Vulcan aces engine tested, but upper-stage anomaly will delay launch for a while – Ars Technica

The Vulcan rocket took a decisive step toward its much-anticipated launch last week with a successful engine launch test. However, a critical problem remains unsolved before the big booster kicks in.

This latest snag involves modifications to the Centaur V rocket’s upper stage, which blew up during a test at the end of March. On Tuesday, the CEO of Vulcan Manufacturer United Launch Alliance, Tory Bruno, wrote on Twitter That the root cause of the failure had been identified, and the investigation was concluded.

As part of recent updates, neither Bruno nor United Launch Alliance has set a new target launch date. Two sources indicated to Ars, however, that this flight likely won’t take place before the last quarter of this year due to the additional work required.

Shooting prepare to fly

United Launch Alliance completed a major milestone on June 7 when it performed a hot test of the Vulcan’s first-stage engines. The BE-4 engines, made by Blue Origin, started the ignition sequence at a T-4.88 seconds and, according to the company, were throttled to the target power level for two seconds before shutting down.

Although the company needs to fully review the data from the test, it appears to be a complete success. This long-awaited launch of the main engines closes what was believed to be the biggest outstanding problem with the missile before its first launch – before the Centaur anomaly occurred. Deliveries of the BE-4 engines were delayed for several years while Blue Origin completed their development and testing.

“The team is reviewing data from systems involved in today’s test, and in parallel is investigating anomalies on the Centaur V test stand,” the company said in a statement after the test launch. “Pending data review and investigation results, we will develop a launch plan. Testing is an integral part of the launch vehicle development program, and we will fly when we believe it is safe to launch.”

Centaur update

In replies on Twitter on Tuesday, Bruno gave the first public confirmation that United Launch Alliance’s investigation into the Centaur fiasco had been completed. Although the report is not public, it appears that the hydrogen tank failed during a pressure test at Marshall Space Flight Center in Alabama.

“The ultra-thin, high-performance steel skin should be thicker near the top of the dome,” Bruno saidAdding “corrective work and re-testing”.

This comment indicates that the Centaur qualification tank will be more powerful then undergoing pressure testing at Marshalls later this summer. It’s unclear if the flight version of the Centaur stage, which has already been delivered to the launch site in Cape Canaveral, Florida, will also need to be modified. If so, this testing and adjustment will likely take a few months.

When asked if the flying tank needs to be modified, Bruno replied cryptically, say“Working on it all now.”

Space Force monitors tabs

Throughout all of this, United Launch Alliance has worked closely with the US Space Force, which has been the company’s most important customer since ULA’s inception nearly two decades ago.

In 2020, as part of the “Space Launch for National Security – Phase 2” program, US Army Scholarships The United Launch Alliance and SpaceX have five-year contracts to launch about 40 missions between fiscal years 2022 and 2028. As part of that program, United Launch Alliance has won 60 percent of launches, and SpaceX has won 40 percent.

However, there have been growing concerns about the readiness of Vulcan, which was supposed to begin launching national security missions in 2022. Now that won’t happen until at least 2024 because Vulcan must fly two “certified” flights before it is deemed safe enough as a satellite. valuable survey.

In particular, in Announcement last FridaySpace Systems Command said it recently commissioned twelve second-stage missions for the two launch companies. These launches were split evenly between the United Launch Alliance and SpaceX rather than a 60-40 split.

In addition, just last week, the US Government Accountability Office a report He stated that the delays caused military officials working on the Phase II launch program to consider their options. “In the event that Vulcan is not available for future missions, program officials have stated that the Phase 2 contract allows for the ability to reassign missions to the other provider,” the report states.