The U.S. Air Force’s next GPS navigation satellite has been closed up inside the payload fairing of its Delta 4 launcher ahead a liftoff from Cape Canaveral scheduled for July 25.
The Lockheed Martin-built spacecraft was encapsulated inside the Delta 4’s payload fairing last week inside an Astrotech payload processing facility in Titusville, Florida. The satellite’s next move will be to the Delta 4’s launch pad at Cape Canaveral Air Force Station, where United Launch Alliance teams have stacked and tested the rocket since late May.
The Delta 4 rocket is set for liftoff from Cape Canaveral’s Complex 37B launch pad during a 26-minute launch window opening at 10:55 a.m. EDT (1455 GMT) on July 25. It will be the final launch of the single-core Delta 4-Medium rocket variant, which ULA is retiring in favor of the less expensive Atlas 5 rocket, and eventually the new Vulcan launcher family set to debut in 2021.
The July 25 launch will mark the 40th flight of a Delta 4 rocket since November 2002, and ULA’s third mission this year.
The Delta 4-Heavy rocket configuration, made by combining three Delta 4 rocket cores together, will continue flying into the 2020s. The National Reconnaissance Office, using the Air Force as a contracting agent, has contracts in place for five more Delta 4-Heavy missions through 2024.
The Delta 4-Medium’s final launch will deliver the second in a new generation of Air Force Global Positioning System satellites into an elliptical transfer orbit ranging more than 12,000 miles (about 20,000 kilometers) from Earth at its highest altitude.
The GPS 3 SV02 navigation satellite, nicknamed “Magellan” and built by Lockheed Martin, arrived at the Florida spaceport in March for final launch preparations. The Air Force said the spacecraft passed final checkouts inside the Astrotech payload processing facility before encapsulation.
The first of the new generation of GPS satellites, named “Vespucci,” launched in December aboard a SpaceX Falcon 9 rocket. The GPS network provides positioning and timing services worldwide for military and civilian users.
The retirement of the Delta 4-Medium rocket also marks the last flight of the Delta 4’s 4-meter-diameter (13.1-foot) payload fairing. The Delta 4-Heavy rockets set for launch over the next five years all use a larger 5-meter (16.4-foot) payload shroud.
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