NOAA intends to award a sole source purchase order to Telops Inc. for critical maintenance and upgrades of the ASSIST II spectrometer, to be performed in Boulder, CO. The sole source determination is based on Telops being the only manufacturer and distributor with the proprietary knowledge and parts required for these highly-specialized repairs. The period of performance runs from award through 140 days. No budget amount is specified. Interested firms that believe they can fully meet the requirements may submit substantiating documentation in writing within 15 days after publication of this notice.