Author Topic: Launch mass of SLS Block 1B  (Read 3192 times)

Offline Kasponaut

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Launch mass of SLS Block 1B
« on: 12/07/2022 11:03 am »
Hi guys!

Do we have any information about the launch mass of the planned and in design SLS Block 1B.
For SLS Block 1 it is just over 2600 metric tonnes.

Also, do we know the thrust of the BOLE SRBs?

/Kasper

Offline Vahe231991

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Re: Launch mass of SLS Block 1B
« Reply #1 on: 12/08/2022 05:10 pm »
Hi guys!

Do we have any information about the launch mass of the planned and in design SLS Block 1B.
For SLS Block 1 it is just over 2600 metric tonnes.

Also, do we know the thrust of the BOLE SRBs?

/Kasper
The SLS Block 1B, and its SRBs, will have the same weight as those used on the SLS Block 1 (5.75 million pounds for launch vehicle, 1.6 million pounds for SRBs). The SLS Block 2 will not only be heavier but use more advanced SRBs.

Offline jadebenn

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Re: Launch mass of SLS Block 1B
« Reply #2 on: 12/09/2022 01:54 am »
The SLS Block 1B, and its SRBs, will have the same weight as those used on the SLS Block 1 (5.75 million pounds for launch vehicle, 1.6 million pounds for SRBs). The SLS Block 2 will not only be heavier but use more advanced SRBs.
EUS is quite a bit heavier than ICPS, though. The vehicle will be more massive.
« Last Edit: 12/09/2022 02:33 am by jadebenn »

Offline Hog

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Re: Launch mass of SLS Block 1B
« Reply #3 on: 12/09/2022 03:53 pm »
The SLS Block 1B, and its SRBs, will have the same weight as those used on the SLS Block 1 (5.75 million pounds for launch vehicle, 1.6 million pounds for SRBs). The SLS Block 2 will not only be heavier but use more advanced SRBs.
EUS is quite a bit heavier than ICPS, though. The vehicle will be more massive.
Yes, if 1st stage acceleration is your thing, Arty-1 through Arty-3 will be your money maker.  Arty-5 will be firing the 4 new build SLS ME at 111%RPL, but that extra 2% of Rated Power Level of thrust(approx. 5,000 lbs-force/ 22,241 N per [email protected] Level or very approx 20,000lbs-force/88,964 N thrust won't be enough to overcome the extra EUS mass as compared to the single engine Interim Cryogenic Propulsion Stage.

Don't count on the BOLE' boosters debuting on Arty-9 to inspire awe any more than the 5 segment RSRMVs in current use because even though their case/propellant mass fraction beats the RSRMV, the BOLE' boosters have an initial loaded mass even greater than RSRMV they're replacing.
Paul

Offline Hog

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Re: Launch mass of SLS Block 1B
« Reply #4 on: 12/09/2022 04:10 pm »
Hi guys!

Do we have any information about the launch mass of the planned and in design SLS Block 1B.
For SLS Block 1 it is just over 2600 metric tonnes.

Also, do we know the thrust of the BOLE SRBs?

/Kasper
Emphasis mine.
No we don't know the exact thrust of the new BOLE' boosters.  More will be known following the first full up BOLE booster firing named Develoment Motor-1 (DM-1).  3 Development Motors and 2 Qualification Motors will be fired for the SLS/BOLE' booster effort.

this NASA document highlights the currently flying RSRMV and its steel cases. 10 segments expended during Arty-1 leaving 70 cases for further flights. 30 of those, or flight sets for Arty-2, -3 have been poured and flight sets for Arty-4 started November 2nd/2021(pictured).
Also is a pictured is the first Composite Case Wind for the BOLE' boosters to be used for all SLS launches beyond Arty-8.
https://www.nasa.gov/sites/default/files/atoms/files/0080_sls_solid_rocket_booster_fact_sheet_final_02092022.pdf

And the excellent article from our own Philip Sloss.  There is a thrust trace in this acrticle that illustrates comparatively the BOLE' thrust vs. the current RSRM-V thrust.  No numbers are conveyed.

https://www.nasaspaceflight.com/2021/07/sls-bole-srbs/
Paul

Offline Kasponaut

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Re: Launch mass of SLS Block 1B
« Reply #5 on: 12/12/2022 08:04 pm »
Thanks for your replies :-)

So to sum it up, no one knows what the SLS Block 1B mass will be at this time. That canít be true.

/Kasper

Offline edkyle99

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Re: Launch mass of SLS Block 1B
« Reply #6 on: 12/13/2022 01:56 am »
My guesstimate for SLS Block 1B GLOW is somewhere in the neighborhood of 2,700-2,750 tonnes.   That compares with a variously reported 2,603-2,625 tonnes for SLS-1. 

And yes, no one outside of NASA and its contractors knows these answers for certain.  Because ITAR I think.

 - Ed Kyle
« Last Edit: 12/13/2022 02:01 am by edkyle99 »

Offline Kasponaut

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Re: Launch mass of SLS Block 1B
« Reply #7 on: 12/13/2022 11:31 am »
Thank you Ed 👍🏻😊

But since the GLOW of the SLS Block 1 is well known, why would the Block 1B be under ITAR?

/Kasper

Offline Robotbeat

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Re: Launch mass of SLS Block 1B
« Reply #8 on: 12/13/2022 11:36 am »
Thank you Ed 👍🏻😊

But since the GLOW of the SLS Block 1 is well known, why would the Block 1B be under ITAR?

/Kasper
Because the default is that rockets are ITAR until NASA lawyers show otherwise. Itís very bad practice IMHO.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Kasponaut

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Re: Launch mass of SLS Block 1B
« Reply #9 on: 12/13/2022 11:46 am »
Okay. I understand and I agree.

The question then is when will the lawyers say okay so it can be released.

/Kasper

Offline edkyle99

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Re: Launch mass of SLS Block 1B
« Reply #10 on: 12/13/2022 02:27 pm »
Thank you Ed 👍🏻😊

But since the GLOW of the SLS Block 1 is well known, why would the Block 1B be under ITAR?

/Kasper
I don't believe that the exact GLOW of Block 1 is well known.  Even JCM was left guessing.  NASA has released vague round numbers only, unlike the Apollo days when such things were detailed to the pound - even to the point that propellant burn before release was accounted.  Note also that Artemis 1 had its own specific GLOW that likely differed from the generic mass typically listed for SLS Block 1.

 - Ed Kyle
« Last Edit: 12/13/2022 02:29 pm by edkyle99 »

Offline TomH

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Re: Launch mass of SLS Block 1B
« Reply #11 on: 12/20/2022 09:16 am »
I don't believe that the exact GLOW of Block 1 is well known......NASA has released vague round numbers only, unlike the Apollo days when such things were detailed to the pound - even to the point that propellant burn before release was accounted. - Ed Kyle

Are you talking pound of weight/mass, or pound of thrust?

I maybe mistaken, but isn't it true that you can be a lot more accurate about thrust with a liquid engine than a solid, simply because you actively regulate (via sensors, algorithms, software) the pump flow rate of prop, whereas with solids, there is no guarantee that the mixed solid prop will burn as precisely the same every single time, i.e. there can be slight deviation in the way the prop burns? I know they will be close, but with liquids, the burn is actively controlled, whereas even though from one solid to the next they will have the same mixture, mass, and internal cross-section, they are not controlled. How much deviation is possible from one to another? Surely more than single pounds? Thus you can be more accurate re. an F-1 a half century ago than you can an SRB today?

Offline Hog

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Re: Launch mass of SLS Block 1B
« Reply #12 on: 12/30/2022 12:11 am »
I don't believe that the exact GLOW of Block 1 is well known......NASA has released vague round numbers only, unlike the Apollo days when such things were detailed to the pound - even to the point that propellant burn before release was accounted. - Ed Kyle

Are you talking pound of weight/mass, or pound of thrust?

I maybe mistaken, but isn't it true that you can be a lot more accurate about thrust with a liquid engine than a solid, simply because you actively regulate (via sensors, algorithms, software) the pump flow rate of prop, whereas with solids, there is no guarantee that the mixed solid prop will burn as precisely the same every single time, i.e. there can be slight deviation in the way the prop burns? I know they will be close, but with liquids, the burn is actively controlled, whereas even though from one solid to the next they will have the same mixture, mass, and internal cross-section, they are not controlled. How much deviation is possible from one to another? Surely more than single pounds? Thus you can be more accurate re. an F-1 a half century ago than you can an SRB today?
emphasis mine

Good question, I think at least somewhat depends on whether F-1 was under closed loop control?  I'm guessing it was not.  Even RS25 wasn't always operated under closed loop.
Paul

Tags: SRB sls block 1b 
 

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