Light (top center) flashed from the Lozano Observatory, about 40 miles north of San Antonio, was easily visible from orbit. Click on the image to see it full-sized.

Radio amateur and ISS astronaut Don Pettit KD5MDT describes how he succeeded in receiving signals on a frequency of 650 THz.

Flashing the International Space Station with beams of light as it passes overhead had never been successfully done—until now.

It sounds deceptively easy. In an earlier post I wrote about the technical requirements. But like so many other tasks, it becomes much more involved in the execution than in the planning.

Early Sunday morning, at 01:27 our time, the San Antonio Astronomical Association, an amateur astronomy group, succeeded in flashing space station with a one-watt blue laser and a white spot light as we passed overhead. 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.

I was ready with cameras for the early morning San Antonio pass and can report that it was a flashing success. Here’s one of the pictures to prove it.

Don Pettit KD5MDT

Light (top center) flashed from the Lozano Observatory, about 40 miles north of San Antonio, was easily visible from orbit. Click on the image to see it full-sized.

Radio amateur and ISS astronaut Don Pettit KD5MDT describes how he succeeded in receiving signals on a frequency of 650 THz.

Flashing the International Space Station with beams of light as it passes overhead had never been successfully done—until now.

It sounds deceptively easy. In an earlier post I wrote about the technical requirements. But like so many other tasks, it becomes much more involved in the execution than in the planning.

Early Sunday morning, at 01:27 our time, the San Antonio Astronomical Association, an amateur astronomy group, succeeded in flashing space station with a one-watt blue laser and a white spot light as we passed overhead. 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.

I was ready with cameras for the early morning San Antonio pass and can report that it was a flashing success. Here’s one of the pictures to prove it.

Don Pettit KD5MDT

André Kuipers PI9ISS on the ISS

Astronaut André Kuipers PI9ISS was calling CQ from the International Space Station on 145.800 MHz FM on both Saturday and Sunday afternoon, Feb. 25-26.

Paul Waddington M6WAD and son Ethan

André worked mainly Dutch stations although one UK Foundation holder Paul Waddington M6WAD was lucky enough to have a contact with him on Sunday.

Paul says “I am absolutely thrilled to have had a QSO with the ISS. I just thought I would put out a random call, as I have done so many times in the past, and he answered me. I must say, when he did reply, I became a little tongue tied in disbelief!!! I use a Yaesu FT7900 to a Comet GP-15N Triband antenna.”

When the astronauts work other radio amateurs back on Earth they transmit on 145.800 MHz FM but operate “split” listening for replies 600 kHz lower on 145.200 MHz. If you are lucky and hear them calling CQ just remember to activate your rigs repeater shift to ensure you reply on the correct frequency. You should never transmit on 145.800 MHz.

The amateur rado station on the ISS runs QRP, just 5 watts of FM to an omni-directional antenna. Despite the low power it is a strong signal and can easily be received on a handheld radio with quarter wave whip.

Get the latest status of the space station at the ISS Fan Club http://www.issfanclub.com/

Read ‘Listening to the International Space Station’ http://www.uk.amsat.org/3491

M6WAD http://www.qrz.com/db/M6WAD

M6WAD Station