Thousands of pieces of debris that have the power to hit and break a space shuttle window orbit our planet. These broken bits of old satellites are a problem, and scientists say this issue will only continue to get worse.

More and more tiny, cheap satellites are being built and launched into orbit, where they can potentially crash into each other, the Washington Post reported. The debris is moving at roughly 25,000 mph, so when they smash into one another, they explode into even more pieces of debris.

Soon, 12,000 new space capsules are expected to be sent up by companies, and many of them are small, motorless nano-satellites, according to the Post. These tiny spacecraft travel farther than their larger counterparts and are more likely to careen into one another since they can’t navigate.

Since the Space Age began in 1957, roughly 5,250 rockets have been launched and 7,500 satellites have been placed in Earth’s orbit, according to the European Space Agency. About 4,300 of these remain in space but only 1,200 are still functioning. About 23,000 debris objects are regularly tracked by the U.S. Space Surveillance Network.

An official with the European Space Agency described a recent study in which scientists found a crowded region of the galaxy which has already become unstable due to the swarm of debris, according to the Post.

During the recent European Conference on Space Debris, University of Southampton aerospace researcher Hugh Lewis announced he and his team of researchers simulated the impact of 270 nano-satellites sent into space every year for 50 years. The results show the odds of space collision more than doubled with the small spacecraft involved.

For now, there is no solution for cleaning up the space junk.

Experts at the conference said voluntary guidelines to mitigate some of the debris, such as taking the inoperable satellite out of orbit within 25 years, have typically been ignored.

“International treaties and national legislation need to impose duties on those engaged in space operations to embed more sustainable practices,” space law specialist Christopher Newman told New Scientist. “Legislators need to act to counter this growing threat to the space environment.”