ULA readies Vulcan pathfinder booster for cryogenic tanking test
United Launch Alliance rolled a test article for its new Vulcan rocket to a launch pad at Cape Canaveral Wednesday, moving the booster into position for a series of cryogenic tanking tests set to begin in the coming days.
The 110-foot-tall (33.5-meter) Vulcan first stage rode a mobile launch platform along rail tracks from ULA’s Spaceflight Operations Center at Cape Canaveral Space Force Station to pad 41, a seaside launch complex teams have modified to support Vulcan missions and continued flights of ULA’s Atlas 5 rocket.
The Vulcan Centaur launch vehicle, which will ultimately replace ULA’s Atlas and Delta rocket families, is scheduled to lift off for the first time next year. Blue Origin’s delivery of flight-ready BE-4 first stage engines is driving the schedule for the first Vulcan test flight.
While ULA’s factory team in Decatur, Alabama, waits for the engine delivery, the company’s launch team at Cape Canaveral is moving forward with “pathfinder” testing using a first stage test article.
ULA shipped the Vulcan pathfinder booster from Alabama to Florida earlier this year. It’s fitted with two BE-4 engine test units previously used for test-firings at Blue Origin’s facility in West Texas.
Mark Peller, ULA’s vice president of major development, said in an interview with Spaceflight Now that the upcoming cryogenic tanking tests will allow engineers to validate how the company plans to load propellant into the Vulcan rocket during a real countdown.
“We have a tremendous amount of experience with cryogenic propellant,” Peller told Spaceflight Now. “Both Atlas and Delta are cryogenic vehicles. Delta has cryogenic fuel as well as oxidizer.”
The Vulcan first stage is fueled by liquified natural gas, instead of the kerosene and liquid hydrogen fuels that power the Atlas 5 and Delta 4 rockets. ULA will continue to use super-cold liquid oxygen — the same oxidizer used on Atlas and Delta rockets — to allow the Vulcan’s BE-4 engines to fire during the first few minutes of flight.
“There are two things that are unique here,” Peller said. “We’ve modified the systems, so we want to validate them. And two, the vehicle is a little bit different scale. So we want to just take time. It helps us validate all of our analysis and predictions, and any extrapolation of data that we’re bringing over from Atlas and Delta. It might take a little bit longer, or it might be a little bit faster to load the vehicle and chill the tanks down and the engines down.”
ULA is taking advantage in a break in Atlas 5 launch operations at Cape Canaveral to complete the Vulcan pathfinder testing. ULA planned to launch an Atlas 5 rocket on an unpiloted test flight of Boeing’s Starliner crew capsule earlier this month, but Boeing called on the mission due to spacecraft valve problems.
The first stage of the Atlas 5 rocket assigned to the Starliner test flight will now be used for ULA’s next launch from Florida. That mission, set for liftoff Oct. 16, will carry NASA’s robotic Lucy asteroid probe into space.
Once the pathfinder tanking tests are complete, ULA will send the Vulcan booster back to the company’s factory in Alabama to be outfitted for a future launch. Meanwhile, factory workers are finishing assembly of a different Vulcan rocket that will launch on the first test flight next year.
The Vulcan rocket can fly with zero, two, four, or six solid rocket boosters. ULA has developed an upgraded dual-engine version of the venerable hydrogen-fueled Centaur upper stage to fly atop the Vulcan rocket.
Ultimately, further upgrades to the new “Centaur 5” upper stage will allow a “single-stick” Vulcan Centaur rocket to outlift ULA’s Delta 4-Heavy rocket, which combines three Delta 4 rocket core stages to give heavy payloads an extra boost into space.
ULA expects to receive the first pair of flight-ready BE-4 engines from Blue Origin at the end of the year, allowing the company to ship the first flight-rated booster to Cape Canaveral in early 2022.
That will kick off another series of tests at the Vulcan launch pad, culminating in a full-up countdown rehearsal that will end with a hold-down test-firing of the two BE-4 engines.
Once the flight readiness firing is complete, ground crews will install a pair of Northrop Grumman solid rocket boosters to the Vulcan core stage and prep the launcher for its first flight.
The inaugural Vulcan launch will loft a commercial lunar lander built by Astrobotic, which will fly science payloads to the moon’s surface under contract to NASA. A second Vulcan Centaur launch scheduled in late 2022 will launch a cargo-carrying spaceplane from Sierra Nevada on a resupply mission to the International Space Station.
If the first two missions are successful, the U.S. Space Force will clear the Vulcan Centaur rocket to start launching critical military satellites.
ULA unveiled the Vulcan rocket in 2015. It’s designed for a new era in the U.S. launch industry marked by increased competition, particularly from SpaceX, and a changing market.
The U.S. military is an anchor customer for ULA. Pentagon officials announced last August that ULA will get 60 percent of the military’s most critical satellite launch contracts awarded through late 2024 for missions that will take off between 2022 and late 2027.
SpaceX will receive 40 percent of the national security launch contracts over the same period, giving the Pentagon two independent companies capable of serving all the military’s medium- and heavy-lift launch needs.
The agreements with ULA and SpaceX cover contracts to launch satellites for the U.S. Space Force, the National Reconnaissance Office, the Missile Defense Agency, and other military services and agencies.
But the Atlas 5 rocket is not going away immediately, and pad 41 will support launches of both types of rockets for several years. ULA plans 30 or more additional Atlas 5 missions before retiring the rocket in favor of the Vulcan Centaur.
