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General Discussion => Space Policy Discussion => Topic started by: Proponent on 07/21/2017 08:37 pm

Title: What would it take to change your mind on SLS/Orion?
Post by: Proponent on 07/21/2017 08:37 pm
If you think the Orion/SLS is a good idea, what new information would make you change your mind?

Same question for those opposed to Orion/SLS.
Title: Re: What would it take to change your mind?
Post by: Ictogan on 07/21/2017 08:44 pm
A fairly significant mission for SLS/Orion that couldn't be done with other available launch vehicles. Right now SLS just seems like a slow and expensive path to nowhere.
Title: Re: What would it take to change your mind?
Post by: mme on 07/21/2017 09:01 pm
A fairly significant mission for SLS/Orion that couldn't be done with other available launch vehicles. Right now SLS just seems like a slow and expensive path to nowhere.
Agree.

A fairly significant, funded, mission for SLS/Orion. Which means that an Administration, House, and Senate would need to be on the same page.  At least long enough to write a mission into law (if that is even possible.)

But if New Armstrong, the NQSBFR and/or the BFR become reality, it will be harder to convince me that SLS is the right choice.
Title: Re: What would it take to change your mind?
Post by: jtrame on 07/21/2017 09:14 pm
I am more inclined to support SLS as a cargo only vehicle.  Commercial should take over the job of placing men aboard the DSH, MTS, or whatever ends up on the plate. These co-manifested flight proposals are old school IMO. But realistically, that may be the only way to get the deal underway for a variety of reasons.

If ITS were real, that would change my mind.  Right now it reminds me of the ship in "When Worlds Collide."  And just about as real.  At this point when propulsive landing of Dragon is cancelled and Falcon Heavy is a difficult birth, ITS seems like a bit of a stretch from that.  The money required just won't be there.  IMO disclaimer of course.
Title: Re: What would it take to change your mind?
Post by: guckyfan on 07/22/2017 06:02 am
My main objection against SLS is price. If they would actually fly at $500 million including fixed cost and in numbers big enough to do some big projects I could come around. I would be willing to forget the enormous development cost and not include them in that price.

That is assuming that SpaceX and BO turn out to be not successful in providing much cheaper lift.

Nothing can change my mind on Orion, ever. It should go as it has no function compared to commercial alternatives.

At present price level I would agree with Donald Trump. Spending that money on fixing potholes will do more for spaceflight than SLS.
Title: Re: What would it take to change your mind?
Post by: pathfinder_01 on 07/22/2017 06:29 am
My Objections are price, lack of missions/low flight rate and the effect it could have on future rocket development/spacecraft development.  I am a big supporter of commercial spaceflight because it allows for faster development. When contracts end or when new contracts are awarded it is an opportunity for new systems to be developed. Those new systems can be cheaper or more capable than the old. Because the rockets and spacecraft remain in private hands they can be upgraded and changed far faster than in a where all funding for changes must come from Congress. Also with luck they can find new roles or missions. 

SLS is much more limited in this respect. NASA can’t so much as change the paint job without funding from Congress and direction from the Administration.  Space X, Orbital, and ULA have made major changes without it. I think if we sit around waiting for another Kennedy or for that magic leadership to come from the White House and the funding behind it to come from Congress we will be sitting around waiting on getting off this planet for eternity. Direction, development, and funding(at least some of it) must come from elsewhere.

I might tolerate SLS if there were missions that could never ever be done in no way possible by private rockets but so far I have not seen any.
Title: Re: What would it take to change your mind?
Post by: jgoldader on 07/22/2017 12:01 pm
I would get behind SLS/Orion (albeit with muttered grumbling about high cost) if there was money appropriated for missions and payloads that made good use of the system.  Instead of being a rocket designed for a mission, SLS continues to *search* for a mission, the Gateway (to where, using what lander?) being the latest thing thrown at the wall to see if it sticks. 
Title: Re: What would it take to change your mind?
Post by: RonM on 07/22/2017 04:30 pm
I complain a lot about SLS and Orion because of the high development costs. They are typical government projects funded at the whim of Congress. That causes delays and greatly increases the cost.

If there were more payloads to launch and a higher flight rate, then SLS and Orion would be a good system. I don't mind spending money as long as we get something for it, like going somewhere.

If and when private companies can compete with SLS, such as Blue Origin or SpaceX, then SLS should be canceled. However, these alternative rockets are not flying yet, so we need to stay the course with SLS or we might end up in the mid 2020s without a large launch vehicle.*

Short answer: Give SLS more payloads like DSG and I'm for it. Once commercial space has operational rockets in the same class, cancel SLS.

* Assuming we really need rockets this large. Since Blue and SpaceX are working on such monster rockets, I think the answer is yes.
Title: Re: What would it take to change your mind?
Post by: Nomadd on 07/22/2017 04:59 pm
 I kind of lost hope when I discovered the insane method for making Orion's heat shield. Not what I'd call a shining example of cost control and efficiency.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Galactic Penguin SST on 07/22/2017 05:31 pm
As I now see SLS/Orion as an interim vehicle to reach beyond LEO as potential commercial BLEO transport solutions ramp up in the 2020s (in fact in such a scenario, most of the SLS/Orion flights would be flown in tandem and in co-operation with the test flights BFR et al.), I think it would take something in the magnitude of SLS/Orion 1st flight slipping beyond 2022 (5 years from now) and plans of Musk et al. completely falling through to really push me into the cancellation camp.

Anything less than that and I think it is worthwhile to keep the program and spend those billions until BFR et al. are in constant operation for at least several consecutive years, because I simply do not believe that anything other than a smooth, uninterrupted handover of transport responsibility from the US government will stop the usage of rockets and such human spacecraft as "pork" (*). Similar programs will, IMHO, re-create like zombies if, say, SLS/Orion is closed right now.

This requires (and encourages) the direct co-operation of both sides in a co-operative program (say, scout missions to the Moon or Mars) with both systems running at the same time.

Ironically it was the successes so far by Musk in the past few years that caused me to stand in the "keep SLS/Orion for now" camp - had no one else rose to the challenge of reaching beyond Earth by 2017 I would have swayed to the cancellation camp by 2015 or so!

(*) And even in the best case, I simply think that "pork" will only be diverted to things like maybe a US government Moon Base/Aldrin Cycler/O'Neill Cylinder/<insert your favorite idea here>. This however is better than nothing.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Jimmy Murdok on 07/22/2017 05:48 pm
Will support SLS when Orion is cancelled and a contract cargo style is proposed for a lunar lander with an APAS for the commercial spaceships.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Lar on 07/22/2017 05:51 pm
(fan)
Change my mind? The MIC deciding, out of the goodness of their heart, to refund 90% of what was spent on SLS/Orion.

That's not happening, so...

(mod)
I wonder how long this topic will last before going off the rails completely. (yeah, my fan post didn't help.) No I'm not starting a poll ,l but let's see if you all can surprise me...
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: butters on 07/22/2017 06:30 pm
I'll support SLS when the commercial launch companies decide, "You know what? Developing large reusable launch vehicles is a silly idea. Instead, let's develop planetary science hardware and launch it on SLS."

Odds of that happening: approximately zero.

Orion has a very specific use-case and certainly isn't the most cost-effective potential solution for this application. But if we're genuinely going to have a cislunar gateway architecture, then it's hard to deny that Orion is the superior cislunar passenger shuttle as compared to Dragon. Mini BFS hasn't fully taken shape yet, so it's hard to say whether there are any near-term commercial alternatives to Orion in a cislunar passenger transport role. For the moment.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: DarkenedOne on 07/22/2017 06:54 pm
I think most of the posters here did not read the OP very carefully.  He said "if you think the Orion/SLS is a good idea."  Most of the posters seem to believe Orion/SLS is a bad idea, and are describing what it would take to change their minds.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Ictogan on 07/22/2017 07:01 pm
I think most of the posters here did not read the OP very carefully.  He said "if you think the Orion/SLS is a good idea."  Most of the posters seem to believe Orion/SLS is a bad idea, and are describing what it would take to change their minds.
If you think the Orion/SLS is a good idea, what new information would make you change your mind?

Same question for those opposed to Orion/SLS.

Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Endeavour_01 on 07/23/2017 06:09 pm
I am also an SLS/Orion supporter. What new information could change my mind?

1. Massive increase in costs or delays. (e.g. double what they cost now, delay of EM-1 to 2024)

2. Appearance of reliable commercial rocket/spacecraft that can do all SLS/Orion can do. (e.g. same or greater payload capacity than SLS/BEO capable capsule with same or greater delta-V than Orion)

3. Cancellation of SLS/Orion would not remove their budget from NASA. (i.e. Congress would agree to fund something else NASA related instead of just pulling the SLS/Orion funding completely)
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: spacenut on 07/23/2017 07:21 pm
I have a hard time supporting SLS due to my taxpaying cost.  NASA could have developed the AR-1 or in house building of the RD-180 and built a large expendable kerolox booster that would be Nova class at 12 million lbs thrust and could get 175 -200 tons of usefull payload to LEO vs the same amount of money spent on SLS to only get 100 tons to LEO.  Makes no sense.  They could also have built a Nautilus X type exploration vehicle for beyond earth orbit using existing launchers and assembling in space for the same amount spent on SLS. 

Face it, solids are very heavy and expensive for the amount of payloads to LEO they can get.  Yes they are very reliable, but so has Atlas V with RD-180 has been at the time this all began. 

Another option that was discarded but we would still be flying is sidemount for cargo and kept the shuttle flying.  Then later adding 5.5m 3 RD-180 engine boosters to replace the solids for even greater payloads. 
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Steven Pietrobon on 07/24/2017 08:03 am
I have a hard time supporting SLS due to my taxpaying cost.

According to link below, the average US taxpayer paid $14,654 tax per year in 2015. SLS/Orion/GSDO budget in 2015 was $3.2115B out of $1,454B. That works out to $32.37 tax for SLS/Orion/GSDO the average US taxpayer paid in the entire year! That will only buy you about one cup of coffee every six weeks. I wouldn't worry about how much SLS is costing. Now just imagine what NASA could do with one cup of coffee a week!

https://www.fool.com/retirement/2017/03/04/whats-the-average-americans-tax-rate.aspx

As to what would make me change my mind? That would be an ITS-16 or New Armstrong sitting on the pad.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: yokem55 on 07/25/2017 09:33 pm
1) Realistically flying SLS 4 times a year at $500 million/flight.
2) Competitively contracting the advanced boosters at a fixed price.
3) Switching the EUS for a more quickly developed ACES.
4) A SMART style reuse plan for the core's engine bay.

Obviously there need to be payloads to justify all this, but these items would go a long way to making SLS worth it.

As for Orion? Take 1/10th the money and figure out how to put the ESA's service module on a dragon or a starliner.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: MATTBLAK on 07/25/2017 10:43 pm
They would have to change it and spend a lot more money on it to satisfy my 'vision' of it - so it would probably be a lost cause. But anyway:

If they are going to throw away that much magnificent hardware each time - maximize and optimize it...

1): Hydrocarbon, reusable, 'flyback' booster powered by F-1Bs or AR1s. These would land at the KCS Shuttle landing facility runway. I know that such boosters were looked at in the Shuttle era; pre-'Columbia'.
2): Increase the corestage RS25E engine quantity to 5 or 6x engines.
3): Upper stage upgrade to a 'stretched' ACES technology stage - long life cryo ability, new, higher-thrust engines than RL-10. Such a stage, coupled with 'high thrust' SEP technology would give significant solar system transport ability. An SLS improved to this level could get about 150 metric tons into Low Earth Orbit in one shot. Enough for single-launch Manned Lunar Missions - 'Apollo On Steroids'. But able to conduct 2-week surface stay missions for a crew of four.

And with an ability to launch 4 or 5x per year, this could allow 2x manned and 3x cargo missions to the Moon per year - or 3x manned and 2x cargo missions per annum. Good enough for long stay Lunar Outpost missions.

And Orion: increase the Service Module propellant quantity to something a lot better than a mere 9 tons, and improve the spacecraft's heatshield to where it could withstand direct, high-speed entry from deep space - such as from Mars. Also, improve it's deep space lifetime to something like three years. Orion may not ever have to go all the way to Mars and back; but in some mission architectures, it might have to. It would function as a Command & Control Module for a Mission Module stack and provide return to Earth duties.

However - all the above improvements would be expensive and not trivial. And the coming New Glenn boosters and SpaceX's 9-meter diameter version of the ITS may make most of the above somewhat obsolete. But this remains to be seen, for some time to come.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: redliox on 07/25/2017 11:11 pm
My mind, as is, is split in half regarding SLS/Orion...

I support the SLS fully, but the Orion I loathe.  Once SpaceX, Blue Origins, etcetera has an equivalent-or-better rocket up and running, of course look into phasing out the SLS.  The SLS was conceived based on the needs of both Mars and Luna enthusiasts, which was the need for a Heavy Lift Vehicle that could be cobbled together (reasonably [which is extraordinarily subjective when you're talking government]) quickly.  The Orion was meant to be a beefier version of the Apollo orbiter.  Both items were dreamed up with good intentions in mind...

Of the 2, Orion is the more lackluster.  But to stay on topic, what it would take to change my mind about it would be a heavy revision of its service module, which ESA seems to be less and less capable of producing (and more so likewise for Lockheed Martin which should have handled it).  The weight problems originally from the Ares I should be wiped clean; restart from an SLS base with the goal of keeping Orion in CisLunar space and capable of reaching essentially 'Medium Lunar Orbit', i.e. anything between NRO and the various elliptical orbits with some utility.

For the moment, NASA seems on a path to revisiting Lunar orbit including with a space station.  I favor the Mars path more, and I believe the SLS could do either.  Orion, on the other hand, is clearly Moon-bound.  Perhaps a Martian and Lunar program could exist simultaneously, just not easily or at current funding.

But in short, I'd say junk the Block I mission, junk the ESA service module, switch directly to Block IB, and cobble together a stronger (and of course all-American) service module if you wish me to have better opinions on both SLS and Orion.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Semmel on 07/26/2017 09:10 am
An interesting view on the topic from Ars Technica:

Quote
One of the SLS critics whom I most highly regard, and who is deeply plugged into Washington space policy and favors commercial space, has rationalized the rocket and Orion like this. While NASA will spend in excess of $3 billion a year for the foreseeable future on “pork” like the rocket and spacecraft, it now also spends $2 billion to $3 billion a year on commercial crew and cargo. That money goes to SpaceX and other companies that push forward more economical means of space transportation. My source views the agency’s payments on SLS and Orion as a “stupidity tax” that allows “good money” to be spent on commercial space.

https://arstechnica.com/science/2016/09/how-i-learned-to-stop-worrying-and-love-the-big-nasa-rocket/

(go to page 4 for the quote)

I dont necessarily agree with the assessment, but calling the SLS a stupidity tax on NASA so that it can do cool stuff is one way to not loose your mind when viewing the influence of Congress on NASA.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: jgoldader on 07/26/2017 12:17 pm
This is probably OT, but...

Having just read a comment about SLS on another website, I feel compelled to interrupt this argument to say how much I appreciate the owners and community here at NSF.com.

NSF plays things straight down the middle; it's as unbiased a news source as I've ever seen.  No one program, company, or country is cheered or jeered at the expense of any others.  If you show me an article that's "pro-SpaceX," I can point to one that's "pro-Orbital ATK," or "pro-ULA," or whatever.  If the place has a bias, it's simply one in favor of the peaceful exploration and use of space.

At the same time, we're all free to share our knowledge and express our opinions, whatever they may be, in these forums.  By and large, we even behave.  I like to believe that's because there's a lot of respect here for the folks who get things done in space (some of whom are frequent commenters).

While we might not all be of the same opinion about SLS, we are at least mostly able to disagree respectfully.  For my part, while I might not think the program is a good use of scarce funds, and I've said so, I sure hope that when it flies, it achieves a 100% mission success rate, and that the people who worked on it can look back on a job well done.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Lar on 07/26/2017 03:23 pm
This is probably OT, but...

Definitely off topic! But can't bring myself to delete it for some reason, LOL (even before I noticed that the Boss Man liked it)  We try. This particular thread just had a lot of cleanup because it was starting to descend into the usual general political stuff.. hopefully all sorted now.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Semmel on 07/26/2017 03:45 pm
At the same time, we're all free to share our knowledge and express our opinions, whatever they may be, in these forums.  By and large, we even behave.  I like to believe that's because there's a lot of respect here for the folks who get things done in space (some of whom are frequent commenters).

I dont run this place, so I am just a regular forum user. But I also appreciate this site a great deal. A news source without an agenda is very rare these days ( or I am just getting older and notice the agendas more ). But even harder is it to have a conversation which does not drift into one or multiple extreme corners of opinion. Especially on topics like SLS, its pretty easy to fall into the trap of making extreme opinionated statements. This has not happened so far in this thread (much to my surprise tbh.) The mods do a good job of limiting this but also most forum members do the same. I certainly do my best but not always with success.

Take for instance the opening question of this thread. Its the scientific approach. Ask what type of information could invalidate your current view on something. Thats EXACTLY what scientists are doing all the time. Thinking hard to find ways to prove them self wrong (at lest the good ones do that). And knowingly or not, this question steered the community in this forum to find responses to SLS that are more positively phrased than anything else I have read so far on the topic of SLS in this forum. I love it for that.

And to put at least some little on-topic information on this: If SLS gets funded adequately to DO useful things with SLS that could not be done with any commercial rocket, I will become pro-SLS. As long as such a program does not exist, SLS has no reason to exist. But I dont shed a tear about the money it costs. Thats put back into the society and is not lost. What we do loose with SLS (if it does not become useful) however is time of talented people. That time is not coming back and if SLS ends as it started: as a jobs program, we have lost all this talent for nothing. We could have used it for things like designing and building surface habitats on the Moon and Mars and let the industry figure out the launcher problem. Would have been a similar jobs program but without the wasted talent.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Kansan52 on 07/26/2017 04:06 pm
This reminds me of a Facebook argument a college buddy and I had over the Ares I and Ares V cancellations. He convinced me that it doesn't matter what vehicle is used, I (like most here) care about the destination.

Going beyond LEO interests me. SLS making that possible interests me. So, no change of mind.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Stan-1967 on 07/26/2017 04:27 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.  

The purpose of SLS as a vehicle of government pork distribution & vote buying negates it's ability to actually accomplish anything.  It  hamstrings the NASA budget agains the fiscal realities of overall space spending.  Irregardless of how little a fraction of overall government spending NASA represents, there are too many competing interests to ever expect NASA's budget to be able to utilize SLS.  If anything, NASA's budget will go down over time.

I would change my mind if I saw SLS realigned into a more vertical program managed by a single entity that is free to manage the program for cost & performance.   I'd really get behind SLS ( Senate Launch System) if "SLS" could be divorced from the hardware, and have "SLS" be the government contracted program to award heavy lift to the most qualified USA based entrant.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: spacenut on 07/27/2017 02:00 am
Someone told me at work, the way the government works today.  That, if we had to fight WWII again, we would loose.  It would take too long to produce anything. 

Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Proponent on 07/27/2017 07:45 am
I don't see anything that will change my mind about this program for years to come.

Do you mean you don't expect anything to change your mind about it, or that there is nothing, even events you regard as unlikely, that could change your mind?
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: deltaV on 07/27/2017 01:59 pm
I currently oppose SLS and Orion.

I would support SLS if (i) NASA gets a big budget increase and (ii) it remains the case that no commercial launch vehicle is available that can launch 40+ tonnes to LEO with 8+ meter diameter payload fairings. (Falcon Heavy presumably can't handle that diameter. New Glenn and ITS could presumably meet both requirements.)

I would support Orion if (i) NASA gets a big budget increase and (ii) Orion has capabilities that couldn't be more cost effectively provided by a commercial capsule or by whatever the capsule is docking with. A moon capsule is better suited to cislunar space than Mars so the recent switch to cislunar destinations should help somewhat.

I do not expect the funding part to happen unless another country starts doing significant things in space that the US hasn't already done.

Title: Re: What would it take to change your mind on SLS/Orion?
Post by: spacenut on 07/27/2017 02:12 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. 
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Jim on 07/27/2017 02:14 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. 

So would be the vehicle you describe
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: RonM on 07/27/2017 02:22 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. 

So would be the vehicle you describe

Theoretically, reusable rockets are cheaper if they fly often, but SLS will only fly once or twice a year. A reusable version of SLS would be more expensive to develop than the current design and would never fly enough to justify the cost.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: GWH on 07/27/2017 05:11 pm
I would support SLS + Orion if the fixed costs didn't consume such a large percentage of the exploration budget for such a limited project flight rate and hardware put into space. It just doesn't make sense to me to have such a large infrastructure solely to fly such a limited average mass per year.  Especially not when commercial offerings that are coming online the same time as SLS are just as capable for their current architecture. If SLS were launching sooner so it could more adequately act as a bridge to these capabilities this point would be lessened.
 
Possible solutions:
- If were another user other than NASA for their human spaceflight (in)ambitions and occasional probe. Be this Military, other space programs or commercial.
- Pull the funding from somewhere else, like state budgets where the jobs are situated - not a realistic solution.
- Increase NASA's budget so more missions can be flown.

The other major detractor for me is with the current deep space gateway plans they are flying combined payloads that can be or extremely close to being within capacity of being broken out into separate smaller launches with the heavy lift commercial vehicles coming on to the market.  The universal stage adapter is largely dead weight for these co-manifested payloads, handicapping the single launch capability of SLS/Orion. The cost of a COTS tug (such as Cygnus bus) for the individual modules should be proven out to determine the value there.
 
The Deep Space Transport on the other hand makes sense to me, as it fully utilizes the capability of SLS with one very large and expensive payload within a single launch that can't be flow be others (excluding a large fairing variant of Vulcan with distributed lift).

The mass of Orion is very limiting to mission architectures, although if in orbit refueling of stages was developed I would be supportive of it.  That way more ambitious missions could be undertaken, and the utility of using Orion as a lifeboat to build a large gateway could be completed faster.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: envy887 on 07/27/2017 05:34 pm
I would support SLS if it wasn't required to use existing Shuttle contracts and contractors, developed some modern restartable/throttleable propulsion, and had a plausible progression path towards full and efficient reusability.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Req on 08/09/2017 07:24 pm
I would support SLS if it was called Ares V and it was landing an Altair on the moon in 2019.  SLS has been lost since the moment it was called SLS, if not long before.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: spacenut on 08/09/2017 07:55 pm
I wish they would take the money spent on SLS and give some to SpaceX, Blue Origin, ULA, and Orbital/ATK. 

Money for SpaceX would go to completing Dragon II, Raptor, and developing BFR/ITS.

Money for Blue would go to developing New Glenn and BE-4.

Money for ULA would go to completing Vulcan and ACES.

Money for Orbital/ATK would go to the solid launch vehicle development as a competitive standby, and maybe a cheaper version of RL-10 and an RL-60. 

Then after the above items are complete, use the money for deep space infrastructure such as fuel depots, moon base, L1 lunar station, and Mars colony. 

I know hind sight is 20-20, but with a reusable ITS, New Glenn, and partially reusable Vulcan.  We would have the launch vehicles for almost any space infrastructure or goal.  With the RL-10 and RL-60, larger deep space probes and robotic equipment can be taken further into space. 
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Proponent on 08/09/2017 10:14 pm
Many of us have views pro or con on SLS, but may I remind all that the point of this thread is for us to examine our assumptions.  What new information would lead you to change your view?
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Avron on 08/09/2017 10:47 pm
If we did not live in a world that was changing rapidly on the launch front, e.g. competition - real competition - new engines from new players - re-flyable - flight proven stages  etc..

Then if the SLS could get a human back onto  the moon in by mid decade ahead of the competition (including China), then I may change my mind - right now its just more of the same and incredible waste of a golden opportunity and talent - I will stop there.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: meberbs on 08/09/2017 11:16 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. 

So would be the vehicle you describe

Theoretically, reusable rockets are cheaper if they fly often, but SLS will only fly once or twice a year. A reusable version of SLS would be more expensive to develop than the current design and would never fly enough to justify the cost.

#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.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: muomega0 on 08/09/2017 11:19 pm
Simply stated: its total costs are less over two decades than the alternatives and, per the original shuttle design goal, a focus on reuse.

Faget: We really need to get behind a really sensible first stage that's completely reusable and piggyback off of that event [till] you get the capability to have a two-stage reusable vehicle. (http://forum.nasaspaceflight.com/index.php?topic=42544.msg1661083#msg1661083)

Slade: That you could reuse over and over again and get it back.

IOW:  It is not, and always was not, *practical* to continue shuttle derived since its 2000s cancellation.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: brickmack on 08/10/2017 09:31 pm
This big issue for me is the achievable flight rate. Right now, even with infinite money, SLS can't be flown more than twice a year, 4 times total before 2027, and with a ~3 year gap between EM-1 and 2. You simply can't do a worthwhile program at that flightrate without major support from other LVs, and at that point why bother with SLS? And the 2 big issues causing that are the upper stage size change, and the expendable RS-25s which take forever to build. Cut the engine section off the aft end of the core stage, stick a heat shield in between, parachute it back down like the sidemount HLV or pre-merger Boeing EELV concepts. Side benefit, you save ~200-300 million dollars in hardware costs per flight, not bad there either. And either keep the iCPS, or use an upgrade path that doesn't change its external interfaces (ACES is about the same size I'd note, and should give a decent performance boost, though not as huge as EUS), or cancel iCPS entirely and start converting the ML for EUS now.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: edkyle99 on 08/11/2017 12:49 am
This big issue for me is the achievable flight rate. Right now, even with infinite money, SLS can't be flown more than twice a year, 4 times total before 2027, and with a ~3 year gap between EM-1 and 2. You simply can't do a worthwhile program at that flightrate without major support from other LVs, and at that point why bother with SLS?
I don't understand this desire for lots of launches.  SLS will be a super-heavy-hauler, each launch flinging a serious load beyond LEO (seven Falcon Heavies-worth).  A good program could be designed around this low flight rate which, as I understand things, will likely settle at 1-2 per year.  Saturn V only flew once or twice per year, with the exception of 1969.  There are active launch vehicle families even today that fly only once or twice per year. 

 - Ed Kyle
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: brickmack on 08/11/2017 02:10 am
I don't understand this desire for lots of launches.  SLS will be a super-heavy-hauler, each launch flinging a serious load beyond LEO (seven Falcon Heavies-worth).  A good program could be designed around this low flight rate which, as I understand things, will likely settle at 1-2 per year.  Saturn V only flew once or twice per year, with the exception of 1969.  There are active launch vehicle families even today that fly only once or twice per year.

No idea where you got 7 FHs worth. FH expendable can send ~19 tons to TLI, block 2 can do a little over 2 FH equivalent missions. And since almost all of those are comanifested with Orions (and at this flight rate, cargo-only missions aren't an attractive option since thats a year without a crew mission, unless you use Dragon or something, and then why have Orion at all?), you can't actually do much. 6-10 tons to high cislunar orbit, thats not very much to work with (single ISS logistics flights require more total mass). You can't build a useful station that way without on-orbit outfitting, you can't bring a lunar lander. Saturn V was big enough (and the Apollo CSM was properly sized to support, unlike Orion) to do a single-launch lunar landing, and that was all it needed to do.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: edkyle99 on 08/11/2017 03:28 am
I don't understand this desire for lots of launches.  SLS will be a super-heavy-hauler, each launch flinging a serious load beyond LEO (seven Falcon Heavies-worth).  A good program could be designed around this low flight rate which, as I understand things, will likely settle at 1-2 per year.  Saturn V only flew once or twice per year, with the exception of 1969.  There are active launch vehicle families even today that fly only once or twice per year.

No idea where you got 7 FHs worth.
https://forum.nasaspaceflight.com/index.php?topic=43073.msg1690830#msg1690830

SpaceX isn't planning to expend Falcon Heavy cores as a standard operation.  If it is, then why all the talk about how Falcon is better than, say, Vulcan because it "recoverable"?

 - Ed Kyle
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: tdperk on 08/11/2017 01:27 pm
I don't understand this desire for lots of launches.

10 FH launches in a year lift about 540 tons to LEO for at most $1.5bn in price (at the outside) for what I believe Musk said was $1bn in R&D cost.

SLS has far higher R&D cost and for $1.5bn in a year lifts only 120 tons when available in block 2, which it isn't yet.  The R&D and per year and per vehicle cost of SLS is so high there is very little left over for hardware for it to lift.

The "lots of launches" means there can be money for hardware.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: tdperk on 08/11/2017 01:32 pm
This reminds me of a Facebook argument a college buddy and I had over the Ares I and Ares V cancellations. He convinced me that it doesn't matter what vehicle is used, I (like most here) care about the destination.

Going beyond LEO interests me. SLS making that possible interests me. So, no change of mind.

SLS makes it impossible, because cost.

A heavy lift vehicle which is close enough to refuel to reuse makes it not merely possible, but plausible, at a cost less than $1000/lb to LEO.  For now that's the FH.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: edkyle99 on 08/11/2017 01:44 pm
I don't understand this desire for lots of launches.

10 FH launches in a year lift about 540 tons to LEO for at most $1.5bn in price (at the outside) for what I believe Musk said was $1bn in R&D cost.
LEO is not the destination.  You are projecting an expendable Falcon Heavy here, which means expending 30 core stages. 

It cost $1 billion just to develop Falcon 9 first stage recovery, according to Mr. Musk.  I can only image what Falcon Heavy is costing, with its many-year delays and completely re-engineered core stage, etc. 

 - Ed Kyle
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: tdperk on 08/11/2017 02:19 pm
I don't understand this desire for lots of launches.

10 FH launches in a year lift about 540 tons to LEO for at most $1.5bn in price (at the outside) for what I believe Musk said was $1bn in R&D cost.
LEO is not the destination.  You are projecting an expendable Falcon Heavy here, which means expending 30 core stages. 

It cost $1 billion just to develop Falcon 9 first stage recovery, according to Mr. Musk.  I can only image what Falcon Heavy is costing, with its many-year delays and completely re-engineered core stage, etc. 

 - Ed Kyle

No.  10 launches in one year will expend the lifecycle as currently anticipated in none year, but the FH expendable capacity is 70+ tons to LEO.  50 tons or so is a recoverable launch profile.

There is no reason to think the development cost is higher than the 1 billion Musk spoke of, yu can imagine whatever BS you like.

LEO is the destination from which any other system can continue from with no notable penalty.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Ictogan on 08/11/2017 02:55 pm
I don't understand this desire for lots of launches.

10 FH launches in a year lift about 540 tons to LEO for at most $1.5bn in price (at the outside) for what I believe Musk said was $1bn in R&D cost.
LEO is not the destination.  You are projecting an expendable Falcon Heavy here, which means expending 30 core stages. 

It cost $1 billion just to develop Falcon 9 first stage recovery, according to Mr. Musk.  I can only image what Falcon Heavy is costing, with its many-year delays and completely re-engineered core stage, etc. 

 - Ed Kyle

No.  10 launches in one year will expend the lifecycle as currently anticipated in none year, but the FH expendable capacity is 70+ tons to LEO.  50 tons or so is a recoverable launch profile.

There is no reason to think the development cost is higher than the 1 billion Musk spoke of, yu can imagine whatever BS you like.

LEO is the destination from which any other system can continue from with no notable penalty.
Do you have any source on those numbers? Because SpaceX sure doesn't claim FH's capability to be 70+ tons. http://www.spacex.com/falcon-heavy
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: tdperk on 08/11/2017 03:05 pm
 
I don't understand this desire for lots of launches.

10 FH launches in a year lift about 540 tons to LEO for at most $1.5bn in price (at the outside) for what I believe Musk said was $1bn in R&D cost.
LEO is not the destination.  You are projecting an expendable Falcon Heavy here, which means expending 30 core stages. 

It cost $1 billion just to develop Falcon 9 first stage recovery, according to Mr. Musk.  I can only image what Falcon Heavy is costing, with its many-year delays and completely re-engineered core stage, etc. 

 - Ed Kyle

No.  10 launches in one year will expend the lifecycle as currently anticipated in none year, but the FH expendable capacity is 70+ tons to LEO.  50 tons or so is a recoverable launch profile.

There is no reason to think the development cost is higher than the 1 billion Musk spoke of, yu can imagine whatever BS you like.

LEO is the destination from which any other system can continue from with no notable penalty.
Do you have any source on those numbers? Because SpaceX sure doesn't claim FH's capability to be 70+ tons. http://www.spacex.com/falcon-heavy

SpaceX says the FH capacity to LEO expendable is 140660 pounds.  I'm quoting them.  That is 70+ tons.

http://www.spacex.com/falcon-heavy

I do not believe this includes all Block5 payload enhancements, so I believe that figure will grow at least a little.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Ictogan on 08/11/2017 03:13 pm
SpaceX says the FH capacity to LEO expendable is 140660 pounds.  I'm quoting them.  That is 70+ tons.

http://www.spacex.com/falcon-heavy

I do not believe this includes all Block5 payload enhancements, so I believe that figure will grow at least a little.
http://www.rapidtables.com/convert/weight/pound-to-ton.htm
Please enter 140660 into this.

Edit: kinda forgot that short tons exist, sorry. But unlike metric tons I have never seen them used in a spaceflight context.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Coastal Ron on 08/11/2017 03:50 pm
SpaceX says the FH capacity to LEO expendable is 140660 pounds.  I'm quoting them.  That is 70+ tons.

This is seriously OT, but I wanted to try to suggest some consistency when talking about capabilities.

I think it's safe to say that most people know that to figure out "tons" (aka "short ton") you just divide "pounds" by 2,000. But in general when people in space related topics talk "tons", they are meaning "metric tonnes", which is equal to 2,204.6 pounds.

Why convert everything to metric? Because the U.S. is not the only nation in space, so it's less confusing to just convert everything into metric. So for Falcon Heavy the 140,660 pounds to LEO becomes 63.8 metric tonnes. Saying "70+ tons" is just adding a layer of confusion.

As a note, the Senate was not very clear on the definition of "ton" when they legislated the requirements for the SLS, so that meant NASA had to interpret the technical specifications for Congress.

Quote
I do not believe this includes all Block5 payload enhancements, so I believe that figure will grow at least a little.

Maybe, maybe not. SpaceX has tended to under-state capabilities while over-stating when they would be available. However since there are no customers demanding more than what current commercial launchers can loft to space, any additional capabilities SpaceX adds to Falcon Heavy will be of interest, but likely not of use for anyone in the near term. Just bragging rights.

My $0.02
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Rocket Science on 08/11/2017 04:04 pm
If the Congress wanted it in SI standard they should write it as tonne... Just sayin'...
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: edkyle99 on 08/11/2017 04:11 pm
SpaceX says the FH capacity to LEO expendable is 140660 pounds.  I'm quoting them.  That is 70+ tons.
This is seriously OT, but I wanted to try to suggest some consistency when talking about capabilities.
Agreed on the metric tons standard.  Also, I would like to suggest that when talking about SLS we compare the real payload numbers, which are NOT to LEO, as we discussed here:   https://forum.nasaspaceflight.com/index.php?topic=43073.msg1690830#msg1690830 


==============================================================
Vehicle          1st Flt   TransLunar   TransMars      GTO   
==============================================================
Falcon 9 Blk 5     2017?    ~3,000 kg?   ~2,500 kg?   5,500 kg
Falcon 9 Blk 5-X   2017?    ~5,500 kg     4,020 kg    8,300 kg
Falcon Heavy       2018?    ~5,500 kg    ~4,900 kg    8,000 kg
Falcon Heavy-X     2018?   ~20,500 kg    16,800 kg   26,700 kg
SLS Blk 1          2019?    24,500 kg    19,500 kg      N/A
Vulcan Centaur 56x 2019?    ~8,300 kg    ~6,200 kg   10,200 kg
New Glenn 2 Stg    2020?    ~7,500 kg?   ~3,000 kg?  13,000 kg
NGL-5xx            2021?    ~6,000 kg    ~4,700 kg    8,500 kg
SLS Blk 1B         2021?    39,000 kg    32,000 kg      N/A
Vulcan ACES 56x    2023?    14,000 kg    10,500 kg   17,200 kg
NGL-5xx-XL         2023?   ~10,300 kg    ~8,200 kg?  14,700 kg
New Glenn 3 Stg    2025?   ~25,000 kg?  ~20,000 kg? ~30,000 kg?
SLS Blk 2          2028?   >45,000 kg   >37,600 kg      N/A
==============================================================
"X" Denotes Expendable Version

Updated 06-16-17



 - Ed Kyle
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: tdperk on 08/11/2017 04:25 pm
I would like to point out that comparing the SLS BLock 2 to payload to LEO in short tons to the FH makes then this a comparison for like per $1.5bn year cost of 130+ to 500+ tons.

And yes, payload to LEO is the proper comparison, because most payloads go there, and all can be designed to depart from there to any destination with no relevant* loss in mission capabilities.

*I suppose it is reasonable to presume employing LEO orbital docking might cost 2 to 5% of the mass of an other wise unitary structure if launched by 1 SLS at max capacity.  So three reusable FH launches gets 150 tons into LEO, and 7.5 tons of that are lost to the capability to dock in LEO and depart from there.  At most this costs $750mn for the launches.  At most.  For 142.5 tons towards the mission goals, all launches completed within 4 months.

The SLS at a cost of at least $1.5bn only puts 120tons towards the mission  These costs presume 1bn year in fixed SLS costs and $500mn per launch.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Hauerg on 08/11/2017 04:38 pm
1. see it fly
2. a few times, that is
3. see PRODUCTION run of NEW RS25
4. see the budget for real SLS class payloads.
5. there is no 5
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: mike robel on 08/11/2017 04:46 pm
I don't understand this desire for lots of launches.

10 FH launches in a year lift about 540 tons to LEO for at most $1.5bn in price (at the outside) for what I believe Musk said was $1bn in R&D cost.

SLS has far higher R&D cost and for $1.5bn in a year lifts only 120 tons when available in block 2, which it isn't yet.  The R&D and per year and per vehicle cost of SLS is so high there is very little left over for hardware for it to lift.

The "lots of launches" means there can be money for hardware.

I note you append "not yet" to the description of the SLS but do not do so for the FH, which is also in the category of "not yet" although it is closer to flight.  Even Musk semi-expects it to blow up, hopefully far enough away form 39 so as not to damage it.  If it does, then "not yet" will be "a while longer".
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: tdperk on 08/11/2017 04:49 pm
I don't understand this desire for lots of launches.

10 FH launches in a year lift about 540 tons to LEO for at most $1.5bn in price (at the outside) for what I believe Musk said was $1bn in R&D cost.

SLS has far higher R&D cost and for $1.5bn in a year lifts only 120 tons when available in block 2, which it isn't yet.  The R&D and per year and per vehicle cost of SLS is so high there is very little left over for hardware for it to lift.

The "lots of launches" means there can be money for hardware.

I note you append "not yet" to the description of the SLS but do not do so for the FH, which is also in the category of "not yet" although it is closer to flight.  Even Musk semi-expects it to blow up, hopefully far enough away form 39 so as not to damage it.  If it does, then "not yet" will be "a while longer".

I know the FH will fly.  Even if it blows up there is no reason to doubt it will fly successfully by mid-year next--SpaceX has no history of uselessly long waits to RTF from losses.

There is good reason to doubt the SLS will fly even once--we are one likely economic downturn away from the useless cost of it being seen as unendurable.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: edkyle99 on 08/11/2017 05:09 pm
And yes, payload to LEO is the proper comparison, because most payloads go there, and all can be designed to depart from there to any destination with no relevant* loss in mission capabilities. 
SLS Block 1B is being designed to boost 32 metric tons (tonnes) trans-Mars.  Falcon Heavy Expendable is expected to lift 16.8 tonnes trans-Mars.  Falcon Heavy "recoverable" (first stage and boosters) would only lift about 4.9 tonnes trans-Mars.  These - or similar numbers to points beyond LEO - are the valid comparisons.  NASA has talked about starting with a Deep Space Gateway - not a LEO Gateway.

 The LEO-rendezvous Falcon Heavy alternative that you propose would require a new deep-space stage, a propellant depot setup, lots of LEO parking and propellant transfer capability that doesn't exist, etc. just to package a mission to the Deep Space Gateway - all of which would cost lots of cash.  SLS is being designed to go straight to the Gateway. 

Much of the LEO mass capability of a Falcon Heavy would be lost to "tare weight", propellant boiloff, parking orbit RCS propellant, etc.  Only about 60% of the liftoff weight of an HTV, for example, is actual cargo.

 - Ed Kyle
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: tdperk on 08/11/2017 05:19 pm
And yes, payload to LEO is the proper comparison, because most payloads go there, and all can be designed to depart from there to any destination with no relevant* loss in mission capabilities.
SLS Block 1B is being designed to boost 32 metric tons (tonnes) trans-Mars.  Falcon Heavy Expendable is expected to lift 16.8 tonnes trans-Mars.  These - or similar numbers to points beyond LEO - are the valid comparisons.

 The LEO-rendezvous Falcon Heavy alternative that you propose would require a new deep-space stage, a propellant depot setup, lots of LEO parking capability that doesn't exist, etc. - all of which would cost lots of cash.  Much of the LEO mass capability of a Falcon Heavy would be lost to "tare weight", propellant boiloff, parking orbit RCS propellant, etc.  Only about 60% of the liftoff weight of an HTV, for example, is actual cargo.

 - Ed Kyle

No, we are discussing travel in space.  The proper figure of merit is dV/lb/$, with the constraint the total dV is high enough.

"  The LEO-rendezvous Falcon ... is actual cargo. "  <--  Nothing you have said here is true and relevant, as you presume the use of non-optimal architectures which are easily avoided.  For that matter, even if your presumptions were true AND relevant, they'd have to amount to more than 11 tons to be to the good of the SLS in comparison solely on the basis of mass.

For example, I was quite pessimistic in allowing 4 months for the three FH launches.  SpaceX will within a few years have two pads built allowing FH launches.  With their already demonstrated turnaround time, the mission being thought of could be launched within a span of two weeks, with the minimal boiloff of a few hours time before departure for destination.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: edkyle99 on 08/11/2017 06:23 pm
"  The LEO-rendezvous Falcon ... is actual cargo. "  <--  Nothing you have said here is true and relevant, as you presume the use of non-optimal architectures which are easily avoided. 
What is the "optimal" alternative architecture?  How much does the currently non-existing hardware needed to make it work cost to develop, build, and fly?

 - Ed Kyle
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: tdperk on 08/11/2017 06:49 pm
"  The LEO-rendezvous Falcon ... is actual cargo. "  <--  Nothing you have said here is true and relevant, as you presume the use of non-optimal architectures which are easily avoided. 
What is the "optimal" alternative architecture?

The one that gets the job done for the least $.

 
How much does the currently non-existing hardware needed to make it work cost to develop, build, and fly?

Dunno, but if the 130+ tons one SLS will lift are instead lifted with FH's, you get up to $750mn saved from the Atlantic to work with.

And the TMI for an FH reusable is about 11.7 long tons to go by past history (I don't know where you are getting 4,900kg from), so you get to keep the rockets.  I'm generously (to ULA) calling the per launch FH cost to be $250mn per, where the quoted cost is $90mn.  I'm also generously presuming SLS costs don't rise further.

SpaceX now states the FH expendable payload to Mars is 16,800kg and the payload for reusables has generally been 70% of expendable.  Even if reusable launch payload drops to 60% of expendable and the price is that unrealistically high $250mn per, the FH still beats the SLS.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Ictogan on 08/11/2017 07:00 pm

Dunno, but if the 130+ tons one SLS will lift are instead lifted with FH's, you get up to $750mn saved from the Atlantic to work with.

And the TMI for an FH reusable is about 11.7 long tons to go by past history (I don't know where you are getting 4,900kg from), so you get to keep the rockets.  I'm generously (to ULA) calling the per launch FH cost to be $250mn per, where the quoted cost is $90mn.

A deep space tug/stage is required anyway.
SpaceX quotes the FH at than $90m up to 8000kg to GTO (http://www.spacex.com/about/capabilities), suggesting that that is the cutoff point for triple core landings. Given that that is roughly the same as expendable F9, a similar TMI capacity as expendable F9 should be expected - F9 can do 4,020kg to TMI. So why do you think it can do 11.7 long tons?
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: tdperk on 08/11/2017 07:29 pm

Dunno, but if the 130+ tons one SLS will lift are instead lifted with FH's, you get up to $750mn saved from the Atlantic to work with.

And the TMI for an FH reusable is about 11.7 long tons to go by past history (I don't know where you are getting 4,900kg from), so you get to keep the rockets.  I'm generously (to ULA) calling the per launch FH cost to be $250mn per, where the quoted cost is $90mn.

A deep space tug/stage is required anyway.
SpaceX quotes the FH at than $90m up to 8000kg to GTO (http://www.spacex.com/about/capabilities), suggesting that that is the cutoff point for triple core landings. Given that that is roughly the same as expendable F9, a similar TMI capacity as expendable F9 should be expected - F9 can do 4,020kg to TMI. So why do you think it can do 11.7 long tons?

(16,800kg to Mars expendable X 0.7 for reusability X 2.2 for kg to lbs conversion) / 2204 for pounds to long tons =~ 11.7

You seem to be presuming the all up Block 5 builds will have the same lower max velocity limits for return ability the current stages do.  Even if they do, it is at most about 40% of the vehicle cost being expended, since the side cores are certainly returnable.

I actually expect SpaceX will be successful at recovering all stages for the F9 and FH in the next several years.  There may well be for TMI and GTO, no practical way to recover the 2nd stage for most launch profiles of interest.  For TLI, a once around free return should be easy to arrange for almost every launch.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: ehb on 08/11/2017 09:57 pm
(16,800kg to Mars expendable X 0.7 for reusability X 2.2 for kg to lbs conversion) / 2204 for pounds to long tons =~ 11.7

From (ugh) https://en.wikipedia.org/wiki/Ton

British [long] ton is 2240 lbs
US [short] ton is 2000 lbs
Metric (seems to be the primary measure used for rocket capabilities) ton [tonne, t (SI), MT (sic)] is 2204.6 lbs

To convert from kg to metric tons, just divide by 1k ;)

-e

edit: removed mT (in response to RonM's subsequent observation). 
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: RonM on 08/11/2017 11:40 pm
(16,800kg to Mars expendable X 0.7 for reusability X 2.2 for kg to lbs conversion) / 2204 for pounds to long tons =~ 11.7

From (ugh) https://en.wikipedia.org/wiki/Ton

British [long] ton is 2240 lbs
US [short] ton is 2000 lbs
Metric (seems to be the primary measure used for rocket capabilities) ton [tonne, MT] is 2204.6 lbs

To convert from kg to mT, just divide by 1k ;)

-e

Be careful with SI symbols, mT is millitesla. The correct SI symbol for tonne is lowercase t.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: envy887 on 08/11/2017 11:51 pm

Dunno, but if the 130+ tons one SLS will lift are instead lifted with FH's, you get up to $750mn saved from the Atlantic to work with.

And the TMI for an FH reusable is about 11.7 long tons to go by past history (I don't know where you are getting 4,900kg from), so you get to keep the rockets.  I'm generously (to ULA) calling the per launch FH cost to be $250mn per, where the quoted cost is $90mn.

A deep space tug/stage is required anyway.
SpaceX quotes the FH at than $90m up to 8000kg to GTO (http://www.spacex.com/about/capabilities), suggesting that that is the cutoff point for triple core landings. Given that that is roughly the same as expendable F9, a similar TMI capacity as expendable F9 should be expected - F9 can do 4,020kg to TMI. So why do you think it can do 11.7 long tons?

SpaceX was planning to attempt 3-core recovery on Red Dragon missions, which would require sending around 10 tonnes through TMI. I don't think 8,000 kg to GTO is at all near the limit for FH with 3-core recovery.

I think this capability will be demonstrated with the lunar Dragon mission. And that that point it will get a bit more difficult to convince me that SLS is worthwhile.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: edkyle99 on 08/12/2017 05:45 am
"  The LEO-rendezvous Falcon ... is actual cargo. "  <--  Nothing you have said here is true and relevant, as you presume the use of non-optimal architectures which are easily avoided. 
What is the "optimal" alternative architecture?

The one that gets the job done for the least $.
That could very well be SLS/Orion.  NASA's goal is $1.5 billion per year for one to two SLS/Orion launches.  The fully-recoverable Falcon Heavy/Dragon cost for the ten flights we've been discussing would exceed $1.8 billion.

 - Ed Kyle
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: guckyfan on 08/12/2017 06:10 am
That could very well be SLS/Orion.  NASA's goal is $1.5 billion per year for one to two SLS/Orion launches.  The fully-recoverable Falcon Heavy/Dragon cost for the ten flights we've been discussing would exceed $1.8 billion.

 - Ed Kyle

How do you get to $180 million per 3 core reusable FH flight? No way that would be more than $100 million with a healthy profit.

Edit: added 3 core reusable
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Proponent on 08/12/2017 08:17 am
Metric (seems to be the primary measure used for rocket capabilities) ton [tonne, t (SI), MT (sic)] is 2204.6 lbs

To be really, really technical and persnickety, the tonne is not an SI unit, though it and the associated symbol 't' are recognized by the International Bureau of Weights and Measures (BIPM).
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: edkyle99 on 08/12/2017 12:26 pm
That could very well be SLS/Orion.  NASA's goal is $1.5 billion per year for one to two SLS/Orion launches.  The fully-recoverable Falcon Heavy/Dragon cost for the ten flights we've been discussing would exceed $1.8 billion.

 - Ed Kyle

How do you get to $180 million per 3 core reusable FH flight? No way that would be more than $100 million with a healthy profit.

Edit: added 3 core reusable
I am comparing cost of launch vehicle and payload.

 - Ed Kyle 
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: AncientU on 08/12/2017 12:28 pm
"  The LEO-rendezvous Falcon ... is actual cargo. "  <--  Nothing you have said here is true and relevant, as you presume the use of non-optimal architectures which are easily avoided. 
What is the "optimal" alternative architecture?

The one that gets the job done for the least $.
That could very well be SLS/Orion.  NASA's goal is $1.5 billion per year for one to two SLS/Orion launches.  The fully-recoverable Falcon Heavy/Dragon cost for the ten flights we've been discussing would exceed $1.8 billion.

 - Ed Kyle

Did you just say that without a wink?

Development costs for SLS/Orion alone will be $2B/flight if amortized over the first 20 flights (which will never actually be flown).  NASA's goal... sure, I believe that. ;)
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: envy887 on 08/12/2017 02:15 pm
That could very well be SLS/Orion.  NASA's goal is $1.5 billion per year for one to two SLS/Orion launches.  The fully-recoverable Falcon Heavy/Dragon cost for the ten flights we've been discussing would exceed $1.8 billion.

 - Ed Kyle

How do you get to $180 million per 3 core reusable FH flight? No way that would be more than $100 million with a healthy profit.

Edit: added 3 core reusable
I am comparing cost of launch vehicle and payload.

 - Ed Kyle

You're comparing 1 Orion to 10 Dragons?
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: edkyle99 on 08/12/2017 02:20 pm
That could very well be SLS/Orion.  NASA's goal is $1.5 billion per year for one to two SLS/Orion launches.  The fully-recoverable Falcon Heavy/Dragon cost for the ten flights we've been discussing would exceed $1.8 billion.

 - Ed Kyle

How do you get to $180 million per 3 core reusable FH flight? No way that would be more than $100 million with a healthy profit.

Edit: added 3 core reusable
I am comparing cost of launch vehicle and payload.

 - Ed Kyle

You're comparing 1 Orion to 10 Dragons?
Yes, as a placeholder.  There has to be some type of smart payload on top of each rocket.  Something to maneuver the cargo in orbit, etc.  Each payload and its integration has a cost.

 - Ed Kyle
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: tdperk on 08/12/2017 03:28 pm
"  The LEO-rendezvous Falcon ... is actual cargo. "  <--  Nothing you have said here is true and relevant, as you presume the use of non-optimal architectures which are easily avoided. 
What is the "optimal" alternative architecture?

The one that gets the job done for the least $.
That could very well be SLS/Orion.  NASA's goal is $1.5 billion per year for one to two SLS/Orion launches.  The fully-recoverable Falcon Heavy/Dragon cost for the ten flights we've been discussing would exceed $1.8 billion.

 - Ed Kyle

But three FH flights duplicate one SLS for at most half the cost.  1/4 the cost is plausible.

And no, there has to be something smart enough and with enough fuel or refuel-able on orbit at the top of one rocket.  Your presuming otherwise is you presuming sub-optimal architectures.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: edkyle99 on 08/13/2017 12:01 am
But three FH flights duplicate one SLS for at most half the cost.  1/4 the cost is plausible.

And no, there has to be something smart enough and with enough fuel or refuel-able on orbit at the top of one rocket.  Your presuming otherwise is you presuming sub-optimal architectures.
The Falcon Heavy upper stage batteries die after several hours at most and there is no means for recharging them.  The stage has no ability to rendezvous or dock with other orbiting objects.  There is no auto docking system for the stage.  There is no propellant transfer system once docked.  You pretend that all of these non-existing capabilities have no cost when, in fact, the cost to develop and test and fly such systems would be quite large.  Dragon can fly in space, rendezvous, and dock, making it a good surrogate for such costs.

 - Ed Kyle
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: tdperk on 08/17/2017 06:30 pm
But three FH flights duplicate one SLS for at most half the cost.  1/4 the cost is plausible.

And no, there has to be something smart enough and with enough fuel or refuel-able on orbit at the top of one rocket.  Your presuming otherwise is you presuming sub-optimal architectures.
The Falcon Heavy upper stage batteries die after several hours at most and there is no means for recharging them.  The stage has no ability to rendezvous or dock with other orbiting objects.  There is no auto docking system for the stage.  There is no propellant transfer system once docked.  You pretend that all of these non-existing capabilities have no cost when, in fact, the cost to develop and test and fly such systems would be quite large.  Dragon can fly in space, rendezvous, and dock, making it a good surrogate for such costs.

 - Ed Kyle

And you are honestly positing these are show stoppers?  That remedying them will cost significantly more than has been SpaceX's history to date of being 1/10th the cost of Old Space to get the same job done innovatively?

Also, the Upper Stage would just deorbit--it's capabilities are not at issue at all.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Lar on 08/17/2017 06:58 pm
Arguing about tons vs tonnes? Stale and boring.

This is a thread about what would change your mind. Maybe some out of the box thinking is needed. The pricing and payload discussions are also stale and boring.

Let's try to up the level shall we?
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: tdperk on 08/17/2017 08:48 pm
What would it take to change my mind on SLS/Orion?

That it had capabilities which it provided less expensively going forward than other plausible options AND that it was not the product of the cost plus business model, such that it trapped it's operators (and passengers) in "Columbia type thinking".  Hat tip to Jim, not that he'll appreciate my use of the phrase.

https://forum.nasaspaceflight.com/index.php?topic=43527.msg1713733#msg1713733
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: oldAtlas_Eguy 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.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Proponent 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.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Political Hack Wannabe 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. 
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: meberbs 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) (https://arstechnica.com/science/2019/07/nasas-large-sls-rocket-unlikely-to-fly-before-at-least-late-2021/) 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 (https://www.nasaspaceflight.com/2019/04/nasa-lsp-studies-alternate-orion-options/) 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 (https://arstechnica.com/science/2019/07/buzz-aldrin-is-looking-forward-not-back-and-he-has-a-plan-to-bring-nasa-along/) 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 (https://arstechnica.com/science/2019/08/rocket-scientist-says-that-boeing-squelched-work-on-propellant-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.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: JohnFornaro 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.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: JohnFornaro 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.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: JohnFornaro 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.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: JohnFornaro 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.
Title: Re: What would it take to change your mind on SLS/Orion?
Post by: Lar 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