Space debris threat 'at tipping point'

Astronauts aboard the space station in June had to shelter as debris came within 1,000 feet

Story highlights

  • Even the tiniest of millions of orbiting particles can cause damage
  • Space station astronauts had to take cover when debris came close
  • Report warns Nasa that budget reductions could threaten its ability to tackle the problem
  • Expanding foam has been one suggestion to clear space of the debris
Satellite failures could become more commonplace, scientists have warned, as the amount of space debris reaches a "tipping point."
Millions of small particles are orbiting Earth. Nasa estimates that about 19,000 of these are larger than 10cm.
This junk travels at enormous speeds and means even tiny fragments can cause severe damage, with the potential to knock out orbiting spacecraft that control modern communications. These include global positioning systems used in car sat-navs and weather-forecasting.
The danger was highlighted in June when astronauts on the International Space Station were forced to take shelter inside two Soyuz capsules when debris came within 1,000 feet.
And this debris is increasing all the time.
In 2009 two satellites smashed into each other over Siberia, destroying a privately owned U.S. communications satellite and a Russian military satellite.
The Chinese also created a huge cloud of space junk in 2007 when they deliberately destroyed an old weather satellite. ESA estimates that it increased the number of trackable space objects by 25%.
Now researchers from the U.S. National Research Council of the National Academies are warning that the situation is in danger of snowballing.
The report, prepared for Nasa and released Thursday, also warns that staff shortages and budget reductions could "threaten the viability and scope" of efforts to tackle the problem.
It urges Nasa to initiate efforts to record, analyze and share information on spacecraft to assess risks from particles too small to track.
Robert Massey from the UK's Royal Astronomical Society says the problem should not be underestimated and deserves more money to protect investment in existing satellites.
"Even if you have to spend $1 billion it's worth it," he said. "We ought to have a stronger international agreement on the table," he told CNN.
The Inter-Agency Space Debris Coordination Committee exists to exchange information on space debris research and identify what it calls mitigation options.
Massey explained: "Most of the time it is about moving things out of the way," adding that most of the other options to clean up space consisted of "relatively untried technology."
Space agencies, including Nasa, also have guidelines on orbital debris. They aim to minimize the risk of collision by reducing the risk of in-orbit explosions and making satellites burn up in the atmosphere at the end of their working life.
Some suggestions found in the bloggosphere appear quite fanciful, such as lasers to vaporize debris or creating huge orbiting junkyards, but other ideas have been considered:
ESA has suggested creating an expanding foam that sticks to debris, slowing it down and causing it to burn up in Earth's atmosphere.

DARPA, an agency of the U.S. defense department, has proposed a space vehicle that can capture debris with lightweight expandable nets.

And researchers working for the U.S. Naval Research Laboratory this year published a study that envisaged releasing tungsten dust into low-Earth orbit. It said the dust would slow the tiny particles enough to pull them into the atmosphere where they would be destroyed.
Without a solution, the disruption and cost could be immense. "We need to find an effective way of cleaning it up and stop making it in the first place," said Massey.