The Blazer

SLS, does it worth it?

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So, I wanted to know what you guys think about the NASA SLS... Will it ever work? Will it be a good replacement for the STS? Do you guys think its better than the Falcon Heavy (It probably sounds crazy compare these two, but I've heard several people comparing them and I wanted to have the KSP community's opinion on this).

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Meh. If you look at it by itself, it's a pretty cool rocket (4 RS-25s on a rocket look awesome), but there are some big issues with it, IMO.

  • For a sustained-presence mission architecture like Artemis, it's really wasteful to throw away a billion-dollar launch vehicle every time you launch something to the Moon (Yes, I know some Artemis payloads are going on commercial launch vehicles, but IIRC the big stuff like LOP-G modules is going on SLS). What you need is a heavy-lift reusable rocket. *cough*Starship*cough*
  • It's using mainly Shuttle components, but throwing them away every time. I mean, RS-25s were literally designed with reusability in mind. Once again, wasteful. They could implement SMART reuse like ULA is doing with Vulcan, but that would probably add five years to the program. They're not even recovering the SRBs.
  • The core stage is being built by Boeing, which is going through some serious shenanigans right now. With all the delays this is causing, I wouldn't be surprised if the first launch date slipped into 2022. The 2024 goal will never be met at that rate.
  • SpaceX is currently developing a fully reusable vehicle that can deliver 100 tons to the surface of the Moon with orbital refuelling. If they can get Starship flying soon, it will pretty much obviate SLS cargo flights, and if they can convince NASA that it's safe for crew then SLS's days will be numbered.

I do look forward to SLS flying, but apart from the cool factor I don't think it's particularly viable for long-term exploration.

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Just now, RealKerbal3x said:

Meh. If you look at it by itself, it's a pretty cool rocket (4 RS-25s on a rocket look awesome), but there are some big issues with it, IMO.

  • For a sustained-presence mission architecture like Artemis, it's really wasteful to throw away a billion-dollar launch vehicle every time you launch something to the Moon (Yes, I know some Artemis payloads are going on commercial launch vehicles, but IIRC the big stuff like LOP-G modules is going on SLS). What you need is a heavy-lift reusable rocket. *cough*Starship*cough*
  • It's using mainly Shuttle components, but throwing them away every time. I mean, RS-25s were literally designed with reusability in mind. Once again, wasteful. They could implement SMART reuse like ULA is doing with Vulcan, but that would probably add five years to the program. They're not even recovering the SRBs.
  • The core stage is being built by Boeing, which is going through some serious shenanigans right now. With all the delays this is causing, I wouldn't be surprised if the first launch date slipped into 2022. The 2024 goal will never be met at that rate.
  • SpaceX is currently developing a fully reusable vehicle that can deliver 100 tons to the surface of the Moon with orbital refuelling. If they can get Starship flying soon, it will pretty much obviate SLS cargo flights, and if they can convince NASA that it's safe for crew then SLS's days will be numbered.

I do look forward to SLS flying, but apart from the cool factor I don't think it's particularly viable for long-term exploration.

Yes, if it was an pretty cheap heavy lift rocket based on the shuttle it would make sense. 
However cost and time has spiraled out of control and it start becoming redundant. Yes it can lift 95, however it will be many time more expensive than falcon heavy with 60 ton. 
And you have future rockets like starship and other future launchers. 

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39 minutes ago, The Blazer said:

So, I wanted to know what you guys think about the NASA SLS... Will it ever work?

Meaning will it fly into space with a payload on top? Certainly.

 

Quote

Will it be a good replacement for the STS?

It was never meant as a replacement for Shuttle, it's not optimized for that (or indeed any mission I can think of).

STS was meant as a crew vehicle to LEO with cargo capacity. SLS is only really meant as a BLEO launch vehicle with a capsule on top. If they built Block 2, with a full diameter fairing on top, it would allow substantial cargo delivery to LEO, and a new station could be built in a few launches. So if they had skipped straight to that, it could compete admirably with STS for station construction.

Quote

Do you guys think its better than the Falcon Heavy (It probably sounds crazy compare these two, but I've heard several people comparing them and I wanted to have the KSP community's opinion on this).

FH has less than half the mass to LEO, and a far smaller fairing to put that cargo in. That said, it's vastly less expensive to fly.

I'm very much not an SLS fan, but they are not doing the same thing (the trouble of course is that SLS was never designed with any particular mission in mind).

Edited by tater

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Good:

NASA needs man-rated rockets, as we do not currently have any.  SLS is intended to be man-rated(manned on the first all-up launch even)

Even if all of the commercial rockets under development go out of business tomorrow, SLS development will continue.

Bad:

The program seems to be designed primarily for the purpose of bringing money to congressional districts, with space exploration only a secondary concern

By the time it flies, it will likely be both more expensive and less functional than other flying rockets(Starship, New Glen)

 

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SLS in current version (Block 1) is too underpowered (and Orion too overweight) to recreate Apollo.

Block 1B can't do so either, and its future looks shaky.

Block 2 could, but it's so far over the horizon as to be effectively never.

SLS is effectively what you'd get it they hadn't decided to all-up test Apollo/SaturnV and the lightened Apollo Block 2 had been cancelled along with SII. Not enough rocket, too much capsule.

Also I note that Falcon 9 will probably be man-rated before SLS will.

Edited by RCgothic

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31 minutes ago, RCgothic said:

Also I note that Falcon 9 will probably be man-rated before SLS will.

 Well, that's a no brainer. Considering that dragon will probably be launching on Falcon 9 sometime in the next 1 or 2 months 

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41 minutes ago, RCgothic said:

Block 2 could, but it's so far over the horizon as to be effectively never.

Can it?

Orion isn't getting any lighter, so it would need a throw to TLI of maybe 62 tonnes to do an Apollo-style mission.

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6 hours ago, RealKerbal3x said:

the cool factor

Well, that makes the rocket worth it's cost.(at least to me)

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7 hours ago, linuxgurugamer said:

 Well, that's a no brainer. Considering that dragon will probably be launching on Falcon 9 sometime in the next 1 or 2 months 

I said probably because there's always a chance something could go wrong with Demo2.

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5 hours ago, RCgothic said:

I said probably because there's always a chance something could go wrong with Demo2.

No-one is using SLS for LEO missions. If Commercial Crew fails, with Ares I gone there is only one option:

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Anyway, back to @The Blazer. SLS is worth it if, and only if, Starship fails, full stop. BO's bid is not entirely credible at this point - plus they are far more likely to shoot themselves in the foot to avoid compromising the ULA.

Bezos isn't going to risk his relationship with the Alphabet Gang.

Edited by DDE

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4 hours ago, DDE said:

No-one is using SLS for LEO missions. If Commercial Crew fails, with Ares I gone there is only one option:

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But the Soyuz is capable to fly unmanned to save the crew?

4 hours ago, DDE said:

Anyway, back to @The Blazer. SLS is worth it if, and only if, Starship fails, full stop. BO's bid is not entirely credible at this point - plus they are far more likely to shoot themselves in the foot to avoid compromising the ULA.

Bezos isn't going to risk his relationship with the Alphabet Gang.

Is not like I'm based on trust, but I don't think Starship fails...

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On 2/11/2020 at 2:51 PM, The Blazer said:

So, I wanted to know what you guys think about the NASA SLS... Will it ever work?

Yes. NASA managed to do harder things in the past. It's a matter of gathering the right people to do the job and the recent failures, besides being an embarrassment at best, on the other hand creates the political willingness to allow the right people to do the job.

 

On 2/11/2020 at 2:51 PM, The Blazer said:

 Will it be a good replacement for the STS? 

No. It will fulfill some tasks previously carried out only by STS, but it will not be able to be used on every kind of mission STS could do.

We can criticise the STS for a lot of things, but the harsh true is that nothing made by man could ever do all the missions STS could do again.

You will need a whole new fleet of different existent, in development or just wishing crafts to completely replace STS.

 

On 2/11/2020 at 2:51 PM, The Blazer said:

Do you guys think its better than the Falcon Heavy (It probably sounds crazy compare these two, but I've heard several people comparing them and I wanted to have the KSP community's opinion on this).

It's crazy to compare Falcon Heavy to STS. Heavy is essentially a first stage, STS was the vehicle itself.

Perhaps it could be possible to compare StarShip to STS - it will be able to bring back stuff to Earth?

Edited by Lisias
Hit "Save" too soon.

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Starship maps to Shuttle in capability (just talking LEO utility). That is, it maps to Shuttle for a version with some crew capability. Minus that, it's a SHLV that is cheaper due to reuse.

SLS doesn't map to "STS" (Shuttle) at all.

31 minutes ago, Lisias said:

No. It will fulfill some tasks previously carried out only by STS, but it will not be able to be used on every kind of mission STS could do.

Which? There are currently zero plans (even notional) to use SLS/Orion in LEO. The only missions I can think of that Shuttle did that have any SLS overlap might be launching planetary exploration spacecraft (like Galileo), but those launched on Shuttle were in fact pretty small, and could be flown far, far cheaper on literally anything that is "not SLS."

 

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55 minutes ago, tater said:

Which?

Building the next Space Station. I talked about tasks, not roles.

Besides, STS was able to bring stuff back to Earth - something that SLS will never will.

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12 minutes ago, Lisias said:

Building the next Space Station. I talked about tasks, not roles.

Besides, STS was able to bring stuff back to Earth - something that SLS will never will.

Starship can bring stuff back to Earth - and that's one of the reasons why I think SLS will be obsolete once Starship is operational.

It's so much more capable than SLS, at a much lower price. But the SLS program will continue nonetheless, because it's primary goal is providing jobs, not the exploration of space. A huge expendable Saturn V-class launcher is not at all an optimal solution for a go-back-to-the-Moon-and-stay-there mission, but NASA seems not to have noticed that yet, and probably won't until commercial launch vehicles are doing it cheaper and better.

Edited by RealKerbal3x

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A huge expendable Saturn V style booster would have been fine; if it were much, much cheaper, probably as a result of not being man-rated.

There's no reason for crew to go up on a big booster and make both functions more expensive by association.

Edited by RCgothic

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17 minutes ago, RCgothic said:

There'sno reason for crew to go up on a big booster and make both functions more expensive by association.

Yes, there're some. It happens there are no technical reason for that. Only political and economic ones.

As @RealKerbal3x said above, SLS will provide way more jobs on the industry than SpaceX, and since politicians depends of votes to be elected, it's way more safe to keep SLS workers happy and willing to vote on you.

And there's the economic factor: the SLS contractors are big and well established industry workhorses, some of them facing some financial troubles (Boeing, are you hearing?)

Shutting down SLS would close a door used by the government to help these jobs behemoths to stay on business, risking them to have to fire a lot of people, badly damaging the country's economy as side effect. What would make a lot of people unhappy. Voting people.

And there also a power play factor. Having SLS at hand will keep Bezos, Musk et all under control. They try some stunt, NASA shuts them down and use SLS instead, besides at huge more costs.

Edited by Lisias
Hit "Save" too soon.

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4 hours ago, The Blazer said:

But the Soyuz is capable to fly unmanned to save the crew?

Is not like I'm based on trust, but I don't think Starship fails...

Think Soyuz can fly unmanned, they have an freight version of it but that can not land as it reduce cargo capacity. 
But if say one of the Soyuz on ISS fails I assume they can launch another unmanned and dock it for the lifeboat capacity. 

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1 hour ago, tater said:

Starship maps to Shuttle in capability (just talking LEO utility). That is, it maps to Shuttle for a version with some crew capability. Minus that, it's a SHLV that is cheaper due to reuse.

SLS doesn't map to "STS" (Shuttle) at all.

Which? There are currently zero plans (even notional) to use SLS/Orion in LEO. The only missions I can think of that Shuttle did that have any SLS overlap might be launching planetary exploration spacecraft (like Galileo), but those launched on Shuttle were in fact pretty small, and could be flown far, far cheaper on literally anything that is "not SLS."

 

Yes, i thought about an shuttle configuration of starship. That is smaller crew cabin but an larger cargo bay. One or ever two arms, excellent EVA capabilities. Main purpose is satellite repair or recovery. 
Benefit is that its much cheaper than the shuttle and it can operate in GEO or even higher with refueling. Another role would be construction in space. 

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3 hours ago, Lisias said:

Building the next Space Station. I talked about tasks, not roles.

I realize that, I was thinking that the only station any SLS would likely ever build would require Block 1B and be some parts of Gateway. I suppose the (entirely notional at this point) Block 2 could loft large station parts, though.

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On 2/13/2020 at 2:10 AM, Lisias said:

Yes. NASA managed to do harder things in the past. It's a matter of gathering the right people to do the job and the recent failures, besides being an embarrassment at best, on the other hand creates the political willingness to allow the right people to do the job.

 

And funding. You forgot funding.

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SLS was as dead as Ares from the start. The post-Apollo government aerospace jobs retention treadmill is coming to a natural stop as spaceflight becomes increasingly commercial and routine. Governments don't generally design their own cars; they purchase commercial models and modify them — in time they will do the same with spacecraft.

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