3Q: Don Boroson on NASA’s record-breaking use of laser communications
Last week, NASA announced that the Lunar Laser Communication Demonstration (LLCD) on its Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft had made history by using a pulsed laser beam to transmit data over the 239,000 miles from the moon to Earth at a record-breaking data-download speed of 622 megabits per second (Mbps). This download speed is more than six times faster than the speed achieved by the best radio system ever flown to the moon. LLCD also demonstrated a data-upload speed of 20 Mbps on a laser beam transmitted from a ground station in New Mexico to the LADEE spacecraft in lunar orbit; this speed is 5,000 times faster than the upload speed of the best radio system sent to the moon. Finally, LLCD provided continuous measurements of the distance from Earth to the fast-moving LADEE spacecraft with an unprecedented accuracy of less than half an inch.These tests were...