NASA Spacecraft, Russian Satellite to Pass Dangerously Close

The Department of Defense is monitoring a close pass between NASA's Thermosphere Ionosphere Mesosphere Energetics and Dynamics Mission (TIMED) spacecraft and the Russian Cosmos 2221 satellite, NASA said in a blog post early Wednesday.

Although the spacecraft are expected to miss each other, a collision could result in significant debris, the U.S. space agency said, adding it was continuing to monitor the situation with the Department of Defense. The statement did not say how close the spacecraft would come to each other.

The two satellites, which cannot maneuver, were expected to make their closest pass about 1:30 am ET (0630 GMT) on Feb. 28, at an altitude of about 373 miles, NASA said.

The TIMED mission is studying the influence of the Sun and humans on the Earth's mesosphere, lower thermosphere and ionosphere.