Alltop.com

See that teeny-weeny blue dot near the center of the picture, above the cluster of lights? That’s how you flash a space station, but it isn’t as easy as you might think, explained astronaut Don Pettit.

This took a number of engineering calculations. Projected beam diameters (assuming the propagation of a Gaussian wave for the laser) and intensity at the target had to be calculated. Tracking space station’s path as it streaked across the sky was another challenge. I used email to communicate with Robert Reeves, one of the association’s members. Considering that it takes a day, maybe more, for a simple exchange of messages (on space station we receive email drops two to three times a day), the whole event took weeks to plan.

Oh well, so much for spontaneity and the element of surprise. No doubt after all that time in space they wouldn’t mind a more old-fashioned variety of flashing, but for now, this will have to do.

Full story at Air & Space Magazine via PetaPixel.

Hello up there!