Space companies, from Elon Musk's SpaceX to start-up OneWeb, are racing to launch satellites into space with the aim of creating global internet coverage on Earth. But there's one big problem, experts say — the creation and threat from so-called "space junk."
This debris floating in space could interfere with future space missions and satellite launches — and even send objects hurtling back to Earth.
The latest episode of CNBC's "Beyond the Valley" podcast looks at London-based start-up OneWeb's mission to launch satellites into space and the issues surrounding space junk and regulation.
There have been over 5,000 launches into space since the late 1950s, according to the European Space Agency (ESA) with nearly 9,000 satellites put up there. About 5,000 are still in space but under 2,000 are actually functioning.
These human-made objects, which can be an entire satellite or even bits of rockets, are dubbed as space junk.
The ESA said there are 22,300 pieces of debris that are traceable but there could be hundreds of thousands more than can't be tracked.
Space junk has gotten worse for a number of reasons. When rockets are launched, certain "stages" of rockets detach from the main body of the vessel. These explode, splintering into lots of pieces. That's one cause of the growing amount of junk.
One particular major event happened in 2009, when two satellites collided with each other, resulting in 2,300 trackable fragments being generated, the ESA said.
The other big problem is countries launching anti-satellite missiles. For example, in 2007, China blew up one of its own missiles, increasing the amount of trackable debris size by 25% in that one incident. And in 2009, India carried out a similar missile launch on one of its own satellites.
As space junk increases, there could be a snowball effect. If more debris is travelling at thousands of miles per hour in space and it hits another object, that can result in more splintering and more junk.
"Imagine how dangerous sailing the high seas would be if all the ships ever lost in history were still drifting on top of the water," ESA Director General Jan Worner said in a statement last year.
The biggest concern right now is the plans for thousands of satellites from various companies being launched into space.
SpaceX and OneWeb are among the companies in this race. The aim is to create so-called mega-constellations that are able to provide internet access to anywhere in the world, even the remotest parts of Earth. Both SpaceX and OneWeb have already begun launching satellites.
There are a number of risks associated with space junk. The first is that this debris could hit spacecraft carrying humans or even the International Space Station.
Another risk is satellites hitting each other. And finally, the ESA warns that large space debris that "reenter into the atmosphere in an uncontrolled way can reach the ground and create risk to the population on ground."
"The space environment is a very delicate one," Christopher Newman, professor of space law and policy at Northumbria University in the U.K., told CNBC's "Beyond the Valley" podcast.
"And for many, many years there was the prevalence of what we call 'big sky theory' — space is big, we don't need to worry about it. But actually the amount of operational space we are using is really quite small and especially now, with the constellations looking to occupy large areas of low Earth orbit, it's becoming even more crowded."
Projects have been authorized with the aim of removing the floating space rubbish.
Last year, ESA commissioned a consortium led by Swiss start-up ClearSpace, to lead a mission to remove a specific item of debris from space.
A video on ClearSpace's website shows how its technology would work. A spacecraft would be sent up toward the junk and an arm would extend out to grab the item. This mission is slated for 2025.
The Japan Aerospace Exploration Agency (JAXA) has commissioned another start-up Astroscale to remove space debris, and the mission is slated to begin in 2022.
"Active debris removal is going to become an area where I think we're going to have to pay increased attention to," Newman said.
Adrian Steckel, CEO of OneWeb, explained how he's trying to make his company's launches sustainable.
"We are making sure that what we are putting up in space … what really matters is you take this stuff down, when we take it down our satellites will disintegrate … upon re-entry (into Earth)," Steckel said during an interview for CNBC's "Beyond the Valley" podcast.
SpaceX did not respond to a request for comment when contacted by CNBC.