EC-135

The sign identifies this as an EC-135 (SN 61-269), an "airborne command post relay" version of the C-135 Stratolifter cargo plane, but it is displayed with a refueling boom, representing a KC-135 Stratotanker configuration, and indeed the museum's web page identifies it as an "EC-135 Stratotanker."

NASA used a pair of KC-135s as zero-G trainers, affectionately called "Vomit Comets" for their nausea-inducing effect, for many year.

Another variant of the C-135 was the Apollo/Range Instrumentation Aircraft, or A/RIA, to provide tracking and telemetry during Project Apollo.