Fri, 04 Mar 2011
SPA's Martin snaps spacewalk astronaut
SPA member Martin Lewis captured an astonishing snapshot of the International Space Station this week - complete with spacewalking astronaut.
|Martin's amazing photo (top) and the man himself
with another of his home-built telescopes
Martin, from St Albans, Herts, produced his image using an ordinary webcam coupled to one of his home-made telescopes, an 8¾-inch reflector.
Martin has photographed the ISS on a number of occasions, always something of a feat considering the speed at which it moves across the night sky.
This week it has appeared especially bright, rivalling Venus, because the space shuttle Discovery is attached on its final mission.
You can clearly see the shape of Discovery in the middle of Martin's photo of the ISS, taken on Wednesday 2 March at 18.48 UT (6.48pm UK time). At the end of a robotic arm called Canadarm is a bright blob which Martin at first believed was NASA astronaut Steve Bowen.
Although further research, with the help of Dutch imager Ralf Vandebergh, whose own pictures you can see here, reveals that this was a different robotic arm, Steve is still in the photo but on the other side of the shuttle.
He was in the middle of a lengthy spacewalk at the time the picture was taken. For details, see the new annotated image below which replaces one we posted earlier. In it Martin has identified various parts of the orbiting ensemble, 350 km (217 miles) above the Earth.
Martin, a software engineer by profession, said: "The image was taken after rushing home from work to get the scope cooling in time for the pass.
"I took it through my homebuilt 8¾-inch reflector from my back garden in St Albans and the telescope was hand-guided to follow the path of the ISS as it rose in the west and passed overhead.
"The camera used was a monochrome, 640x480-pixel webcam running at 60 frames per second and I took 4,700 images combining the best 30 or so to produce the image. The astronauts were 3hr 30min into a 6hr 30min EVA at the time I took my shot and part of this EVA involved Steve Bowen riding the Shuttle’s Canadarm."
Martin's annotated image using NASA TV shots of the spacewalk. Click on
the image to view full-size in a new window.
Added by: Paul Sutherland