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This was dropped on NSF and is interesting.

https://oiir.hq.nasa.gov/asap/documents/2014_ASAP_Annual_Report.pdf

It talks about SLS/Orion Loss of Crew risks.

1:300 for ascent

1:150 for the cislunar mission portion

1:300 for entry

1:75 Total Mission

NASA assesses the Artemis crew risk (not counting Gateway or landings) at 1 in 75 for LOC. That's pretty awful, honestly.

 

 

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Crew Dragon is 1:276 for a complete ISS mission. That strongly implies a safer ascent.

So much for SLS's lofted safety. That was *the one thing* about this launcher that was previously unassailable.

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17 hours ago, RCgothic said:

The most powerful static fire this year until BN1 lights up its four engines.

It's just insane to me that Raptor has significantly more thrust than the RS-25 in a package that is that much smaller. I've stood right next to the one they reconstructed at the Smithsonian and it feels like it should be closer to the thrust of an F-1 than to the thrust of Raptor. If you put a SL Raptor inside the RS-25's nozzle, it would only protrude by 28 cm.

Then again, I suppose the RS-25 really isn't nearly as "large" as it looks since that is really a vacuum nozzle.

7 hours ago, tater said:

This was dropped on NSF and is interesting.

https://oiir.hq.nasa.gov/asap/documents/2014_ASAP_Annual_Report.pdf

It talks about SLS/Orion Loss of Crew risks.

1:300 for ascent

1:150 for the cislunar mission portion

1:300 for entry

1:75 Total Mission

NASA assesses the Artemis crew risk (not counting Gateway or landings) at 1 in 75 for LOC. That's pretty awful, honestly.

Well that's horrifying.

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4 minutes ago, sevenperforce said:

Well that's horrifying.

IKR?

That's from 2014. What's shocking is that in the last 6 years we have not heard how SLS/Orion has taken that LOC data, changed their design, and lowered that risk.

 

5 minutes ago, kerbiloid said:

How many flights are supposed to be in total?

LOL. 1 every year or two.

They can fly decades before anyone likely dies.

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1 hour ago, sevenperforce said:

It's just insane to me that Raptor has significantly more thrust than the RS-25 in a package that is that much smaller. I've stood right next to the one they reconstructed at the Smithsonian and it feels like it should be closer to the thrust of an F-1 than to the thrust of Raptor. If you put a SL Raptor inside the RS-25's nozzle, it would only protrude by 28 cm.

Then again, I suppose the RS-25 really isn't nearly as "large" as it looks since that is really a vacuum nozzle.

Well that's horrifying.

Does the Raptor really have significantly more thrust than the SSME? I was under the impression they were both just about 2 MN, a little less at sea level.

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24 minutes ago, RyanRising said:

Does the Raptor really have significantly more thrust than the SSME? I was under the impression they were both just about 2 MN, a little less at sea level.

High thrust variant of raptor is aiming for 2.9MN (300te) last I heard.

The difference a denser propellant makes.

Edited by RCgothic
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29 minutes ago, RyanRising said:

Does the Raptor really have significantly more thrust than the SSME? I was under the impression they were both just about 2 MN, a little less at sea level.

In August 2020, a Raptor on a test stand achieved 330 bar chamber pressure with thrust levels of 2.21 MN, at sea level.

Maximum sea level thrust for the RS-25D at 109% power is 1.86 MN. 

So Raptor is already about 19% more powerful than the most powerful RS-25 configuration.

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1 hour ago, RyanRising said:

Does the Raptor really have significantly more thrust than the SSME? I was under the impression they were both just about 2 MN, a little less at sea level.

25 minutes ago, sevenperforce said:

In August 2020, a Raptor on a test stand achieved 330 bar chamber pressure with thrust levels of 2.21 MN, at sea level.

Maximum sea level thrust for the RS-25D at 109% power is 1.86 MN. 

So Raptor is already about 19% more powerful than the most powerful RS-25 configuration.

And Superheavy will have 28 or more on the bottom.

WeeklyUnitedFawn-size_restricted.gif

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53 minutes ago, sevenperforce said:

In August 2020, a Raptor on a test stand achieved 330 bar chamber pressure with thrust levels of 2.21 MN, at sea level.

330 - 90 = 240

Ok for Venus.

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40 minutes ago, GuessingEveryDay said:

And Superheavy will have 28 or more on the bottom.

WeeklyUnitedFawn-size_restricted.gif

Total first-stage thrust at liftoff:

  • Falcon 9: 7.6 MN
  • Delta IV Heavy: 9.42 MN
  • New Glenn: 17.1 MN
  • Falcon Heavy: 22.8 MN
  • Long March 9: 24 MN
  • Space Shuttle Stack: 30.3 MN
  • Energia: 34.8
  • Saturn V: 35.1 MN
  • SLS: 36.6 MN
  • N1: 45.4 MN
  • Superheavy: 76 MN

I did not realize SLS will actually have more thrust at launch than the Saturn V.

I also did not realize that Superheavy literally has more than twice the thrust of SLS. The equivalent of ten Falcon 9 boosters strapped together.

Edited by sevenperforce
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13 hours ago, tater said:

This was dropped on NSF and is interesting.

https://oiir.hq.nasa.gov/asap/documents/2014_ASAP_Annual_Report.pdf

It talks about SLS/Orion Loss of Crew risks.

1:300 for ascent

1:150 for the cislunar mission portion

1:300 for entry

1:75 Total Mission

NASA assesses the Artemis crew risk (not counting Gateway or landings) at 1 in 75 for LOC. That's pretty awful, honestly.

Those are programmatic minimums. In that same thread on NSF, someone dug up the ESD requirements, which, while incomplete, paint a much different picture.

LanPXYc.png

https://ntrs.nasa.gov/api/citations/20200001592/downloads/20200001592.pdf

Edited by jadebenn
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3 hours ago, sevenperforce said:

So Raptor is already about 19% more powerful than the most powerful RS-25 configuration.

RS-25E will run at 113% iirc.

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4 minutes ago, Barzon said:

RS-25E will run at 113% iirc.

If we make it to Artemis 5. 

By 2026 I would be shocked if we don't have the fixed-thrust, non-gimbaled Raptors already operating. At 2.94 MN, those will be 53% more powerful than the proposed RS-25E.

 

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