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[New] Space Launch System / Orion Discussion Thread


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12 minutes ago, Minmus Taster said:

think it's safe to say NASA's human spaceflight has been a joke since the space shuttle.

For all Shuttle's problems and high costs, it was a broadly capable vehicle for human LEO work.  Sure, ISS construction was "make work" in small sections with Shuttle vs launching a few large elements with a big, dumb booster, and similarly many other missions (launching sats, etc) could have been done more efficiently with other LVs. None the less, if you came up with some LEO task for humans, Shuttle could likely do that.

If you come up with a BLEO task (cislunar being the most likely) for SLS/Orion—it can't do it. It;s not a matter of it being a small subset of tasks, there are not really ANY it can accomplish except "going somewhat closer to the Moon than Earth already is."

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2 minutes ago, tater said:

For all Shuttle's problems and high costs, it was a broadly capable vehicle for human LEO work.  Sure, ISS construction was "make work" in small sections with Shuttle vs launching a few large elements with a big, dumb booster, and similarly many other missions (launching sats, etc) could have been done more efficiently with other LVs. None the less, if you came up with some LEO task for humans, Shuttle could likely do that.

Looking back at how DIRECT was admittedly overpowered for LEO work (not that the Shuttle wasn't), I wonder if it would have been possible to do a smaller version with just one SRB for launching Orion Lite to the ISS.

One SRB strapped to a smaller tank -- maybe something like the Delta IV Common Booster Core? Lots of gimbal action to keep the COM in the right place on the way up. And then just a single SSME.

screenshot345.png

 

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22 hours ago, Minmus Taster said:

I have to say this feels like a waste of money on NASA's part.

For over ten years they've been just slogging along slowly as a snail and at this point I'm desensitized to to the delay's and problems.

And to think SpaceX has flown several prototypes in a few months of they're larger more ambitious rocket and only been developing for a few years, I think it's safe to say NASA's human spaceflight has been a joke since the space shuttle.

NASA is not the one allocating and ear-marking those funds for SLS.

They may have more discretion on other things, but NASA is being given that money and being ordered to spend it on SLS.  As a government organization, they don't really have a choice in the matter, refusal will just mean the people trying to refuse will be replaced by those willing to abide by the legal requirements being placed upon them.

If you want to say that the US government is wasting that money, I can only say: meh, it is hardly the most egregious budget item in a given year, and at least it is helping to pay some NASA salaries.

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21 hours ago, sevenperforce said:

Looking back at how DIRECT was admittedly overpowered for LEO work (not that the Shuttle wasn't), I wonder if it would have been possible to do a smaller version with just one SRB for launching Orion Lite to the ISS.

One SRB strapped to a smaller tank -- maybe something like the Delta IV Common Booster Core? Lots of gimbal action to keep the COM in the right place on the way up. And then just a single SSME.

screenshot345.png

 

If you put the tank on top of the booster, made it smaller and a vacuum engine (J-2X), you'd have an Ares rocket (one prototype made in 2009).

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14 minutes ago, wumpus said:

If you put the tank on top of the booster, made it smaller and a vacuum engine (J-2X), you'd have an Ares rocket (one prototype made in 2009).

Right, same basic idea.

The original Ares I was supposed to use an SSME on the second stage but they would have had to rebuild for air-starts.

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  • 2 weeks later...

So first SLS is "the most powerful rocket ever" and now this-

First skip reentry attempt for a human spacecraft was Zond 6, first successful one was Zond 7. Both were fully capable 7K-L1 spacecraft, and could have carried crews (they were not prototypes).

Do NASA PR people not know that much about spaceflight history outside of America? The NASA History Office itself has a book about the Soviet space program where they could have learned this.

Or did someone in the PR department literally say "SLS-Orion doesn’t have much going for it, so take the innovative stuff (or stuff that worked) from the Soviet crewed lunar program and use it to make SLS-Orion look like an efficient and useful component of the Artemis program"?

Edited by SunlitZelkova
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36 minutes ago, kerbiloid said:

If 20 g overload is normal for regular flights.

I think that was Zond 4 and Zond 5, which had a ballistic reentry. In any case, “the first skip reentry for a human spacecraft” would be incorrect, no matter the G-load.

Of course on the other hand, Orion will be the first skip reentry with people on board once Artemis II happens.

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1 hour ago, SunlitZelkova said:

I think that was Zond 4 and Zond 5, which had a ballistic reentry.

At ballistic trajectory they achieved 32, iirc. A turtle's eye had been popped out,
The 15..20 was on gliding/diving one.

Soyuz capsule ogive shape is appropriate for LEO, but has low L/D compared to the conical Apollo-style ones, so on the return trajectory the overloads were up to ~1.5 times higher.

Edited by kerbiloid
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As long as we're complaining about stolen firsts, even if the real firsts were unsurvivable:

At 37 seconds in, they say Orion will travel over 280,000 miles (ew, miles) from Earth, farther than any human spacecraft has ever flown. I assume that means a spacecraft designed to carry humans inside, but even so, Snoopy's ascent module went to heliocentric orbit! That was NASA's own doing. They could have clarified returning spacecraft, space capsule, survivable journey, but as it stands it's just false from any angle I can see that statement from.

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2 minutes ago, RyanRising said:

At 37 seconds in, they say Orion will travel over 280,000 miles (ew, miles) from Earth, farther than any human spacecraft has ever flown. I assume that means a spacecraft designed to carry humans inside, but even so, Snoopy's ascent module went to heliocentric orbit! That was NASA's own doing. They could have clarified returning spacecraft, space capsule, survivable journey, but as it stands it's just false from any angle I can see that statement from.

 

4 hours ago, SunlitZelkova said:

So first SLS is "the most powerful rocket ever" and now this-

First skip reentry attempt for a human spacecraft was Zond 6, first successful one was Zond 7. Both were fully capable 7K-L1 spacecraft, and could have carried crews (they were not prototypes).

Do NASA PR people not know that much about spaceflight history outside of America? The NASA History Office itself has a book about the Soviet space program where they could have learned this.

Or did someone in the PR department literally say "SLS-Orion doesn’t have much going for it, so take the innovative stuff (or stuff that worked) from the Soviet crewed lunar program and use it to make SLS-Orion look like an efficient and useful component of the Artemis program"?

I think you guys are really over analyzing this. America is returning to the moon for the first time in a while (don't want to do math). I doubt they care if a spent crew cabin was out further than orion, its space junk. And NASA could care less about what some soviet spacecraft where doing . All space programs are democratic propaganda machines and they really don't need to mention what happened in the Soviet Union. 

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3 minutes ago, SpaceFace545 said:

 

I think you guys are really over analyzing this. America is returning to the moon for the first time in a while (don't want to do math). I doubt they care if a spent crew cabin was out further than orion, its space junk. And NASA could care less about what some soviet spacecraft where doing . All space programs are democratic propaganda machines and they really don't need to mention what happened in the Soviet Union. 

Even so, I'd prefer they not lie about their accomplishments. I think going back to the moon is fantastic, but making false claims about the accomplishments makes it seem like NASA thinks what they're actually doing isn't good enough, unintentional though that may be.

Edited by RyanRising
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On 3/29/2021 at 12:20 PM, Minmus Taster said:

I have to say this feels like a waste of money on NASA's part.

For over ten years they've been just slogging along slowly as a snail and at this point I'm desensitized to to the delay's and problems.

And to think SpaceX has flown several prototypes in a few months of they're larger more ambitious rocket and only been developing for a few years, I think it's safe to say NASA's human spaceflight has been a joke since the space shuttle.

Edit; And I would at least take the program seriously if they didn't calling S.L.S (Space Launch System? Really? What kind of name is that???)

Every single starship prototype has failed in one way or another but never in the same way. SpaceX isn't really American or with NASA. SpaceX just wants to "colonize mars" for some reason not explore space for the American people.

Also, what else would they call it, SLS makes since, a natural derivative from STS. SLS makes more literal sense than Starship.

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2 minutes ago, SpaceFace545 said:

I think you guys are really over analyzing this. America is returning to the moon for the first time in a while (don't want to do math). I doubt they care if a spent crew cabin was out further than orion, its space junk. And NASA could care less about what some soviet spacecraft where doing . All space programs are democratic propaganda machines and they really don't need to mention what happened in the Soviet Union. 

The tweet says first skip entry for a human spacecraft. I doesn't say a US spacecraft.

Not that Artemis I's CSM could actually carry crew.

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On 3/29/2021 at 1:38 PM, sevenperforce said:

Looking back at how DIRECT was admittedly overpowered for LEO work (not that the Shuttle wasn't), I wonder if it would have been possible to do a smaller version with just one SRB for launching Orion Lite to the ISS.

One SRB strapped to a smaller tank -- maybe something like the Delta IV Common Booster Core? Lots of gimbal action to keep the COM in the right place on the way up. And then just a single SSME.

screenshot345.png

 

That looks like Atlas V 411

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A huge problem is Orion, honestly.

Orion was intentionally made over heavy. Not over heavy for capability, over heavy so it could only launch on Constellation vehicles to ensure the program at the time. It was purpose-designed such that Atlas could not take it to LEO, Ares I had to.

Since Ares I was the godawful monstrosity it was, the LES became insanely huge as well (because it had to pull the capsule off %$#@%@# firework (seriously, putting humans on top of solid rocket motors is a special kind of stupid).

The plus of the Constellation Program vs SLS/Artemis is the notion that the crew vehicle rides to orbit on a smaller LV dedicated to that purpose, and the giant rocket is a cargo beast. The downside of course is that Ares I was garbage, and pretty expensive for what it was into the bargain (I want to say that would have been a billion $ per launch being a figure I saw—to LEO).

A secondary problem is the idiocy of the SRBs. SRBs make sense if they are as cheap as they should be. Sadly for SLS, the SRBs are just shy of a billion $ per set. Literally 10X more expensive than they should be.

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38 minutes ago, tater said:

A huge problem is Orion, honestly.

Orion was intentionally made over heavy. Not over heavy for capability, over heavy so it could only launch on Constellation vehicles to ensure the program at the time. It was purpose-designed such that Atlas could not take it to LEO, Ares I had to.

Since Ares I was the godawful monstrosity it was, the LES became insanely huge as well (because it had to pull the capsule off %$#@%@# firework (seriously, putting humans on top of solid rocket motors is a special kind of stupid).

The plus of the Constellation Program vs SLS/Artemis is the notion that the crew vehicle rides to orbit on a smaller LV dedicated to that purpose, and the giant rocket is a cargo beast. The downside of course is that Ares I was garbage, and pretty expensive for what it was into the bargain (I want to say that would have been a billion $ per launch being a figure I saw—to LEO).

A secondary problem is the idiocy of the SRBs. SRBs make sense if they are as cheap as they should be. Sadly for SLS, the SRBs are just shy of a billion $ per set. Literally 10X more expensive than they should be.

I agree, Orion is way too heavy but are there any other options. Not like anyone is willing to ditch Orion but if they have too?

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8 hours ago, SpaceFace545 said:

I agree, Orion is way too heavy but are there any other options. Not like anyone is willing to ditch Orion but if they have too?

CST-100 is effectively "Orion Lite," I supposed that design (when it's ever flight ready) could have the TPS beefed up. The point obviously would be to keep Vulcan as the LV (or NG, or indeed F9), then dump putting crew on top of SLS at all. The SRBs require a massive LES because of the nature of SRB risk (Challenger showed this, as after the tank RUD, the SRBs kept flying, so any LES system needs to be able to pull away faster than SRBs can fly minus the vehicle they used to be attached to.

Maybe once the thing need not be "crew rated," they could cheapen it up, though at 99M$ per RS-25E going forward in the distant future, that's simply impossible. Future SLS (no Orion counted here) has $400M in engines on the core, $971M in SRBs (hey, let's assume they can drop that by >20% to $775M for a pair for giggles). So that's $1.175B, and we still need an upper stage, and the core stage.

The only cost data we have on the core stage is what NASA paid for the first 2 flight articles, plus the one they destructively tested and the pathfinder(s), including some EUS dev (uses same tank welding), and that was $6.681B There is no way each flight core stage (just the tubes) costs much less than $1B. No possible way. That would mean that all the dev costs, etc for making tubes based on Shuttle Main Tank (because it was faster and cheaper!) would be more than half that budget. OK, benefit of the doubt and call it $2B for 2 flight, 1 test stage for lowest possible SLS cost (it's more likely a billion each)—that's $666M each.

We now have $1.175B + $0.667B = S1.842B for the core plus SRBs... ICPS is ~$160M per stage, bringing each to an even $2B. EUS will obviously cost more, not less than ICPS, but there is no possible way SLS launches ever drop below 2 billion each. Not including Orion (over a billion per CSM), not ever.

Where could they reduce costs to make an SLS cheaper cargo version?

$666M for each core stage seems like a starting point. Off the shelf propane tank cost is not a lower limit for SLS, as the tanks have to hold Hydrogen which is more expensive to design for. A quick google shows that using current hydrogen storage transport container costs, tank capacity large enough to hold that much LH2 would cost $50M. That might not be a bad lower limit, but for ground use, mass clearly doesn't matter, either, so I of course don't expect that to be a reasonable number. But it seems like heading towards that number an order of mag lower (at least) than the core stage costs should be possible. NG is 7m, 83% of SLS diameter, and they plan to compete in price with F9. They have to be making those stages (overbuilt for reuse) for not more than $100M. $200M for SLS made in a way that doesn't rip us off?

That gets SLS to $1.8B, or maybe holds it at $2B with EUS (assume EUS is ~2X ICPS).The next place are the fireworks on the side. There is simply zero reason that 2 SRBs should be $971M, that's criminally high. Old information seems to imply Shuttle SRBs were more like $50M for a set. Dunno why we (taxpayers) are being ripped off by a factor of ~20, but we are. So if the SRBs were properly contracted at $50M for a set, or even just 10X less at $97M for a pair, we could drop the SLS launch price to $1.26B!

That's starting to get someplace. Now we just need to get RS-25s down to a reasonable price. There's not really any reason for a rocket engine to cost more than even $10M for disposable engines IMO. Heck, in constant dollars SSMEs were $50M new, right? How about half that for expendable versions? Now SLS has $100M on the bottom, instead of $400M. We're now at $826M per launch (block 1B cargo). If EUS could be made not $360M, we could drop that further, and $360M is criminal for that, as well (Delta IVH cost for a single stage? yeah, no). No single upper stage should cost as much as any single stick liquid rocket launch retail. Call it $60M. That gets us down to $526M per launch.

If SLS was not literally ripping off taxpayers, half a billion would be an entirely reasonable cost for that capability, and I'd be a huge fan.

 

EDIT: turns out Shuttle external tanks cost... $75M. SLS has new tanks, so new they are not at all the same (removing all commonality). Still, the core stage is just 18m longer, so call it 50% more cost. If we pay more than ~$113M for the core stage... we're being ripped off. You can round that up slightly, as ET-94 was delivered to NASA in 2001, so whatever inflation does to that in 20 years (not much).

Edited by tater
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SLS / Orion are the least essential bits of Artemis, tbh.

Take away the commercial support of Falcon Heavy, Vulcan, Starship or HLS, and people don't walk on the moon period.

Take away SLS/Orion and we can still make something work by Earth Orbit Rendezvous, probably for a good deal less money.

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42 minutes ago, RCgothic said:

Take away SLS/Orion and we can still make something work by Earth Orbit Rendezvous, probably for a good deal less money.

Yeah, but it is funded, regardless. It will fly until there is some off the shelf alternative that makes it look stupid.

My point is that it could fly many more times than it will for the same money. The thing could be well under a billion a flight, and still make money for the contractors.

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It seems to me that Orion will be the part of SLS getting to Mars and back.

Maybe even when fusion engines get ready.

Because they anyway need an escape pod, and that's it.

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10 hours ago, kerbiloid said:

At ballistic trajectory they achieved 32, iirc. A turtle's eye had been popped out,
The 15..20 was on gliding/diving one.

Soyuz capsule ogive shape is appropriate for LEO, but has low L/D compared to the conical Apollo-style ones, so on the return trajectory the overloads were up to ~1.5 times higher.

Thanks for the info! I was unaware.

7 hours ago, tater said:

(because it was faster and cheaper!)

Are there any real engineering reasons why SLS and Orion have taken so long? I do recall seeing accusations of Boeing deliberately taking their time with the core stage to make more money going around in much older posts in the thread, but I wonder if they (NASA and the contractors) have given any real reason for not launching in 2016 (which they were congressionally mandated to do) apart from "delays".

Obviously you were being sarcastic, but something to note is that Crew Dragon, which started development in the same year as SLS (or maybe a little bit after, Commercial Crew started in the same year), was both faster and is cheaper than SLS. BLEO and ISS transport are different things but still...

3 hours ago, kerbiloid said:

It seems to me that Orion will be the part of SLS getting to Mars and back.

Maybe even when fusion engines get ready.

Because they anyway need an escape pod, and that's it.

It is unclear. The most recent crewed Mars mission architecture with the Deep Space Transport has them leaving the Orion at the Gateway, and boarding the DST there and then going to Mars. But NASA is still making blog posts about Orion's heat shield stating it needs to "survive the heat of a Martian reentry".

Edited by SunlitZelkova
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5 minutes ago, SunlitZelkova said:

Are there any real engineering reasons why SLS and Orion have taken so long? I do recall seeing accusations of Boeing deliberately taking their time with the core stage to make more money going around in much older posts in the thread, but I wonder if they (NASA and the contractors) have given any real reason for not launching in 2016 (which they were congressionally mandated to do) apart from "delays".

SLS dev from 2011 on has not been that bad, really. It's "slow" compared to the legal requirement of flight by the end of 2016, clearly, but that was set by the same people that set the SLS design standards—the new head of NASA, in fact, who knows exactly nothing about rockets, or at least no more than any random airline passenger knows about building a 747.

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BTW, I added an edit to my last SLS cost post. ET-94, the light weight tank built for Columbia, and delivered to NASA in 2001, cost $75M brand new. SLS core is a little more than a third larger. Call it 50% larger to slop up the cost. Corrected for inflation and the larger than it should be increased size (50% larger), that's $171M, I said 112 I think. Oops.

Still, that drops the cost of what SLS should cost to 100(4*RS-25)+171(core)+88(25% larger SRBs)+60(EUS*) = $419M

 

Edited by tater
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12 hours ago, tater said:

Yeah, but it is funded, regardless. It will fly until there is some off the shelf alternative that makes it look stupid.

My point is that it could fly many more times than it will for the same money. The thing could be well under a billion a flight, and still make money for the contractors.

Yes, that's the thing that annoys me most. Not that it's a badly designed architecture that can't accomplish any mission by itself, but that it shouldn't be as expensive as it is and it could be flying over four times as often for the same money.

The opportunity cost is staggering.

12 hours ago, kerbiloid said:

It seems to me that Orion will be the part of SLS getting to Mars and back.

Maybe even when fusion engines get ready.

Because they anyway need an escape pod, and that's it.

If any part of SLS/Orion goes to Mars it'll only be because the vast majority of the work was done by some other boosters. It's completely incapable of constructing any practical mothership in either LEO or at Gateway at any reasonable cost or timescale.

"SLS /Orion is how we get to Mars" is one of those statements I classify as *lies to investors*.

8 hours ago, tater said:

BTW, I added an edit to my last SLS cost post. ET-94, the light weight tank built for Columbia, and delivered to NASA in 2001, cost $75M brand new. SLS core is a little more than a third larger. Call it 50% larger to slop up the cost. Corrected for inflation and the larger than it should be increased size (50% larger), that's $171M, I said 112 I think. Oops.

Still, that drops the cost of what SLS should cost to 100(4*RS-25)+171(core)+88(25% larger SRBs)+60(EUS*) = $419M

 

In which case it'd be somewhat competitive to Falcon Heavy, we could build five times as many for the same price, four cargos for every crewed, and the extra launches would cover Orion's weak points.

That'd be the kind of SLS I could get along with.

9 hours ago, SunlitZelkova said:

It is unclear. The most recent crewed Mars mission architecture with the Deep Space Transport has them leaving the Orion at the Gateway, and boarding the DST there and then going to Mars. But NASA is still making blog posts about Orion's heat shield stating it needs to "survive the heat of a Martian reentry".

Well they have to pretend Gateway is useful for something.

Even with full ISRU I'm not convinced fuelling a Mars mission at Gateway (LLO would be better) is worth it compared to assembling in LEO. 

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