[New] Space Launch System / Orion Discussion Thread

[Cuky]

Fair enough, teething problems for new hardware (wether reused old parts or brand new parts) are kinda expected.

 

What isn't expected is for manufacturers and operator to be so far behind schedule due to problems occuring in testing, them not understanding the cause and how to fix them dven after they show up in further testing. And then to just wing it in a hope that they won't appear for first launch attempt. Going by what was reported as problems and their attempts to solve them I would hazard a bet that Boeing, Bechtel, NASA and others still. have no idea ehat exact problem they are having and how to solve them

[tater]

 

[RCgothic]

23 hours ago, intelliCom said:

Well, anyone with little knowledge on the subject would think that it really is 'peak NASA' with all of this marketing fluff about it being the "most powerful rocket ever built".

I'm pretty sure it having the greatest thrust out of any rocket isn't out of the question; but its payload to LEO is somehow less than Starship and Saturn V. Curious...

SLS isn't the most powerful rocket ever built - Superheavy is.

It isn't the most powerful rocket ever stacked - Starship Superheavy is.

It isn't the most powerful rocket ever fired - Superheavy is.

It won't be the most powerful rocket ever fired at full thrust - N1 is.

It won't be the most powerful rocket ever launched - N1 is.

It may, briefly, be the most powerful rocket ever to reach orbit.

But only if you don't define power by payload to orbit - in which case Saturn V is.

Sure, SLS is one of the most thrusty rockets ever built. But it's quite inefficient with that thrust. Most of the propellant is low-ISP SRBs with heavy casings, and the core stage is an enormously heavy sustainer architecture. Thrust doesn't directly feature in the rocket equation. Only ISP and mass ratio are of primary importance.

Edited September 9, 2022 by RCgothic

[Beccab]

13 minutes ago, RCgothic said:

SLS isn't the most powerful rocket ever built - Superheavy is.

It isn't the most powerful rocket ever stacked - Starship Superheavy is.

It isn't the most powerful rocket ever fired - Superheavy is.

It won't be the most powerful rocket ever fired at full thrust - N1 is.

It won't be the most powerful rocket ever launched - N1 is.

It may, briefly, be the most powerful rocket ever to reach orbit.

But only if you don't define power by payload to orbit - in which case Saturn V is.

Sure, SLS is one of the most thrusty rockets ever built. But it's quite inefficient with that thrust. Most of the propellant is low-ISP SRBs with heavy casings, and the core stage is an enormously heavy sustainer architecture. Thrust doesn't directly feature in the rocket equation. Only ISP and mass ratio are of primary importance.

Let's not forget, it isn't excessively big either - block 1 is shorter than both the N1, Saturn V and Starship (in this order), despite what Forbes may write about it



Block 1B will beat some of them, but by that point it will probably be racing against the Long March 9 given that it's slipping closer to 2030 every day

[kerbiloid]

The metastable metallic hydrogen wouldn't leak...

[intelliCom]

6 hours ago, RCgothic said:

SLS isn't the most powerful rocket ever built - Superheavy is.

It isn't the most powerful rocket ever stacked - Starship Superheavy is.

It isn't the most powerful rocket ever fired - Superheavy is.

It won't be the most powerful rocket ever fired at full thrust - N1 is.

It won't be the most powerful rocket ever launched - N1 is.

It may, briefly, be the most powerful rocket ever to reach orbit.

But only if you don't define power by payload to orbit - in which case Saturn V is.

Sure, SLS is one of the most thrusty rockets ever built. But it's quite inefficient with that thrust. Most of the propellant is low-ISP SRBs with heavy casings, and the core stage is an enormously heavy sustainer architecture. Thrust doesn't directly feature in the rocket equation. Only ISP and mass ratio are of primary importance.

If we're counting theorheticals, then neither superheavy nor N1 count. The moment they do though, dear lord NASA's gonna have to do some re-branding or reconsideration as to whether they should keep using SLS or not.

[SunlitZelkova]

1 hour ago, intelliCom said:

If we're counting theorheticals, then neither superheavy nor N1 count.

Why?

Starship/Super Heavy may as well be in the same stage of development at the moment.

Another thing I have thought of is that the decision not to do a full WDR roughly mimics the decision not to static fire the first stage of the N1.

Hopefully SLS doesn’t pay the same price as the N1 did for such shortcuts.

[Ultimate Steve]

IMO N1 counts because it was proven to generate the amount of thrust advertized. Super Heavy has not, yet, and will not until it does a full static fire, and arguably won't until it actually leaves the ground.

You can measure it as "most thrust assembled" "most thrust generated in a single assembled rocket" and "most thrust generated in flight." Neither SLS or Super Heavy have achieved the required thrust levels to count for level 2.

[intelliCom]

8 minutes ago, SunlitZelkova said:

Why?

Starship/Super Heavy may as well be in the same stage of development at the moment.

Another thing I have thought of is that the decision not to do a full WDR roughly mimics the decision not to static fire the first stage of the N1.

Hopefully SLS doesn’t pay the same price as the N1 did for such shortcuts.

Sorry I mean "only if we're counting theorheticals, then superheavy and N1 count". Not much point saying "Sea Dragon is most powerful launch vehicle" when it wasn't even built, let alone launched. N1 isn't remembered so much for a similar reason; three launches, all mid-flight failures. Is it a launch vehicle if it doesn't launch anything to space? I'd argue Buran-Energia is a proper launch vehicle because it did have a successful flight; attained LEO. USSR just didn't have the funding to continue the program.

I guess the language I'm looking for is "most powerful launch vehicle with at least one successful flight", but that's a bit of a mouthful. In this regard, Saturn V is the most powerful rocket to put anything into space.

Calling Starship-Superheavy the "most powerful launch vehicle" is the equivalent of calling a bugatti/lambo you haven't purchased yet the "most powerful car you own".

[kerbiloid]

A Tsar-rocket competition.

N1, SuperHeavy, SLS.

(Tsar-Cannon never shot. Tsar-Bell never ringed. Continue the logical sequence.)

3 hours ago, intelliCom said:

N1 isn't remembered so much for a similar reason; three launches

Four. And the reason is secrecy.

3 hours ago, intelliCom said:

USSR just didn't have the funding to continue the program.

USSR just dropped that technical stillborn in favor of Energy which had flown twice.

Edited September 10, 2022 by kerbiloid

[RCgothic]

I believe I included all the applicable caveats.

[DDE]

15 hours ago, Beccab said:

despite what Forbes may write about it

"I'd volunteer my genitals for a papercut rather than give clickbait to Forbes"

- unknown, as retold on Twitter by a Forbes journo

On 9/8/2022 at 5:11 PM, Geonovast said:

The SRB expiration I get, the number of fuel tank fills I get, the FTS battery stuff I get...

But what's the rollout number about?  What gets degraded on the rocket from the rollouts?

https://en.m.wikipedia.org/wiki/Galileo_project#High_gain_antenna_problem

While the huge crawler shouldn't be as shaky, I wouldn't be surprised that there's still appreciable vibration.

[kerbiloid]

Do they carry the rocket from the crawler to the launcpad and back?

Do they refuel it?

Maybe this matters.

[Rutabaga22]

IS the sls launch tower in any way similar to the Saturn V's other than looks? The definitely have a very similar structure.

[RCgothic]

I believe it's similar to the launch umbilical tower, but there's no equivalent to Saturn's Mobile Service Structure or Shuttle's Rotating Service Structure which allowed those vehicles to be serviced on the pad.

[DDE]

55 minutes ago, RCgothic said:

I believe it's similar to the launch umbilical tower, but there's no equivalent to Saturn's Mobile Service Structure or Shuttle's Rotating Service Structure which allowed those vehicles to be serviced on the pad.

The amount of extra costs arising from failed attempts at economy is astounding. N1 has been holding SLS's beer...

[kerbiloid]

SLS supports the SRB makers, SH doesn't.

SLS supports the RS-25 makers, SH doesn't.

Drop SLS, and RS-25 will follow F-1.
While all those Raptors and BE-4 are just hydrocarbonic, not hydrolox.

So, why not rename SLS into White Elephant?

[tater]

1 minute ago, kerbiloid said:

SLS supports the SRB makers, SH doesn't.

SLS supports the RS-25 makers, SH doesn't.

Drop SLS, and RS-25 will follow F-1.
While all those Raptors and BE-4 are just hydrocarbonic, not hydrolox.

So, why not rename SLS into White Elephant?

While much of that is true, SS/SH was not a thing when this project started. Arguably it is a rebranding of Constellation. Yeah, different engines (RS-25 vs RS-68), but the rough concept is the same.

SLS/Orion was and remains a tech jobs program.

 

[Barzon]

On 9/8/2022 at 3:11 PM, Geonovast said:

The SRB expiration I get, the number of fuel tank fills I get, the FTS battery stuff I get...

But what's the rollout number about?  What gets degraded on the rocket from the rollouts?

I was told that the holddown posts have a limited number of uses, and are the main constraint for the number of rollouts. Didn't get a number on how many rollouts they can support,  so I can't confirm or disconfirm the number Eric gave for remaining uses.

 

  

On 9/3/2022 at 5:52 PM, tater said:

 

 

Haha, had to do a double take on this calendar. Thought it was a diff one and was very surprised to see it posted on a public forum.

Edited September 11, 2022 by Barzon

[Beccab]

12 minutes ago, Barzon said:

Haha, had to do a double take on this calendar. Thought it was a diff one and was very surprised to see it posted on a public forum.

Now I'm curious, what was the one you were thinking of? This one perhaps?

[Barzon]

5 minutes ago, Beccab said:

Now I'm curious, what was the one you were thinking of? This one perhaps?

Nah, its one that's not public. Similar to the calendar tater posted, but with a lot more information.

Edited September 11, 2022 by Barzon

[kerbiloid]

SLS. The first unscrewed test...

[SunlitZelkova]

On 9/9/2022 at 5:28 PM, intelliCom said:

Sorry I mean "only if we're counting theorheticals, then superheavy and N1 count". Not much point saying "Sea Dragon is most powerful launch vehicle" when it wasn't even built, let alone launched. N1 isn't remembered so much for a similar reason; three launches, all mid-flight failures. Is it a launch vehicle if it doesn't launch anything to space? I'd argue Buran-Energia is a proper launch vehicle because it did have a successful flight; attained LEO. USSR just didn't have the funding to continue the program.

I guess the language I'm looking for is "most powerful launch vehicle with at least one successful flight", but that's a bit of a mouthful. In this regard, Saturn V is the most powerful rocket to put anything into space.

Calling Starship-Superheavy the "most powerful launch vehicle" is the equivalent of calling a bugatti/lambo you haven't purchased yet the "most powerful car you own".

True indeed.

The mainstream criteria is just whether it has fired. So even if it is just a static fire, SH will join “the club” once it does that.

”That has launched a payload” certainly is a valid categorization though.

On 9/9/2022 at 8:47 PM, kerbiloid said:

A Tsar-rocket

I feel like this is what Americans would have called the N1, UR-700, UR-700M, or UR-900 if any of them had been successful.

Energia is short despite its payload and I wouldn’t be surprised if a fair number of people mistook it for an ET and SRBs, so it didn’t get that name despite having successful flights.

[RCgothic]

24 minutes ago, SunlitZelkova said:

True indeed.

The mainstream criteria is just whether it has fired. So even if it is just a static fire, SH will join “the club” once it does that.

Superheavy has already fired. Not on all engines and not at full thrust, but it's still a static fire of a flight vehicle.

[SunlitZelkova]

40 minutes ago, RCgothic said:

Superheavy has already fired. Not on all engines and not at full thrust, but it's still a static fire of a flight vehicle.

I meant full static fire, although as you have also said in prior posts, “vehicle that has fired” (regardless of how many engines) is a category in its own right.