NASA forecasts next Artemis I launch attempts on Sept. 23 or Sept. 27

NASA officials now believe another launch attempt of Artemis I could occur on Sept. 23 or Sept. 27 assuming all goes well with repairs following a liquid hydrogen leak during fueling that led to a scrub of the mission on Saturday, the second scrub in recent days.

Crews have been working all week on the launch pad to investigate and repair the area of the leak, located at a quick disconnect where a liquid hydrogen line from the ground feeds into the Space Launch System rocket at the base of the 320-foot combined rocket and Orion spacecraft structure.

Crews expect to repair one or possibly two seals on the interface between the ground and rocket after seeing an indication of a very narrow notch in one 8-inch seal, officials said at a news conference on Thursday. Crews were working on the rocket inside a temporary plastic tent erected on launch pad 39B.

Engineers suspect a sudden change in pressurization of the liquid hydrogen being pushed manually into the rocket via a feed line on Saturday was behind the leak but need more investigation to be sure. 

Part of the issue is that the interface is made of new metal and sealant materials and liquid hydrogen is being pumped into the rocket at super cold temperatures at minus-420 degrees F. Other parts of the SLS rely on refurbished parts from past shuttle missions, but not the area of the leak.

“It’s a totally different tanking system [from past shuttle missions] and volumes and pressures and seals are different on purpose,” said Jim Free, associate administrator for NASA’s exploration systems development mission directorate.   “It really is the highest performing rocket engine on the planet…We will get to operational status…I think we’ll get that system nailed down in short order…We have an obligation to get this right and if we fail, the cost would be incredibly high.”

John Blevins, SLS chief engineer, added, “There’s a lot more to flying a rocket than launching. This is going into deep space. This is not driving to the grocery store.”

Officials plan to fill the rocket core tank with liquid oxygen and liquid hydrogen on Sept. 17 after repairs are made to check for any leaks or other irregularities.  Successfully completing a tanking test that day would allow the necessary four days before another launch attempt on Sept. 23.

During the tanking operation on Sept. 17, officials plan to use a “kinder, gentler approach” to adding pressure on the liquid hydrogen line, said Mike Bolger, exploration ground systems program manager.

NASA could face an issue with needing to charge batteries in various types of equipment on the rocket which could require rolling back to an enormous Vehicle Assembly Building.

Should a launch attempt occur on Sept. 23, the launch window would open at 6:47 p.m. EDT and remain open two hours. If that launch occurs, the Orion spacecraft would circle the moon and return to Earth on oct. 18. 

For a launch on Sept. 27, the launch window would open at 11:37 a.m. EDT for 70 minutes with a return of Orion on Nov. 5.

RELATED: UPDATE: NASA scrubs second launch attempt of Artemis I due to large liquid H2 leak