Author Topic: What would it take to change your mind on SLS/Orion?  (Read 34558 times)

Offline oldAtlas_Eguy

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Re: What would it take to change your mind on SLS/Orion?
« Reply #80 on: 10/16/2017 05:09 pm »
What would it take to change my mind on SLS/Orion?

NASA developing a large 35-40mt BEO single element payload that cannot be broken down into 10-25mt elements.

There are other methods (LVs) much cheaper to get manned capsules and 15mt cargo payloads into a Lunar orbit which will exist (launch) prior to SLS-1B/Orion launch and as well even before SLS-1A/Orion launch.

NASA does not have such 35- 40mt payloads on its "radar" in the conceivable future out through 2030. Why such a large payload would change my mind? Anything smaller than 35mt BEO could be launched with Vulcan/ACES-DL (Distributed Launch). Even then if BO is not to tardy with its NG development a 3 stage NG with some DL capabilities could do the up to 40mt BEO. So a large BEO payload is not an assured thing for justification of SLS. And definitely not for Orion.

There is a likely case that a manned Dragon 2 Lunar flyby will occur before even EM-1. If D2 is BEO capable then what is the reason to have Orion? If there was a continuously manned BEO station or Lunar base then having two different systems would be of some reasoning. But there are other options than Orion for even that case that are much cheaper.

The closet thing for justification of the expense of an SLS (not Orion though) is the Europa Clipper and Europa Lander because of truncated mission time that SLS offers these programs. Such complex missions and a standing army of experts to support the mission causes a several year decrease in mission time does two things. Decrease the after launch mission expenses to almost in half and increases mission success because time in space for a probe is the biggest threat to success. A tremendous shortened mission time means a tremendous boost in probable mission success. At the moment the DV that SLS can offer these probe missions can not be duplicated by  other LVs existing or soon to exist that can be provided by SLS within the timeframe for EC. But EL (Europa Lander) with an unsure launch date which may be at the end of the 2020s, something else may come along that can get close to it or even exceed SLS.

In other words it would take a lot to change my mind about the SLS/Orion program. The program doesn't even challenge the technology existing for space Launch which could have gotten me to be a marginal proponent. It does not do other than some very minor tech upgrades of systems that have flown for more than 30 years. In some cases the exact same systems as flown 30+ years ago. NOTE such a system is Orion's heat shield which is an 50+ year old Apollo era design.

Offline Proponent

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Re: What would it take to change your mind on SLS/Orion?
« Reply #81 on: 10/16/2017 06:13 pm »
The closet thing for justification of the expense of an SLS (not Orion though) is the Europa Clipper and Europa Lander because of truncated mission time that SLS offers these programs. Such complex missions and a standing army of experts to support the mission causes a several year decrease in mission time does two things. Decrease the after launch mission expenses to almost in half and increases mission success because time in space for a probe is the biggest threat to success. A tremendous shortened mission time means a tremendous boost in probable mission success. At the moment the DV that SLS can offer these probe missions can not be duplicated by  other LVs existing or soon to exist that can be provided by SLS within the timeframe for EC

My understanding from reading Blackstar's posts is that the benefit of the faster trajectory is not in higher reliability but in less testing.  In other words, if the mission is longer, then the hardware is tested more extensively to bring it to the same reliability over the longer lifetime.  That additional testing is expensive, and its elimination results in a significant savings.  In fact, IIRC, the savings from reduced testing likely exceeds the savings from fewer years of operations to fund.

While the faster mission is undeniably a benefit, what's missing, as always in the case of SLS, is any analysis of whether the it is worth the additional cost of the launch vehicle.

Given the more onerous testing regime for longer missions, using SLS increases the risk of failure, because the launch vehicle will have little track record.  EC will be an extremely expensive test weight if it flies on the first EUS (though not as expensive as the alternative, namely the first Orion crew). 

Compare to Atlas V's long and nearly perfect record.

EDIT:  "launch vehicle" -> "the launch vehicle" in penultimate paragraph.
« Last Edit: 10/16/2017 08:26 pm by Proponent »

Offline Political Hack Wannabe

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Re: What would it take to change your mind on SLS/Orion?
« Reply #82 on: 10/16/2017 08:10 pm »
Very simply - show me how SLS actually enables space settlement. 

IMHO - if something in our human space program isn't about enabling settlement, we shouldn't be doing it.  And if we aren't settling space, no reasons to send humans. 
It's not democrats vs republicans, it's reality vs innumerate space cadet fantasy.

Offline meberbs

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Re: What would it take to change your mind on SLS/Orion?
« Reply #83 on: 09/01/2019 07:05 pm »
#1 on my list of what it would take for me to support SLS would be for it to actually be designed for a reasonable flight rate. It is currently working on adding more evidence to the pile that a low flight rate will lead to a horrendously expensive rocket.

That said, I wouldn't actually advocate for cancelling it for another couple years, when Vulcan/New Glenn/mini-ITS are far enough along to have more confidence in them actually flying. This is not me supporting SLS, but acknowledging that my expectations about these rockets could be wrong so I can understand why some support SLS for now.

I would also like to see them skip to Block 1B for EM-1. Even with what has already been done, this seems like it would still likely be a cheaper and faster method of getting SLS running, though really it should have been done when they first decided not to do EM-2 on Block 1. As a bonus, the delay would mean it wouldn't fly before we get to the point where I expect the commercial capabilities to be far enough along, which would hopefully make cancellation easier.
It has now been the couple of years since I made my previous post in this thread, and evidence against SLS is more than I would have thought. I was going to wait to post this for Musk's Starship update to have as much information as possible, but even without that, there has been enough evidence that SLS should be cancelled for a while now, and the last flight of Starhopper is a good enough milestone on that end.

Unsurprisingly SLS dates have continued to slip, with the current official goal being end of 2020, although a realistic date is actually more like mid-2021. The SLS is far enough along that I would actually believe the mid 2021 estimate, except Eric Berger has written (article) that the real date is currently NET late 2021, which makes 2022 the realistic date as he elaborated on in a tweet.

https://twitter.com/SciGuySpace/status/1151599532721004544

As far as the SLS mission itself, there is the study that reviewed alternative ways to launch Orion. The study did not have a fair starting point since it was based around beating the June 2020 date that SLS had no realistic chance of meeting to begin with, which was well understood at that point even if it wasn't officially announced. While the study didn't come up with any viable alternatives under its constraints, it did show that Orion could potentially be launched by Falcon Heavy. There obviously is not enough performance for a direct launch, but they considered Earth Orbit Rendevous with a departure stage which would eliminate that issue. This was eliminated from the study because of timeline issues with the development of that capability, in part related to the fact that the EM-1 Orion doesn't actually have docking capability developed yet. Given more time, and considering that SLS launches will be more than twice as expensive as any other current or planned launch vehicle, it seems clear that developing such a capability would be straight up better on cost,  as good or better on performance, and considering that the SLS launch date doesn't seem to get closer no matter how much progress is made, it likely would be faster as well.

To make it even more clear that there are simply better architectures out of there, Buzz Aldrin has proposed an alternative architecture which unsurprisingly involves astronauts meeting up with Orion in LEO, and being sent to the moon via a tug. Orion is only included because it is the vehicle that currently is being man-rated for deep space, not because it is the best long term option. This even keeps some of the gateway components around, so the only thing it completely kills is SLS.

None of this is really news, since it has always been obvious that exploration architectures have been based around justifying the existence of SLS, rather than determining a good architecture in general. Including SLS in an exploration architecture at all produces significant limits, because its low flight rate does not allow it to support continuous, sustained exploration. Even just looking at current plans for using the SLS, commercial launchers are used for everything except the manned launch itself, indicating that existing launchers are actually capable of supporting an exploration architecture, providing even more support for the feasibility of alternative proposals such as Aldrin's.

If there ever was any doubt that the high price and slow flight rate causes SLS to do more to hold back space exploration and development than it helps, the recent revelations about the cancellation of any work on depots really puts the issue to bed. While this isn't really surprising that it happened, it is still shocking to see such a blatant form of corruption spelled out so plainly. When I say corruption here, I don't mean there was anything that meets the legal definition of corruption (though I wouldn't be all that surprised if there was.) I am referring to the fact that plainly bad general decisions were forced to be made purely for the benefit and interests of the person/people forcing the decisions.

Now that I have covered all of the evidence that SLS is literally holding back space exploration, such that its cancellation would therefore enable more space exploration to happen even if its portion of the budget was entirely removed from NASA, since NASA would then be working on better architectures using existing vehicles with its remaining budget (such as more effective use of the gateway.) I can now move on to actually mentioning future vehicles. (Note: I sincerely doubt that it is realistic that the entire amount of the SLS budget would be removed from NASA. Funding for NASA has remained very flat for a long time, with money just being redistributed between programs, there would potentially be some drop in funding by removing the SLS, but some of the SLS money would just go to other projects.)

Before mentioning Starship, I should mention some of the less extreme future options out there such as Vulcan/ACES, which if Boeing and Lockheed would let ULA actually put full effort into could be of major use by lowering costs through partial first stage reuse, and notably the in-space refuelling and tug capabilities of ACES, which is a gamechanger for space exploration. There is also Blue Origin which is the closest behind SpaceX in actually implementing good reusability of rockets, even though they haven't put anything in orbit yet. Also, while they don't talk about it much in public, based on their company goals, they almost certainly have internal plans relating to various forms of manned space exploration.

And now for Starship. Starship with its size and full reusability obsoletes basically every other rocket in existence or planned on basically every reasonable metric. Current schedules put the prototypes in orbit in well under 6 months, even doubling that timeframe puts it well ahead of any other planned vehicle. (No really, 1 month from now seems like enough time for them to finish up the Starshhip prototypes, and based on observed rate of production, a Super Heavy produced in 6 months is quite reasonable, and they have 2 build sites, so even a single natural disaster wouldn't set the date back.) 1st stage reuse for it is a given, it is basically no different than what SpaceX already does, so that has little risk. Even if the reusability of the upper stage is harder than expected, requires a heavier heatshield and more refurbishment, it has so much spare capability that it still would be no more expensive than SpaceX's current rockets with more capability even assuming they miss their goals by a wide margin. DearMoon was scheduled to put people around the moon in 2023, but SpaceX has accelerated their development schedule since then. With real flight hardware in existence, and test flights already performed, it is no longer reasonable to completely dismiss Starship.

However, as I already said Starship is a bonus, you can consider it a backup option until it goes orbital for the first time (talk to me in a year in that case,) even without it, all of the exploration goals of NASA can be done better, cheaper, and faster by dropping the ball and chain that SLS has become.

So to answer the thread title, nothing can change my mind on SLS short of it being completely rearchitected to fit with an actually affordable exploration architecture. At that point, it would be changed so much that it would no longer be called SLS. Orion has at least some potential of fitting in to such an architecture, but that seems unlikely to be a good long term solution from my perspective.

Offline JohnFornaro

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Re: What would it take to change your mind on SLS/Orion?
« Reply #84 on: 09/02/2019 01:18 pm »
To the OP:

"What would it take to change your mind on SLS/Orion?"

The question presupposes that changing one's mind is a two way street.  That is, one could change one's mind from an SLS supporter to a detractor, or change one's mind from an SLS detractor to a supporter.

Traditionally, since Saturn V, NASA has provided heavy lift capability.  In principle, SLS would be a continuation of this tradition.  However, mechanical artifacts which cannot launch anything anywhere, do not provide heavy lift capability.   SLS today, after the expenditure of a lot of money, including, to be fair, the money spent on Ares to recreate an unmanned Mercury launch  has still not accomplished anything.

A lot of minds would be changed from detractor to supporter if SLS could actually launch a payload.  One thing that would help accelerate the SLS schedule would be for it to provide cargo only launch services.  The Orion capsule should be made available for private manned launch services, and its attachment interface should be standardized.
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: What would it take to change your mind on SLS/Orion?
« Reply #85 on: 09/02/2019 01:18 pm »

By and large, we even behave...

Some of us do struggle with the network news acronyms, but still, this is the best site for spaceflight, period.
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: What would it take to change your mind on SLS/Orion?
« Reply #86 on: 09/02/2019 01:19 pm »
I come down on the side against SLS.  Not because I think the rocket is flawed ( I admire it technically), or too expensive ( which it is), but because I see SLS as part of an overall problem that prioritizes symbolism vs. actual accomplishment.  


My characterization of the financial problem is slightly different.  They prioritize profit over actual accomplishment. I like SLS in principle, if the principle really were launching significant payloads to LEO or the Gateway.
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: What would it take to change your mind on SLS/Orion?
« Reply #87 on: 09/02/2019 01:19 pm »
One think that might change my mind is if they replace the solids with reusable kerolox boosters.  Have them land back at the cape to refuel and fly again.  Also, if they use a shorter reusable kerolox core, and add a second stage.  I believe costs would come down with a mostly reusable boosters and core.  Payloads would go up at the same time.  Existing rocket is an expensive kludge with todays technology.

SpaceX is starting to demonstrate that, as you probably already know.
« Last Edit: 09/02/2019 01:19 pm by JohnFornaro »
Sometimes I just flat out don't get it.

Offline Lar

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Re: What would it take to change your mind on SLS/Orion?
« Reply #88 on: 09/02/2019 04:15 pm »
There is some similarity/congruity with the "what would it take to cancel SLS" thread... both are good reads.

https://forum.nasaspaceflight.com/index.php?topic=48929.0

props to meberbs for the detailed analysis
« Last Edit: 09/02/2019 04:16 pm by Lar »
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
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