Astronaut photographer - Douglass Wheelock

Occasionally we get to see pictures taken by astronauts while they are in outer space. The pictures are usually out of this world (pun intended). So why don't we see even more of these pictures? I believe the reason is that you need to be quite an acomplished photographer to take the kind of pictures that astronaut Douglass Wheelock took. Camera gear being a big addition to the payload, I doubt if you can just bring along your heavy camera gear, unless you have been specially appointed for the task. Point-and-shoot cameras just won't cut it.

Here is a link for Douglass Wheelock's pictures: http://www.brobible.com/bronews/photo-gallery-astronaut-douglas-wheelocks-30-coolest-twitpics-of-earth-from/page-2

I can imagine the challenges Wheelock faced; long shutter speed being the foremost one. He will have to shoot through a small window with thick glass (how many f-stops down?), and maybe do a spacewalk to clean the outside of the window (tongue-in-cheek). Some shots are perhaps taken while doing a space walk, but certainly not those near to earth. In the cabin though, he cannot move around to get the best angle. He has to anticipate and catch each photo opportunity as it comes up. Taking pictures near to earth would be subject to vibration coming from the engines when approaching or departing earth. No sirree, being there alone is not enough to capture such images. You have to be quite an accomplished photographer too.