What's next for NASA's Artemis 1? Engineers work to fix moon rocket at Florida launchpad

Working on the SLS rocket while it's outside will require engineers to set up an enclosure around the work area to protect the hardware.

After two unsuccessful launch attempts of the Artemis 1 mission, NASA is now focusing on fixing its mega moon rocket before scheduling another launch date.

Most recently, NASA began fueling the Space Launch System rocket with the uncrewed Orion spacecraft during a countdown on Saturday from Kennedy Space Center in Florida. However, a fuel leak of liquid hydrogen to the SLS caused the launch director to scrub the liftoff after engineers couldn't solve the problem in time.

NASA is attempting to launch the SLS and Orion on a test flight around the moon as the space agency prepares to launch astronauts on a similar mission next year and ultimately land humans on the moon for the first time in 50 years. 

Technical issues caused both scrubs last week, first due to a sensor error on one of the rocket's four RS-25 engines on Aug. 29 and then the liquid hydrogen leak on Saturday. During the most recent attempt, NASA had hoped to begin engine cooling earlier in the countdown to troubleshoot the problem during the first launch attempt, but the countdown never made it that far. 


The SLS requires more than 700,000 gallons of supercold liquid hydrogen and liquid oxygen propellant to provide the fuel to lift the 322-foot-tall rocket off the launchpad and into space. While an efficient rocket fuel, hydrogen is a tiny molecule that easily leaks and also created problems for the space shuttle program. 

"I think the summer of 1990 was the summer of hydrogen, where shuttle had been launching for nine years, and they spent a whole summer chasing hydrogen leaks," Jim Free, NASA's associate administrator for exploration systems development, said after the latest launch attempt. "I'm not saying that's an excuse. That's just a fact. And we've seen a couple of different hydrogen leaks."

SLS has also experienced hydrogen leaks during wet dress rehearsal tests and a small leak during the first launch attempt. NASA managers said the most recent leak was considered a major leak.

Rocket repairs underway

Because the rocket can only be fueled while on the launchpad, engineers are now attempting to repair the leak while the rocket is still on launchpad 39B in hopes of conducting a test with fuel to check the leak. 

NASA said in an update Tuesday that engineers are working to replace a seal known as a quick disconnect between the hydrogen fuel feed line, the mobile launch and the SLS. 

Working on the rocket while it's outside will require extra finesse versus rolling it back to the Vehicle Assembly Building (VAB) hangar.  

"Performing the work at the pad requires technicians to set up an enclosure around the work area to protect the hardware from the weather and other environmental conditions, but enables engineers to test the repair under cryogenic, or supercold, conditions," NASA wrote in a blog post. "Performing the work at the pad also allows teams to gather as much data as possible to understand the cause of the issue."


Regardless of a successful repair, the rocket will need to roll back to the VAB before another launch attempt due to safety requirements by the Eastern Range for the flight termination system and to reset the system's batteries. 

With the repair work ahead and another journey back to the hangar, NASA is now looking at October for the Artemis 1 launch. 

NASA needs to consider the Earth and moon alignment and can only launch the SLS on select days. The next launch window opens in mid-September, but it's unlikely the rocket will be ready by that time. After that, a mid-October launch window looks most favorable.

NASA said managers plan to provide an update on the next steps for the mission on Thursday at 11 a.m. ET.