Lockheed Martin was awarded a $44 million contract from the Latvian National Armed Forces for two long-range AN/TPS-77 transportable air surveillance radar systems, as well as options for long-term technical support. Included in the contract were priced options for up to four additional TPS-77 radars for Estonia and Lithuania. The AN/TPS-77 is a transportable radar that provides continuous 3-D surveillance on aircraft targets at ranges out to 250 nautical miles. The AN/TPS-77 shares commonality with Lockheed Martin's AN/FPS-117 radar with regard to maintenance activity and Line Replaceable Units. There are 26 AN/TPS-77s and 127 AN/FPS-117 systems operational in more than 20 countries.