NASA Will Move Its Moon Rocket Off Launchpad for Repairs

NASA’s new big moon rocket is headed back to the garage for some minor repairs, possibly delaying its maiden launch to late summer or later. That means NASA is giving up, for now, trying to complete what it calls a wet dress rehearsal for the rocket, a detailed countdown practice that’s called “wet” because it includes loading more than 700,000 gallons of ultracold and liquid-liquid hydrogen. oxygen in the rocket fuel tanks.

For the past month, the rocket, called the Space Launch System, has been sitting on the launch pad at the Kennedy Space Center in Florida to undergo tests of ground-based systems. The tests had to culminate with the wet dress rehearsal.

However, three attempts in that exercise ended early due to a variety of technical glitches during the countdown. The purpose of the test with a new missile system is to identify and solve such problems.

Technicians also discovered that a valve in the upper stage was malfunctioning, and for the third rehearsal attempt last Thursday, the test was modified so that only the propellant tanks were filled in the booster stage. But then a hydrogen leak was detected in what is called the tail service mast umbilical that attaches to the bottom of the rocket, and the test was scrubbed. The oxygen tank was not quite half full and the hydrogen fuel had just started.

Last week, NASA officials said they hoped to fix the hydrogen leak while the rocket was still on the launchpad. But on Monday they said they had changed their minds. Next week, the rocket will return to the Vehicle Assembly Building, where technicians can more easily access rocket parts. That will allow the replacement of the reluctant upper stage valve.

At the same time, a third-party supplier that supplies nitrogen gas, used to purge hazardous gases, will be upgrading its systems. During two of the trial attempts, interruptions in the nitrogen supply delayed the countdown.

“The lunar mega rocket is doing very well,” said Tom Whitmeyer, associate administrator for common exploration systems development at NASA, during a news conference on Monday. “I think we’re getting smart with this rocket. But we have a little more work ahead of us.”

The Space Launch System, a key component of NASA’s Artemis program to send astronauts back to the moon, is years behind schedule and billions of dollars over budget. With the latest problems, preparing the rocket in time for a launch over two weeks in early June would be challenging, Mr Whitmeyer said. Additional two-week opportunities are beginning in late June and late July.

“We are currently working on a couple of different timeline options that we will review with the management team over the week,” said Charlie Blackwell-Thompson, launch director.

One would be to make the minimum number of repairs necessary (the upper stage valve and the hydrogen leak) and return to the launch pad as quickly as possible for the wet dress rehearsal. A second option would involve some additional work needed to get the rocket ready for launch. Both options would require one more trip back to the vehicle assembly building.

A third option would be to have the rocket fully ready for launch and then perform both the test and launch without returning to the building.