Dubbed “Hannah”, a heavily modified Boeing 707 is operated by MIT Lincoln Laboratory for the Air Force as a communications and sensor testbed used in the development of integrated networking and airborne sensing.

https://theaviationist.com/2017/04/17/new-photos-show-the-rare-heavily-modified-b-707-operated-by-mit-as-a-communications-and-sensor-testbed-for-the-u-s-air-force/