CAPE CANAVERAL, Fla. – United Launch Alliance launched its Delta IV Medium rocket Thursday morning on its 15th and final mission.
After nearly 17 years in service, a Delta IV lifted off one more time into a mostly clear sky carrying the second Global Positioning System III satellite for the U.S. Air Force Space and Missile Systems Center.
Delta IV rumbled off from Launch Complex 37 at Cape Canaveral Air Force Station six minutes into the 9 a.m. launch window.
At Jetty Park in Cape Canaveral, locals were joined by onlookers visiting from around the world for the final rumble of a "single-stick" Delta IV rocket.
Alex Martinez, from the United Kingdom, said rocket launches are what makes the U.S. great and said the experience is among his favorite memories.
"After the birth of my children, it's probably up there," Martinez said. "It was one of the best things I've ever seen."
The Delta IV Medium will be replaced by ULA’s next generation rocket, the Vulcan Centaur, which is still in development. ULA CEO Tory Bruno said the company's new rocket is on track for its first launch in 2021.
Brevard County resident Pietro Scuito is looking forward to the next generation of rockets.
"It was the last launch, now maybe they're going to have new generations and I hope it's going to be better," Scuitos aid.
Here are five things to know about the Delta IV and its final launch:
What is the final mission The Air Force named GPS III Magellan in honor of Ferdinand Magellan, the first explorer to lead an expedition around the world. The spacecraft built by Lockheed Martin will join a constellation of 31 satellites that provides powerful navigation, timing, positioning capabilities for civil, commercial and military users.
"The GPS signal is also important to about 3.3 million jobs in the U.S. across agriculture, aviation, banking, across all of the industries," Kristine Jones, with L3 Harris Technology, said.
Delta IV Medium: A history The ULA rocket first launched in late 2002 and since then has launched multiple times on diverse missions including national security missions for the U.S. Air Force, GPS satellites and National Reconnaissance Office programs.
Swan song, but not goodbye While this is the final launch of the medium configuration of Delta IV, the heavy configuration will continue to launch after 2020 until ULA’s Vulcan Centaur rocket is operational.
The Delta IV Medium has one center booster core and either two or four solid rocket motors strapped to the core whereas the heavy-lift rocket has a center core and an additional two boosters strapped to the side of the center core.
[PICTURES: Final Delta IV lifts off from Cape Canaveral]
"It's the last time that this configuration will fly," Katie Qian, of Northrop Grumman said ahead of launch."This is kind of a special flight for us because this is the last time we're going to fly the GEM-60 boosters."
Northrop Grumman manufactures the Graphite Epoxy Motors-60 strap-on rocket motors Delta IV uses to provide thrust at liftoff.
"The boosters provide the initial thrust, the majority, at takeoff so that there is enough energy to bring the vehicle up to altitude," Qian said.
For this launch, Delta IV Medium needed only two solid rocket motors, those separate from the center core about 1 minute and 40 seconds after liftoff.
1 rocket, 5 states The hardware for the Delta IV Medium configuration rocket is manufactured in five states: California, Utah, Colorado, Alabama and Florida. The rocket is assembled and the spacecraft is encapsulated in the nose cone in Florida ahead of the launch.
Meet Vulcan ULA’s next generation rocket, the Vulcan Centaur, that will replace Delta IV Medium and the company’s workhorse rocket Atlas V is still in development. ULA is calling Vulcan a “more affordable” option compared to its predecessors. The rocket’s main booster will be powered by Blue Origin’s BE-4 engine and has six solid rocket boosters.
According to the company’s website, the Vulcan Centaur will pack a liftoff thrust punch up to 3.8 million pounds with the capability to carry 56,000 pounds to low Earth orbit, 33,000 pounds to a geo-transfer orbit and 16,000 pounds to geostationary orbit.