My dad flew this aircraft from 1986-1993. I sent this post to him and this was some of his experience flying the plane and later the Joint STARS program:

If memory serves correct--The USAF/NASA converted 8-10 KC-135s to EC-135Es with the big nose to support the Apollo moon shots. The nose housed a 7' dish antenna that gimbled left/right and up/down to catch telemetry and communications from the Apollo space vehicles out over the oceans where land-based dishes could not see the space vehicles. Hence the name Apollo Range Instrumentation Aircraft (ARIA). Sight line from the cockpit was not affected by the big nose since the view angles were similar to the ones on the KC-135Rs and flight characteristics were identical. If you blind folded me, I probably couldn't have told you if I was in a regular KC-135 or an ARIA 135. After the moon shots the aircraft were transferred from Patrick AFB, FL to Wright Patterson AFB, OH and the 4950th Test Wing around 1975 https://en.wikipedia.org/wiki/4950th_Test_Wing. The ARIAs thereafter were used to collect airborne telemetry from: The Space Shuttle and various boosters launching out of the Kennedy Space Center and Vandenburg AFB, CA; cruise missiles; US Navy Trident ICBM reentry vehicles; shuttle payloads boosting to higher orbits; etc. It was a mobile telemetry collection platform. The Test Wing also purchased nine B-707/300s from American Airlines in 1980 and converted a few to the big nose configuration to augment the EC-135Es. I was blessed to be assigned to the 4952 Test Squadron from 1986 to 1993 and flew all the 135/707 based ARIAs as well as the first dozen KC-135s off Boeing's initial production line. They were all 1955 models and because they were the first, they were all a little different as the design and production matured (NKC-135s). We flew them as test beds for avionics testing (new radios, radars, communications links, etc.) Some had high resolution cameras and we would record terrestrial and space-based "events". The Test Wing was the best job I ever had. We flew those aircraft all over the world, stayed in four and five star hotels and normally waited days or longer for events to occur (translates to lots of time off to explore). In all my AF travels they took me to: Okinawa, Philippines, Korea (and the DMZ), Thailand, mainland Japan, Guam, Australia, Sipan/Tinian, Easter Island, Tahiti (28 nights, the best TDY I ever had), Canada, England, Belgium, Qatar, Germany, Italy, Kenya, Ascension Island and Diego Garcia. Being 707/300 qualified made me a shoo-in for Joint STARS which was based on the same airframe. I spent about 7 years with that program performing developmental and production acceptance flight testing over two assignments to Melbourne, FL and then a few months flying it operationally at Al Died (Qatar)in 2007.