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NASA SLS/Orion/Payloads


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4 minutes ago, tater said:

According to Berger the suggestion came from SpaceX, so they are amenable to whatever is required, apparently, by definition.

Yep, that’s what I thought as well. Amazing that a single FH can (in theory) do EM-1. 39A is plumbed for hydrogen, right?

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1 hour ago, sh1pman said:
1 hour ago, sevenperforce said:

 

 Isn’t 39A already plumbed for hydrogen? 

1 hour ago, sevenperforce said:

Oh, right! But it hasn't been used in like 8 years... It could have been altered, disabled, or it could have worn out in that time.

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7 minutes ago, sh1pman said:

Isn’t 39A already plumbed for hydrogen? 

Not since 2011.

7 minutes ago, sh1pman said:

DCSS is 5m wide, a bit less than F9 fairing diameter. It’ll probably look silly, but not sillier than Atlas V with Starliner. Payload adapter can be redesigned for heavy payloads.

Useable internal diameter of the F9 upper stage is 4.6 meters, and that's only for the first 6.7 meters after the PAF, after which it begins to narrow. If we go without any fairing then we have to do full reworking of OML and aero.

Don't know if the actual energy works out for launching something that heavy to LEO though.

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1 minute ago, sevenperforce said:

Useable internal diameter of the F9 upper stage is 4.6 meters, and that's only for the first 6.7 meters after the PAF, after which it begins to narrow. If we go without any fairing then we have to do full reworking of OML and aero.

Don't know if the actual energy works out for launching something that heavy to LEO though.

They can’t use standard fairing anyway, because there’s Orion with LES on top, it needs crew access, etc. It’ll need to be a custom fairing between S2 and DCSS, maybe integrated with redesigned payload adapter. SLS has this Launch Vehicle Stage Adapter which is also a fairing between the core and ICPS. Something similar should be done for FH.

SLSview-min.jpg

 

9 minutes ago, sevenperforce said:

Don't know if the actual energy works out for launching something that heavy to LEO though.

Of course it does, SpaceX advertises it on their website.

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Hmm...

Orion CSM: 26 tons

Falcon 9/Heavy second stage dry mass: ~4 tons

Mating equipment: ~1 ton?

Total: 31 tons

Merlin vacuum isp: ~311 seconds

90 tons total, 59 tons of propellant gets you 3.25km/s of Delta-V. So it cannot be done with a single expendable Falcon Heavy.

 

...But, with the propellant we have, max 31 tons for a total mass of 62 tons, that gives us 2.1km/s. Orion's service module has 1.8km/s IIRC. If the service module propellant was used, and the mission was only a flyby, then it could work in one launch.

Plus, Block V has had some upgrades that we haven't seen numbers for. Maybe it has a few percent more performance than it previously did.

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11 minutes ago, sevenperforce said:

Not since 2011.

They removed the hardware?

1 minute ago, Ultimate Steve said:

Merlin vacuum isp: ~311 seconds

348 s.

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8 minutes ago, sh1pman said:
9 minutes ago, Ultimate Steve said:

 

348 s.

Ah. I must have had the numbers for the normal Merlin 1D in a vacuum, not the vacuum version in a vacuum... One sec...

That wasn't much better. 2.36km/s with an expendable FH.

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1 minute ago, Ultimate Steve said:

Ah. I must have had the numbers for the normal Merlin 1D in a vacuum, not the vacuum version in a vacuum... One sec...

That wasn't much better. 2.36km/s with an expendable FH.

I'm a little confused about these numbers.  Are you talking about getting from LEO to the Moon and back?  With a full Falcon second stage, but no hyrdrolox upper stage?

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Just now, Ultimate Steve said:

Ah. I must have had the numbers for the normal Merlin 1D in a vacuum, not the vacuum version in a vacuum... One sec...

That wasn't much better. 2.36km/s with an expendable FH.

I like the DCSS + Orion on FH scheme more. RL10B-02 has an ISP of 462 s, DCSS mass 30.7t wet, 3.5t dry. Should be more than enough dv.

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3 minutes ago, Aegolius13 said:
6 minutes ago, Ultimate Steve said:

 

I'm a little confused about these numbers.  Are you talking about getting from LEO to the Moon and back?  With a full Falcon second stage, but no hyrdrolox upper stage?

Yes. Launching the whole thing on one mostly off the shelf rocket eliminates the need to create docking hardware.

1 minute ago, sh1pman said:
6 minutes ago, Ultimate Steve said:

 

I like the DCSS + Orion on FH scheme more. RL10B-02 has an ISP of 462 s, DCSS mass 30.7t wet, 3.5t dry. Should be more than enough dv.

True. However, rockets are not lego, and DCSS plus Orion is really big for FH.

Also, facepalm, S2 mass isn't included in propellants, so FH would actually do 2.57km/s, still not enough though.

With your method, we have 1t of misc hardware, 26t Orion, and 31t DCSS. That's 58 tons. That leaves 4t of propellant in the Falcon stage as well. Dry mass of 31 and mass of 58 gives 2.84km/s. The extra F9 propellants would give  213m/s, for a total of around 3.05km/s. Orion would still need to use its service module a little bit, but not much.

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1 minute ago, Ultimate Steve said:

rockets are not lego

KSP taught me otherwise. Look at SLS!

3 minutes ago, Ultimate Steve said:

Orion would still need to use its service module a little bit, but not much.

So it is technically doable. Which method is more pain, this one or double launch?

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HOLY FRICKIN’ ****! Here I’m hypothesizing about a possible FH-DCSS-Orion stack, and then this guy releases a video about exactly that! 

 

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9 hours ago, Bill Phil said:

Shuttle-C wouldn’t have required a redesigned external tank, redesigned SRBs, or anything of the sort...

SLS is not using that much actual Shuttle hardware. Shuttle-C would have.

A lot would come down to how much control NASA had over the design of Shuttle-C vs. the Senate.  While SLS may have be designed by the Senate, the Shuttle was more or less a tight fit for a plethora of government requirements.  I doubt NASA would be allowed to build the Shuttle-C without it morphing into the SLS.

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2 hours ago, tater said:

According to Berger the suggestion came from SpaceX, so they are amenable to whatever is required, apparently, by definition.

Putting Orion on Falcon Heavy, and sending up crew on a Dragon 2, Falcon 9 to dock and enter, for something like EM-2? Sure. But I don't think SpaceX is suggesting flying EM-1 as a single stack.

I don't think that Pad 39A can accommodate launching Orion on Falcon Heavy, then refitting for Dragon 2, then refitting for a Falcon Heavy again to send up the TLI stack, for EM-2. So you'd need a TLI stage from ULA or someone else. I will have to play with the numbers and see if an empty Falcon 9 flown expendable can put up enough residuals to get an EM-2 mission going.

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1 hour ago, sevenperforce said:

Putting Orion on Falcon Heavy, and sending up crew on a Dragon 2, Falcon 9 to dock and enter, for something like EM-2? Sure. But I don't think SpaceX is suggesting flying EM-1 as a single stack.

I don't think that Pad 39A can accommodate launching Orion on Falcon Heavy, then refitting for Dragon 2, then refitting for a Falcon Heavy again to send up the TLI stack, for EM-2. So you'd need a TLI stage from ULA or someone else. I will have to play with the numbers and see if an empty Falcon 9 flown expendable can put up enough residuals to get an EM-2 mission going.

Just throwing out crazy ideas -- I wonder if they could launch the Dragon 2 / Falcon 9 from Vandenberg, during the retrograde launch window (so the rocket would go mostly west)?  I would think it has enough delta-v -- though it would require a more inclined orbit than launching everything out of the Cape.  Of course, they don't have the crew infrastructure out there now, but maybe they'll eventually want it anyway (or NASA could make it worth their while).  

Edited by Aegolius13
This made no sense... apologies.
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6 minutes ago, Aegolius13 said:
1 hour ago, sevenperforce said:

 

Just throwing out crazy ideas -- I wonder if they could launch the Dragon 2 / Falcon 9 from Vandenberg, during the retrograde launch window (so the rocket would go mostly west)?  I would think it has enough delta-v -- though it would require a more inclined orbit than launching everything out of the Cape.  Of course, they don't have the crew infrastructure out there now, but maybe they'll eventually want it anyway (or NASA could make it worth their while).  

Why would you want to send Dragon into a retrograde orbit? You can't exactly get to the ISS that way.

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1 minute ago, Ultimate Steve said:

Why would you want to send Dragon into a retrograde orbit? You can't exactly get to the ISS that way.

Yeah, you're right - I had a total brain fart.  You' could hit the same orbit but going the wrong direction...

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For EM-1, we know FH expendable has a payload of 26.7 tonnes to GTO. If my math is right, TLI is only 460 m/s beyond GTO. That's within Orion's capabilities five times over. No sweat.

Same with EM-2, though they would either have to man-rate FH or send crew up on Dragon 2, which runs into pad issues.

Orion's whole point is to be able to dock with LOP-G. Well, first Altair, then DSG, and now LOP-G. Have they not even figured THAT out yet?

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7 hours ago, sh1pman said:

KSP taught me otherwise. Look at SLS!

*laughs in Yenisei*

5 hours ago, Aegolius13 said:

Of course, they don't have the crew infrastructure out there now

How much of the old SLC-6 is left?

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14 minutes ago, Canopus said:

Yeah this isn't going to happen, someone is desperate to launch EM-1 while he is still president.

Rather, he tries to force NASA to keep the deadline that NASA set itself?

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