My friend Paul works on this. They have a mandate to track all asteroids that might hit by 2020 but need some new tools that would put them well over what NASA wants to spend. Placing an observatory satellite near Venus to look at near-Earth asteroid trajectories doesn't come cheap.
NASA runs a program called the Spaceguard Survey to track the largest potentially hazardous objects, those greater than 3,300 feet in diameter that could devastate most life if they hit. That is what scientists believe happened to the dinosaurs some 65 million years ago. This program, using ground-based observatories, is budgeted at $4.1 million a year through 2012.This is really an insurance policy that pays off in the long run but politicians don't want to fully fund so they do a half-assed job. Kinda like the Army Corp of Engineer dikes around New Orleans.
Donald K. Yeomans, director of the Spaceguard program, said that there were believed to be 1,100 of these larger objects and that the survey had cataloged about 73 percent of them. The initial goal of tracking 90 percent of them should be reached by 2010, more than a year later than originally planned, he said.
Mr. Yeomans, attending a planetary defense conference here last week at George Washington University, said the goal of surveying 90 percent of potentially hazardous objects could be reached more cheaply than in the NASA study by using only ground-based observatories. But Congress would have to change its goal from 2020 to 2026, he said.