NASA to return SLS to assembly building tomorrow
According to its most recent update, NASA is now planning on rolling its SLS rocket back to the Vehicle Assembly Building (VAB) no sooner than tomorrow, February 24, 2026, in order to begin its investigation into the helium flow issue in the rocket’s upper stage that has now delayed any launch until April at the earliest.
Returning to the Vehicle Assembly Building at Kennedy is required to determine the cause of the issue and fix it.
Teams are reviewing the exact time to begin the approximately 4 mile, multi-hour trek. The quick work to begin preparations for rolling the rocket and spacecraft back to the VAB potentially preserves the April launch window, pending the outcome of data findings, repair efforts, and how the schedule comes to fruition in the coming days and weeks.
The present launch window closes on April 6, 2026. For a launch to occur, NASA engineers need to identify and fix the flow issue. They will also need to test it, which suggests they will have to do some form of fueling test once the rocket is returned to the launchpad.
All of this takes time. First we have one week to get back to the VAB. Then at least a full two weeks in the VAB to identify and fix the upper stage. Then another week to roll the rocket back to the launch pad. And then another week to do another fueling test on the launchpad. That brings us to the beginning of April.
In other words, NASA has no time margin at all. If anything takes just a little longer than planned, it will not make the April launch window.
None of this is a surprise. SLS in its first launch attempt in 2022 missed its spring launch window due to similar issues and ended up launching six months later (after more launch scrubs). I predicted it would happen again now. NASA at this moment has not revealed any later launch windows, so we don’t yet know how long a delay to expect if it misses this window. Based on 2022, I suspect the delay would be until the fall.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
According to its most recent update, NASA is now planning on rolling its SLS rocket back to the Vehicle Assembly Building (VAB) no sooner than tomorrow, February 24, 2026, in order to begin its investigation into the helium flow issue in the rocket’s upper stage that has now delayed any launch until April at the earliest.
Returning to the Vehicle Assembly Building at Kennedy is required to determine the cause of the issue and fix it.
Teams are reviewing the exact time to begin the approximately 4 mile, multi-hour trek. The quick work to begin preparations for rolling the rocket and spacecraft back to the VAB potentially preserves the April launch window, pending the outcome of data findings, repair efforts, and how the schedule comes to fruition in the coming days and weeks.
The present launch window closes on April 6, 2026. For a launch to occur, NASA engineers need to identify and fix the flow issue. They will also need to test it, which suggests they will have to do some form of fueling test once the rocket is returned to the launchpad.
All of this takes time. First we have one week to get back to the VAB. Then at least a full two weeks in the VAB to identify and fix the upper stage. Then another week to roll the rocket back to the launch pad. And then another week to do another fueling test on the launchpad. That brings us to the beginning of April.
In other words, NASA has no time margin at all. If anything takes just a little longer than planned, it will not make the April launch window.
None of this is a surprise. SLS in its first launch attempt in 2022 missed its spring launch window due to similar issues and ended up launching six months later (after more launch scrubs). I predicted it would happen again now. NASA at this moment has not revealed any later launch windows, so we don’t yet know how long a delay to expect if it misses this window. Based on 2022, I suspect the delay would be until the fall.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
I shocked some fellow space advocates before the launch of the first test flight by saying that I hoped it blew up on the pad, certainly putting it and us out its misery and forcing a rethink. Of course I want this manned flight to succeed!!! However, it is almost guaranteeing that the next words spoken from the lunar surface will be in Mandarin.