Realignments of existing Global Positioning System (GPS) satellites are expected to be completed by early summer, creating the most optimal geometry in the navigation system’s 42-year history, according to the U.S. Air Force, which manages the GPS system.

Meanwhile, several GLONASS system satellites also have been realigned to maximize coverage from the Russian system, which currently has 22 satellites in service.

The GPS satellite realignment project, called Expandable 24, involved shifting the positions of six existing satellites. It began in January 2010 and is expected to be complete in June 2011 when the final satellite reaches its new position.

“When fully complete, Expandable 24 will increase global GPS coverage and provide civil, military and commercial GPS users with a more robust signal and a higher probability of signal acquisition in terrain-challenged environments,” according to an Air Force news release.

Several new GPS and GLONASS satellites are set to be launched in 2011. A U.S. GPS IIF-2 satellite is scheduled for launch at Cape Canaveral on June 23. Launch dates for four new GLONASS satellites also have been announced, including a single satellite in March, and three in June.

The GLONASS launches follow the failed launch of a trio of satellites in December 2010. According to news reports, it failed when the launch rocket blew up because excess fuel had been loaded in error.