Last week, NASA postponed the latest attempt to refuel Artemis 1's massive Space Launch System (SLS) rocket for the third time.
The mission team had been attempting to fuel the 322-foot-tall (98-meter-tall) Artemis I rocket stack at Kennedy Space Center in Florida, which included NASA's Space Launch System and Orion spacecraft, but had run into a series of difficulties.
According to the agency, the rocket is still in a steady and safe configuration. But NASA recalled the spacecraft to its laboratories to repair numerous stages and components.
In this handout provided by the National Aeronautics and Space Administration (NASA), NASA's Space Launch System (SLS) rocket with the Orion spacecraft aboard is seen atop a mobile launcher at Launch Complex 39B, Friday, March 18, 2022, after being rolled out to the launch pad for the first time at NASA's Kennedy Space Center in Florida. Ahead of NASA's Artemis I flight test, the fully stacked and integrated SLS rocket and Orion spacecraft will undergo a wet dress rehearsal at Launch Complex 39B to verify systems and practice countdown procedures for the first launch.
NASA Pulls Out Artemis I SLS Mega Moon Rocket Out Of Launchpa
NASA disclosed the status of the SLS rocket for the Artemis I mission after it underwent multiple tests to determine what the spacecraft needed for future missions.
The primary focus here is on NASA bringing the complete Space Launch System rocket back to its labs so that the crew can work on repairs and prepare it for testing.
NASA stated that the spacecraft had a defective upper stage check valve, emphasizing a minor issue with the rocket. In addition, the space agency found a tiny leak on the rocket's tail service mast.
The space agency added that an announcement for the Artemis mission would be made soon, addressing the space agency's future duty.
Another issue that the Artemis Moon mission and the SLS rocket are now dealing with is a dangerous shortage of a rare gas called nitrogen for the rocket.
An off-site nitrogen provider will be performing modifications for its firm, and will be unable to deliver to NASA. The agency also took the opportunity to address a number of SLS's concerns.
Faulty Helium Valve Seen
Engineers discovered the problem over the weekend - a faulty helium check valve.
During fuelling, helium is utilized to purge the engine before adding supercold propellant (the wet in wet dress rehearsal). Check valves prevent backflow by allowing gas or liquid to flow only in one direction.
In this example, the portion that isn't working is around 3 inches long (7.6 cm) and prevents helium from leaking out of the rocket.
While the rocket is on the launchpad, it is impossible to reach the valve, but it may be replaced or repaired once the run-through is completed.
However, to assure the safety of the rocket's flight gear, the modified form of the wet dress rehearsal is still required.
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The improved test will reduce the strain on the valve and top rocket stage with fewer propellant activities.
The crew had planned to ultimately fuel the core and top stages of the rocket during this test, but the valve issue prohibited them from doing so.
According to CNN, examinations will evaluate whether more testing is required.
How NASA Found The Leak
The rocket and spacecraft were turned on Wednesday night, and the crew met at 6 a.m. ET on Thursday to examine the weather and discuss the status of operations.
NASA said the crew prolonged a pause that was supposed to last an hour and a half to two hours after suffering a problem with an outage at an off-site vendor of gaseous nitrogen utilized within the rocket before fuel loading. This problem is comparable to one that occurred on April 4 on a prior effort.
The gaseous nitrogen is utilized to purge oxygen from the rocket before it is fuelled, and it serves as a safety precaution after 8 a.m. ET, the crew was able to re-establish the supply of gaseous nitrogen and resume fuelling.
The core stage of the rocket's fueling begins with the cooling of liquid oxygen lines.
According to the agency, the core stage is then filled with liquid oxygen and liquid hydrogen through these pipes, which are topped up and replenished when part of the supercold propellant boils away.
Due to the current valve issue, the crew will also cool propellant lines for the rocket's upper stage but will not release any propellant.
The core stage of the Artemis rocket can contain 198,000 gallons (900,126 liters) of liquid oxygen chilled to minus 297 degrees Fahrenheit (negative 182 degrees Celsius). When the core stage is fully fuelled, a total of 537,000 gallons of propellant will be placed into the rocket.
While loading the liquid oxygen and liquid hydrogen, the crew endured multiple pauses and starts. The most recent issue was a leak "discovered in the tail service mast umbilical," attached to the rocket's core stage and positioned at the foot of the mobile launcher the rocket stands atop.
NASA said in a tweet that hydrogen is exceedingly toxic, cold, and a tiny molecule renowned for leaking, according to
Before the wet dress rehearsal, the space agency noted that the systems had been sealed, leak checked, and tested to the greatest extent feasible.
To collect additional data, the crew will freeze down the hydrogen lines attached to the rocket's upper stage, and there are no plans to put liquid hydrogen or liquid oxygen into the upper stage tanks.
The liquid hydrogen tank in the core stage was around 5% full, while the liquid oxygen tank was 49% full. The propellant will be emptied, and the crew will investigate the leak and devise a strategy for moving forward.
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