Dealing with space debris presents a thorny political issue that must be addressed, according to an international foundation's brief to the United Nations.

In an address to the U.N.'s Committee on the Peaceful Uses of Outer Space, the Secure World Foundation ? a non-profit organization committed to space sustainability ? emphasized the importance of developing a legal framework and protocol for cooperating to address this problem.

Yet tensions between countries about the best way to deal with space junk could make a solution difficult, experts say.

"In order to keep the ability to work in space, we need to reduce as much as possible the amount of debris that we put in orbit," Secure World Foundation Executive Director Ray Williamson told "The reason for that is that as we go to much higher-than-Earth altitudes, the debris tends to stay in space for many years. And if you go to 1,000 km [600 miles], when you get to those altitudes, debris in space stays for centuries."

Messy place in space

A head-on collision between an American communications satellite and a defunct Soviet spacecraft in 2009 woke up many to the seriousness of the orbital debris problem. Adding over a thousand pieces of trackable debris to orbit, the crash was the first of its magnitude, and impressed upon the world the necessity of creating programs to reduce junk in space and keep track of existing debris to avoid further accidents, Williamson said.??

Currently, the build-up is worst at some of the most crowded orbital areas, such as over Earth's poles and the equator.

Of the 21,000 objects bigger than 4 inches (10 cm) in diameter now being tracked by the Department of Defense's U.S. Space Surveillance Network., 1,000 are working satellites. Experts estimate that hundreds of thousands more objects exist that are too small to track.

Space collision tracking

Before the 2009 collision, the United States calculated possible collisions in orbit only for U.S. working satellites. Now the Space Surveillance Network attempts to monitor potential conjunctions among the whole world's satellites when possible because of its unique capacity to do so, and the issue's importance for space sustainability, Williamson said.

No restrictions exist for which countries can put satellites into orbit, but hairy issues arising from the process of removing debris make a collaborative legal framework a necessity, he said.?

"The U.S. wouldn't like it a bit if China were to take out an old U.S. satellite and bring it back," Williamson said. "And they wouldn?t like it if we took one of theirs and brought it back. We need to work on protocol. This makes things very complicated."

In the long run, these legal and policy issues are more important than today's technological challenges with removing the debris, he added.

Codes of conduct that direct international response are also needed for planetary defense against asteroids. But Williamson said the space debris issue is even more pressing.