United Launch Alliance’s final Delta 2 rocket is now on display at the Kennedy Space Center Visitor Complex in Florida, a monument to an industry workhorse that helped build the GPS navigation satellite fleet and enabled a new era of Mars exploration.
The 155th and final flight of a Delta 2 rocket took off Sept. 15, 2018, from Vandenberg Air Force Base in California with NASA ICESat 2 satellite to measure changes in Earth’s land and sea ice.
The launch added an exclamation point to a streak of 100 straight successful Delta 2 missions from 1997 through 2018. ULA had hardware for one more Delta 2 rocket, but the company did not sell the launcher. Instead, ULA donated the Delta 2 to become the newest attraction in the Rocket Garden at the KSC Visitor Complex.
“Thank you United Launch Alliance for making this amazing addition,” said Therrin Protze, chief operating officer at the Visitor Complex, in a grand opening ceremony March 23. “This addition is timely as more people are visiting to learn all about space.”
The Delta 2, with its recognizable blue color scheme, joins the Juno 1, Juno 2, Mercury-Redstone, Mercury-Atlas, Atlas-Agena, Thor-Delta and Gemini-Titan 2 vehicles standing in the Rocket Garden. A Saturn 1B rocket is displayed nearby on its side.
The Delta 2 is the second largest rocket displayed in the Rocket Garden, exceeded only by the Saturn 1B.
“This is a monumental occasion as the legacy of Delta 2 will be preserved here for years to come, taking its place among the iconic giants here in the Rocket Garden,” said Ron Fortson, ULA’s director and general manager of launch operations. “This is the final Delta 2. Since it won’t be launching, we couldn’t think of a better place for it to be than right here being preserved in this fitting location with all these other iconic rockets.”
The Delta 2’s basic design traces its origins to the Thor intermediate range ballistic missile in the late 1950s. Engineers uprated the Thor missile by adding a series of more capable upper stages, extending the size of its propellant tanks, and installing strap-on solid rocket boosters to carry heavier satellites into orbit.
The Thor’s evolution into a reliable satellite launcher culminated in the Delta 2 rocket, which debuted in 1989 and lofted 48 GPS navigation satellites, Mars rovers, interplanetary probes, and numerous military and communications payloads in its nearly 30-year career.
The Delta 2 displayed in the Rocket Garden stands 128 feet (39 meters) tall, topped by a 10-foot-diameter (3-meter) payload fairing. Most of the rocket was built as a flight-worthy launch vehicle, with the exception of three unfueled solid rocket boosters mounted around the base of the first stage.
The payload shroud is painted shark’s teeth, an insignia that harkens back to Delta 2 launches with GPS navigation satellites. Those rockets also carried the shark’s teeth, an Air Force tradition that dates back to the “Flying Tigers” group of volunteer pilots that fought against Japan in China during World War 2.
Delta 2 rockets launched with three, four, or nine strap-on solid rocket boosters to assist the first stage’s Aerojet Rocketdyne RS-27A main engine, which consumed kerosene and liquid oxygen propellants during the first four-and-a-half minutes of flight.
A second stage powered by an AJ10-118K engine fed by a storable fuel blend known as Aerozine 50 finished the job of placing payloads into orbit. On many missions, the Delta 2 flew with a solid-fueled third stage to propel spacecraft into higher orbits or toward interplanetary destinations.
“The Delta 2 has been a workhorse for NASA throughout its career,” said Bob Cabana, director of NASA’s Kennedy Space Center. “We’ve sent probes all over our solar systems with the Delta 2, to the planets, to the sun, and missions right here to planet Earth, making the Earth a better place, all because of that rocket.”
The Delta 2 rocket exhibit is the first major addition to the Visitor Complex since the opening of the shuttle Atlantis display in 2013.
“When Atlantis moved into the Atlantis facility, it was kind of heartbreaking for me to see that,” said Cabana, a former astronaut. “That’s a real rocket behind us, it could have flown in space, but instead — just like Atlantis — it’s on its second career right now. It’s on a mission of inspiration for the future generations.”
Of the 155 Delta 2 missions, 153 were successful. Delta 2 rockets lofted satellites to help forecast the weather, monitor Earth’s changing climate, and explore the moon, Mars, Mercury, comets, and asteroids.
NASA’s Mars Pathfinder mission, which carried the first rover to the Red Planet, took off from Cape Canaveral on a Delta 2 rocket in 1996. The Spirit and Opportunity rovers launched toward Mars on Delta 2 rockets in 2003, followed by the Phoenix lander in 2007, which became the first spacecraft to touch down on the Martian polar plains.
NASA’s Mars Global Surveyor and Mars Odyssey orbiters also launched on Delta 2 rockets in 1996 and 2001. Mars Odyssey is still operating today, making it the longest-lived Mars mission in history.
A Delta 2 rocket launched NASA’s Stardust spacecraft in 1999 to collect dust particles from comet Wild 2, and another Delta 2 mission in 2005 deployed NASA’s Deep Impact spacecraft to release a copper projective that slammed into comet Tempel 1, collecting data on the comet’s internal structure composition.
The final Delta 2 launch from Cape Canaveral took off Sept. 8, 2011, with NASA’s GRAIL mission, a pair of probes to measure the moon’s gravity field. Five more Delta 2s lifted off from Vandenberg, a spaceport suited for launches into polar orbit, which is often used by Earth-observing satellites.
“The missions have been amazing and varied: GPS that has changed our lives, weather satellites, mobile satellite telephones, space telescopes, trips to the moon, Mars and Mercury, comets and asteroids, and countless spacecraft studying our beloved Mother Earth,” said Tim Dunn, a launch director at NASA’s Launch Services Program.
“The unfailing Delta 2 team that earned this rocket’s virtues and its appropriate nickname, the workhorse,” Dunn said. NASA has a terrific history on the Delta 2 rocket. Of the 155 total Delta 2 missions, NASA had 54 of them, and every single one of them successful.”
Apart from the missions of exploration, Delta 2 rockets launched satellites to begin the full-scale deployment of the U.S. military’s Global Positioning System. The first Delta 2 launch on Valentine’s Day of 1989 delivered the first of 48 GPS satellites Delta 2 rockets would carry into orbit.
The military utility of the GPS network was demonstrated in the Gulf War in 1991, the first conflict that widely employed satellite navigation using spacecraft launched on Delta 2 missions.
“The Gulf War was considered in many ways the first space war,” said Brig. Gen. Stephen Purdy, commander of the 45th Space Wing and Cape Canaveral Space Force Station. “It’s where the space elements within the Air Force really started coming into their own. You could say a lot of the groundwork was laid then for the creation of the Space Force.”
Now billions of civilians around the world use GPS navigation signals to guide their journeys by land, sea, and air.
“If you have GPS, you have Delta 2 to thank for the capabilities we have in that arena,” Fortson said.
Delta 2 rockets also launched numerous satellites for Iridium and Globalstar, pioneering companies in the mobile telecommunications industry.
“From national security to space exploration, the Delta 2 has changed what we know about the world we live in today and it’s affected all of our lives,” Fortson said.
Engineers who worked on the Delta 2 program are now working on ULA’s other rockets, like the Atlas 5, Delta 4, and the next-generation Vulcan Centaur. Others have moved on to other space companies.
“All these groups of engineers, analysts and technicians benefited from this rocket’s unprecedented record of success and consistent performance,” Dunn said. “I believe the success of this rocket has left a huge ripple effect on the launch systems we have today.”
Additional photos of the Delta 2 rocket exhibit are posted below.
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