Threat Level Increases as Space Junk Hits 'Tipping Point'

Space debris orbiting the earth is becoming increasingly hazardous, researchers warn, with junk posing increasing danger to astronauts and space missions.

The current space environment is growing increasingly hazardous to spacecraft and astronauts, said Donald Kessler, chair of the committee that wrote the report and retired head of NASA's Orbital Debris Program Office.

Kessler predicted in 1978 that the number and size of objects in Earth's orbit would eventually reach a critical point where they would collide, and the resulting debris would cause further collisions.

Some scenarios, generated by the National Research Council show that debris has reached that tipping point already, with enough currently in orbit to continually collide and cascade.

NASA needs to determine the best path forward for tackling the multifaceted problems caused by meteoroids and orbital debris that put human and robotic space operations at risk, Kessler said.

The orbiting objects include ejected rockets and broken satellites. The junk not only puts satellites in jeopardy, but people as well.

The International Space Station was nearly destroyed in June when an unidentified object came within 1,100 feet. 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 any strategy, it emphasizes the need for NASA to come up with a plan and better utilize its resources to tackle the problem.

For example, it recommended NASA should initiate a new effort to record, analyze, report, and share data on spacecraft anomalies. NASA should lead public discussion of orbital debris and emphasize that it is a long-term concern for society that must continue to be addressed.

But removal of orbital debris introduces another set of complexities, the report adds, because only about 30 percent of the objects can be attributed to the United States.

According to international legal principle, no nation may salvage or collect other nations' space objects. Therefore, the report recommends, NASA should engage the U.S. Department of State in the legal requirements and diplomatic aspects of active debris removal.

The Cold War is over, but the acute sensitivity regarding satellite technology remains, explained committee vice chair George Gleghorn, former vice president and chief engineer for the TRW Space and Technology Group.