debris

NASA's double sledgehammer shot to the moon succeeded early this morning when an empty rocket stage and a lunar probe each crashed into separate craters. But the host of telescopes and other instruments pointed at the impact sites did not immediately spot huge plumes of lunar debris.

Thousands of manmade pieces of space junk orbit the Earth, threatening astronauts and unmanned missions alike. Now the U.S. Air Force Space Command wants an electronic "space fence" that could track any orbital object larger than two inches in width.

Such a surveillance system would require a global network of sensitive S-band radar stations that operate in the gigahertz range of the electromagnetic spectrum. The U.S. Air Force currently relies on a system dating back to 1961, which only covers the continental United States, and can only track objects 20 inches in width or larger.

Look out! says NASA. Three crew members evacuated the International Space Station earlier today. What could have caused such action? Garbage. A 13-centimeter-wide piece of space junk was projected to come within 4.5 kilometers of the space station. Not willing to take any risks, NASA told the crew to jump ship.