Home / Science / The Delta IV Heavy rocket has again delayed, raising concerns about aging infrastructure

The Delta IV Heavy rocket has again delayed, raising concerns about aging infrastructure



The United Launch Alliance has been attempting to launch a spy satellite for the National Reconnaissance Office worth more than $ 1 billion for some time now. On Tuesday evening, just hours before the company’s last attempt to launch the large Delta IV Heavy booster, the mission was cleaned up again.

Time at the launch site was far from optimal, but the mission was delayed due to a glitch with the launch pad. What is remarkable is that this is now the file third problem the company, ULA, encountered with its ground systems at Space Launch Complex-37 in Cape Canaveral, Florida for this flight.

The mission, named NROL-44, was originally supposed to be launched in June. When it was postponed until the end of August, military officials did not cite a reason for the program delay. However, on Aug.29, everything looked nominal as the three-core rocket counted down for takeoff from its Florida-based launch pad. The countdown hit zero, the three RS-68 main engines fired up and the launch conductor said, “Take off!”

But the rocket didn’t take off. Instead, even as fires increased around the three cores, the rocket remained stationary during the fire interruption. This last-second cleanup delayed the mission by a few weeks as engineers investigated the issue and eventually determined that a ground systems regulator caused the launch to abort. Essentially, three of these regulators on the pad deliver high-pressure helium into the main engines. The controller for the core motor has failed.

On Twitter, the company’s CEO, Tory Bruno, he wrote, “Found root cause of regulator stuck on side of pad. Diaphragm torn, which can occur over time. Check condition of other 2 regs. We will replace or rebuild as needed.” Eventually the company would remove the regulators for all three engines, refurbish and reinstall them. (Bruno did not respond to a request for comment for this story).

Almost a month later, the company is once again preparing to launch the NROL-44 mission, even passing a review of launch readiness. Then, one day before the launch date of September 26, the company delayed take-off again. This time the culprit was a problem with the launch pad swing arm retraction system, which pulls fuel lines and other links back from the rocket just before takeoff. It took the company a few days to fix this before setting a new launch date on September 29, Tuesday evening, just before midnight.

Then, the disaster struck again. Local storms caused a delay in pre-launch preparations. And when the mobile service tower supporting the rocket started rolling away just hours before launch, she too had a problem. “When the MST roll began, we discovered a hydraulic leak in the earth system needed to move the tower which needs further evaluation,” the company tweeted.

Assuming the problem can be resolved quickly, the NROL-44 launch is now scheduled no earlier than 11:54 PM ET on Wednesday (03:54 UTC Thursday). The company has an admirable safety record and we can be sure it will only launch when everything is ready.

“There are only a few launches left”

So what’s going on here with all these technical delays? Without being in-house or working directly on systems in Florida, it’s hard to know for sure. But there are some unassailable facts to consider.

One, the Launch Complex-37 infrastructure is aging. NASA first built this platform in 1959 to support the Saturn I rocket. Pad “A” has since fallen into disuse, but ULA took over Launch Complex-37B about two decades ago and modified it in 2001 to support its single-core Delta IV and triple-core Delta IV heavy missiles. The first Delta IV rocket launched from the platform in November 2002.

The idea that the Delta IV pad infrastructure is getting a little long in the tooth is supported by Bruno’s comment that the regulators wear over time, as well as problems with the retraction arm and tower. mobile service.

Another problem is that this pad is rarely used. The latest Delta IV rocket flew from this launch site in August 2019 and the flight speed has been around one rocket per year since late 2016. Some of the ground systems involved in a launch can only be tested in launch conditions, so problems with the equipment can only crop up at the critical moment.

Finally, there is the question of the future of the launch pad. ULA has already retired the single-core Delta IV rocket and plans to fly the Delta IV Heavy rocket only four more times after this mission before its retirement in favor of the cheaper Vulcan-Centaur rocket. Only two of those four flights will take place from Space Launch Complex-37, so the company doesn’t have a great incentive to invest heavily in infrastructure.

“The Delta IV Heavy has only a few launches left and Space Launch Complex-37 is headed for the cemetery,” a Florida-based launch source said. “I’m sure the money will move to Vulcan and its launch pad, Space Launch Complex-41. These scrubs are sure to frustrate other users in the range.”

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