Not exactly. It might be based on a B747-200 airframe, but it's actually a Boeing E-4 Advanced Airborne Command Post. One of only 4 currently in service with the USAF, although two are currently out of service due to damage suffered as a result of a tornado that struck Offutt AFB in June.

Thought It was the new Air Force " 1 " but then it's not because it doesn't have the shinney bottom

Why does the leftmost engine (right in the picture) look bigger than the others?

And what's the hump on top of the hump?

What's the hump on top of the hump?

The hump is part of the electronics functions on board.

Clearly testing a new thruster.

Nice pic

This aircraft has been around for quite some time. Boeing-Wichita upgraded the equipment on these about 12 years ago. One of these 4 is always in the air at all times.