Further Findings

The collision of two satellites 500 miles above the Earth created more than 600 pieces of debris and sent shock waves through satellite operators around the world.

We asked Byron Tapley, director of the Center for Space Research in the Cockrell School of Engineering, if there’s concern about the GRACE mission.

GRACE stands for Gravity Recovery and Climate Experiment. It is a joint operation of NASA and the German Center for Air and Space Flight. Tapley is the project’s principal investigator.

GRACE consists of two satellites that orbit the Earth in unison at an altitude of 311 miles–and have since March 2002. They measure changes in the Earth’s gravity and have provided data for scores of scientific papers.

“The collision is a significant concern for all Earth orbiting missions,” Tapley said in an e-mail message. “The GRACE satellites are at a lower altitude that the satellites that collided and in principal are not subject to immediate threat, but the pieces created by the collision will eventually come down.”

He said it will take time to determine what threat the debris might pose to the GRACE satellites,

The satellites have the capability to avoid collisions, he said.

“The assessment of the probability for impact is an on-going concern and the actions would be planned as a threat is identified,” Tapley said.

He added, “The project has a task to consider minimizing the probability of collision with other satellites.”