8 times per second, engineers at NASA Goddard fire a laser that travels about 250,000 miles to hit the minivan-sized Lunar Reconnaissance Orbiter (LRO) spacecraft moving at nearly 3,600 miles per hour as it orbits the moon.
The first laser ranging effort to track a spacecraft beyond low-Earth orbit on a daily basis produces distance measurements accurate to about four inches (10 centimeters). For comparison, the microwave stations tracking LRO measure its range to a precision of about 65 feet (20 meters).
"Current lunar maps are not as accurate as we'll need to return people safely to the moon," said Ronald Zellar of NASA Goddard, team lead for the LRO laser ranging system. "In order to make an accurate map, first you need to know where you are. Knowing the precise range to LRO is necessary for its instruments to produce much more accurate maps, with errors reduced to the size of humans or rovers."
"A further benefit of laser ranging to LRO is that it can improve knowledge of the moon's orientation and gravity, which are central to understanding its interior structure and to precision navigation," said Gregory Neumann, a Geophysicist at NASA Goddard.
More at: http://www.nasa.gov/mission_pages/LRO/news/LRO_lr.html
Link to this comment:
All Comments (0)