File photo of a Delta 4 rocket being installed on the launch. Credit: NASA

The bright orange and white launcher is scheduled for blastoff May 20 during a window extending from 11:29 to 11:48 p.m. EDT.

Initial assembly of the rocket, including mating of the cryogenic upper stage to the Common Booster Core first stage using a precision laser alignment system, was completed in the nearby Horizontal Integration Facility.

After a diesel-powered transporter moved the 165-foot-long rocket to the Complex 37 pad, hydraulic pistons beneath the pad's tilt-table lifted the rocket upright at about 10 a.m. EDT Thursday. The vehicle was stood upright within minutes.

Over the coming weeks, a full pre-launch test program will be carried out and the final rocket assembly steps will be completed by attaching the solid-fuel motors to the first stage and mounting the payload aboard.

The rocket's mission is the safe delivery of the GPS 2F-1 satellite into orbit for the U.S. military. The bird is the first of a dozen new navigation spacecraft that Boeing is building to sustain and upgrade the GPS constellation.

The company shipped the satellite to the launch site inside a C-17 airlifter on February 11 from the manufacturing facility in El Segundo, California. It's now undergoing pre-launch activities at a processing hangar at the Cape.

"The GPS 2F system will afford major performance improvements over the legacy satellites and will sustain and dramatically improve the GPS constellation for civil, commercial and defense users alike," Craig Cooning, vice president and general manager of Boeing Space and Intelligence Systems, said recently.

The current network of orbiting GPS satellites is comprised of earlier generations made by Boeing and Lockheed Martin. Some of the oldest craft still in operation were launched almost two decades ago.

The GPS 2F era is meant to replace aging satellites and keep the navigation signals going strong.