13.05.2023
ULA prepares for new round of Vulcan tests
WASHINGTON — United Launch Alliance plans to resume tanking tests of its Vulcan Centaur rocket and test fire its main engines as early as next week, the company announced May 11.
“Vulcan is in position atop SLC-41 at Cape Canaveral Space Force Station to undergo a full launch day rehearsal tomorrow and flight readiness firing test of its main engines planned for next week,” ULA said.
ULA rolled the rocket on Thursday to Space Launch Complex 41 in preparation for tests.
ULA’s CEO Tory Bruno in tweets on Wednesday said Vulcan was returning to tanking tests although the investigation of a Centaur upper-stage testing anomaly that occurred on March 29 has not yet been completed.
Before the upper-stage incident, ULA had announced a May 4 target date for Vulcan’s first launch, known as Cert-1.
Targeting summer launch
Bruno on Wednesday said ULA plans to livestream the flight-readiness test firing of the BE-4 main engines. The test fire is expected to last about six seconds, he said. “A short burn, but a very long time to be on the pad.”
ULA has not provided a new target launch date for Vulcan.
“With success here, and a resolution of the Centaur V ground test anomaly, we are projecting for a Vulcan Cert-1 launch this summer,” Bruno wrote.
Cert-1 is the first of two certification launches that Vulcan must complete to be able to fly national security launch missions for the U.S. Space Force.
The debut launch will carry Astrobotic’s Peregrine lunar lander, two demonstration satellites for Amazon’s Project Kuiper broadband constellation and a payload for space memorial company Celestis.
ULA preparing for Vulcan Centaur static fire
WASHINGTON — United Launch Alliance expects to conduct a static-fire test of its Vulcan Centaur rocket in several days, but the timing of the vehicle’s first launch will depend on the outcome of an ongoing investigation of a test anomaly.
ULA rolled the Vulcan rocket from the pad at Space Launch Complex 41 at Cape Canaveral, Florida, back to its Vertical Integration Facility (VIF) building on May 15. The vehicle had been on the pad for several days to conduct a tanking test and practice countdown.
Tory Bruno, president and chief executive of ULA, said in a May 15 tweet that the company needed to “adjust a handful of parameters and set points” for the vehicle before performing what the company calls the Flight Readiness Firing (FRF), a static-fire test of the booster’s BE-4 engines on the pad. That work would be done while the rocket is back in the VIF.
In a May 16 interview after a speech at the Humans to Mars Summit here, Bruno said that work involved a combination of minor adjustments to both pad infrastructure and the vehicle. The former includes adjusting set points in a hydraulics system and changing the rate of liquid oxygen flowing into the rocket to top off tanks after recycling the countdown. Those adjustments, he said, could be done in software.
On the booster, he said there was an issue during the pad tests with flowing gas through spark torch igniters used to ignite the BE-4 engines. The gas is intended to make sure that the igniters are dry and can light, but the timing was off. That could involve some combination of adjustments on the rocket and ground infrastructure.
“There’s nothing wrong with the engines,” he added. “We’ve lit the engines a zillion times on the test stand at Blue,” a reference to test stands by engine manufacturer Blue Origin.
That work is done more easily inside the VIF, he said, where there is protection from the weather and where work can continue when other range operations might cause a halt to work on the pad.
Once those fixes are complete, Bruno said the vehicle will roll back out to the pad for the FRF. “It’ll be a few days,” he said of the timing of the test, which will depend on both when the work is complete and getting approval from the range for test, which is required since it is considered an “energetic” event.
Assuming there are no problems with that firing, the last major obstacle before launch is completing an investigation into a March 29 incident during testing of the Centaur upper stage. Hydrogen leaked from the structural test article and ignited, creating a fireball.
Bruno said the investigation was delayed because it took time to remove equipment on top of the Centaur, such as a payload adapter and mass simulators for the payload and payload fairing. Only in the last week and a half was ULA able to get access to the dome section of the Centaur where the leak was located.
Engineers have isolated a small region on that dome where they believe the leak came from, as well as the likely ignition source. “I’m pretty confident that we’re going to find the leak, and once we find the leak we’ll know if we have to take corrective action or not on the flight vehicle,” he said.
If ULA doesn’t need to modify the Centaur, that would allow the Cert-1 launch to take place in early summer, he said. “If we do, it could take longer, but I don’t expect it to get out of the year.”
Complicating launch scheduling is the requirement for the primary payload, the Peregrine lunar lander from Astrobotic, which has a launch window that is open only for about four to five days per month. Before the Centaur test anomaly, ULA had been working towards a May 4 launch, which Bruno said in February was the start of a window about four days long.
“In the big picture, it’s a steel pressure vessel and it had a leak,” he said. “We’re going to understand it and we’re going to fix it. It’s not like other things that go wrong on rockets like engines that blow up. It’s just a piece of structure. We’ll fix it.”
Quelle: SN
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Update: 26.05.2023
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Watch Vulcan Centaur rocket test-fire its engines on the launch pad for 1st time today
The test is set for 6 p.m. on Thursday (March 25).
Update for 9 a.m. on May 25: United Launch Alliance (ULA) has confirmed the Flight Readiness Firing (FRF) test of its new Vulcan Centaur rocket will happen at 6 p.m. EDT (2200 GMT) on Thursday (May 25). Watch it here courtesy of ULA.
United Launch Alliance (ULA) is gearing up for a critical test firing of its next-generation rocket after a recent fueling check, and it could happen as soon as this week.
On Monday morning (May 22), Bruno stated on Twitter that the company's new Vulcan Centaur rocket was returning to Space Launch Complex 41 at Cape Canaveral Space Force Station. Now that the rocket is back at the pad, Vulcan's static fire test (in which the rocket's engines are ignited while it remains on the ground) could happen any day. "We are targeting as soon as tomorrow for the Flight Readiness Firing," a representative from ULA told Space.com on Tuesday (May 23), "but it will depend on range availability." On Wednesday (March 24), ULA CEO Tory Bruno intimated on Twitter that the test could happen as soon as Thursday (March 25).
If all goes according to plan, and Vulcan's static fire and wet dress rehearsal go smoothly, the rocket's first launch will be its next major milestone. Bruno has previously indicated sometime in June or July as Vulcan's earliest likely launch date, with launch windows available 4 to 5 days every month.
ULA previously completed a successful tanking test on the company's new Vulcan on May 12, filling the rocket with over a million pounds of fuel during the test. ULA engineers then evaluated the fueling test results against Vulcan's design expectations.
Two days after the successful tanking, Bruno indicated in a May 15 tweet that the tests were "good," but that teams would be making some parameter adjustments ahead of Vulcan's first static fire. That milestone moved Vulcan one step closer to its first launch, with only a static test firing of the engines and wet dress rehearsal left to validate the vehicle.
The rocket's main booster BE-4 engines use liquified natural gas (LNG) and liquid oxygen for fuel, and will be able to produce over half a million pounds of thrust at liftoff. Vulcan's Centaur V second stage RL10 engines are powered using liquid hydrogen and liquid oxygen.
The 202-foot (62-meter) Vulcan Centaur will be capable of lifting 7.7 tons (7 metric tonnes) of payload to geostationary orbit, over 22,000 miles (36,000 km) above the Earth. The rocket was designed to replace ULA's veteran Atlas V and Delta IV launch vehicles that have been in service for two decades.
Already, NASA has added Vulcan to its lineup of rockets for future missions. Amazon has also contracted ULA for 38 Vulcan launches to support the deployment of its Project Kuiper communications satellite constellation.
Quelle: SC