As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAKEOFF AND INITIAL CLIMB OUT ALL CREWMEMBERS NOTICED ABNORMAL SMELL; MISSION SPECIALISTS (2) NOTED HAZE THROUGHOUT CABIN WHICH REDUCED VISIBILITY, NON-FLYING PILOT CONFIRMED; IFR CANCELLED, FLYING. PILOT EXECUTED REVERSAL AND PRECAUTIONARY LANDING BACK AT DEPARTURE POINT.