STORY: The Earth is ringed with a growing cloud of junk, made up of dead satellites and the like.

And some see an opportunity in the mess.

Wednesday saw a stellar stock market debut for Japanese startup Astroscale.

Its shares jumped 51% in early trades.

The firm has won government backing from Japan, the U.S. and UK for a plan to clear up space junk.

It aims to develop an orbital gripper that can catch old satellites and other garbage, and then nudge them back towards Earth to burn up in the atmosphere.

The company says there is about 10,000 tons of junk in orbit, posing a threat to active satellites and space stations.

Astroscale boss Nobu Okada says demand for its shares far outstripped supply.

The firm was able to price the offering right at the top of its planned range as a result.

Its debut comes amid growing investor interest in Japan’s space technology firms.

Last year saw stock market listings for moon explorer ispace, and radar satellite maker iQPS.

Tokyo has pledged billion-dollar grants and contracts in a bid to double the size of its space industry and boost national security.