More delays for SLS?
According to a report today at Ars Technica, there is an engine issue with the SLS rocket presently being prepared for a February unmanned test flight that could delay the launch for months.
The info is buried at the very bottom of the article:
There’s an issue with an SLS engine controller. This past weekend, rumors emerged about a problem with the controller for one of the four RS-25 engines that power the Space Launch System. NASA has not officially commented, but Aviation Week’s Irene Klotz spoke with Aerojet’s RS-25 program manager, Jeff Zotti. Troubleshooting the problem began on November 22, Aviation Week reported.
Schedule impacts yet to be determined … If necessary, “replacing a line or a component … we’re probably talking about multiple days. Replacing an engine, we’re probably talking about multiple weeks,” Zotti told the publication. “On top of that, we have to assess what that does and how that affects the vehicle and the integration activities that are going on,” he added. All of that must be factored into a potential delay of the launch, presently scheduled for February 12. A summer launch for the SLS now seems far more likely than spring.
Any delay beyond March poses a very serious and complex problem. The solid rocket strap-ons have a one year life expectancy once stacked, and both were initially stacked about a year ago. The February launch pushes that life span somewhat. A longer delay is more than can be waived.
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
According to a report today at Ars Technica, there is an engine issue with the SLS rocket presently being prepared for a February unmanned test flight that could delay the launch for months.
The info is buried at the very bottom of the article:
There’s an issue with an SLS engine controller. This past weekend, rumors emerged about a problem with the controller for one of the four RS-25 engines that power the Space Launch System. NASA has not officially commented, but Aviation Week’s Irene Klotz spoke with Aerojet’s RS-25 program manager, Jeff Zotti. Troubleshooting the problem began on November 22, Aviation Week reported.
Schedule impacts yet to be determined … If necessary, “replacing a line or a component … we’re probably talking about multiple days. Replacing an engine, we’re probably talking about multiple weeks,” Zotti told the publication. “On top of that, we have to assess what that does and how that affects the vehicle and the integration activities that are going on,” he added. All of that must be factored into a potential delay of the launch, presently scheduled for February 12. A summer launch for the SLS now seems far more likely than spring.
Any delay beyond March poses a very serious and complex problem. The solid rocket strap-ons have a one year life expectancy once stacked, and both were initially stacked about a year ago. The February launch pushes that life span somewhat. A longer delay is more than can be waived.
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
I wonder if NASA insisted that the Starship launch pad now being constructed at the Cape was out of sight from all SLS press areas. Could be embarrassing to see an in-construction tower in the background of first SLS launch and it’s leaning tower that will be scrapped soon after.
Eric Berger actually fielded a question about that three days ago on Twitter. He says his sources indicate that NASA can go as late as July on the SRB stacking. If that’s true, they have a bit of margin to play with. But they really can’t afford too much more in the way of delays. And not just because the weather at the Cape gets dodgier the deeper you get into spring.
Man, if state of the art SLS needs weeks to change an engine, clearly Starship/SuperHeavy are going to be impossible. I mean 29/33 engines (SH) or 6 engines (Starship) it would take years to simply install them all.
If NASA can’t do it, obviously, no one can. Alas.
I fear for our future.
(For reference, SpaceX install 29 engines in 14 hours, now not fair, since they did not connect everything, it was for a photo op, but still).
SLS = Senate Launch System
What goes wrong with the boosters? Some sort of internal chemical reaction that makes them what? Unstable-er? Less efficent? Thanks.
Everybody seems to be having engine problems-this a black box…Musk and others need to check for sabotage…these were tested at Stennis.
How old are those engine? Not the design, the actual engines. 30 years? After a full system, full power, full duration test, what could go wrong? Maybe the brand new parts aren’t as good as the old ones?
Meanwhile Rocket Labs announced yet another fresh designed CH4 O2 engine, with a gas generator cycle that it will start testing next year.
Ah the tragedy of sunk cost obsession
“What goes wrong with the boosters?”
“Solid” propellant isn’t actually all that solid. After a year or so of standing on end, it begins to physically slump.
“Something Wonderful Will Happen”
2010 The Year We Make Contact
https://youtu.be/yM25-lz1Yms
0:37
Rocket science is hard. But why do private entities make it look easier, while public entitles make it look difficult?
That’s almost a rhetorical question.
I fired an AeroTech “White Lightning” composite motor after 20 or more years of sitting around my garage, and it worked fine! No slumping or surface changes were seen. I‘m sure they have plenty of margin for error here.
Increasing the linear size of a similarly-compounded engine would increase the mass by the cube, so there could be substantial differences in the stability of the two.
Nothing is truly solid.
Back in the day…in graduate aerospace engineering…I took a class in viscoelasticity. I called it everything you wanted to know about creep. Anyway, one of the example problems dealt with solid rocket propellant deformation. Of course, that dealt with missiles that sat in their silos for extended periods. And the greater the missiles diameter, the quicker the deformation.