Behind the Black by Robert Zimmerman 4/26/2022
https://behindtheblack.com/behind-the-black/points-of-information/sls-rocket-rolled-back-to-vab/NASA’s SLS rocket has now been rolled back to the vehicle assembly building (VAB) so that engineers can assess the various problems that prevented the agency from completing a full dress rehearsal countdown last week.
Over the next several days, the team will extend the work platforms to allow access to SLS and Orion. In the coming weeks, teams will work on replacing a faulty upper stage check valve and a small leak within the tail service mast umbilical ground plate housing, and perform additional checkouts before returning to the launch pad for the next wet dress rehearsal attempt.
More details about these problems can be found here.
The bottom line is that these engineering fixes are certain to take at least two months to fix. Then NASA must decide what next to do. If it decides to redo the dress rehearsal countdown, then an actual launch cannot happen sooner than July, and only if they proceed directly to launch after completing the rehearsal. If the rocket is rolled back to the VAB after the next rehearsal the launch will be delayed further, into August or September.
And all that assumes the next rehearsal goes perfect, something that seems unlikely based on what has happened so far.
The delays are a problem because the first stage’s two strap-on solid rocket boosters are already well past their “use-by” date of January ’22. The possibility that NASA will have to unstack this rocket and replace these boosters is growing. If that happens the launch cannot occur sooner than early ’23, if then.
Worse, these delays cause all other subsequent SLS launches to be delayed as well. Right now the manned mission to the Moon, presently scheduled for ’25, is likely going to be pushed back to ’26.
