The ISS should be operating SSTV on August 3 and 4, using the Robot36 mode. I’ll go ahead and see if I can catch some pictures from space that way. Should work well, after my success with AO-51.

SSTV Aug 3 & 4 | ISS Fan Club.

Addendum: If you want to test your SSTV software before hand, you might want to use a recording that I made. Go here and fetch the linked .wav recording, and use it to test your SSTV software. It will also help you know what an SSTV signal sounds like.