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The Tech Behind SpaceX’s New Engine

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Re: The Tech Behind SpaceX’s New Engine

#51

Post by Rebelgecko »

mabbo wrote: post #37

> While the Space Shuttle has long since retired, a variation of the engine itself will go on to power the Space Launch System. It will be the most powerful rocket NASA has ever built and is slated to begin missions in 2020. 2020? I honestly doubt we'll see the SLS launch before 2024 at it's current rate.

I would bet money that SLS+Orion launches before Falcon Super Heavy+Starship. It looks like SLS is already doing integration testing for the various cores and starting to assemble the main components. I'd guess 2021 at the latest, as long as there's no multi-month government shutdowns in the meantime.

Re: The Tech Behind SpaceX’s New Engine

#52

Post by ceejayoz »

clanrebornsx wrote: post #26
jlv2 wrote: post #18

Earlier quoted context omitted.

It is -- it's B1019. I suspect that's why they are a janitor.

Sorry I've PhD in Particle Physics. Not able to find any work, so I am doing janitor work. Why do you insult Janitor's intellect?

You're kinda dodging the important point that your original assertion that it's a "fake rocket" is entirely false.

https://en.wikipedia.org/wiki/Falcon_9_booster_B1019

It wouldn't be shocking if they've removed some ITAR-covered parts so no one can sneak up in the middle of the night and steal rocket tech, but it appears to be the actual booster.

Re: The Tech Behind SpaceX’s New Engine

#53

Post by trhway »

Eridrus wrote: post #35
buboard wrote: post #21

Earlier quoted context omitted.

Wikipedia has some stats comparing their current engines (probably speculative for the raptor) Raptor: Thrust 1900 KN / 330 specific impulse Merlin 1D: 480KN / 275 s.i. i can't find the weight of the Raptor. Merlin is 630Kg

So, for the folks like me who don't know anything about rockets, it seems like "specific impulse" is the measure of how much "impulse" is generated per unit of fuel. So 330/275 = 20% better.

>So 330/275 = 20% better.

due to the exponential nature of the rocket equation, 100 tons of fuel will result in 2 tons to LEO in the former case and just 1 ton in the later.

Re: The Tech Behind SpaceX’s New Engine

#54

Post by CarVac »

twic wrote: post #34
wolf550e wrote: post #29

Earlier quoted context omitted.

This is only viable for small engines, like expander cycle is only viable for small engines. The specific energy of electric batteries cannot compare to that of kerolox or methalox. Closed cycle is not a new idea: https://en.wikipedia.org/wiki/Staged_combustion_cycle#Histor...

I still have a soft spot for expander cycles - they seem so elegant compared to staged combustion cycles, and apparently i am not the only person who thinks that: https://blogs.nasa.gov/J2X/2014/03/24/inside-the-leo-doghous...

Interestingly the expander bleed cycle mentioned at the end is going to be used in the Blue Origin BE-3U, a change from the combustion tap-off of the older BE-3.

Re: The Tech Behind SpaceX’s New Engine

#55

Post by [deleted] »

twic wrote: post #34
wolf550e wrote: post #29

Earlier quoted context omitted.

This is only viable for small engines, like expander cycle is only viable for small engines. The specific energy of electric batteries cannot compare to that of kerolox or methalox. Closed cycle is not a new idea: https://en.wikipedia.org/wiki/Staged_combustion_cycle#Histor...

I still have a soft spot for expander cycles - they seem so elegant compared to staged combustion cycles, and apparently i am not the only person who thinks that: https://blogs.nasa.gov/J2X/2014/03/24/inside-the-leo-doghous...

[deleted]

Re: The Tech Behind SpaceX’s New Engine

#56

Post by debt »

"For example, the turbine of the V-2 rocket was spun with steam ..."

Steam technology and rocket technology have a shared history.

That kind of bottleneck shape that a is quintessential shape of a rocket engine, is actually a Steam-Engine-era technology called a de Laval nozzle.

I didn't know they used a tiny steam engine inside a V-2.

I think it's cool that the design of such an old technology, the steam engine, lives on inside the design of such a new technology, the rocket.

Re: The Tech Behind SpaceX’s New Engine

#57

Post by skunkworker »

Rebelgecko wrote: post #51
mabbo wrote: post #37

> While the Space Shuttle has long since retired, a variation of the engine itself will go on to power the Space Launch System. It will be the most powerful rocket NASA has ever built and is slated to begin missions in 2020. 2020? I honestly doubt we'll see the SLS launch before 2024 at it's current rate.

I would bet money that SLS+Orion launches before Falcon Super Heavy+Starship. It looks like SLS is already doing integration testing for the various cores and starting to assemble the main components. I'd guess 2021 at the latest, as long as there's no multi-month government shutdowns in the meantime.

SLS Block I maybe, but definitely not SLS Block 2.

The Starship hopper will definitely be working long before either of those two take flight.

Re: The Tech Behind SpaceX’s New Engine

#58

Post by trhway »

debt wrote: post #56

"For example, the turbine of the V-2 rocket was spun with steam ..." Steam technology and rocket technology have a shared history. That kind of bottleneck shape that a is quintessential shape of a rocket engine, is actually a Steam-Engine-era technology called a de Laval nozzle. I didn't know they used a tiny steam engine inside a V-2. I think it's cool that the design of such an old technology, the steam engine, liv…

>I didn't know they used a tiny steam engine inside a V-2.

it wasnt steam engine per.se., it was catalytic peroxide decomposition.

Re: The Tech Behind SpaceX’s New Engine

#59

Post by [deleted] »

trhway wrote: post #53
Eridrus wrote: post #35

Earlier quoted context omitted.

So, for the folks like me who don't know anything about rockets, it seems like "specific impulse" is the measure of how much "impulse" is generated per unit of fuel. So 330/275 = 20% better.

>So 330/275 = 20% better. due to the exponential nature of the rocket equation, 100 tons of fuel will result in 2 tons to LEO in the former case and just 1 ton in the later.

[deleted]

Re: The Tech Behind SpaceX’s New Engine

#60

Post by nisten »

The reason this is important is not the really the few % savings in fuel weight.

Any small improvement in exhaust velocity of the engine makes a huge difference(sort of exponential) in the amount of payload it can take to orbit. In this case the 2 pre-burners also make relighting the engine in a vacuum a lot more reliable.

For more on the math: https://en.wikipedia.org/wiki/Tsiolkovsky_rocket_equation

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