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NASA SLS/Orion/Payloads

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Posted (edited)

As I said the last time we slammed heads;

  • SLS benefits everyone as the experience NASA learns is made available to everyone and isn't limited to one company as a 'company secret'. Information benefits the whole industry and companies like Blue Origin and SpaceX can utilize NASA's data and expereience to build their machines more efficient and more effective. Rather than make mistakes that NASA would otherwise discover on their own. Saves SpaceX and Blue Origin money to let NASA learn for them.
  • SLS is a stop-gap until BFR/New Glenn are proven effective and reliable.
  • SLS doesn't need to fly 5+ times a year like the Atlas V which flew 8 times in 2016. Even the Saturn V during it's height only launched at a peak of 4 times in a single year, but that was in 1969, when NASA was pressured by the entire nation to reach the moon before the end of that year (spoiler, they did).
  • NASA, and subsequently the SLS, isn't responsible for meeting the demands of armchair aerospace engineers, but rather those who are funding it.

 

That said, I'm stepping out again. SLS is nearly ready for it's maiden flight, and instead of banging down NASA's door screaming about their inefficiency, I will be present, as close as I can be, to see it fly.

Edited by ZooNamedGames

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Posted (edited)
17 minutes ago, ZooNamedGames said:

As I said the last time we slammed heads;

  • SLS benefits everyone has the experience NASA learns

How to not manage a large program? That seems like the biggest take away.

To the extent SLS is using Shuttle tech, there's little new to learn, anyway (on the SLS side).

Quote
  • SLS is a stop-gap until BFR/New Glenn are proven effective and reliable.

Yes, and while I don't fault them starting the program before SpaceX and Blue Origin had any remote chance of replacing SLS capability, I do fault them for spending 10s of billions on a system that was not well thought out.

Assume everything about SLS being roughly the same in terms of contractors, money, etc. Design it to maximize utility. That means setting a range of goals that they can actually do (payloads for cargo, or something for crew vehicle to do), then design the LV(s) required. If they can only manage a huge Block 2 sized payload every 3 years, then that's how often they should fly that. The program (which costs 2.5+ B$/year doing nothing at all) then works on the LEO crew vehicle flights, on the off years (while prepping the large SLS). So they should have simultaneously gone for a crew LV, that flies at least once a year (ISS crew an obvious choice, and acts as Orion shakedown cruises).

Note that they could have leveraged commercial crew. Since part of the funding was to man-rate F9 and Atlas V, they could had added a requirement for the added capability to loft Orion to LEO (we're talking several years ago, after all). A LEO Orion (as a third commercial crew vehicle in effect) would need a tiny SM, and might be able to be lifted by A5 or F9 as-is. Again, this goes to program design, not specifics of SLS.

That would be a sustainable system.

 

Quote
  • SLS doesn't need to fly 5+ times a year like the Atlas V which flew 8 times in 2016. Even the Saturn V during it's height only launched at a peak of 4 times in a single year, but that was in 1969, when NASA was pressured by the entire nation to reach the moon before the end of that year (spoiler, they did).

It doesn't need to fly at all if it cannot achieve a needed mission goal. It;s too big for LEO, and not big enough for human cislunar. It could launch things like Europa Clipper, but NASA doesn't have the budget to make a multi-billion dollar science probe every single year forever. Launching every year matters. Why? Because the program costs a few billion every year if they launch or not. If they launch every other year, each launch effectively costs over 5 billion dollars. A program that produces no results, and costs a great deal is a drain. They talk about a marginal launch cost of something like 500 million, but that's nonsense if they launch every other year, and the program costs as 5-6 billion in that timeframe. It is worth 5 billion $ (ignoring R&D) to send people to be really far from the Moon for a week once every 2 years in perpetuity?

 

Quote
  • NASA, and subsequently the SLS, isn't responsible for meeting the demands of armchair aerospace engineers, but rather those who are funding it.

 

That said, I'm stepping out again. SLS is nearly ready for it's maiden flight, and instead of banging down NASA's door screaming about their inefficiency, I will be present, as close as I can be, to see it fly.

I fund it. We're net taxpayers (more than our per capita share of expense).

BTW, "nearly ready" is 2 years from now (unless them cutting corners all of a sudden buys them 6 months).

Edited by tater

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Posted (edited)

EDIT: the Orion capsule is a little over 10 tonnes. The current dunno-what-for SM is over 15t. A LEO variant would need nothing remotely like a 15 tonne SM. CST-100 is ~13 tonnes, and Atlas V can loft it, and has put over 20 tonnes in LEO before. F9 could lift Orion with a smaller SM as well. If LockMart was smart, they'd look into this (making a LEO, LV agnostic version). NASA would like it as well, as it would give them a backup for ISS crew, and leverages the expense already put into Orion, because it can then be used more.

Edited by tater

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3 hours ago, tater said:

EDIT: the Orion capsule is a little over 10 tonnes. The current dunno-what-for SM is over 15t. A LEO variant would need nothing remotely like a 15 tonne SM. CST-100 is ~13 tonnes, and Atlas V can loft it, and has put over 20 tonnes in LEO before. F9 could lift Orion with a smaller SM as well. If LockMart was smart, they'd look into this (making a LEO, LV agnostic version). NASA would like it as well, as it would give them a backup for ISS crew, and leverages the expense already put into Orion, because it can then be used more.

Only one critical flaw with your logic: it's logic. rofl.gif We all know that logic must be discounted when discussing any post-shuttle launchers for NASA-only use.

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Some content has been removed from this thread. Please discuss the topic rather than each other. 

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On ‎3‎/‎29‎/‎2019 at 11:52 AM, tater said:

(ie: they should have stuck with Ares V)

I don't know... According to some guys at MSFC Ares V wasn't doing very well either. Some of the trajectory analysis was done making certain assumptions that turned out to be very inaccurate if not downright impossible. And with Orion growing in mass the EDS probably couldn't deliver both Altair and Orion to TLI.

That said, NASA should've skipped straight to SLS Block II Cargo with 5 SSMEs on the core, which is basically a less powerful Ares V using SSMEs. 5 SSMEs would lower gravity losses (one of the biggest handicaps SLS suffers from - 4 SSMEs just don't give enough thrust to efficiently launch the stack). So with 5 engines it could potentially rival the proposed Ares V. Might have to deal with a smaller lander than the proposed Altair, though. Also I'm not sure about EUS's capabilities if a Constellation style mission was performed. 

If they do want to return to the Moon by 2024 that's going to require Block 1B at the least, Block 2 preferably. Block 1 should be cancelled (cutting losses on ICPS) and then either Block 1B or Block 2 developed, hopefully fixing some of the problems. However they'll also need a serious change in project management just to make it remotely possible. Lander development would need to start now, but they'd need to do mission analysis first to find out what exactly the lander would need to be capable of given limitations of SLS and Orion. If they can get away with a new SM with more delta-v for Orion that would be preferable as well.

Of course all that is not likely to happen.

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43 minutes ago, Bill Phil said:

I don't know... According to some guys at MSFC Ares V wasn't doing very well either. Some of the trajectory analysis was done making certain assumptions that turned out to be very inaccurate if not downright impossible. And with Orion growing in mass the EDS probably couldn't deliver both Altair and Orion to TLI.

You are right I think. I should have perhaps said that a vehicle that matched the Ares V specs would be a reasonable target, not that Ares V itself was that vehicle. Even perhaps the "Direct", Jupiter vehicles (closer to current SLS specs, really).

The underlying point is that useful architectures need to be considered, then a vehicle (or set of vehicles) need to be designed to meet those goals. This needs to include launch cadence issues, as well.

If the goal is a cislunar program that includes stations, tugs, and landers, then the system should be able to accomplish some nominal mission goal. If that requires 3 launches in a short time span, then if the system cannot cope with that, the design needs to change, or the vehicles need to be enlarged until the mission can be accomplished given the number they can fly in that time span. If only 1 a year, then the stack needs to be able to do any mission alone, and since Orion is larger than Apollo, the mass to LEO would then need to exceed Saturn V. If they can launch 2 a short time apart, then they need half the Saturn V mass to LEO, but they have to launch 2 in rapid succession to use in a single mission.

If they want to save SLS, they should, as you say, go right to block 2. They should then work on how to get Orion to space without SLS. FH is an obvious choice here. The claim it could not be crew rated is silly, as it is Orion is supposed to fly with crew on a LV flown exactly once before, and had Boeing not blown the EUS money they were given on (Place something here that Bender from Futurama might say, I'll leave that as an exercise for the reader) , then NASA would in fact have flown crew on the very first all-up launch (of B1b), period.

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And also due to the upgrades with Block 5 FH, it could probably lift the current design of Orion (Just relaying stuff I read)

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6 minutes ago, Barzon Kerman said:

And also due to the upgrades with Block 5 FH, it could probably lift the current design of Orion (Just relaying stuff I read)

That seems like a stretch with the LES on top, that thing is huge, I think it masses around 5000kg (more?) That would up the Orion CSM mass to over 30 tonnes.

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oh. i thought orion was "only" 26tons?

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16 minutes ago, Barzon Kerman said:

oh. i thought orion was "only" 26tons?

I see the CSM figure as 26t, and it's hard to nail down the LAS. The aeroshell is just shy of 1500kg, and the abort motors are apparently 3400. Unsure of other systems on there. It doesn't get carried all the way to LEO, though, so maybe it comes out in the wash, as nominal F9 payload mass to LEO is for under the fairing, not including the fairing...

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2 hours ago, Barzon Kerman said:

And also due to the upgrades with Block 5 FH, it could probably lift the current design of Orion (Just relaying stuff I read)

Block 5 FH should have no problem lifting Orion to LEO, but why would you want it there? The stack is supposed to be sent to the Moon, and I don’t think that even Block 5 expendable FH has that kind of capacity.

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On 3/29/2019 at 3:32 PM, ZooNamedGames said:
  • NASA, and subsequently the SLS, isn't responsible for meeting the demands of armchair aerospace engineers, but rather those who are funding it.

This is the problem, it is a rocket designed for politicians to keep the pork flowing, not the needs of NASA

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2 hours ago, sh1pman said:

Block 5 FH should have no problem lifting Orion to LEO, but why would you want it there? The stack is supposed to be sent to the Moon, and I don’t think that even Block 5 expendable FH has that kind of capacity.

The point in this case would be an architecture closer to Constellation. EOR, in other words. Send a large vehicle (lander and TLI stage) to LEO with the HLV, then send Orion to meet it, then the stack heads to cislunar space.

The difference between this concept and what they are currently proposing is that They are sending Orion to cislunar by itself, and the lander, etc is sent to cislunar via... magic, presumably. OK, not they are proposing sending the lander in multiple small pieces to cislunar space, then doing LOR with those, then LOR with Orion, etc. Unless they go with fully storable props, they need to get ZBO tanks ASAP, because the current architecture requires sending a lot of stuff well ahead of Orion.

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2 hours ago, sh1pman said:

Block 5 FH should have no problem lifting Orion to LEO, but why would you want it there? The stack is supposed to be sent to the Moon, and I don’t think that even Block 5 expendable FH has that kind of capacity.

The solution would be a return to the Constellation architecture. SLS Block 2 (or at least 1B) to send a lander/cargo and TLI stage to LEO; separate vehicle for crew and Orion. Here, FH for Orion. Easy.

And FHb5e can send Orion just past GTO, but that's far enough for Orion's SM to complete the TLI and still have enough dV to brake into a DRHO or DRO and return. Not that we need that.

2 minutes ago, tater said:

The point in this case would be an architecture closer to Constellation. EOR, in other words. Send a large vehicle (lander and TLI stage) to LEO with the HLV, then send Orion to meet it, then the stack heads to cislunar space.

The difference between this concept and what they are currently proposing is that They are sending Orion to cislunar by itself, and the lander, etc is sent to cislunar via... magic, presumably. OK, not they are proposing sending the lander in multiple small pieces to cislunar space, then doing LOR with those, then LOR with Orion, etc. Unless they go with fully storable props, they need to get ZBO tanks ASAP, because the current architecture requires sending a lot of stuff well ahead of Orion.

Sniped.

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Take away? "Boeing, get your act together."

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FH can send Orion to TLI without ICPS if Orion uses its own engine for the end of the burn.

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4 hours ago, sevenperforce said:

FH can send Orion to TLI without ICPS if Orion uses its own engine for the end of the burn.

They said in the video that while that is correct, the orion would not have enough delta V to enter into orbit

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Just now, insert_name said:

They said in the video that while that is correct, the orion would not have enough delta V to enter into orbit

Maybe EM-1 is back to orbit, and just EM-2 is the useless flyby?

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Just now, insert_name said:

They said in the video that while that is correct, the orion would not have enough delta V to enter into orbit

EM-1 was planned to be a flyby only, so it wouldn't need fuel for orbit. And I believe it would have enough for a DRO anyway.

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51 minutes ago, sevenperforce said:

EM-1 was planned to be a flyby only, so it wouldn't need fuel for orbit. And I believe it would have enough for a DRO anyway.

He said in the video that it wouldn't have enough fuel.

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2 hours ago, tater said:

Maybe EM-1 is back to orbit, and just EM-2 is the useless flyby?

I thought he was saying that if they did a commercial EM-1, the first actual SLS mission would probably be a module delivery to LOP-G or something like that. Seems like they would want to put that SLS to productive use rather a redundant Orion test.  But at the same time they probably don't want crew on the first flight.  Seems like a decent plan, assuming we're stuck with LOP-G to begin with.

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Posted (edited)
7 hours ago, Aegolius13 said:

I thought he was saying that if they did a commercial EM-1, the first actual SLS mission would probably be a module delivery to LOP-G or something like that. Seems like they would want to put that SLS to productive use rather a redundant Orion test.  But at the same time they probably don't want crew on the first flight.  Seems like a decent plan, assuming we're stuck with LOP-G to begin with.

Assuming they can crank EUS out by 2023?

Edited by tater

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8 hours ago, insert_name said:

He said in the video that it wouldn't have enough fuel.

You're right; I finally watched it in full.

It's odd because I have FH+Orion completing lunar injection and return with nearly 700 m/s to spare:

Spoiler
  • FHB5e throw weight to GTO: 26.7 tonnes
  • dV to GTO from 300 km parking orbit, 28.5°: 2605 m/s
  • FHB5e residuals before GTO burn with 26.7-tonne payload (348 s isp on MVac, est. 4.5-tonne dry stage mass)35.74 tonnes
  • Mass of Orion + ESM: 25,848 kg
  • FHB5e remaining dV in parking orbit with Orion + ESM and 35.74 tonnes of residuals: 2656 m/s
  • Minimum dV for trans-lunar injection (4.04 km/s - 1.31 km/s): 2730 m/s
  • Orion + ESM velocity to TLI at MVac minimum residual shutdown: -74 m/s
  • Orion + ESM onboard dV: 1855 m/s
  • Orion + ESM onboard dV after completing TLI: 1781 m/s
  • dV budget for High Lunar Orbit (OTA, LOI, maintenance, and TEI): 1084 m/s
  • dV budget for NRHO (lunar flyby injection, insertion, injection, and additional flyby) 840 m/s
  • dV budget for DRO: 957 m/s
  • Orion + ESM dV margin after launch on FHB5e:
    • NRHO: 941 m/s
    • DRO: 824 m/s
    • HLO: 697 m/s

I mean, they're the rocket scientists, not me. Maybe Orion mass growth has cut back its onboard dV, or maybe they want bigger margins? But still, -74 m/s seems like a small difference between FHe and SLS.

In any case, the fact that Bridenstine admits FHB5e can put ICPS+Orion+ESM into the same orbit as the SLS core and boosters really calls into question why we need the SLS core and boosters.

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