Posted on 02/25/2018 9:31:24 PM PST by BenLurkin
How can a rocket engine achieve more than a 100-percent thrust? Well, RS-25 engines were first designed more than 40 years ago, for use with NASA's space shuttle, and the power level they were capable of achieving at the time is the margin known as 100-percent thrust, according to NASA. RS-25 engines are former space shuttle engines that have been modified to perform more powerfully than ever before.
"Increased engine performance is crucial for enabling SLS missions to deep space as the rocket evolves to be larger and carry astronauts and heavy cargo on a single flight," NASA officials said in the statement.
When the space vehicle is assembled and ready for launch, four of these formidable engines will create a combined 2 million lbs. of thrust, according to the statement. And there's more: A pair of boosters on the SLS will work with the RS-25 engines to supply the rocket with a whopping 8 million lbs. of total thrust.
...
In addition to RS-25 ignition, the "brain" of the engine underwent testing. The new flight controller is one of the latest modifications to the engine design and will help provide precision control as it communicates with the rest of the SLS rocket. And in an ongoing effort to make SLS more affordable, operators also tested out a shock-absorbing component on Feb. 21, manufactured through 3D printing.
(Excerpt) Read more at space.com ...
Yes, but we are discussing what happens when that gas hits the endless/boundless absolute vacuum of “space”.
Highlight “endless” or “boundless” or make it “infinite”.
What happens in this hypothetical? Those gases are dispersed in a boundless absolute vacuum faster than any forward movement or velocity could occur, plus you are forgetting the problem of building a structure that can withstand the pressure of this boundless infinite and absolute vacuum.
Spoken like a disgusting paid troll, certainly no Christian or conservative.
Such filthy language. Sad. And second time you’ve violated FR rules for abuse.
Sad also that you believe that Elon Musk idiocy.
https://www.youtube.com/watch?v=0pVm7p4nkwo
Since no one has responded to this actual video, please explain the guy with the big head next to the shuttle model, faking space.
Sadly LOL, but LOL nonetheless.
A thrust chamber is not “boundless”; it has a finite volume, a fixed inlet area, and a fixed outlet area. When fuel and oxygen are injected into the chamber, the flow rate in is greater than the flow rate out, as you have agreed that the flow rate out of a chamber is limited.
So, just as the water level in a leaky bucket can rise if the flow rate in is greater than the flow rate out, the pressure in the chamber rises. Then, when ignition occurs, it occurs not in zero pressure.
It's the reflection of the astronauts head from the payload bay window. Good grief...
Correct. But once iginition happens, you no longer have a vacuum in a chamber that resembles the “endless, boundless absolute vacuum of space”, so the leaky bucket analogy doesn’t hold.
Good grief. That doesn’t explain the shadow of the spinning shuttle widgit on his face, nor the lightsource.
But, just giving you some rope here, which shuttle astronaut is that? (Sadly LOL again)
Forget it. After reviewing this thread, I think I’ll just ignore you.
That’s okay. I would have agreed with you a few years ago but the corruption of BushObama opened my eyes a few years back to the Uniparty Deep State hoaxers who hate this nation and the Lord.
Have a pleasant evening.
I’ve just stated that prior to ignition, the pressure in the thrust chamber is greater than zero. Once ignition occurs, the pressure and temperature rise so that the mass flow in equals the mass flow out (flow equlibrium). So, the only difference before and after ignition is the temperature and pressure in the chamber, and in both cases, the pressure is greater than zero.
Right. So, what is your problem? In a boundless, infinite absolute vacuum, you cannot have thrust because ignition can’t occur.
In a finite thrust vacuum chamber, you can get some ignition because the vacuum is not absolute ( and therefore it is not longer a vacuum, but just a container or chamber).
I was thinking about this overnight and there must be a mathmatical formula for this hypothetical phenonmena we are both trying to describe. I believe the problem is balancing out the pressure of a boundless infinte vacuum to whatever you are trying to have occur. Wondering if a nuke would even explode in a boundless, infinite absolute vacuum, or what would happen.
That’s a test I’d like to see.
Lord bless.
Interesting theories; is this what they said they used to get to the moon?
Would love a real explanation, now that NASA reports they lost the technology to go back to the moon, and have lost most of the moon film footage.
Again, the rocket ignition never occurs in a vacuum; but the exhaust gas from the thrust chamber can be expelled into a vacuum.
Going back to my original post, the second link explains the de Laval nozzle. I will summarize:
In the thrust chamber after ignition, the pressure and temperature reach equilibrium. As the flow of gases moves toward the throat, it accelerates to the local speed of sound, which is roughly proportional to the square root of temperature. Then, after the throat, there is the nozzle, which keeps the flow captured from boundless space. As the flow moves down the nozzle, the pressure and temperature get lower, and the exhaust accerates until it reaches it maximum velocity, as described at the link.
The mathematics of this nozzle date back to 1880’s, and allows for zero exit pressure.
Yes, that is exciting but how can it be tested in a true boundless and absolute vacuum? How could a nozzle have more output than a boundless absolute vacuum?
I suppose the question is, what is the construction of this sort of nozzle that would withstand the pressure of a boundless infinite vacuum?
It’s all interesting stuff, thanks for your posts.
messierhunter, please knock off any abusive PMs and tone it down. Sontagged, please take a physics class if you want to get the rhetoric toned down. A vacuum has nothing to do with it, as spacecraft carry their own fuel and oxidants. Otherwise, space exploration as we know it could not happen.
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