scientist at the Union of Concerned Scientists. The first explorers of the new frontier "didn't feel like they needed laws. They dumped their trash anywhere."
Now, new binding international agreements are needed to bar anti-satellite tests like the one China did and require that countries that launch satellites and other spacecraft be more careful about what gets left behind in space, Wright said. Otherwise, "all the great things you want to use space for beneficially could be much, much more difficult to use."
Meanwhile, the United States and other countries have an extensive system for tracking space debris, using telescopes and computer modeling. Bob Plemmons, professor of mathematics and computer science at Wake Forest University, does some of the tracking for the Air Force. The problem is getting worse as more and more countries put up satellites, he noted: "With technology today, it's essential to have good communications satellites."
And the end of the space shuttle program will mean some data collected on weather conditions and the positions of other satellites will need to be collected by new satellites, adding to the risk, he said.
In higher orbits, such as those for satellites, the debris is going even faster, Heelis pointed out. And it's farther from Earth, so it takes longer to be destroyed -- decades or centuries instead of years.
"Space is large, so the chances of [debris] hitting you are very small," Heelis said. "But if it does hit you, the consequences are very large."
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