Northrop Grumman Space and Mission Systems Corp., Redondo Beach, Calif., is being awarded a $16.6 million cost plus award fee contract modification to provide for the National Polar-orbiting Operational Environmental Satellite System, to incorporate into the Acquisition and Operations Contract and Engineering Change Proposal to mitigate the adverse effects of radio frequency interference from ground-based, anthropogenic transmitters on the Conical Scanning Microwave Imager/Sounder (CMIS) instrument. The CMIS is being developed by Boeing Satellite System, a subcontractor to Northrop Grumman Space Technology. The modification will result in a redesign of the system to incorporate sub-banding. This change affects both satellites in the phase of this contract. The National Environmental Satellite, Data and Information Service, Silver Springs, Md., is the contracting organization.