IIR-21(M) Rises

摘要

The U.S. Air Force successfully launched the last of eight modernized GPS MR satellites built by Lockheed Martin Navigation Systems on August 17. It is expected to be set healthy for navigation users in September.rnGPS IIR-21 (M) joins the constellation of 30 operational satellites on-orbit; it will assume plane E, slot 3 position, replacing space vehicle number 40.