SLS General Discussion Thread 8

[RickA]

Also cost is by far not the only metric that needs to be considered when evaluating project / national decisions. Anybody who has ever done a basic Project Management course will be looking at Time, Cost and Quality. But in reality there are a lot of extras that get split down or added. Time, Cost, Quality (Capability), Risks (Program and Safety) and Politics (National Prestige[1], Public vs Private, local economies) for a start.

And that's before you factor in considerations like retaining strategic national capabilities (the UK has been seriously bitten by this in the past).

Yeah, and SLS is going to lose on every one of these metrics.

I'm puzzled how anyone could think SLS is some sort of "National Prestige", <Loads of stuff deleted>

Stop right there. Where did I say that? More importantly, where did I say that I *thought* that? And what did I do to justify any of the thoughts you followed it with.

In fact where did all your assumptions about where I stand on various issues come from?

For the record I spent the first 15 years of my career helping evaluate large programme options for the UK government where lives, even national existence, were at stake. As a result when presented with two options I now evaluate all three and I try to be as fair as is possible under the circumstances. As I explicitly said I can see advantages and disadvantages with a whole variety of options and decisions, past and future. And I'm a fan of exactly none of them, partly because I know what I don't know.

And when you compare programs you also need to be fair to both. When evaluating the route to SLS it is disingenuous to behave as if the success of SpaceX and the route to Falcon was pre-ordained or to evaluate past decisions as if Starship was already done and dusted at that point. Similarly comparing Starship with SLS whilst ignoring existing program risks to one and not the other is completely disingenuous and a political game rather than anything informative.

Again something I wouldn't be surprised to see comparison between Starship and SLS risks that included Hurricane risks to the latter but not the former.

It's disingenuous to pretend SpaceX/Starship is the only way to replace SLS.

Again, where said?

And it's weird that you seem to think SLS has a better handle on hurricane risks.

Again, where exactly do I say that? I mention hurricane risks only in the context of the behaviour of some people here.

----

THIS is a large part of why I left NSF many years ago and why I will probably do so again very shortly. Try to be helpful or get people to be balanced about their thinking and you will be roasted for it.

[libra]

THIS is a large part of why I left NSF many years ago and why I will probably do so again very shortly. Try to be helpful or get people to be balanced about their thinking and you will be roasted for it.

I have similar feelings at times... more and more often. You have my sympathy.

[Mackilroy]

THIS is a large part of why I left NSF many years ago and why I will probably do so again very shortly. Try to be helpful or get people to be balanced about their thinking and you will be roasted for it.

There’s at least three parts to the problem (and these are general statements): people assuming they know others’ positions and meanings, when they often don’t; and combined with that, a lack of familiarity with other people that adds context where otherwise it’s hard to know. Pile on top of that some heavily ideological arguments around the SLS, often exacerbated by dodging difficult issues when doing so would mean admitting they were wrong about something, and it’s a recipe for frustration and thread locks.

[yg1968]

THIS is a large part of why I left NSF many years ago and why I will probably do so again very shortly. Try to be helpful or get people to be balanced about their thinking and you will be roasted for it.

There’s at least three parts to the problem (and these are general statements): people assuming they know others’ positions and meanings, when they often don’t; and combined with that, a lack of familiarity with other people that adds context where otherwise it’s hard to know. Pile on top of that some heavily ideological arguments around the SLS, often exacerbated by dodging difficult issues when doing so would mean admitting they were wrong about something, and it’s a recipe for frustration and thread locks.

The SLS General discussion thread is one of the worst thread in terms of ideological arguments (it is essentially a lets replace SLS with something else thread). If you are getting frustrated with these arguments, it is a good idea to avoid these threads.

[Mackilroy]

I’m not speaking to my own feelings - as I said, all of that was a general statement.

[Jim]

THIS is a large part of why I left NSF many years ago and why I will probably do so again very shortly. Try to be helpful or get people to be balanced about their thinking and you will be roasted for it.

The anti SLS is warranted.   Anything else is better.   It is the SpaceX only fanatical young males are the issue.

[Todd Martin]

THIS is a large part of why I left NSF many years ago and why I will probably do so again very shortly. Try to be helpful or get people to be balanced about their thinking and you will be roasted for it.

The anti SLS is warranted.   Anything else is better.   It is the SpaceX only fanatical young males are the issue.

I'm with Rick.  95% of the discussion on this thread has been to complain about cost, schedule and flight rate.  While valid issues, it is a dispiriting drumbeat.  I would much rather have discussions on technical and programmatic changes that could improve the SLS program.  The latter discussion would educate and maybe lead to positive improvements.  For example:
* Design improvements to mitigate hydrogen leaks and improve sensor reliability
* FTS design changes to increase the batter life or allow for charging after installation
* Pad flow improvements to reduce roll-out times
* Identify and resolve bottleneck issues to increase production rate of SLS so that you could have a higher flight rate.
* Co-manifest options with Orion
* Mobile launcher upgrades to improve serviceability, weight, and alignment issues
* Refueling of the core hydrogen tank in LEO as a cryo depot or wet workshop, perhaps after BOLE is implemented that could get the core into a stable LEO orbit.
* Recovery and reusability upgrades for SLS components
* Material science discussion on alternatives to the foam insulation around the core tank.

Those are just a few ideas, many more are out there.       

[Coastal Ron]

I think the point here is that ignoring failed attempts is not educational. In other words, if you don't learn from the past, then are you may be doomed to repeat it. So accounting for the total costs that it takes NASA to develop a "Shuttle successor" is certainly a valid way to assess success or failure.

And as I stated previously, tracking just the SLS portion of the costs is fine - important in fact, since it was a restart of the "Shuttle successor" effort. But the prior costs should not be ignored either.

We are not (or at least I am not) speaking of the cost to develop a Shuttle successor. In fact there is no Shuttle successor other than COTS and CCP.

You are forgetting history here. The retirement for the Shuttle was announced in 2004. At that time Boeing and Lockheed Martin had not merged into ULA, so they were flying their own rockets, but the U.S. was going to be without a way for accessing space with humans on a U.S. Government vehicle. Commercial options were not even a consideration back then.

So Constellation was the official effort to replace our LEO access ability with a new U.S. Government transportation system to send astronauts first to the International Space Station, then to the Moon, and then to Mars and beyond.

SLS' mission is to give the US its own crewed BLEO capability, something Shuttle never had. SLS is in a completely different class than Shuttle, it is not a successor or a replacement.

The SLS program was started in 2010, before it was known that commercial companies could develop and operate crew vehicles. So one of the mandates of the SLS+Orion was to serve as a backup for supplying and supporting the ISS cargo and crew requirements. It is in the legislation.

It would be more accurate to say "money down the drain", since the work on the Constellation program was mostly wasted. Which is all the more reason to remember the history of how much it has cost the U.S. Taxpayer to build a "Shuttle successor".

Meanwhile the private sector is building new launch systems that will cost a fraction to develop, and cost a fraction to launch.

A private-sector super-heavy rocket is yet to be proven.

We have never needed a "super-heavy rocket" to do anything in space. The SLS, if anything, is too small to move the Orion to a useful lunar orbit, and the global fleet of commercial and NASA international partner rockets can move far more mass into space every year, for far less money, than the SLS can.

ULA pointed this out in 2009 with their study "A Commercially Based Lunar Architecture", where they stated:

The use of smaller, commercial launchers coupled with orbital depots eliminates the need for a large launch vehicle. Much is made of the need for more launches- this is perceived as a detriment. However since 75% of all the mass lifted to low earth orbit is merely propellant with no intrinsic value it represents the optimal cargo for low-cost, strictly commercial launch operations.

Just read the first page of the study and you'll see it refutes all your arguments.

SpaceX is making great strides and they seem to be on the right track.

We don't need the SpaceX Starship to return to the Moon in a robust way. We could have already been returning to the Moon using Atlas V, Delta IV Heavy, Falcon 9/H, Ariane 5/6, etc. Once new launchers come online they can be added, but we have had the ability to return to the Moon without a SHLV since before the SLS was created.

[Mackilroy]

I'm with Rick.  95% of the discussion on this thread has been to complain about cost, schedule and flight rate.  While valid issues, it is a dispiriting drumbeat.  I would much rather have discussions on technical and programmatic changes that could improve the SLS program.  The latter discussion would educate and maybe lead to positive improvements.  For example:
* Design improvements to mitigate hydrogen leaks and improve sensor reliability
* FTS design changes to increase the batter life or allow for charging after installation
* Pad flow improvements to reduce roll-out times
* Identify and resolve bottleneck issues to increase production rate of SLS so that you could have a higher flight rate.
* Co-manifest options with Orion
* Mobile launcher upgrades to improve serviceability, weight, and alignment issues
* Refueling of the core hydrogen tank in LEO as a cryo depot or wet workshop, perhaps after BOLE is implemented that could get the core into a stable LEO orbit.
* Recovery and reusability upgrades for SLS components
* Material science discussion on alternatives to the foam insulation around the core tank.

Those are just a few ideas, many more are out there.       

That’s because the SLS isn’t viewed in a vacuum; it’s always compared to what else can be done in terms of opportunity, cost, time, etc. If you can convince people that the SLS deserves to exist, then such ideas would no doubt get more discussion. You could probably also create a topic specifically for that purpose, and ask that debates on the SLS’s value and validity be kept elsewhere.

For myself, when it comes to the ideas you’ve raised, I’d compare them to rearranging the deck chairs of the Titanic as it’s sailing towards the iceberg. Useful in isolation, but not the best, or even a middling, use of resources under the circumstances. Some are likely not even possible, such as recovering SLS components; the core stage is going extremely fast when ICPS stages, much faster than Falcon 9 or Heavy do when they stage. To modify the core stage for recovery, if it can be done, would likely mean additional years of delay and billions spent - and what would be the point, versus NASA spending those same billions on payloads? Don’t look at the SLS just in terms of capabilities or what we’ve already spent on it, consider what the ongoing costs will be, and what the nation could get if the same funding were invested elsewhere.

[mn]

THIS is a large part of why I left NSF many years ago and why I will probably do so again very shortly. Try to be helpful or get people to be balanced about their thinking and you will be roasted for it.

The anti SLS is warranted.   Anything else is better.   It is the SpaceX only fanatical young males are the issue.

I'm with Rick.  95% of the discussion on this thread has been to complain about cost, schedule and flight rate.  While valid issues, it is a dispiriting drumbeat.  I would much rather have discussions on technical and programmatic changes that could improve the SLS program.  The latter discussion would educate and maybe lead to positive improvements.  For example:
* Design improvements to mitigate hydrogen leaks and improve sensor reliability
* FTS design changes to increase the batter life or allow for charging after installation
* Pad flow improvements to reduce roll-out times
* Identify and resolve bottleneck issues to increase production rate of SLS so that you could have a higher flight rate.
* Co-manifest options with Orion
* Mobile launcher upgrades to improve serviceability, weight, and alignment issues
* Refueling of the core hydrogen tank in LEO as a cryo depot or wet workshop, perhaps after BOLE is implemented that could get the core into a stable LEO orbit.
* Recovery and reusability upgrades for SLS components
* Material science discussion on alternatives to the foam insulation around the core tank.

Those are just a few ideas, many more are out there.     

We've been doing hydrogen for many many years, the SLS implementation must be state of the art, the best that engineering can do. Boeing started with a clean slate and all the accumulated knowledge of past experience. I can't imagine this can be improved upon.

BTW what's the correct emoji for sarcasm, my local teenager is not here to help me.

[LaunchedIn68]

"SLS isn’t viewed in a vacuum"
That may be, BUT aren't NSF Threads in a vacuum?  Talk about another rocket outside SLS thread will get you a nasty message, so how/why compare to other rockets in the first place?

"If you can convince people that the SLS deserves to exist, then such ideas would no doubt get more discussion."
1. OK, SS has not flown yet.  What if unlike F9, SpX can't make it work?  Or at least can't make it work without investing more money than Elon can afford or not for another 5 or 6 years?

2. What if BO scraps NG? Or again can't make it work or quits?

Isn't having SLS about having choices?  More than one option?  Face the fact that Congress is never going to through money at Musk or Bezos carte blanche.  When there is an alternative up and running, THEN the comparisons can be made outside the vacuum.

[Mackilroy]

"SLS isn’t viewed in a vacuum"
That may be, BUT aren't NSF Threads in a vacuum?  Talk about another rocket outside SLS thread will get you a nasty message, so how/why compare to other rockets in the first place?

Yes and no. If it can be compared, it probably will be. The challenge is always making a comparison relevant. So far as nasty messages, ignore them, or report them and move on. Why compare rockets in the first place? Why not?

"If you can convince people that the SLS deserves to exist, then such ideas would no doubt get more discussion."
1. OK, SS has not flown yet.  What if unlike F9, SpX can't make it work?  Or at least can't make it work without investing more money than Elon can afford or not for another 5 or 6 years?

The SLS’s value isn’t improved if Starship fails. Coastal Ron has frequently posted a paper by ULA showing an expansive lunar program using Atlas V and DIVH; NASA itself created a paper comparing SHLVs versus orbital refueling and commercial launch vehicles; the late Paul Spudis described an architecture relying on LVs with no more than a 60 metric ton LEO capacity to take us back to the Moon. Using LVs that were available all the way back in 2009 would have been sufficient to get started, and if we’d needed larger vehicles, there’d be more justification to fund them. Before you then ask why Starship is getting funded, keep in mind I’m strictly referring to government projects.

2. What if BO scraps NG? Or again can't make it work or quits?

See my answer above.

Isn't having SLS about having choices?  More than one option?  Face the fact that Congress is never going to through money at Musk or Bezos carte blanche.  When there is an alternative up and running, THEN the comparisons can be made outside the vacuum.

No. Congress didn’t sign the SLS into law because they cared about having choices. If they did, they’d have funded a competing launcher and manned vehicle at the same time, and they never did. I’m not arguing - nor do I believe anyone else here is - for giving Musk or Bezos all of NASA’s funding. There are plenty of options that don’t involve either man’s company that would be great for NASA to fund more. As the SLS itself is not operational, and won’t be fully ready until 2025 or later, objections to comparisons seem more about preventing opposition versus honest debate.

[Jim]

The latter discussion would educate and maybe lead to positive improvements.  For example:

1  FTS design changes to increase the batter life or allow for charging after installation
2.  Identify and resolve bottleneck issues to increase production rate of SLS so that you could have a higher flight rate.
3.  Co-manifest options with Orion
4.  Mobile launcher upgrades to improve serviceability, weight, and alignment issues
5.   Refueling of the core hydrogen tank in LEO as a cryo depot or wet workshop, perhaps after BOLE is implemented that could get the core into a stable LEO orbit.
6.   Recovery and reusability upgrades for SLS components
7.  Material science discussion on alternatives to the foam insulation around the core tank.
   

Can answer most of them here.

1.  Charging is not allowed.  It is an isolated system.  Just have to qual batteries with longer life
2.  they are known but there is no need to change them.  The flight rate doesn't need to go above 2 per year.
3.  Those are discussed with the manifested missions.  See I-Hab
4.  See ML 2.  ML1 is only for ICPS
5.  Never goes to happen.  Wetworkshops don't work unless there is an existing infrastructure on orbit for manufacturing.  Too much scarring is required without the infrastructure. 
6.  Not going to happen with SLS.  Not recovering boosters and the design does not allow for reusability.
7.  There isn't any.  It will be foam.  Nothing is cheaper or as light. 

Also, there is real for improvements.  It is going to have a life long enough to warrant such changes.  It is no going to last like shuttle or Delta IV.  It isn't even going to have 10 launches by 2030

[Jim]

Face the fact that Congress is never going to through money at Musk or Bezos carte blanche.  When there is an alternative up and running, THEN the comparisons can be made outside the vacuum.

They are but:
a.  There is more than just them
b.  Heavy lift can work like NASA does for every other science or crew mission.   You have competition for launch services. 
c.  NASA has/had IDIQ contracts with Delta IV and II, Atlas II, III & V, Pegasus, Vulcan, Taurus, Antares, Athena, Falcon9 & H, NG, etc.  Starship will be added soon.  NG and Vulcane will be useable once they fly.

[Mark S]

You are forgetting history here. The retirement for the Shuttle was announced in 2004. At that time Boeing and Lockheed Martin had not merged into ULA, so they were flying their own rockets, but the U.S. was going to be without a way for accessing space with humans on a U.S. Government vehicle. Commercial options were not even a consideration back then.

So Constellation was the official effort to replace our LEO access ability with a new U.S. Government transportation system to send astronauts first to the International Space Station, then to the Moon, and then to Mars and beyond.

Yes, that's what I meant. After the cancellation of CxP, COTS and CCP were the commercial replacements for Shuttle. There is no government-owned replacement for Shuttle.

The SLS program was started in 2010, before it was known that commercial companies could develop and operate crew vehicles. So one of the mandates of the SLS+Orion was to serve as a backup for supplying and supporting the ISS cargo and crew requirements. It is in the legislation.

Yes, I know that LEO operations, and in fact all cis-lunar operations, were supposed to be part of the SLS mission plan according to the legisation. However, as soon as the final SLS design was revealed in 2011 all LEO operations went out the window. The SLS design does not lend itself to being useful for LEO operations in any meaningful way.

We don't need the SpaceX Starship to return to the Moon in a robust way. We could have already been returning to the Moon using Atlas V, Delta IV Heavy, Falcon 9/H, Ariane 5/6, etc. Once new launchers come online they can be added, but we have had the ability to return to the Moon without a SHLV since before the SLS was created.

I believe Congress wanted the US to have assured access to space using government-owned resources. And they wanted single-launch capability, instead of coordinating and depending on multiple commercial launches.

If you remember back to the time after Columbia, the consensus was that NASA had reached too far with Shuttle and that we needed to get back to basics for a simple, reliable, expendable, in-line launcher. The idea was that re-use and other advanced concepts put our astronauts at risk for not much return. I might add the fuel depots and in-space refueling can arguably be categorized as advanced concepts and risks that NASA wanted to minimize.

I think we can all agree that it took way too long for SLS to be completed. But it finally did get finished, and now Congress has the single-launch capability they wanted. Let's see what NASA can do with it.

[Jim]

I believe Congress wanted the US to have assured access to space using government-owned resources. And they wanted single-launch capability, instead of coordinating and depending on multiple commercial launches.

and they are wrong.  It is a fallacy and a guise to fund certain congressional districts (the shuttle hardware mandate).   The DOD doesn't depend on government-owned resources and they rely on coordinating and depending on multiple commercial launches.

[darkenfast]

THIS is a large part of why I left NSF many years ago and why I will probably do so again very shortly. Try to be helpful or get people to be balanced about their thinking and you will be roasted for it.

The anti SLS is warranted.   Anything else is better.   It is the SpaceX only fanatical young males are the issue.

And fanatical old taxpayers! I drank the Kool-Aid on Ares I/V (and should've known better). SLS isn't a real improvement and has been ripping us off for years.

[clongton]

The SLS, if anything, is too small to move the Orion to a useful lunar orbit, and the global fleet of commercial and NASA international partner rockets can move far more mass into space every year, for far less money, than the SLS can.

That's what happens when launch vehicles are designed by Congressional people with no motive but jobs, who completely ignore the advice of real rocket designers who actually know what they are talking about. It's also what happens when you design a rocket that has no mission at it's inception and gets one assigned after the fact by shoe-horning it in.

It's exactly as Ron has stated: SLS is too small to do the job it was "supposedly" intended for, and too large and expensive to do literally anything else.

Having said that I wish Artemis-1 well. I hope it succeeds - I really do. But if it doesn't, then it's time for NASA to cut its losses and revamp it's entire approach to HSF.

[SpeakertoAnimals]

You are forgetting history here. The retirement for the Shuttle was announced in 2004. At that time Boeing and Lockheed Martin had not merged into ULA, so they were flying their own rockets, but the U.S. was going to be without a way for accessing space with humans on a U.S. Government vehicle. Commercial options were not even a consideration back then.

So Constellation was the official effort to replace our LEO access ability with a new U.S. Government transportation system to send astronauts first to the International Space Station, then to the Moon, and then to Mars and beyond.

Yes, that's what I meant. After the cancellation of CxP, COTS and CCP were the commercial replacements for Shuttle. There is no government-owned replacement for Shuttle.

The SLS program was started in 2010, before it was known that commercial companies could develop and operate crew vehicles. So one of the mandates of the SLS+Orion was to serve as a backup for supplying and supporting the ISS cargo and crew requirements. It is in the legislation.

Yes, I know that LEO operations, and in fact all cis-lunar operations, were supposed to be part of the SLS mission plan according to the legisation. However, as soon as the final SLS design was revealed in 2011 all LEO operations went out the window. The SLS design does not lend itself to being useful for LEO operations in any meaningful way.

We don't need the SpaceX Starship to return to the Moon in a robust way. We could have already been returning to the Moon using Atlas V, Delta IV Heavy, Falcon 9/H, Ariane 5/6, etc. Once new launchers come online they can be added, but we have had the ability to return to the Moon without a SHLV since before the SLS was created.

I believe Congress wanted the US to have assured access to space using government-owned resources. And they wanted single-launch capability, instead of coordinating and depending on multiple commercial launches.

If you remember back to the time after Columbia, the consensus was that NASA had reached too far with Shuttle and that we needed to get back to basics for a simple, reliable, expendable, in-line launcher. The idea was that re-use and other advanced concepts put our astronauts at risk for not much return. I might add the fuel depots and in-space refueling can arguably be categorized as advanced concepts and risks that NASA wanted to minimize.

I think we can all agree that it took way too long for SLS to be completed. But it finally did get finished, and now Congress has the single-launch capability they wanted. Let's see what NASA can do with it.

Except that SLS is not complete. 1st partial test flight hasn't launched, ML-2 will need an extensive rebuild and the larger 2nd stage is late. And it is not single-launch capable for its only mission.

[su27k]

Stop right there. Where did I say that? More importantly, where did I say that I *thought* that? And what did I do to justify any of the thoughts you followed it with.

In fact where did all your assumptions about where I stand on various issues come from?

Huh? I thought this is about SLS, how did this become about *you*?

You listed metrics we should use to evaluate SLS, I did the evaluation for a few of them and found SLS extremely wanting, it's as simple as that.

For the record I spent the first 15 years of my career helping evaluate large programme options for the UK government where lives, even national existence, were at stake. As a result when presented with two options I now evaluate all three and I try to be as fair as is possible under the circumstances. As I explicitly said I can see advantages and disadvantages with a whole variety of options and decisions, past and future. And I'm a fan of exactly none of them, partly because I know what I don't know.

Evaluation is exactly what I did, yet you think it's some sort of personal attack that I didn't give SLS all the praises, I hope that's not how real work where lives and national existence are at stake are done...

There is NO advantages for having SLS, if you don't want to listen to me, Jim already made this clear enough.

It's disingenuous to pretend SpaceX/Starship is the only way to replace SLS.

Again, where said?

You said "When evaluating the route to SLS it is disingenuous to behave as if the success of SpaceX and the route to Falcon was pre-ordained or to evaluate past decisions as if Starship was already done and dusted at that point.", it's pretty clear by this statement that you think SpaceX/Starship is the only viable replacement for SLS, otherwise you should say "it is disingenuous to behave as if the success of anything besides SLS and the route to any other rocket besides SLS was pre-ordained", you put SpaceX on the spot, not me.

And it's weird that you seem to think SLS has a better handle on hurricane risks.

Again, where exactly do I say that? I mention hurricane risks only in the context of the behaviour of some people here.

You said "I wouldn't be surprised to see comparison between Starship and SLS risks that included Hurricane risks to the latter but not the former.", clearly you think taking hurricane risk into account would make the evaluation more favorable to SLS, otherwise why would you mention it in the first place?

Again you put hurricane risk under the spot light, don't blame others for taking issue with it.