A Soyuz rocket is poised for launch early Saturday from a Russian space base with a next-generation Glonass navigation satellite.

The upgraded Soyuz 2-1b launcher, featuring advanced digital avionics and a more powerful third stage engine, is scheduled to lift off at 0307 GMT Saturday (10:07 p.m. EST) from the Plesetsk Cosmodrome in northern Russia.

The Soyuz and a Fregat upper stage will haul the first Glonass K satellite into a nearly 12,000-mile-high orbit to join Russia's navigation network in space. The next-generation satellite, built by ISS Reshetnev, has a longer design life, more navigation channels and is smaller than previous Glonass spacecraft.

Launch was postponed from early Thursday by a technical issue, but Russian officials report the mission is on track for liftoff Saturday.

These photos show the Soyuz rocket rolling to the launch pad at Plesetsk earlier this week.

Photo credit: Roscosmos