NASA Johnson Space Center (JSC) has built a zenith-staring Liquid Mirror Telescope (LMT) near Cloudcroft, NM. This telescope was built to gain a better understanding of the LEO and MEO (low and middle earth orbit) optical orbital debris environments, especially in the important (but difficult to track) one to ten centimeter size range. The mirror of the LMT consists of a three-meter diameter parabolic dish containing several gallons of mercury that spins at a rate of ten revolutions per minute. At video rates the LMT is detecting objects down to about 3 cm (assming 0.1 albedo) at a range of 1000 km. A disadvantage of the LMT is its inability to point in any direction other than the zenith. However, this is not a major limitation for statistical sampling of the LEO and MEO orbital debris population.
展开▼
