NASA completes assembly of SLS’s first two solid rocket boosters
The stacking and assembly of the first two solid rocket boosters for the first launch of SLS has been completed at Cape Canaveral.
The boosters, built by Northrop Grumman, now only wait for the arrival of Boeing’s core stage, which is still awaiting the successful completion of its final static test, now tentatively set for sometime in the next week or so.
Stacking of the boosters began in November 2020, which means that the first SLS launch must happen by November ’21 because the boosters have a limited life span of about a year. To make that November launch happen on time however is becoming increasingly difficult. Assuming the mid-March core static static fire test in Mississippi is successful, NASA will have to then ship the stage to Florida and get it assembled with those two boosters. NASA has previously said it will take about six months to do this. Their margin between now and November is thus getting quite tight.
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The stacking and assembly of the first two solid rocket boosters for the first launch of SLS has been completed at Cape Canaveral.
The boosters, built by Northrop Grumman, now only wait for the arrival of Boeing’s core stage, which is still awaiting the successful completion of its final static test, now tentatively set for sometime in the next week or so.
Stacking of the boosters began in November 2020, which means that the first SLS launch must happen by November ’21 because the boosters have a limited life span of about a year. To make that November launch happen on time however is becoming increasingly difficult. Assuming the mid-March core static static fire test in Mississippi is successful, NASA will have to then ship the stage to Florida and get it assembled with those two boosters. NASA has previously said it will take about six months to do this. Their margin between now and November is thus getting quite tight.
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
From what I’ve been seeing elsewhere, that one year limit on the stacked boosters is predicated on the whole booster being stacked in more or less one go. They delayed the process, adding additional stacks over time, so that the bottom segments haven’t had as much downward pressure on them so far as if they’d been completely stacked all along. Just how much time this gains them is not something I’ve heard, but presumably it’s enough to get to them to the currently projected launch date in 2022 Q1. Of course, if it slips again…
I believe the operative limit on the boosters is now January 2022, not November 2021. This is still problematic, as I’m hearing that internal NASA schedules showed a February 2022 launch date even before the recent delay in the static fire. I’m also hearing that Boeing believes SLS can still be launched by the end of the year even after the recently delay. Presumably that’s if everything goes perfectly from here on out. What are NASA’s plans if everything doesn’t go perfectly? I have no idea.
Wondering why they stacked the boosters so early? If they started in November and just finished, then it takes about four months to complete. So why not wait until let’s say five months before scheduled launch to start the process?
Andi: Now that is a great question. It also illustrates the inefficient nature of how NASA operates.
My guess is they stacked them early to show “progress”.
At least we will likely get a payload per every SLS. Starship is expendable as well at this point. A production Starship/Super-Heavy stack might well also be a billion a pop by the end-with a higher part count. SLS is a pretty conservative stage-and-a-half-to-orbit design which should be cheaper. Boeing wanted to sell scores of D-IVs originally-so that recalcitrance worries me. Must keep doing my breathing exercises :-/
SLS should been have been cheaper per unit, except that the inherent low flight rate reverses the should. And a production Starship will be reusable as opposed to the expendable test articles. So at a billion a pop, how much per flight at a hundred flights per airframe? And at a thousand?
Not including the difference in development cost and time.
SLS isn’t trying to be a spacecraft though. Now, we hope Starship works. I at least want to see Exploration upper stages atop Super-Heavy…maybe even allowing solids if he gets more infrastructure.
Jeff Wright wrote: “At least we will likely get a payload per every SLS. Starship is expendable as well at this point.”
I love how people keep conflating flight units and development test items. NASA and Boeing are now verifying their first space flight unit, their final design, but SpaceX is still figuring out how to build and operate future development test item designs.
As for expense, I agree. SpaceX is spending a whopping $2 billion for a radically new design and methods, a new alloy, a dozen test items, new manufacturing facilities and methods, and new test facilities and launch pads. Meanwhile, Boeing is able to reconfigure STS into SLS for a mere $20 billion. We can see which one is focused on cost efficiency and cost effectiveness.