Aloha from Maui One of the things I do here is work for UH IfA which has a contract w/ NASA to operate the TLRS-4 Ranging Laser ( http://www.slas.us/gallery2/main.php?g2_itemId=720 ). We ping satellites and get timings for NASA. I work as a Laser Range Safety Officer and my job is to spot aircraft that may be near the beam path as well as during calibrations to make sure that people and/or vehicles are not near the calibration retro-reflectors. It was calculated that w/ the laser output and the narrow pulse width at full power output, the beam leaves the station w/ 1.1 gigawatts of output. When operating at this output, no aircraft out to 75 miles cannot come w/in 20ยบ of the beam. The beam is not visible during the day, at night, a great laser light show!! We watch for aircraft visually and w/ a synthetic radar on the laptop and it was calculated that even w/o observers that a possible hit (according to NASA) would happen once in 50 years. Lighting up an aircraft at 50 miles out would cause permanent eye damage immediately, so far we have been 100% safe. Aloha Rob