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NASA SLS/Orion/Payloads

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15 hours ago, Canopus said:

A big monolithic lander would require just as many launches to be refueled as a multistage lander to be launched and assembled. and in the end be far less flexible.

Yes and no. Unless your lander is really long-endurance, having an orbital element restricts destination latitudes. It’s the much-touted advantage of DA designs.

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16 minutes ago, DDE said:

Yes and no. Unless your lander is really long-endurance, having an orbital element restricts destination latitudes. It’s the much-touted advantage of DA designs.

Both landers start from the gateway so there should be no difference there

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41 minutes ago, Canopus said:

Both landers start from the gateway so there should be no difference there

My concern is with inclination mismatch and the resulting surface wait time for launch into target plane. Is NRHO so high that it’s easily reached from any LLO inclination? I still doubt the mechanics would play out.

Edited by DDE
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17 minutes ago, DDE said:

My concern is with inclination mismatch and the resulting surface wait time for launch into target plane. Is NRHO so high that it’s easily reached from any LLO inclination? I still doubt the mechanics would play out.

This might have some information: 

https://engineering.purdue.edu/people/kathleen.howell.1/Publications/Conferences/2018_AAS_WhiDavBurMcCPowMcGHow.pdf

Edited by Canopus

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Whatever a lander might look like, it's not getting there with SLS.

If they were going to leave a stage on the surface, it seems to me a better architecture would be to use drop tanks, and leave those on the surface, not a whole stage (and given SLS, probably a 30 M$ RL-10 (or 2, or 3)). Such tanks might actually be useful on the Moon, too (assuming some sort of base is the surface goal vs sorties). For example, something like XEUS, where the ACES tank is left on the surface, and the hypergolic landing engines lift the framework to LLO to meet the tug. Refilling is done via mounting a new tank, instead of prop transfer. The tank on the surface could get a nanoracks-style wet lab job done on it (they're using that very tank as their baseline).

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22 hours ago, Kerbal7 said:

The most reliable estimates I've seen on a human trip to Mars is around a trillion dollars.

I see your trillion dollars, and raise you 9 trillion more!

https://spacenews.com/letter-mars-costs-likely-to-hit-10-trillion/

I am pretty sure that this guy(who wrote the op-ed) is being sarcastic. Because if he is not, then he's a real dumb dumb.....

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Hot fire for the Orion Jettison Motor:

 

 

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Russia likely to pull out of the Gateway project, because, quote

Quote

"Making an empty barrel for Americans is, of course, humiliating. The new management has declared that it will not do, and we will independently explore the moon. ”

From here

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3 minutes ago, MinimumSky5 said:

So, Roscosmos is not going to the moon today. Or any time in the next few decades. 

Well, Luna-25-28 landers are still planned for 2021-25, and Angara-based super heavy moon rocket for 2028, but it probably belongs to another thread. 

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18 hours ago, sh1pman said:

Luna-25-28 landers are still planned for 2021-25

I heard whispers that the Luna-26 procurement docs are missing in action, meaning schedule slippage.

18 hours ago, MinimumSky5 said:

So, Roscosmos is not going to the moon today. Or any time in the next few decades. 

Stow the bagpipes for now. Roscosmos is simply politicking and trying to get a larger role... which would likey lead to begging for cash down the line.

Edited by DDE
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3 hours ago, DDE said:

Stow the bagpipes for now. Roscosmos is simply politicking and trying to get a larger role... which would likey lead to begging for cash down the line.

4D underwater chess.

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On 11/24/2018 at 12:56 PM, sh1pman said:

4D underwater chess.

Oh, please. It’s why I view all international projects somewhat dismissively - not only do the many cooks spoil the broth, they also try to get as much of the broth while doing as little as possible.

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1 hour ago, DDE said:

Oh, please. It’s why I view all international projects somewhat dismissively - not only do the many cooks spoil the broth, they also try to get as much of the broth while doing as little as possible.

To be fair, ISS is international, even if the US foots the lion's share of the bills.

It's nice to have something where the civilized people of the world can just do something productive together, even if it's just ISS.

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On 11/23/2018 at 6:02 AM, sh1pman said:

Well, Luna-25-28 landers are still planned for 2021-25, and Angara-based super heavy moon rocket for 2028, but it probably belongs to another thread.

The Russians have announced any number of plans over the last thirty odd years.  Very few have produced anything more than a press release.

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16 hours ago, DerekL1963 said:

The Russians have announced any number of plans over the last thirty odd years.  Very few have produced anything more than a press release.

Granted, it’s a lot more difficult for Anglophone speakers to distinguish a one-off publicity statement - also a dime a dozen in the Anglosphere - from a more or less concerted effort. Luckily, there’s 44-FZ, which makes Russian state procurement very transparent . So we know, for example, that Keldysh did run a program for development of a droplet radiator for a deep-space nuclear powerplant.

In fact, at times it makes the situation far more transparent than desireable: https://forum.nasaspaceflight.com/index.php?topic=45734.0

Edited by DDE
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21 minutes ago, DDE said:

Granted, it’s a lot more difficult for Anglophone speakers to distinguish a one-off publicity statement - also a dime a dozen in the Anglosphere - from a more or less concerted effort.


No, not at all.  There's plenty of experts in the matter who speak Russian and have long experience watching both the Soviet and Russian programs.  Not to mention we're not talking about one-off publicity statements, we're talking official statements of intent made by persons in a place to make said statements and and ongoing repetitions of such statements over a period a time.  We're also talking mockups and prototype hardware being built, and then the program silently vanishing.  We're also talking partially built hardware languishing for years at a time.  We're also talking Russian authorities in active negotiations with Western authorities.  Etc... etc... etc...

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46 minutes ago, Nightside said:

All tests and no flights make RS25 a dull boy.

Wow....thats a hydrogen leak out the top of the powerhead ??

NSF guys think its close to the high pressure fuel turbopump.

They let it go for many seconds (30s?) before shutting down.

Strange the engine controller didn't pick up the problem on its telemetry.

https://twitter.com/nextspaceflight/status/1072966252170305536/video/1

Quote

An RS-25 engine just had a significant anomaly during a test fire at @NASAStennis. The test was aborted just seconds in.

 

Edited by RedKraken
HPFT leak?

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1 hour ago, Nightside said:

All tests and no flights make RS25 a dull boy.

Will we be looking at accidental holes and bent sensor pins by 2020?

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Apparently it was test stand plumbing that caused the leak, not the engine.

 

Still... Not very encouraging. They're going to wear out the engines before SLS flies at this rate.

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1 hour ago, MaverickSawyer said:

They're going to wear out the engines before SLS flies at this rate.

Then they’ll be able to report the first SLS as cheaper thanks to the expendable engines version. 

I’m assuming.

Don’t tell me the new RS-25 variant is costlier than the old one...

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Depends on how you establish their price... From my understanding, they're simply modifying the existing SSMEs for the mission and throwing them away. So, they're cheaper than new-build engines... but in terms of the amount of money sunk into the hardware over the years, they're stupidly expensive.

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6 hours ago, DDE said:

Don’t tell me the new RS-25 variant is costlier than the old one...

This seems impossible, as the RS-25 cost something like 40 M$ each new, and apparently they cost 127 M$ each to ready for reflight.

Baby needs a new pair of shoes, etc.

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1 hour ago, tater said:

This seems impossible, as the RS-25 cost something like 40 M$ each new, and apparently they cost 127 M$ each to ready for reflight.

Here's your proof that reuse doesn't work! Booster landings - cheap publicity stunt! ;)

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