Spreading Internet across the globe is definitely an achievement worth having, but it turns out that the path towards that goal takes us through space. Satellites are required to bring Internet to some of the most remote places on Earth and if the current rate of satellite deployment continues, the space debris situation could soon get out of hands, scientists warn.
At a conference in Germany, scientists sounded an alarm over space junk stating that the situation has become concerning and the problem needs a solution at global scale. Scientists said that in less than a quarter of a century, the number of orbiting fragments large enough to destroy a spacecraft has more than doubled.
Currently there are approximately 150 million tiny space objects orbiting Earth. The peril from debris comes from hypervelocity. Travelling at up to 28,000 kilometres (17,500 miles) per hour, even a minute object impacts with enough energy to damage the surface of a satellite or manned spacecraft.
In 1993, monitoring by ground-based radar showed there to be around 8,000 manmade objects in orbit that were larger than 10 centimetres (4.5 inches) across, a size big enough to inflict catastrophic damage, said Holger Krag, in charge of ESA`s space debris office.
Currently the things are much worse with roughly 5,000 objects with sizes larger than 1 metre (3.25 feet), roughly 20,000 objects with sizes over 10 centimetres… and 750,000 `flying bullets` of around one centimetre” (half an inch).
Risks of a collision are statistically remote, but they rise as the litter increases and more and more satellites are deployed.
The conference in Darmstadt, whose opening speeches were broadcast on the internet, is the biggest-ever gathering dedicated to space debris.
Experts will spend four days discussing the problem, including measures to mitigate space litter such as by “de-orbiting” satellites at the end of their working lives.Krag pointed to two events that had amplified the problem at a stroke, creating debris fields with the potential to generate further junk as pieces smashed into each other.
The first was in January 2007, when China tested an anti-satellite weapon on an old Fengyun weather satellite — a move that sparked an outcry by debris experts at the time.
The other was in February 2009, when an Iridium telecoms satellite and Kosmos-2251, a Russian military satellite, accidentally collided.
Given enough warning, satellites can shift position to avoid a collision, but this uses up fuel and potentially shortens operational life.
ESA receives a high-risk alert of collision every week on average for its 10 science satellites in low-Earth orbit, Krag said. Each has to resort to “one or two” avoidance manoeuvres per year.
In a message to the conference from the ISS, French astronaut Thomas Pesquet said the manned outpost in space was shielded for objects up to 1 cm across.
The ISS often has to make manoeuvres to avoid debris, but needs 24 hours` warning to be able to do this, using its onboard thrusters, he said.
If there is less time, “our crew will have to close all the hatches and enter the safe haven which is our Soyuz spacecraft so that we can depart the ISS in the case of a collision,” he said.
“This has happened four times in the history of the ISS programme.”