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4 hours ago, Hannu2 said:

That green flame is spectacular. Maybe they should add little bit copper containing chemical in fuel in those missions do not need 100 % capacity.

If you want a spectacular green flame then you should go with pentaborane(9) and oxygen difluoride, and you'll get a whopping 361 seconds of specific impulse at sea level and 432 seconds of specific impulse in a vacuum, with a propellant mix bulk density 17% greater than kerolox, 46% greater than methalox, and 314% greater than hydrolox.

Of course, your exhaust will be toxic and carcinogenic and your fuel has the unpleasant attribute of spontaneously bursting into flame upon exposure to air, but at least you never have to worry about an ignition system.

If that's not enough bang for your buck, you can always go extra fancy and melt liquid lithium and then burn it with liquid fluorine and gaseous hydrogen. Don't ask me why the hydrogen has to be injected in gaseous form. It will get you 542 seconds but you have to come up with a way to effectively store and then mix a liquid fuel at 181°C with a liquid oxidizer at -189°C, so good luck with that.

4 hours ago, Hannu2 said:

Do you know was that unexpected anomaly or did they some destructive or intentionally risky testing?

The amount of smoke and debris is concerning...I imagine there had to have been some damage to the test stand, which must not have been intentional. But I would think whatever this was, it was clearly intentionally risky.

Edited by sevenperforce
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22 hours ago, Hannu2 said:

That green flame is spectacular. Maybe they should add little bit copper containing chemical in fuel in those missions do not need 100 % capacity.

Do you know was that unexpected anomaly or did they some destructive or intentionally risky testing?

It's not intentionally destructive testing.

18 hours ago, sevenperforce said:

The amount of smoke and debris is concerning...I imagine there had to have been some damage to the test stand, which must not have been intentional. But I would think whatever this was, it was clearly intentionally risky.

Intentionally risky, perhaps, but to my understanding the vertical stand is for confirmation firings (Ik thats not the right word but I can't remember it rn), and the horizontal stand is for the more experimental, destructive tests.

Edited by Barzon
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21 hours ago, sevenperforce said:

If you want a spectacular green flame then you should go with pentaborane(9) and oxygen difluoride, and you'll get a whopping 361 seconds of specific impulse at sea level and 432 seconds of specific impulse in a vacuum, with a propellant mix bulk density 17% greater than kerolox, 46% greater than methalox, and 314% greater than hydrolox.

Of course, your exhaust will be toxic and carcinogenic and your fuel has the unpleasant attribute of spontaneously bursting into flame upon exposure to air, but at least you never have to worry about an ignition system.

If that's not enough bang for your buck, you can always go extra fancy and melt liquid lithium and then burn it with liquid fluorine and gaseous hydrogen. Don't ask me why the hydrogen has to be injected in gaseous form. It will get you 542 seconds but you have to come up with a way to effectively store and then mix a liquid fuel at 181°C with a liquid oxidizer at -189°C, so good luck with that.

Why stop there? Dioxygen difluoride & hexanitrohexaazaisowurtzitane. Go big or go home. -_-

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On 9/14/2022 at 4:42 PM, Hannu2 said:

That green flame is spectacular. Maybe they should add little bit copper containing chemical in fuel in those missions do not need 100 % capacity.

Do you know was that unexpected anomaly or did they some destructive or intentionally risky testing?

I say it would be better to look for green and then shut that engine off asap. that engine burned green for some seconds before blowing up, who is bad, now also you want the trust structure to also works as armored bulkheads isolating the engines.

Even if not an destructive test SpaceX know my previous statement and might simply wanted to see that happened if an engine kept running. Other fail modes are more catastrophically. 
Passenger jets  needs some sort of armoring to prevent an disintegrating jet engine to damage the cabin or wing 

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4 hours ago, CatastrophicFailure said:

Why stop there? Dioxygen difluoride & hexanitrohexaazaisowurtzitane. Go big or go home. -_-

…expialiadocious.

Even though its exotherm is something quite atrocious.

Do try not to sneeze near it, or you’ll wind up on Venus…

hexanitrohexaazaisowurtzitane…

…expialiadocious.

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20 hours ago, CatastrophicFailure said:

Why stop there? Dioxygen difluoride & hexanitrohexaazaisowurtzitane. Go big or go home. -_-

Good luck to apply license to use all those environmentally friendly and very safe fuels. Do not forget chlorine trifluoride. If it is too weak stuff for engines you can use it to ignite campfire on Moon or Mars.

Maybe you could jump straight to the deep end of pool and build an Orion (that original version form 50's, not modern capsule).

 

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On 9/15/2022 at 12:27 PM, CatastrophicFailure said:

Why stop there? Dioxygen difluoride & hexanitrohexaazaisowurtzitane. Go big or go home. -_-

Actually, Hexanitrohexaazaisowurtzitane seems to be used as solid propellant oxidizer in China...
 

Spoiler

Hi everyone!
Long time lurker. Couln't resist using hexanitrohexaazaisowurtzitane in my first post here :)

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22 hours ago, Krakotte said:

Actually, Hexanitrohexaazaisowurtzitane seems to be used as solid propellant oxidizer in China...
 

  Hide contents

Hi everyone!
Long time lurker. Couln't resist using hexanitrohexaazaisowurtzitane in my first post here :)

Heh, why am I not surprised? :unsure:
 

But you’ll fit right in around here. :D

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So I got this image in my head of a lunar orbit rendezvous version of lunar starship where the tail end stays in orbit as a "service module" and only the top 3rd or quarter or so separates and lands on the moon.  The idea being that the lander could be optimized for a lunar landing mass-wise and the payload bay would end up a safer and closer distance to the surface once landed

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2 hours ago, darthgently said:

So I got this image in my head of a lunar orbit rendezvous version of lunar starship where the tail end stays in orbit as a "service module" and only the top 3rd or quarter or so separates and lands on the moon.  The idea being that the lander could be optimized for a lunar landing mass-wise and the payload bay would end up a safer and closer distance to the surface once landed

The issue I see with that is reentry. The point where they connect would be very weak as they hit the atmosphere.

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4 hours ago, Rutabaga22 said:

The issue I see with that is reentry. The point where they connect would be very weak as they hit the atmosphere.

It could be an overlapping sleeve type of connection with a foot of overlap; with interlocking tiles... But yeah, complicated.

But more importantly, I think the current lunar Starship concept is  without tiles and once in space would stay there and never be required to reenter. 

Why would one need it to? Just ferry up to it and use it for LEO to moon and back, lather, rinse, repeat

Edited by darthgently
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