Flir Systems Inc. announced it has been awarded a $6.3 million firm fixed-price contract from Science Applications International Corp., a San Diego research and engineering company, for the US Air Force for the delivery of Star Safire II airborne thermal imaging systems to the Air Force Space Command. The units are to be installed on UH-1N helicopters for use on security missions. Deliveries are expected to begin in the third quarter of this year and to be completed in 12 months.    . . .    Douglas W. Reilly has been named vice president of operations at NanoOpto Corp., a Somerset, N.J., developer of nanomanufacturing and nano-optics technology used to manufacture optical components. Reilly was formerly vice president of operations at Optium Corp. and previously had senior operations positions at JDS Uniphase.    . . .     Siemens Medical Solutions and Gamma Medica Inc., a Northridge, Calif., maker of nuclear medical imaging cameras and equipment, announced they have expanded their marketing agreement to include the worldwide market. Siemens has had exclusive US marketing rights for Gamma Medica's molecular imaging product, X-SPECT, since 2003. The systems combine single-photon emission computed tomography with anatomical imaging provided by computed tomography; they are used primarily in the study of disease processes and for drug development. Siemens Medical Solutions, part of Siemens AG, is a supplier to the health care industry, with headquarters in Malvern, Pa., and Erlangen, Germany.