Same 2 ufos in 3 NASA videos

I noticed 2 objects appear in 3 videos NASA had made public on their website.

I cannot tell if they are stationary or moving, but either way it raises questions in my head.

What are they? If they are satellites how comes they are the only ones visible in these videos and how comes they are so close? What would be the purpose of having 2 satellites in such close orbit?

As i say, i cannot tell if they are moving, or have moved, or are moving during the photography.

LINK TO VIDEOS:

http://eol.jsc.nasa.gov/Videos/CrewEarthObservationsVideos/