The astronaut in these pictures is Michael Collins, who was
later to be part of the Apollo 11 mission, and the first
picture is of him practicing his Space walk within a high
altitude airplane. When Collins finally achieved the Space
walk, NASA released several pictures of the event. If you
look closely at picture 2, you will see that the picture is
in fact picture 1 reversed and a Space background has been
added. This is proof that at least some of the pictures were
faked.
It begs the question of "why"? NASA was in a space
race with the Soviet Union. They had done a space
walk, and it was important that the USA do one to respond.
It could be that the pictures of the actual walk didn't come
out well, so they used a faked picture to use as "proof" it
took place.
For whatever reason, the picture obviously is a doctored
fake, so NASA can't even claim it was issued "by accident",
because it was doctored to make it look 'real'.
It speaks to the credibility of NASA... if they could try
to fake this... then what else could they have tried to
fake?