NASA/NSSC intends to issue a sole source contract to MISSION SYSTEMS DAVENPORT INC. for PBG Oxygen Regulator Tester Repair and Calibration, as they are determined to be the sole provider. Performance of the services will be located at NASA/Armstrong Flight Research Center (AFRC). Interested organizations may submit their capabilities and qualifications in writing by 4:00 a.m. Central Standard Time on 6/11/2026 for consideration of a competitive procurement. No budget amount is specified in the description. This notice serves to assess interest, with the government retaining discretion on whether to compete the effort.