What G. is saying is that you are currently getting the position of your shuttle (a single point) and then making sure that point is in the bounds of your space. However, your shuttle is not a single point. Your shuttle is a whole rectangle. The single point is the top left corner of the shutle rectangle, but you also need to take into account the bottom right point of the rectangle too. There are a couple of ways to do this. One of them being something like this
...
Vector2f point2 = obj.ship_s.getPosition();
point2.x += shuttleSpriteWidth;
point2.y += shuttleSpriteHeight;
if (bound.contains(point) && bound.contains(point2))
{
...
Alternatively, like zsbzsb mentioned, you could get the bounds of your shuttle sprite the same way you get the bounds of your space. Then you could just do something like
if (bound.intersects(shuttleBound))
{
...
However, I don't think this is quite what you want because it would allow your shuttle to only be partly inside of your space. It sounds like you are more interested in keeping the the shuttle completely inside of the space, which is what that first solution would do.
Edit: Also as G. mentioned, your back() function calls move(1,1). If you are moving right then this function is just going to move you more right when you actually probably want to go left.