Author Topic: SLS General Discussion Thread 3  (Read 310880 times)

Offline ncb1397

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Re: SLS General Discussion Thread 3
« Reply #20 on: 07/06/2018 08:06 am »

Any chance people could stop misrepresenting data so that we can keep this thread on topic for a change?

The NRC pathways report was done in 2014. The budget has not been flat since then. Their assumptions didn't pan out. And it wasn't really an assumption. It was an "if then" statement. One that really doesn't apply 5 years later.
« Last Edit: 07/06/2018 08:22 am by ncb1397 »

Offline woods170

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Re: SLS General Discussion Thread 3
« Reply #21 on: 07/06/2018 08:38 am »

3. "to enable human expansion across the solar system and to bring back to Earth new knowledge and opportunities.": Since SLS is projected to eat up all the funding, it's obviously not going to enable anything. Even if there's funding for payloads, SLS is limited to just 2 launches per year, that's just enough to send humans to the Moon for an Apollo style flag and footprint mission, no way it will be able to send humans further into the solar system.


Twice per year is 4 launches per mars opportunity. That is IMLEO of 380,000-520,000 kg per launch window. BFR is supposedly 100 people with an IMLEO mass in the 1,500,000 kg range. That is only 15,000 kg per person. In fact, SLS could launch a fueled ~1/10th scale BFR-like vehicle with a crew of ~10 in one launch
Going back to item 1.2 of su27k's response: SLS and Orion are sucking the budget dry leaving no money available for the development of landers. As indicated by NASA's very own life cycle cost analysis.

So I ask you: what BFR-like vehicle with a crew of ~ 10?

There isn't any funding to develop it.
« Last Edit: 07/06/2018 08:43 am by woods170 »

Offline ncb1397

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Re: SLS General Discussion Thread 3
« Reply #22 on: 07/06/2018 08:46 am »

3. "to enable human expansion across the solar system and to bring back to Earth new knowledge and opportunities.": Since SLS is projected to eat up all the funding, it's obviously not going to enable anything. Even if there's funding for payloads, SLS is limited to just 2 launches per year, that's just enough to send humans to the Moon for an Apollo style flag and footprint mission, no way it will be able to send humans further into the solar system.


Twice per year is 4 launches per mars opportunity. That is IMLEO of 380,000-520,000 kg per launch window. BFR is supposedly 100 people with an IMLEO mass in the 1,500,000 kg range. That is only 15,000 kg per person. In fact, SLS could launch a fueled ~1/10th scale BFR-like vehicle with a crew of ~10 in one launch
Going back to item 1.2 of su27k's response: SLS and Orion are sucking the budget dry leaving no money available for the development of landers. As indicated by NASA's very own life cycle cost analysis.

So I ask you: what BFR-like vehicle with a crew of ~ 10?

There isn't any funding to develop it.

A 10% reduction across the board in HSF programs would generate ~$1 billion per year. But any landers should be targeted to the moon as it is more representative of general space environments.
« Last Edit: 07/06/2018 08:48 am by ncb1397 »

Offline woods170

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Re: SLS General Discussion Thread 3
« Reply #23 on: 07/06/2018 08:55 am »

Any chance people could stop misrepresenting data so that we can keep this thread on topic for a change?

The NRC pathways report was done in 2014. The budget has not been flat since then. Their assumptions didn't pan out. And it wasn't really an assumption. It was an "if then" statement. One that really doesn't apply 5 years later.

With all due respect I disagree. The budget is still flat. Including this FY2018 the NASA budget, over the past 20 years, has constantly varied between ~$18B and ~B21B in constant dollars. (I suggest you read up on the subject of constant dollars).

See the figures here: https://en.wikipedia.org/wiki/Budget_of_NASA

And mind you, the figures presented there come straight from the US Office of Management and Budget (OMB) and NASA itself.
They are official figures coming from US government agencies and very clearly show that NASA's budget is still flat.
« Last Edit: 07/06/2018 08:57 am by woods170 »

Offline woods170

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Re: SLS General Discussion Thread 3
« Reply #24 on: 07/06/2018 09:00 am »

3. "to enable human expansion across the solar system and to bring back to Earth new knowledge and opportunities.": Since SLS is projected to eat up all the funding, it's obviously not going to enable anything. Even if there's funding for payloads, SLS is limited to just 2 launches per year, that's just enough to send humans to the Moon for an Apollo style flag and footprint mission, no way it will be able to send humans further into the solar system.


Twice per year is 4 launches per mars opportunity. That is IMLEO of 380,000-520,000 kg per launch window. BFR is supposedly 100 people with an IMLEO mass in the 1,500,000 kg range. That is only 15,000 kg per person. In fact, SLS could launch a fueled ~1/10th scale BFR-like vehicle with a crew of ~10 in one launch
Going back to item 1.2 of su27k's response: SLS and Orion are sucking the budget dry leaving no money available for the development of landers. As indicated by NASA's very own life cycle cost analysis.

So I ask you: what BFR-like vehicle with a crew of ~ 10?

There isn't any funding to develop it.

A 10% reduction across the board in HSF programs would generate ~$1 billion per year. But any landers should be targeted to the moon as it is more representative of general space environments.

Good luck trying to convince US Congress to annually shave ~$1B from the SLS and Orion programs to fund a lander. Not going to happen with the current gravy-train addicts in US Congress.

Offline blasphemer

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Re: SLS General Discussion Thread 3
« Reply #25 on: 07/06/2018 09:26 am »
BFR is supposedly 100 people with an IMLEO mass in the 1,500,000 kg range.

Weight of a fully refueled BFS loaded with cargo is 1335 tons. SpaceX wants to send two cargo ships in 2022, then two cargo ships and two crew ships in 2024. Total IMLEO for initial SpaceX manned mission is thus around 8000 tons (and I doubt it will have anywhere near 100 people). Good luck sending that up on a SLS.
« Last Edit: 07/06/2018 09:29 am by blasphemer »

Offline spacenut

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Re: SLS General Discussion Thread 3
« Reply #26 on: 07/06/2018 01:11 pm »
The only long term way I see SLS staying around past the mid-2020's is if they replace the solids with reusable liquid rockets to cut costs.  Then adding a 5th engine on the core for greater lift capability, then adding a reusable upper stage/spaceship like SpaceX is planning.  The core could still be expended or at least put the engines in a pod for return and reuse. 

Reusable solids (steel cased) are expensive to recover, disassemble, clean, repack with fuel, and reassemble.  Cost about the same as new.  Graphite composite are less expensive to produce, are lighter, but cannot be reused, and still more expensive than a reusable liquid rocket. 

Monolithic solids made from steel could be made reusable, but limited in power.  Also recovery could be a problem with 6-8 parachuting down in the ocean, and having to get a crew to each one and sealing the nozzle before they fill with water and sink.  Unless, they are light enough to be air retrieved by helicopter or slow flying plane.  Then how large can a monolithic solid be and still use existing infrastructure for manufacturing and transport.  10-12' in diameter is as wide as one could be and still be transported by road or rail, but the length and weight could be a problem. 

I know I am rambling, but I just can't see SLS surviving past 2025 with BFR/BFS, New Glenn, Vulcan, and maybe others from other countries coming on line during this time.  Also they will be fully or partly reusable, and can all do distributed launch.  Competition is everything, and SLS will not be able to compete on pricing in the future. 

Offline johnfwhitesell

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Re: SLS General Discussion Thread 3
« Reply #27 on: 07/06/2018 02:10 pm »
The only long term way I see SLS staying around past the mid-2020's is if they replace the solids with reusable liquid rockets to cut costs.

The SLS boosters have more thrust then a Falcon 9.  Landing a booster requires a fully capable vehicle.  You aren't talking about a booster, you are talking about developing a new reusable medium-heavy rocket.

Offline mike robel

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Re: SLS General Discussion Thread 3
« Reply #28 on: 07/06/2018 02:11 pm »
@SU27K:  (I have a hard time mastering quote trimming)

You ask:

Is there really that much difference? Your quote specifically said it's also a goal ("commit itself to achieving the goal"). Comparing the two the only difference I can find is the lack of when, who/what/where/why are all there.

So I say again: The national goal or mission or whatever is there, "who/what/where/why" is not a mystery, "when" is not included probably because they couldn't commit the funding necessary to meet a "when", but that's ok as long as you're making progress towards the goal. What's not ok is the government ignoring their own goal and heading in the opposite direction.


In my view:

"When" is the key point.  Without a when and a main effort (or proper support), that is just a laundry list made by the good idea fairy, and you cannot focus your resources or planning on the most important task.

We are now squarely into Space Policy and I risk censure and derailing the thread.  I will start a new thread up there named something like NASA Mission and Goals, and put my first post into it.

Moderator:  I request after I create the thread, you move the posts dealing with goals and missions to that thread.


Here is the new thread:  https://forum.nasaspaceflight.com/index.php?topic=45959.msg1835840#msg1835840
« Last Edit: 07/06/2018 02:29 pm by mike robel »

Offline meberbs

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Re: SLS General Discussion Thread 3
« Reply #29 on: 07/06/2018 02:20 pm »

Any chance people could stop misrepresenting data so that we can keep this thread on topic for a change?

The NRC pathways report was done in 2014. The budget has not been flat since then. Their assumptions didn't pan out. And it wasn't really an assumption. It was an "if then" statement. One that really doesn't apply 5 years later.
So that is a "no" to my request to stop misrepresenting data then.

My graph is from 2015, so approximately as up to date as the one on Wikipedia that woods170 pointed you to. Using the recent data from your post, it is obvious the budget is flat since then. sticking with 2% inflation as a good annual estimate, the 5% drop you mentioned is closer to 7% in real purchasing power. You can clearly see this dip that was still present in 2015 in the graph I shared. Taking your other numbers 1.062*1.01*1.072/(1.02*1.02*1.02) = about 8.3% combining that with the "5%" drop is just enough to cancel out leaving 1% growth. That is well within the historical variation and is far from indicating any meaningful NASA budget growth.

Offline whitelancer64

Re: SLS General Discussion Thread 3
« Reply #30 on: 07/06/2018 02:23 pm »
*snip*
Reusable solids (steel cased) are expensive to recover, disassemble, clean, repack with fuel, and reassemble.  Cost about the same as new.  Graphite composite are less expensive to produce, are lighter, but cannot be reused, and still more expensive than a reusable liquid rocket. 
*snip*

That's why SLS isn't recovering the SRBs.
"One bit of advice: it is important to view knowledge as sort of a semantic tree -- make sure you understand the fundamental principles, ie the trunk and big branches, before you get into the leaves/details or there is nothing for them to hang on to." - Elon Musk
"There are lies, damned lies, and launch schedules." - Larry J

Offline mike robel

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Re: SLS General Discussion Thread 3
« Reply #31 on: 07/06/2018 02:42 pm »
2. "with commercial and international partners": This part is obvious, SLS is not partnering with commercial companies. No international partners either, but that's a good thing since the current international space cooperation model is completely broken (another topic).

True for SLS and EGS, but not for Orion and LOP-G.

Quote
Even if there's funding for payloads, SLS is limited to just 2 launches per year, that's just enough to send humans to the Moon for an Apollo style flag and footprint mission, no way it will be able to send humans further into the solar system.

Sortie missions to the Moon is a lot better than what we've had for the last 46 years. Also, Apollo was much more than Flags and Footprints. Our knowledge of the Moon (and the rest of the planets) was fundamentally changed by what was learned from the Apollo missions.

I agree 100% with Steven.  What people call "Flags and Footprints" is reconnaissance.  Without reconnaissance, there is no way to focus other efforts on the best opportunities and to better define missions and goals.

Offline envy887

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Re: SLS General Discussion Thread 3
« Reply #32 on: 07/06/2018 03:47 pm »
*snip*
Reusable solids (steel cased) are expensive to recover, disassemble, clean, repack with fuel, and reassemble.  Cost about the same as new.  Graphite composite are less expensive to produce, are lighter, but cannot be reused, and still more expensive than a reusable liquid rocket. 
*snip*

That's why SLS isn't recovering the SRBs.

Reusable LRBs would be much cheaper, but would have to fly more to justify the development and initial costs. And SLS flight rate is constrained by core stage production, which is very expensive to ramp up.

I don't see any viable way to get SLS above 1 to 2 flights a year consistently that also decreases the overall price. It probably would not even decrease the marginal price without at least doubling the total spend.

Offline ncb1397

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Re: SLS General Discussion Thread 3
« Reply #33 on: 07/06/2018 04:46 pm »

3. "to enable human expansion across the solar system and to bring back to Earth new knowledge and opportunities.": Since SLS is projected to eat up all the funding, it's obviously not going to enable anything. Even if there's funding for payloads, SLS is limited to just 2 launches per year, that's just enough to send humans to the Moon for an Apollo style flag and footprint mission, no way it will be able to send humans further into the solar system.


Twice per year is 4 launches per mars opportunity. That is IMLEO of 380,000-520,000 kg per launch window. BFR is supposedly 100 people with an IMLEO mass in the 1,500,000 kg range. That is only 15,000 kg per person. In fact, SLS could launch a fueled ~1/10th scale BFR-like vehicle with a crew of ~10 in one launch
Going back to item 1.2 of su27k's response: SLS and Orion are sucking the budget dry leaving no money available for the development of landers. As indicated by NASA's very own life cycle cost analysis.

So I ask you: what BFR-like vehicle with a crew of ~ 10?

There isn't any funding to develop it.

A 10% reduction across the board in HSF programs would generate ~$1 billion per year. But any landers should be targeted to the moon as it is more representative of general space environments.

Good luck trying to convince US Congress to annually shave ~$1B from the SLS and Orion programs to fund a lander. Not going to happen with the current gravy-train addicts in US Congress.

No, across the board. ISS, SLS, Orion, EGS, pure research programs. Changing standard crew rotations to 9 months essentially does the majority of this for the ISS program without affecting anything else. That also happens to be over standard trip times to Mars. As far as Congress cutting SLS and Orion, the budget for those was flat between 2017 and 2018, which actually represents a cut of ~2% adjusted for inflation. EGS grew to put away money for the 2nd mobile launcher, but that is going to fall very rapidly going forward (looks like a reduction of at least $100 million for FY 2019 which represents a 14% drop after inflation). People said this about LOP-G/DSG or what ever - that there was no money for it. Somehow half a billion was found somewhere. A lander would be more (in the $.5 - 1 billion range).

And BTW, NASA is getting a 3-4% raise (or more if the conference comes back with a number higher than both versions which has happened before). In real terms, that is 1-2% or $200-$400 million. So, a few percentage points here and there are signifcant amounts. If the budget rose by 5%, people could still make the argument that it is essentially flat, but that is still a swing of a billion dollars.

People have been saying that it couldn't increase because it was a flat budget for many years going back to 2014 and probably earlier. But from 2014, it has gone up. Look at the graph posted above.
« Last Edit: 07/06/2018 05:59 pm by ncb1397 »

Offline meberbs

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Re: SLS General Discussion Thread 3
« Reply #34 on: 07/06/2018 07:35 pm »
And BTW, NASA is getting a 3-4% raise (or more if the conference comes back with a number higher than both versions which has happened before). In real terms, that is 1-2% or $200-$400 million. So, a few percentage points here and there are signifcant amounts. If the budget rose by 5%, people could still make the argument that it is essentially flat, but that is still a swing of a billion dollars.

People have been saying that it couldn't increase because it was a flat budget for many years going back to 2014 and probably earlier. But from 2014, it has gone up. Look at the graph posted above.
The bolded statement is an outright lie. The bit over plus or minus $1 billion shifts have been explicitly mentioned:

With all due respect I disagree. The budget is still flat. Including this FY2018 the NASA budget, over the past 20 years, has constantly varied between ~$18B and ~B21B in constant dollars. (I suggest you read up on the subject of constant dollars).
This happens for a variety of reasons based on politics and the current state of major programs. The graph above shows the "increase" you are talking about is just a return to average levels after a temporary dip. There might be a temporary increase above the average to follow, but there is no indication that the average is moving anywhere.

Please stop with the strawman arguments, and stop cherry picking data to pretend that a temporary shift is anything other than a temporary shift.

Online Coastal Ron

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Re: SLS General Discussion Thread 3
« Reply #35 on: 07/06/2018 08:21 pm »
No, across the board. ISS, SLS, Orion, EGS, pure research programs

Maybe I'm not interpreting what you wrote correctly, so let me clarify:

ISS - a National Laboratory that does applied and pure research, and is helping to lay the foundation for future human activity in space.

SLS and Orion - transportation systems that are currently funded for development, but not yet funded for operations.

EGS (Exploration Ground Systems) - "...established to develop and operate the systems and facilities necessary to process and launch rockets and spacecraft during assembly, transport and launch." In other words, infrastructure.

So out of those four items listed, only the ISS is related to research.

Quote
Changing standard crew rotations to 9 months essentially does the majority of this for the ISS program without affecting anything else.

If the U.S. wants to end the mission of the ISS by 2024 (which is one of the possibilities being discussed), then it makes no sense to reduce the science tempo on the station at this time.

Quote
That also happens to be over standard trip times to Mars.

NASA has no specific plans to go to Mars anytime soon, so this would not be a benefit.

Quote
As far as Congress cutting SLS and Orion, the budget for those was flat between 2017 and 2018, which actually represents a cut of ~2% adjusted for inflation.

As a reminder, the SLS program never had a budget target, and Congress has never shown any indication it cares about a budget target. Nor does Congress seem to care that the SLS will be at least 4 years late in becoming operational.

So based on that, how much Congress is willing to allocate to the SLS program is not really connected to any specific goals for the United States of America.

In other words, you can't discern patterns in the funding levels of the SLS, because they are not based on logic...  ;)
If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Offline spacenut

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Re: SLS General Discussion Thread 3
« Reply #36 on: 07/06/2018 11:10 pm »
I never said anything about on my post about using Falcon 9 as a booster and I know it would take 4 Falcon 9's to match the solids.  This has been discussed before, and it can't be done they way he core is built. 

I said a reusable liquid booster.  NASA did mention a possibility of using a 5.5m booster using either two old F-1 engines each or using AR-1's.  Reuse could be built into a liquid booster IF they wanted to, but that would have to be down the road. 

« Last Edit: 07/07/2018 02:30 am by spacenut »

Offline johnfwhitesell

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Re: SLS General Discussion Thread 3
« Reply #37 on: 07/06/2018 11:36 pm »
I agree 100% with Steven.  What people call "Flags and Footprints" is reconnaissance.  Without reconnaissance, there is no way to focus other efforts on the best opportunities and to better define missions and goals.

I think the word exploration is much more appropriate in this circumstance.

If you are going to explore of raconteur, the value of the mission is the information you are going to get.  You are saying the information is needed to assess lunar opportunities.  I think there are a number of high value questions to answer in that regard:
-What is the composition of those caves on the moon? (can we build habitats in them?)
-What is the water content of the lunar poles? (can we make fuel?)
-What other elements are present at the poles? (can we make a self sufficient settlement?)
-Does the hydrogen content of the moon increase if you start drilling downward?

I am aware of no SLS mission that will get us the answer to any of these questions.  What is the information about lunar opportunities you believe the SLS will get us?

It's also well within the abilities of NASA to answer all of these questions with moon rovers.  Compared to the herculean tasks they have done with martian rovers and deep space missions, these missions would be child's play.  If exploring the moon is worth so many billion dollars then could we please spare a billion to answer these questions?
« Last Edit: 07/07/2018 09:28 pm by johnfwhitesell »

Offline mike robel

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Re: SLS General Discussion Thread 3
« Reply #38 on: 07/07/2018 02:23 am »
I agree 100% with Steven.  What people call "Flags and Footprints" is reconnaissance.  Without reconnaissance, there is no way to focus other efforts on the best opportunities and to better define missions and goals.

I think the word exploration is much more appropriate in this circumstance.

If you are going to explore of raconteur, the value of the mission is the information you are going to get.  You are saying the information is needed to assess lunar opportunities.  I think there are a number of high value questions to answer in that regard:
-What is the composition of those caves on the moon? (can we build habitats in them?)
-What is the water content of the lunar poles? (can we make fuel?)
-What other elements are present at the poles? (can we make a self sufficient settlement?)
-Does the hydrogen content of the moon increase if you start drilling downward?

I am aware of no SLS mission that will get us the answer to any of these questions.  What is the information about lunar opportunities you believe the SLS will get us?

It's also well within the abilities of NASA to answer all of these questions with moon rovers.  Compared to the herculean tasks they have done with martian rovers and deep space missions, these missions would be child's play.  If exploring the moon is worth so many billion dollars then could we please spare a billion to answer these questions?

Launching one or possibility of two per year for over $1 billion cost to me is a waste of my taxpayer money especially once newer reusable rockets come on line.   

Please reread the first post of the thread.

I'm okay with the use of exploration.  I, even though I am a booster fan boy, don't think SLS is anything but a tool to (possibly) get us to where we want to go.  We have defined a capsule with about the same sortie (?) capability as Apollo, a possible station* to orbit the moon (something that can be done with unmanned satellites just as well, if not better), but not anything to explore the surface.

*The Lunar Outpost may provide good information on long duration habitats, but in my thinking, it would be just as effective to do it in LEO. 

Offline Proponent

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Re: SLS General Discussion Thread 3
« Reply #39 on: 07/07/2018 02:39 am »
The only long term way I see SLS staying around past the mid-2020's is if they replace the solids with reusable liquid rockets to cut costs.  Then adding a 5th engine on the core for greater lift capability, then adding a reusable upper stage/spaceship like SpaceX is planning.

At the very low flight rates projected for SLS, reusability would likely cost more than its worth.  I would say that the current fully expendable design is the right way to go.
« Last Edit: 07/07/2018 02:41 am by Proponent »

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