NASA SLS/Orion/Payloads

[Cunjo Carl]

On 4/9/2019 at 2:11 PM, tater said:

What would it take to make SLS/Orion more useful?

...

1b. If The advanced boosters were the liquid type proposed, cargo goes to 150t. Loft Orion some other way, and you can do whatever with that.

Were you referring to the Pyrios boosters with this? Man, I would love if Rocketdyne finally got to build those. I haven't heard any ruminations on that starting back up, but I wonder what the possibility is from here.

Edit: Nevermind, just saw the conversation upstream that I'd missed. Cheers!

Edited April 13, 2019 by Cunjo Carl

[StrandedonEarth]

Well, Rocketdyne won’t build it until they get a (presumably cushy) contract to. Maybe if they built it on their own dime and offered it up commercially?

 The thing to remember with LF boosters is that it has been proven that they can be recovered. May as well make the effort to do it right.

And yeah, as said before, SRBs are rumbley 

[ZooNamedGames]

also I'd like to see a formal report that dates after Bridenstine's latest reports of intentions to land on the moon by 2025, that also states the EM-1 is still going to miss it's 2020 launch window. There's problems, but the biggest factors remaining are assembly, and 2 tests. One of these tests, are planned to be replaced by a hotfire on the pad. So I don't see much reason why EM-1 would slip further.

The engines are proven. The fuel tanks are made. The engine mount is built and ready. The adapter to the upper stage is built. The second stage is built. Orion is built. Orion's dummy SM is built. The LAS is built and proven. There's little left to do, that would warrant a 2021 launch date.

[Bill Phil]

1 hour ago, ZooNamedGames said:

also I'd like to see a formal report that dates after Bridenstine's latest reports of intentions to land on the moon by 2025, that also states the EM-1 is still going to miss it's 2020 launch window. There's problems, but the biggest factors remaining are assembly, and 2 tests. One of these tests, are planned to be replaced by a hotfire on the pad. So I don't see much reason why EM-1 would slip further.

The engines are proven. The fuel tanks are made. The engine mount is built and ready. The adapter to the upper stage is built. The second stage is built. Orion is built. Orion's dummy SM is built. The LAS is built and proven. There's little left to do, that would warrant a 2021 launch date.

Launch safety considerations and vehicle integration take a lot of time to work out. 

In fact there’s a major issue about the core potentially reentering over Hawaii.

[Xd the great]

38 minutes ago, Bill Phil said:

In fact there’s a major issue about the core potentially reentering over Hawaii.

Aim for the volcano...

[jadebenn]

20 hours ago, tater said:

All 4 rockets.

EM-1 is 2021 right now, short of cutting a corner to move it back into 2020. Unsure where EM-2 stands, maybe it stays 2022 (though as a block 1, something that was never supposed to happen). Once they pull the trigger on Block 1b+, then there is a 33 month delay to ready the MLP/VAB, regardless (unless they were lying about that timing before to cover other schedule issues).

I'd like to correct some things here tater, as your info's slightly out-of-date.

The best thing to happen to the SLS program in a long time has been the decision to switch from the 33-month rehab plan for the Block I mobile launcher you're speaking of, to a new plan where they instead just build a new mobile launcher for Block IB. This is the reason that many of the Block IB missions have been moved to Block I - that mandatory gap you're speaking of no longer exists, so Block I can launch more than once without pushing Block IB back.

If this moon push all goes to plan, you should see them begin construction on said second mobile launcher fairly soon, coupled with a retooling of the EUS to optimize it for TLI. Block I will likely be the main workhorse for this initiative (so much for it being an "Interim" Cryogenic Propulsion Stage), but I think they're hoping they can at least have Block IB ready by the final year or so of it, which would really help with re-stocking the reusable lander down the line.

Edited April 13, 2019 by jadebenn

[jadebenn]

Also, I'd like to add, the complete turnaround in regards to usage of the SLS Block I has some interesting effects on the likely design for SLS Block IB. Since it's looking more and more like Block I will be the main variant of the SLS (at least for the next 4-5 years or so), most, if not all, of the shuttle legacy parts are going to be depleted by the time Block IB comes into service. Stuff like the SRB casings and the old SSMEs have replacements lined up if course, and for the SSMEs in particular, I believe they're already in production, but the original plan had the Block IB flying for several years using this extraneous STS hardware, and a full switch to new SLS hardware only occurring with the Block II. Now it's looking more like IB will maybe fly one or two times with the old STS stuff before they run out. Basically: the transition date's moved up.

An interesting possiblity this opens up is an "early switch" so to speak. NASA may decide that it'd be more efficient to design Block IB to fly with the more advanced replacements from the beginning, instead of switching halfway through. This is speculation, but such a plan might allow some optimization of the Block IB design work. The remaining shuttle hardware would either be used up on the final launches of the Block I or placed back into storage. The new, better-performing hardware would be used to give Block IB a bigger 'kick.'

Now, many of you may have read that neat little discussion a few pages back about the advanced boosters plan made when Block IA was the successor to Block I. Still, let me restate what happened with that just to make it clearer. 

The original plan for the SLS was an upgrade path called Block IA. Block IA was essentially Block I, but with the solids replaced with an advanced booster design. The first of the two contenders for those boosters was Rocketdyne's proposal. They proposed to replace the SRBs with an F1 derivative powered by RP-1 strap-on tanks. The second proposal was that of Orbital ATK. They proposed to stick with solids, but use a better, more powerful design they christened the "Dark Knight," named such due to its distinctive black appearance thanks to its more advanced materials.

The primary advantage of Rocketdyne's proposal was power. The F1-B strap-on would undeniably make the SLS Block IA the most powerful rocket ever made. SLS performance issues would cease to be an issue. There were disadvantages however, namely in the fact that it would require significant modifications to the launch infrastructure at KSC, including (but not limited to), the pad, VAB, and mobile launcher.

The primary advantage of Orbital ATK's proposal was backwards compatibility. For the same reason Rocketdyne's proposal would've been difficult, ATK's would've been easy. The disadvantage was that the Dark Knights, while significantly more powerful than their predecessors, weren't going to meet the requirements for SLS Block II.

Ultimately, it was a moot question. After some deliberation, NASA decided that neither proposal would be used then, and that the Block IB development path would be easier than that of the Block IA. The advanced boosters upgrade would be deferred indefinitely.

With the Dark Knights out of the running, Orbital ATK could still capitalize on their engineering work. Their new engine design was solid (pun not intended), but there was room for refinement. As part of their work on OmegA, they made a new SRB design, one that shared an old name, but is undoubtedly new. They called it CASTOR-1200.

Still with me? We're almost done. Okay, so, now that the SLS is looking into the advanced boosters again, Orbital ATK (now part of Northrop-Grumman) submitted a new proposal for the Booster End-of-Life Extension (BOLE), and it knocks the Dark Knights out of the water.

The new boosters would allow a payload performance of roughly 45 mT to TLI with the SLS Block IB, which is basically on-par with the Saturn V! Needless to say, this would be a substantial increase in the Block IB's performance (and, IMO, another nail in the Block II's coffin). Ultimately, it might end up that the SLS Block IB surpasses the Saturn V, if this all goes to plan.

If any of you are super-nerds like me, you can find more info about the new boosters here

Edited April 13, 2019 by jadebenn

[tater]

Yeah, I read that the MLP was funded (500 million), so that 33 months I guess is concurrent with current dev (as of last year, too). So that's a major plus.

Bumping Block 1b to a more useful vehicle would be a major improvement.

ULA is flying Vulcan in Spring 2021, but the Heavy variant not until 2023. This si interesting (the latter), because that pushes 5m Centaur into maybe 2021/2022 (they plan to fly it as the upper stage for Delta IVH, I think, so that it is tested before Vulcan). Vulcan Heavy can get Orion to LEO with some margin. Then use B2 to get a payload to dock with it...

[jadebenn]

3 minutes ago, tater said:

Yeah, I read that the MLP was funded (500 million), so that 33 months I guess is concurrent with current dev (as of last year, too). So that's a major plus.

It'll probably take a little less than 33 months with an all-new ML-2. Much easier to build new than to dismantle an existing ML, re-route all the pipes and wires, add your new stuff, and put it back together.

Let's not forget that the current SLS ML-1 is actually the Ares I's. It had to be heavily modified and is now overweight because it wasn't originally designed to handle a rocket as bighuge as the SLS. A new SLS ML-2 wouldn't suffer from those issues.

[ZooNamedGames]

27 minutes ago, jadebenn said:

If any of you are super-nerds like me, you can find more info about the new boosters here

Please. If you have any technical documents, throw them down. This is what I enjoy reading!

[Bill Phil]

I’m pretty sure a Block 1b with advanced boosters is called Block 2.

And the issue with using Block 1 for longer than it was intended means they have to man-rate ICPS. Which adds delays. At that stage it’d be easier to just cut Block 1 and build Block 1b.

Honestly I’d’ve preferred a vehicle more akin to the Saturn V, specifically the staging setup. Kerolox first stage, hydrolox second stage, and potentially optional hydrolox third stage. With more efficient engines by a good tens of seconds of ISP and making  use of 3d printing, a “modern Saturn V” could’ve been a great vehicle, though it wouldn’t be a Saturn V at all. Of course it would’ve never happened for a variety of reasons. But some issues would be almost nonexistent, like the hydrostatic pressure in the core.

[jadebenn]

Just now, Bill Phil said:

I’m pretty sure a Block 1b with advanced boosters is called Block 2.

I thought so too, but the report I linked kept calling it Block IB enhanced, so I figure they probably know something I don't.

1 minute ago, Bill Phil said:

And the issue with using Block 1 for longer than it was intended means they have to man-rate ICPS. Which adds delays. At that stage it’d be easier to just cut Block 1 and build Block 1b.

They considered that plan. It turned out that it'd delay the first SLS launch until 2023 or so, mainly because the EUS is so behind schedule. Any delays from man-rating ICPS are going to be peanuts compared to that. 

4 minutes ago, Bill Phil said:

Honestly I’d’ve preferred a vehicle more akin to the Saturn V, specifically the staging setup. Kerolox first stage, hydrolox second stage, and potentially optional hydrolox third stage. With more efficient engines by a good tens of seconds of ISP and making  use of 3d printing, a “modern Saturn V” could’ve been a great vehicle, though it wouldn’t be a Saturn V at all. Of course it would’ve never happened for a variety of reasons. But some issues would be almost nonexistent, like the hydrostatic pressure in the core.

Ultimately, I think that's kind of the contradiction at the heart of the SLS's problems. With the role it's grown into (basically a slightly smaller Ares V), it probably would've been better to have done a clean-sheet design and not be shackled by the shuttle's limitations. But with the role it started with (keep the shuttle industrial base alive and minimize the transition time), sticking with the shuttle hardware was undoubtedly the way to go. Since it tried to do both, it ended up doing neither very well. Although I will say that it's doing a lot better in the "be a heavy launcher" realm than it ever did in the "don't let the shuttle industrial base dry up" one. The latter... didn't really pan out. At all.

[Bill Phil]

3 hours ago, jadebenn said:

I thought so too, but the report I linked kept calling it Block IB enhanced, so I figure they probably know something I don't.

They considered that plan. It turned out that it'd delay the first SLS launch until 2023 or so, mainly because the EUS is so behind schedule. Any delays from man-rating ICPS are going to be peanuts compared to that. 

From what I've seen Block 1b is specifically Block 1 with the EUS, and Block 2 is Block 1b with advanced boosters.

They may be trying to call it "Block 1b enhanced" since Block 2 is basically dead as of now.

I mean they should've never even considered an interim stage to begin with and started with the EUS from the beginning. That's why chucking the ICPS out and focusing on EUS would delay it - they put themselves in a pretty not good situation...

And honestly I'd rather wait for SLS to launch in 2023 than see Block 1b never developed (as that may be likely...).

Edited April 13, 2019 by Bill Phil

[jadebenn]

2 hours ago, Bill Phil said:

 I mean they should've never even considered an interim stage to begin with and started with the EUS from the beginning. That's why chucking the ICPS out and focusing on EUS would delay it - they put themselves in a pretty not good situation...

 And honestly I'd rather wait for SLS to launch in 2023 than see Block 1b never developed (as that may be likely...).

I think it's a bit premature to declare IB dead. I know the President's initial budget request didn't include the EUS, but that budget request is completely out-of-date now that the 2024 moon program goal's been announced. I wouldn't be surprised if the amended request (which will pop up sometime soon) has it back, as well as additional funding requests for the various lunar systems that now need to be thrown into full-gear.

It ultimately comes down to Congress, though. They are free to listen to or ignore these budget requests at their sole discretion. They might fund an EUS even though it's not in the proposal. Or (hypothetically), they might kill it even though NASA asks for it. If past experience shows, odds are pretty good that Block IB will emerge unscathed.

EDIT: You know, if I may speculate, it may be that the reason that they make a distinction between SLS Block IB enhanced and SLS Block II may be because even with these BOLE SRBs, they might still be short of the payload mandate for Block II. That would fit with what I've heard elsewhere: That the Block II's capacity suffered a lot because of the decision to drop the 5th RS-25E on the core pretty early on into the program.

Edited April 14, 2019 by jadebenn

[Canopus]

@jadebenn i'm sure Block 2 was supposed to have the Liquid Pyrios Boosters with F-1 engines, and have an even Larger upper stage using J-2x but that version seems to have been abandoned very early on.

Edit: I looked again and later version of block two just appear to use advanced SRBs and the normal EUS, so it might just be the fifth RS-25 thats makes the difference.

Edit 2: looking further i found this:

showing only four engines.

Edited April 15, 2019 by Canopus

[jadebenn]

35 minutes ago, Canopus said:

i'm sure Block 2 was supposed to have the Liquid Pyrios Boosters with F-1 engines, and have an even Larger upper stage using J-2x but that version seems to have been abandoned very early on.

Edit: I looked again and later version of block two just appear to use advanced SRBs and the normal EUS, so it might just be the fifth RS-25 thats makes the difference.

Edit 2: looking further i found this:

-image snip-

showing only four engines.

Right, yeah. What I'm trying to articulate though, is that I'm willing to speculate that Block 2 configuration you linked would not meet the 130 mT requirement. I've heard credible rumors that the dropping of the 5th RS-25 and the J-2X upper stage early on in the SLS program meant that some sort of supplement would be required in the future in order to beef up Block 2. Thus, they may be re-designating what they were recently calling Block 2 as Block 1B enhanced (since it doesn't make that figure), and pushing out the new Block 2 further into the future, with a new upper stage or side-mounted LRBs so that it does meet the 130 mT payload requirement. Y'know, if it's ever built.

It's just speculation, but it would explain why the BOLE document referred to the SLS configuration with their boosters as Block 1B enhanced instead of just calling it Block 2. That seems too intentional to just be an oversight or mistake.

Edited April 15, 2019 by jadebenn

[tater]

From interview with Bridenstein:

 

[Nightside]

I had to look one of those acronyms up.

PPE: Power Propulsion Element

what do we know about this thing? How will this compare with previous electric propulsion?

[ZooNamedGames]

https://www.nasaspaceflight.com/2019/04/boeing-nasa-finish-sls-core-stage-end-year/

[Ultimate Steve]

I'm glad to see that they're shaking this up and taking it seriously!

[MinimumSky5]

Don't forget:

2023: Yusaku Maezawa waves on his way past! 

[Canopus]

I so hope that it's not just a two person surface mission. I really think this accelerated plan is a bad idea.

[Ultimate Steve]

19 minutes ago, Canopus said:

I so hope that it's not just a two person surface mission. I really think this accelerated plan is a bad idea.

Yeah. I think that the design should be able to hold the 4 people on Orion. Getting stuck with an interim lander intended to be replaced by something more powerful in the future could very well end up going the way of the ICPS...

But if it's a choice between 2 people or 0 people, I'd choose 2.

[tater]

Original Gateway idea is at least 18 years old. This one made more sense, too.

https://history.nasa.gov/DPT/Architectures/Libration Points & In-Space Ops Libration Point Gateway Final Report DPT Oct_01.pdf

 

[ZooNamedGames]

1 hour ago, MinimumSky5 said:

Don't forget:

2023: Yusaku Maezawa waves on his way past! 

Assuming nothing goes wrong and there aren’t any delays or changes in the design which will result in delays.

Though I do think that the bulk of #dearmoon’s ticket purchase is a contractual agreement to launch by 2023. Hence why Musk is taking such an aggressive approach to getting it running. But we’ll see if that tactic pays off.