Space junk such as
debris from rockets must be removed from the Earth's orbit to avoid crashes
that could cost satellite operators millions of euros and knock out mobile and
GPS networks, the European Space Agency (ESA) said.
At the current density
of debris, there will be an in-orbit collision about every five years, however
research presented at a conference hosted by ESA in Germany showed that an
increase in such junk made more collisions likely in the future.
Five to 10 large
objects need to be collected from space a year to help cut down on smashes and
stem the risk of fragments being sprayed into space that could cause more
damage, it said.
Scientists estimate
there are about 29,000 objects larger than 10 cm (four inches) orbiting Earth
at average speeds of 25,000 kph (15,500 mph) — about 40 times faster than
airplanes travel.
At that speed, even
small pieces of fast-traveling debris can damage or destroy spacecraft and
satellites — which could cost billions of dollars to replace and disrupt mobile
phone communication or satellite navigation.
"Within a few
decades, there are going to be collisions among large objects that will create
fragments that can do further damage," Heiner Klinkrad, the head of ESA's
Space Debris Office, told Reuters.
"The only way to
keep this from happening is to go up there and remove them," he said.
"The longer you wait, the more difficult and far more expensive it is
going to be."
Space debris includes
any man-made litter left in space — parts of rocket launchers, inactive
satellites and broken parts from past collisions.
Space agencies around
the world are cooperating on space debris research, and ESA's Clean Space
initiative, launched in 2012, aims to develop the technology to safely capture
and remove space debris.
Researchers are looking
at several different methods for removing space debris from orbit, Klinkrad
said, ranging from the use of propulsion packages, conductive tethers or
lasers, to nets and harpoons.
But any decision to go
ahead with a mission, as well as funds to pay for it, would need to come ESA's
20 member states, which include France, Germany, Italy and Britain.
Demand for the removal
of objects from orbit could eventually offer opportunities for private
companies, Klinkrad said, though many issues, including legal ones, surrounding
space debris would need to be settled first.
Sources :
http://www.voanews.com/content/european-space-agency-esa-space-junk-removal-earth-orbit-gps/1648848.html
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