To learn more about what's happening on the International Space Station at any given time, check out NASA's frequently-updated ISS blog or their page about the research and development work happening on ISS.
Depends on your body type and metabolism and your routine. But usually it takes around 3 to 4 weeks for visible results. For me it took me a couple of months to actually see any progress visually.
Noticeable results vary by person, but most people start seeing results halfway through the regimen, with full results upon completion. If speed is a priority, try Crest 3D White Whitestrips Advanced Vivid or Professional Effects to start seeing results after 3 days.