Problem pops up during SLS roll back after wet dress rehearsal countdown
Not so fast! According to an update posted by NASA today, during the process to roll back the SLS rocket from the launchpad following the wet dress rehearsal countdown two days ago, crews suddenly detected “interrupted helium flow” in the upper stage that appears to be of some concern.
NASA is taking steps to potentially roll back the Artemis II rocket and Orion spacecraft to the Vehicle Assembly Building (VAB) at the agency’s Kennedy Space Center in Florida after overnight Feb. 21 observing interrupted flow of helium in the SLS (Space Launch System) rocket’s interim cryogenic propulsion stage. Helium flow is required for launch.
Teams are actively reviewing data, and taking steps to enable rollback positions for NASA to address the issue as soon as possible while engineers determine the best path forward. In order to protect for troubleshooting options at both Pad B and the VAB, teams are making preparations to remove the pad access platforms installed yesterday, which have wind-driven constraints and cannot be removed during high winds, which are forecasted for tomorrow. This will almost assuredly impact the March launch window. NASA will continue to provide updates. [emphasis mine]
The helium flow is likely used to fill the tanks as the actual and dangerous fuel is pumped out. They need to drain those tanks in order to roll the rocket from the launchpad. If it has stopped flowing, it means they can’t drain the tanks as planned.
During launch the helium is also likely pumped into the tanks to maintain pressure as the fuel burns. If during launch the helium stopped flowing it would almost certainly result in a failed launch.
This issue not only impacts the tentative March 6th launch date that NASA announced yesterday, if a fix is not found quickly it almost certainly means no launch can occur before this launch window closes on April 6th.
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
Not so fast! According to an update posted by NASA today, during the process to roll back the SLS rocket from the launchpad following the wet dress rehearsal countdown two days ago, crews suddenly detected “interrupted helium flow” in the upper stage that appears to be of some concern.
NASA is taking steps to potentially roll back the Artemis II rocket and Orion spacecraft to the Vehicle Assembly Building (VAB) at the agency’s Kennedy Space Center in Florida after overnight Feb. 21 observing interrupted flow of helium in the SLS (Space Launch System) rocket’s interim cryogenic propulsion stage. Helium flow is required for launch.
Teams are actively reviewing data, and taking steps to enable rollback positions for NASA to address the issue as soon as possible while engineers determine the best path forward. In order to protect for troubleshooting options at both Pad B and the VAB, teams are making preparations to remove the pad access platforms installed yesterday, which have wind-driven constraints and cannot be removed during high winds, which are forecasted for tomorrow. This will almost assuredly impact the March launch window. NASA will continue to provide updates. [emphasis mine]
The helium flow is likely used to fill the tanks as the actual and dangerous fuel is pumped out. They need to drain those tanks in order to roll the rocket from the launchpad. If it has stopped flowing, it means they can’t drain the tanks as planned.
During launch the helium is also likely pumped into the tanks to maintain pressure as the fuel burns. If during launch the helium stopped flowing it would almost certainly result in a failed launch.
This issue not only impacts the tentative March 6th launch date that NASA announced yesterday, if a fix is not found quickly it almost certainly means no launch can occur before this launch window closes on April 6th.
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
Ah….I now see that Isaacman has posted an update just a little bit ago:
_____
“As an update to my earlier post.
– The ICPS helium bottles are used to purge the engines, as well as for LH2 and LOX tank pressurization. The systems did work correctly during WDR1 and WDR2.
– Last evening, the team was unable to get helium flow through the vehicle. This occurred during a routine operation to repressurize the system.
– We observed a similar failure signature on Artemis I.
– The Artemis II vehicle is in a safe configuration, using ground ECS purge for the engines versus the onboard helium supply.
– Potential faults could include the final filter between the ground and flight vehicle, located on the umbilical, though this seems least likely based on the failure signature. It could also be a failed QD umbilical interface, where similar issues have been observed. It could also be a failed check valve onboard the vehicle, which would be consistent with Artemis I, though corrective actions were taken to minimize reoccurrence on Artemis II.
Regardless of the potential fault, accessing and remediating any of these issues can only be performed in the VAB.
As mentioned previously, we will begin preparations for rollback, and this will take the March launch window out of consideration.
I understand people are disappointed by this development. That disappointment is felt most by the team at NASA, who have been working tirelessly to prepare for this great endeavor. During the 1960s, when NASA achieved what most thought was impossible, and what has never been repeated since, there were many setbacks. One historic example is that Neil Armstrong spent less than 11 hours in space on Gemini 8 before his mission ended prematurely due to a technical issue. A little over three years later, he became the first man to walk on the Moon.
There are many differences between the 1960s and today, and expectations should rightfully be high after the time and expense invested in this program. I will say again, the President created Artemis as a program that will far surpass what America achieved during Apollo. We will return in the years ahead, we will build a Moon base, and undertake what should be continuous missions to and from the lunar environment. Where we begin with this architecture and flight rate is not where it will end.
Please expect a more extensive briefing later this week as we outline the path forward, not just for Artemis II, but for subsequent missions, to ensure NASA meets the President’s vision to return to the Moon and, this time, to stay.”
Link:
https://twitter.com/NASAAdmin/status/2025249086908125630
So, March is definitely out now.
Again, it is good to see Isaacman getting out front with information, if nothing else.
Looks like another issue “fixed” after Artemis 1. Pattern recognition kicking in…
Note that Isaacman blathers about wonderful Artemis is, but fails to note that if this failure had occurred during launch, the launch would have failed and Orion would have had to do a launch abort.