LEFT - An image of Earth orbit and the region of space within 2,000 km of the Earth's surface to show the most concentrated area for orbital debris. RIGHT- This image is generated from a distant oblique vantage point to provide a good view of the the larger population of objects over the northern hemisphere is due mostly to Russian objects in high-inclination, high-eccentricity orbits. (NASA Orbital Debris Program Office/Johnson Space Center)

Space debris has passed the “tipping point,” according to a report released Thursday by the National Research Council, which called on NASA to find ways to better monitor and clean up the orbiting junk threatening active satellites and manned spacecraft.

“We’re going to have a lot more [debris] collisions, and at an increasingly frequent rate,” said Don Kessler, a former NASA scientist who chaired the committee that prepared the report. The orbiting objects include ejected rockets and broken satellites.

Kessler first predicted in 1978 that the number and size of objects in Earth’s orbit would become so large that they would continually collide with one another and create even more debris — a chain reaction known as a “collision cascade.”

Recent data underscore the growing problem. Two collisions since January 2007 helped at least double the number of trackable debris fragments that are in Earth’s orbit, according to the NRC report.

U.S. Strategic Command, a military unit able to track man-made objects 10 centimeters and larger, says there are more than 22,000 such pieces in orbit. NASA estimates there could be hundreds of thousands — or even millions — of smaller, non-trackable pieces of debris also in space.

Active satellites are at risk of damage and “as the amount of debris increases, there will be increases in the cost of operating” satellites, said Brian Weeden, a technical adviser with the Secure World Foundation, which focuses on space sustainability.

Manned spacecraft are also in danger. The international space station had a close call in late June, when an unidentified object came within 1,100 feet but caused no damage; astronauts were preemptively evacuated to emergency spacecraft.

NASA’s chief of safety and mission assurance, Bryan O’Connor, asked the National Research Council in 2010 to independently examine the agency’s work on debris. While the report does not offer many specifics for strategy, it emphasizes the need for NASA to devise a plan that centralizes staff members and better utilizes the agency’s limited resources.

“We thank the National Research Council for their thorough review in this report,” NASA spokeswoman Beth Dickey said. “We will study their findings and recommendations carefully and use them to advise our future actions in this important area of work.”

The agency has several programs related to debris with only one staff member each, according to the NRC report, making those programs vulnerable to staff changes and budget cuts. Kessler said NASA will have to make trade-offs and reallocate funding to improve debris management.

The NRC also recommends engaging the State Department for work on the international front. Less than one-third of space debris can be attributed to the United States, and it will be important to have Russia, China and other players in space pursue cleanup, Weeden said.

The report provides no timeline for NASA to implement changes in its debris programs, but given the tipping point we have passed, Kessler said, “The earlier we [deal with the problem], the cheaper it’s going to be in the long run.”

Weeden said space debris won’t be a major concern in the next couple of years, but it will be within 10 or 20 years — and that’s a relatively short lead time given the scope of the issue, he said.

“You can’t fix the problem quickly,” Weeden said. “We’ve had 50-plus years of activity in space bring us to this point, so the answers are not going to be easy.”