Hmm... an object in space does pose an interesting problem. Normally I would suggest placing your camera lower to convey size, but in a place without a horizon that's not very helpful.
You may want to move the camera closer and reframe the shot so the effects of perspective are more visible. The only way to convey the size in a wide shot like this is comparison, and none of the objects in the scene are helping:
1) The laser doesn't help much, the size can change, and we actually expect it to be small
2) And the earth, which really doesn't help.
Also, it looks very much like a common satellite, which we are trained to view as only a few feet across.
Possibly having more of the sat. off screen would help.
Zack