Small deadly and invisible

摘要

Panicky news headlines in recent months have warned of the perils of the fiery debris that might rain down on us as three derelict spacecraft re-entered the atmosphere. In the end, NASA's (JARS satellite, Germany's ROSAT X-ray telescope and Russia's crippled Mars probe, Phobos-Crunt, all burned up or ditched harmlessly in the oceans, But at least mission controllers knew where they were headed - the craft were around the size of an SUV, and so were easy to track via radar.