Question: Is it possible to project lasers through space?

Monique Henson answered on 17 Nov 2015:

Yep! Lasers don’t need a medium to travel through, so you can send them through space. In fact, I think people have used lasers to measure the distance between the Earth and the Moon. There’s a good description of the experiment on its Wikipedia page here. Basically there are reflectors on the moon that were left there in the Apollo missions in the late 1960s and early 1970s. Scientists fire a laser at these reflectors and detect the reflected signal that bounces back. By timing how long it takes for the signal to get back they can figure out the distance between the Earth and the Moon.