SLS dress rehearsal countdown scrubbed an hour before T-0
Yesterday’s first dress rehearsal countdown for NASA’s SLS rocket managed to get within an hour of T-0 with its oxygen tanks half full when mission control scrubbed the countdown.
During chilldown of the lines in preparation for loading the liquid hydrogen, the teams encountered an issue with a panel on the mobile launcher that controls the core stage vent valve. The purpose of the vent valve is to relieve pressure from the core stage during tanking. Given the time to resolve the issue as teams were nearing the end of their shifts, the launch director made the call to stop the test for the day. A crew will investigate the issue at the pad, and the team will review range availability and the time needed to turn systems around before making a determination on the path forward.
No word as yet when they will attempt the next full dress rehearsal. The delays with SLS have so far caused several further delays for Axiom’s private mission to ISS, since NASA has given SLS priority over the range. It has now been pushed back to April 8th.
Note that none of these problems should be a surprise. This is the first time the rocket and mobile launcher have been placed under flight conditions, so minor issues should be expected. At the same time, dealing with these issues now, just before actual launch, rather than earlier in development, illustrates the backwards way NASA’s management has run this program. You can never design anything new perfectly. You need to test and fail and fix along the way. NASA avoids testing because it can’t build anything at a reasonable cost. The result is that when it comes time to launch, lots of previously unidentified minor issues pop up that need fixing.
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
Yesterday’s first dress rehearsal countdown for NASA’s SLS rocket managed to get within an hour of T-0 with its oxygen tanks half full when mission control scrubbed the countdown.
During chilldown of the lines in preparation for loading the liquid hydrogen, the teams encountered an issue with a panel on the mobile launcher that controls the core stage vent valve. The purpose of the vent valve is to relieve pressure from the core stage during tanking. Given the time to resolve the issue as teams were nearing the end of their shifts, the launch director made the call to stop the test for the day. A crew will investigate the issue at the pad, and the team will review range availability and the time needed to turn systems around before making a determination on the path forward.
No word as yet when they will attempt the next full dress rehearsal. The delays with SLS have so far caused several further delays for Axiom’s private mission to ISS, since NASA has given SLS priority over the range. It has now been pushed back to April 8th.
Note that none of these problems should be a surprise. This is the first time the rocket and mobile launcher have been placed under flight conditions, so minor issues should be expected. At the same time, dealing with these issues now, just before actual launch, rather than earlier in development, illustrates the backwards way NASA’s management has run this program. You can never design anything new perfectly. You need to test and fail and fix along the way. NASA avoids testing because it can’t build anything at a reasonable cost. The result is that when it comes time to launch, lots of previously unidentified minor issues pop up that need fixing.
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
Isn’t it about time that SpaceX asked NASA about what word in “Manned missions should take priority” don’t they understand? Or as a notorious admin assistant I knew used to say: “Your lack of planning does not constitute my emergency.”
“Given the time to resolve the issue as teams were nearing the end of their shifts, the launch director made the call to stop the test for the day”.
Stopping a test for a shift change with a rocket with half full oxygen tanks is all you need to know about the work culture of NASA.
I am disappointed. I thought they had the whole core thing fully tested at Stennis. Why does the launch pad have active components that should be in the rocket? It should be strap on those SRBs and away we go.
Why does the launch pad have active components that should be in the rocket? It should be strap on those SRBs and away we go.”
I think this is consistent with SpaceX’s “stage-zero” concept to maximize payload.
GSE fails are on the contractor-if not the lightning strike. That worries me.
George C asked: “Why does the launch pad have active components that should be in the rocket?”
Because they should not be in the rocket.
Adding unnecessary weight means reduced capabilities of the rocket. Adding unnecessary components to the rocket makes the rocket more complex, and when problems arise then the component is not as easily accessible as it would be on the Ground Support Equipment. If the component were on the rocket, then would they have to roll the rocket back to the assembly building to fix it?
Ray Van Dune related: “Or as a notorious admin assistant I knew used to say: “Your lack of planning does not constitute my emergency.”
I have a coffee cup printed with that exact sentiment. Or, in a more general form, ‘Your inability does not constitute my obligation.’