There’s Still Hope for SLS to Launch in September

After two scrubs for Artemis I, there was serious concerns there will be no further launch attempts at least until mid-October. But it looks like we might see the maiden flight of SLS in September after all.

NASA already had two scrubs of the SLS launch. The first one on August 29th was due to a problem with one of the main engines of the rocket. The RS-25 number 3 failed to cool down to a working temperature. After some investigation, it was determined that the engine itself was functioning correctly. the problem was due to a faulty temperature sensor. So, NASA decided to make another attempt on September 3rd, which also ended up scrubbed. This time there was a leak of liquid hydrogen during the fueling process.

After two failed attempts, many were worried that NASA would have to once again roll back SLS to the Vehicle Assembly Building. The problem is that SLS has a Flight Termination System (FTS) that runs on batteries. This system allows blowing up the rocket in mid-air if something goes wrong. It is one of the safety requirements for the launch. The certified launch period of the system ended on September 6th. After that, a battery retest is required. Which can only be done in the VAB.

Getting the rocket back into the Vehicle Assembly Building will mean that the launch will be delayed approximately to mid-October. But it seems like NASA has a solution that will not require waiting for this long.

New Plan for the SLS Launch

SLS Launch. Preparations at the Kennedy Space Center
Image credit: NASA/Bill Ingalls

During a media event, NASA officials announced that they are trying to fix the hydrogen leak problem by replacing seals on two of the hydrogen lines straight on the launchpad. NASA also asked to extend the certification on the FTS. They believe that the batteries still have considerable time remaining on them. If the Eastern Range approves of that, there will be no need to get the SLS back to the VAB.

If everything goes to the new plan and there are no new problems discovered, NASA will make another launch attempt of Artemis I on September 23rd. Another reserved launch date is September 27th. However, the rocket will need to pass a fueling test on September 17th. It will check if the hydrogen leaks were properly dealt with.

For now, you can mark your calendars for September 23rd. The launch window opens at 6:47 AM Eastern time and will last for 2 hours. It looks like there is a solid chance for an SLS launch before the end of the month, after all. We’ll keep you posted in case something changes. But let’s hope this time they will get it right.

Lead image credit: NASA/Eric Bordelon


At the moment the plans have been adjusted. Current schedule:

  • September 21, Fueling test
  • September 27, Launch (70-minute window opening at 11:37 EDT/ 15:37 UTC)
  • October 2, Reserve date (under review)