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[New] Space Launch System / Orion Discussion Thread


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17 minutes ago, jadebenn said:

It is not. I wish it was, but it is not.

They're aiming to have it complete by December.

That's what I thought, which is why I don't understand their official social media saying otherwise.

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6 minutes ago, jadebenn said:

I was talking about the core stage.

Our reply thread was regarding Orion, not SLS core.

I'm sure Orion is largely complete, but I reserve "complete" for "if SLS was ready in the VAB to roll out tomorrow, and we could integrate it magically, it's ready to go to space."

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1 hour ago, tater said:

Our reply thread was regarding Orion, not SLS core.

Sorry, I misread.

To play devil's advocate regarding the "complete" Orion remark: for whatever reason they've actually removed parts that were previously outfitted to it. The Orion undergoing acoustic testing had all its tiles, for example, and the ESM had its solar panels until a few days ago.

Maybe some problems came up, or maybe the parts are undergoing seperate testing, but they did used to be attached.

Edited by jadebenn
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I cant really begrudge them trying to drum up some press. Finished or not. 

side note: Is this the crew capsule or the tester they are slinging on EM-1?

or is the tester for EM-1 going to become the EM-2 capsule with further work after retrieval?

 

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6 minutes ago, Dale Christopher said:

I cant really begrudge them trying to drum up some press. Finished or not. 

side note: Is this the crew capsule or the tester they are slinging on EM-1?

or is the tester for EM-1 going to become the EM-2 capsule with further work after retrieval?

Artemis 2 was originally going to reuse the avionics and some parts from the capsule flown on Artemis 1, but to avoid schedule impacts, the two have now been completely decoupled. Artemis 2 will now use all-original parts to avoid any potential delays caused by Artemis 1.

Also: Green run confirmed to be happening. I believe that to be the right decision, but it's one that almost certainly puts the final nail in the coffin for a 2020 launch. This is probably why Bridenstine was saying 2021 in that one hearing.

Edited by jadebenn
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Green run is indeed critical, as SLS core has nothing in common with Shuttle at this point, arguably not even the engines as they have been improved in thrust.

Hopefully it all goes to plan, as any issues that crop up delay the launch by as long as they take to fix.

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8 minutes ago, tater said:

Green run is indeed critical, as SLS core has nothing in common with Shuttle at this point, arguably not even the engines as they have been improved in thrust.

Not nothing, but yeah, I get your sentiment. There is very little shared apart from some of the guts in the MPS, the RS-25 engines, and the tank diameter. The core stage is closer to being an entirely new rocket than it is to the old Shuttle ET. 

I would say that the engines are basically unchanged though. The SSMEs were always capable of those thrust levels, they just weren't used because testing revealed they wore out the engines really fast, and NASA really didn't want to take any risks with things on the orbiter post-Challenger. Since these RS-25s will not be recovered and the SLS has an LES, neither of those things are an issue.

8 minutes ago, tater said:

 Hopefully it all goes to plan, as any issues that crop up delay the launch by as long as they take to fix.

Cross your fingers!

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19 hours ago, jadebenn said:

Not nothing, but yeah, I get your sentiment. There is very little shared apart from some of the guts in the MPS, the RS-25 engines, and the tank diameter.

The diameter doesn't count for anything, IMO. once they changed the tooling, etc. Some of the MPS guts. OK, and I accept whatever the consensus is on SSME modifications. Still, it's close enough to clean sheet, they should have really considered clean sheet.

I tend to fundamentally think that a sustainer architecture is just a bad idea. It makes sense for people using ridiculously overpriced engines, I suppose, since that's a huge chunk of the cost. The whole shuttle derived aspect (since it quickly went sideways from there) was a mistake (unless they really made it overlap with extant (at the time) Shuttle).

19 hours ago, jadebenn said:

Cross your fingers!

Any really bad outcome at green run would be pretty catastrophic to the program, as the chance of it being superseded by off the shelf alternatives is only going to increase over time.

I fully expect SLS to fly for a few years, but I can't imagine it ever becoming a work horse, for it to have served that roll I think it needed to fly on the original schedule (it was required to have flown by the end of 2016, after all).

This is a cool read, BTW:

https://www.nasa.gov/exploration/news/ESAS_report.html

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2 hours ago, tater said:

The diameter doesn't count for anything, IMO.

It counts for a lot of the manufacturing, transportation, and ground support infrastructure. Allowed some of it to be carried over from the STS program, such as the Pegasus barge (which, admittedly, still had to undergo some pretty major refurbishment).

2 hours ago, tater said:

Any really bad outcome at green run would be pretty catastrophic to the program, as the chance of it being superseded by off the shelf alternatives is only going to increase over time.

I doubt this, but, well, I tend to disagree with a lot of people's predictions about the trajectory of spaceflight in the future anyway, even disregarding stuff like Starship.

IMO, the real test of the longevity of the commercial launch providers will be the next recession. I'm certain they'll stick around (as I'm fairly certain the US government would intervene if it looked like they had a chance of failing), but that could spell an end to much of their higher aspirations beyond their currently-existing systems. Probably off-topic to discuss this any further, though.

2 hours ago, tater said:

Ah, the ESAS report. You know, this is the report that spawned Constellation, and all the good and bad that came out of that.

Real-talk: One of the things that frustrates me most is how few people seem to remember that whole deal. I wasn't even into spaceflight when all that was going down, but I've at least done my homework on it!

To me, the biggest lessons of Constellation are twofold:

  1. Consistency is the most important thing in HSF
  2. A bad part of a decent plan can bring the whole thing down.

I have to roll my eyes when some people try and act like Ares I had a smoother development history than SLS. It didn't. It really, really, didn't. I guess I should be happy those people cared enough to look into Constellation at all, but they invariably only know enough to be dangerous.

Ares I, as flawed as it was, would almost certainly be flying people to the ISS right now, yet Ares I's flaws are precisely the reason the whole program fell apart. It's a balancing act, I guess.

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33 minutes ago, jadebenn said:

I doubt this, but, well, I tend to disagree with a lot of people's predictions about the trajectory of spaceflight in the future anyway, even disregarding stuff like Starship.

I don't mean catastrophic in the sense of "Epic fail! You're cancelled, we're gonna buy Starships!" I mean that given their complete lack of schedule margin, the program would be very seriously harmed in terms of time. Artemis-1 (assuming a RUD or something on green run) would be pushed back at least a year, probably 2. They'd need to redo the green run with the second core, for example. Vulcan starts flying, as likely does NG (assuming they get Be-4 working...). While Starship development is, um, non-traditional (LOL), it's clearly moving forward, and while planning around any of those 3 vehicles is fraught, it's not like NASA has cargoes for any of them (or SLS) anyway. The longer first flight stretches out, the more likely one of these vehicles reaches the finish line and starts eating into possible SLS mission use cases.

33 minutes ago, jadebenn said:

IMO, the real test of the longevity of the commercial launch providers will be the next recession.

I think that 2 of the 3 are in it for other reasons, though clearly SpaceX has the most to lose here. It's fair to note that they tend to "bet the company" on new ideas, so Starlink is fairly important for them moving forward. They are certainly vulnerable to economic setbacks, which is prehaps why they are pushing so hard on SS. If it exists, it cannot be ignored. BO, OTOH, has the luxury of being funded literally with Bezo's #@$!-you money, lol. That said, BO is building a more cost effective Moon rocket (or lunar transportation system, at least) regardless of the economy, or NASA. Part of the reason I want them to hurry up a little is you just never know when something bad will happen to people, and BO is the creature of Bezos (maybe he has money in a trust to fund it after he's gone to further his goals).

33 minutes ago, jadebenn said:

Ares I, as flawed as it was, would almost certainly be flying people to the ISS right now, yet Ares I's flaws are precisely the reason the whole program fell apart. It's a balancing act, I guess.

Yeah, the only bit of Constellation I like is a concept, not the specific vehicles. I prefer the concept of separating crew and heavy cargo, and generally I think EoR is a more sustainable system than the current push for LoR systems. Nothing is gained by being in NRHO (other than cumulative radiation exposure for the crew... yay!(?)), and everything is harder.

Edited by tater
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16 minutes ago, tater said:

I don't mean catastrophic in the sense of "Epic fail! You're cancelled, we're gonna buy Starships!" I mean that given their complete lack of schedule margin, the program would be very seriously harmed in terms of time. Artemis-1 (assuming a RUD or something on green run) would be pushed back at least a year, probably 2. They'd need to redo the green run with the second core, for example. Vulcan starts flying, as likely does NG (assuming they get Be-4 working...). While Starship development is, um, non-traditional (LOL), it's clearly moving forward, and while planning around any of those 3 vehicles is fraught, it's not like NASA has cargoes for any of them (or SLS) anyway. The longer first flight stretches out, the more likely one of these vehicles reaches the finish line and starts eating into possible SLS mission use cases.

Ah, okay. Yeah, that's reasonable. There's more margin than you think, though. Even if a failure were to happen in 2021, you could "steal" the SLS for Europa Clipper, or perhaps even order a new one if there's enough slack in the production line. The biggest difficulty would be getting an Orion ready in-time for Artemis 4 (which would be the new Moon landing mission instead of Artemis 3 if such a failure were to occur). I don't know enough about the timeline for procurement and production of Orion spacecraft to say for-certain whether or not you'd be able to get one put together in-time in such a scenario, though.

Edited by jadebenn
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43 minutes ago, tater said:

Nothing is gained by being in NRHO (other than cumulative radiation exposure for the crew... yay!(?))

I’m not really a fan of NHRO either, I’d prefer that if a craft was too big to make it to lunar orbit that it used its DV getting to LEO and was refueled by a second launch in LEO before heading off directly to lunar orbit. 

It’s a weird one. I feel like there must be a bigger picture somewhere that justifies it better than the reasons I’ve seen so far coming from Bridenstine

(and something better than simply it’s limited by SLS)

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14 minutes ago, jadebenn said:

you could "steal" the SLS for Europa Clipper,

Is SLS as LV a done deal for that mission? Given it fits in the standard fairing for ICPS (DCSS 5m), it's fairly LV agnostic (it's always been shown using the short, 14m DIVH fairing option on SLS, which is basically the same size as F9/FH). Clearly FH lacks the C3 for a direct mission, but NASA is considering it (and FH exceeds the C3 of DIVH when expended, even without a cryo upper stage).

The other issue with "stealing" the clipper one is that you're assuming the problem would not make stealing one already built a problem (ie: if the part you are stealing needs tobe redesigned). That's clearly unlikely, but my statement was about that unlikely occurrence (a RUD or similar during green run).

Orion would be fine, no Orion on top for the test :)

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41 minutes ago, Ultimate Steve said:

Is this a new version of the EUS or the old version that had so many problems (not sure whether mechanical or management or both)?

Bit of both? The old EUS was only delayed because NASA getting appropriations for ML-2 placed it outside of the critical path, so resources were redirected to more pressing needs, such as the core stage. They've been using the extra time to optimize the EUS's design for maximum mass to TLI, so there's been some design changes.

Edited by jadebenn
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6 minutes ago, jadebenn said:

They've been using the extra time to optimize the EUS's design for maximum mass to TLI, so there's been some design changes.

NASA asked them to do this about a year ago, with the idea that maybe they squeeze an extra 1-2 tons to TLI. You have something we can read that shows they've actually spent money working on that?

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Just now, tater said:

NASA asked them to do this about a year ago, with the idea that maybe they squeeze an extra 1-2 tons to TLI. You have something we can read that shows they've actually spent money working on that?

Just comes from the person I talk to at MSFC.

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2 minutes ago, tater said:

I guess the camera on the test stand must date to the Shuttle era, lol.

Also: what is pictured? That's not the SM, right?

I'm guessing it's a thruster since the fuel on Orion is exceptionally toxic. (Hypergols), not to mention it lacks the AJ10 engine bell (unless their testing the pumps and fuel flow systems and not the actual thrust generated?).

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1 minute ago, ZooNamedGames said:

I'm guessing it's a thruster since the fuel on Orion is exceptionally toxic. (Hypergols), not to mention it lacks the AJ10 engine bell (unless their testing the pumps and fuel flow systems and not the actual thrust generated?).

It doesn't look like an OMS engine, and the tweet implies that they used the whole SM on the stand.

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17 minutes ago, tater said:

It doesn't look like an OMS engine, and the tweet implies that they used the whole SM on the stand.

They probably have multiple variants of OMS depending on the vector and their angle. That and they could've tested the whole SM and just not shown it in the photo. 

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