SLS launch early on November 16th remains uncertain
Despite repeated assurances that the November 16, 2022 1:04 am (Eastern) launch of NASA’s SLS rocket remains on target, managers have also noted that damage to a small piece of caulking at the base of the shroud protecting the Orion capsule remains an issue that could cause a scrub.
But high winds from Nicole caused a thin strip of caulk-like material known as RTV to delaminate and pull away from the base of the Orion crew capsule’s protective nose cone at the top of the rocket. The material is used to fill in a slight indentation where the fairing attaches to the capsule, minimizing aerodynamic heating during ascent. The fairing fits over the Orion capsule and is jettisoned once the rocket is out of the dense lower atmosphere. “It was an area that was about 10 feet in length (on the) windward side where the storm blew through,” said mission manager Mike Sarafin. “It is a very, very thin layer of RTV, it’s about .2 inches or less … in thickness.”
Engineers do not have access for repairs at the pad and must develop “flight rationale,” that is, a justification for flying despite the delaminated RTV, in order to proceed with the launch. Managers want to make sure any additional material that pulls away in flight will not impact and damage downstream components.
In plain language, NASA managers would either have to issue a waiver that says this small piece of caulking poses no risk, or scrub and roll the rocket back to the assembly building to fix it. The second option would delay the launch another month, at a minimum.
A waiver however would continue NASA’s pattern with the shuttle (and continuing with SLS) to dismiss potential engineering problems simply to avoid schedule delays. With the shuttle, this pattern twice caused the loss of a shuttle and crew. With SLS, NASA has already waived by more than a year its rules concerning the stacked life of the rocket’s solid-fueled boosters. Agency managers have also waived the full test requirements from the dress rehearsal countdown, so that this test did not test everything it should.
It is expected that NASA managers will announce the waiver today on this problem. Whether it matters when the rocket goes through maximum dynamic pressure shortly after lift-off will likely determine the future of SLS.
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 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
Despite repeated assurances that the November 16, 2022 1:04 am (Eastern) launch of NASA’s SLS rocket remains on target, managers have also noted that damage to a small piece of caulking at the base of the shroud protecting the Orion capsule remains an issue that could cause a scrub.
But high winds from Nicole caused a thin strip of caulk-like material known as RTV to delaminate and pull away from the base of the Orion crew capsule’s protective nose cone at the top of the rocket. The material is used to fill in a slight indentation where the fairing attaches to the capsule, minimizing aerodynamic heating during ascent. The fairing fits over the Orion capsule and is jettisoned once the rocket is out of the dense lower atmosphere. “It was an area that was about 10 feet in length (on the) windward side where the storm blew through,” said mission manager Mike Sarafin. “It is a very, very thin layer of RTV, it’s about .2 inches or less … in thickness.”
Engineers do not have access for repairs at the pad and must develop “flight rationale,” that is, a justification for flying despite the delaminated RTV, in order to proceed with the launch. Managers want to make sure any additional material that pulls away in flight will not impact and damage downstream components.
In plain language, NASA managers would either have to issue a waiver that says this small piece of caulking poses no risk, or scrub and roll the rocket back to the assembly building to fix it. The second option would delay the launch another month, at a minimum.
A waiver however would continue NASA’s pattern with the shuttle (and continuing with SLS) to dismiss potential engineering problems simply to avoid schedule delays. With the shuttle, this pattern twice caused the loss of a shuttle and crew. With SLS, NASA has already waived by more than a year its rules concerning the stacked life of the rocket’s solid-fueled boosters. Agency managers have also waived the full test requirements from the dress rehearsal countdown, so that this test did not test everything it should.
It is expected that NASA managers will announce the waiver today on this problem. Whether it matters when the rocket goes through maximum dynamic pressure shortly after lift-off will likely determine the future of SLS.
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 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
“a thin strip of caulk-like material known as RTV”
So they used gasket sealer from autozone? While there are Aircraft grade versions, it is still just Room Temperature Vulcanizing silicon sealant. Why am I not surprised it is on this rocket?
Am I reading this right? The rocket couldn’t handle the winds from Nicole but can withstand the aerodynamics of a launch? What were the the winds on the cape? 50-60mph?
I refuse to even use that stuff in my bathroom let alone on anything outdoors.
I used to rebuild classic cars and didn’t even use it then.
And they are using it for aerodynamic use? And almost a quarter of an inch thick?
80 mph wind rips it out and they think it hangs on during lift off?
They spent enough on this craft why not send the fairing back to be either modified to fit better or build a whole new one?
More than likely the area they are covering with RTV does not even have an aerodynamic problem and they are just using it to keep out the rain and bugs.
If they had a gantry that could reach all around the rocket they could just reapply it in place.
How’s this for a “flight rational”?:
1. The sealant material that detached during an 80-mph wind will not likely further detach during the hypersonic ionized airflow expected in the later stages of launch.
2. Even if it does, it will be unlikely to harm anything important because it is soft, even going at thousands of feet per second.
3. Even if it does, and its absence generates excessive heat there is nothing critical nearby, except the rim of the reentry heat shield, which will not be needed until the end of the mission.
4. Recommend launch!!
“Whether it matters when the rocket goes through maximum dynamic pressure shortly after lift-off will likely determine the future of SLS.”
I think I recall from ground school many years ago that some aerodynamic phenomenon like flutter actually depend on true airspeed, instead of apparent. That MIGHT mean that the susceptibility of the sealant could continue to increase to flutter-induced type failure, even beyond Max-Q. Just a hunch!
Mother Nature gives NASA a hint.
NASA….What?