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Space Science Coverage / Re: Astronomy Thread
« Last post by Star One on Today at 08:36 PM »
EXPLOSIVE VOLCANOES SPAWNED MYSTERIOUS MARTIAN ROCK FORMATION

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Explosive volcanic eruptions that shot jets of hot ash, rock and gas skyward are the likely source of a mysterious Martian rock formation, a new study finds. The new finding could add to scientists’ understanding of Mars’s interior and its past potential for habitability, according to the study’s authors.

The Medusae Fossae Formation is a massive, unusual deposit of soft rock near Mars’s equator, with undulating hills and abrupt mesas. Scientists first observed the Medusae Fossae with NASA’s Mariner spacecraft in the 1960s but were perplexed as to how it formed.

https://news.agu.org/press-release/explosive-volcanoes-spawned-mysterious-martian-rock-formation/
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New selfie from @MarsCuriosity rover shows the huge dust storm raging in the background. Processing: @_TheSeaning (link: https://www.flickr.com/photos/seandoran/42803766882/in/photostream/) flickr.com/photos/seandor…

https://mobile.twitter.com/coreyspowell/status/1008768321569935361
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I've been thinking about the possibility of a new rocket engine design that uses molten salt to heat water into steam in a de Laval nozzle.

Water expands at a ratio of 1:1600 plus when it is converted to steam. From what I understand, typical steam rocket engines store the heat in pressurized water and then release the water. Some of that water converting to steam as it is released is what provides thrust. The problem with that is water is almost uncompressable and can't store enough heat by itself to convert all the mass to steam. Molten Salt has around 19x the heat capacity of water.

So, if you treat this like a bi-propellant engine and have a tank of almost boiling water and a tank of molten salt heated right before launch to about 1000c. Then feed a small flow of molten salt into the chamber of the nozzle and spray water at it at a 19:1 ratio. The molten salt would heat the water almost immediately into steam, producing an incredible amount of pressure and converting nearly all the water mass into steam. This should be able to surpass the chamber pressure of a Merlin engine. In a fine tuned engine, the water should stay supercritical in the reaction chamber and actually expand a little more as the temperature and pressure reduce in the bell.

These temperatures are within the limits of stainless steel, so a vacuum insulated molten salt tank within a larger water tank should be viable. The water tank will have very little pressure and no extreme temperatures. It could almost be made of plastic (though probably not). The temperature in the reaction chamber would not be extreme to the levels of combustion engines either, so pressure tubes could feed directly from the chamber to the water and salt tanks to provide back pressure, with valves on these to control throttle and mixture.

I am an electrical acoustical engineer by trade, so I couldn't be less qualified to design something like this. But from the math I know how to do, this seems like a decent little engine. It may be buildable as a hobby project since it does not require exotic materials or cryogenics. It would be a great headline project because you could heat the salt with solar energy and call it "the world's first solar powered rocket". There is a lot of math here that I haven't wrapped my head around yet that would determine the actual performance of this thing, but I can determine that as I go by learning the math and by trial and error. Or if anyone thinks this might be fun and wants to apply their expertise, I'd be grateful.

This also may not be the correct section, or even the correct forum for this. So please correct and forgive me. I'm to the point where I'm going to start making spreadsheets and 3D models, so I thought I'd share. Let me know what you think.
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- "President and CEO United Launch Alliance, that's a combination of Boeing and Lockheed on the Space Launch System, SLS. I don't like when Boeing and Lockheed get together because the pricing only goes up, but that's okay – in this case.

"I don't know, I don't love that stuff, we're going to have to talk about that, your joining those two companies. Oh boy, look at Dennis, Dennis is so happy. I don't like that stuff, Mike."

Pence, laughing nervously, responds: "Yes sir."

Trump can be so cute sometimes, even when he's clueless what message he's supposed to be staying on.

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- "America's vital interests in space lost out to special interests in Washington... except of course for the Senators and Congressmen here, they would never do it – right Dana [Rohrabacher]?"

It's always "them"...

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- Regarding a return to the moon: "This time we will do more than plant our flag and leave our footprints. We will establish a long-term presence, expand our economy, and build the foundation for an eventual mission to Mars, which is actually going to happen very quickly.

Of course we'll have to see how much "political capital" Trump is willing to spend to get Congress to fund such an effort. And as to "quick", he obviously doesn't understand the rate of progress NASA has with the SLS and Orion.

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"But they do like, explain that (where's Eric?) they do like rockets for some reason. They like those rockets. But you know what, as long as he's... as long as it's an American rich person that's good, okay? They can beat us. We'll save a little money and they can beat us and we're taking full credit for it, don't worry about it."

Yep, because it's all about who get credit. What gets done, that's secondary.

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- "And once more we will proudly lead humanity – and that's what it is, humanity – beyond the Earth and into those forbidden skies. But they will not be forbidden for long. ... because we are giving you a platform the likes of which nobody has every been given before. I am a big believer.

We will see how much he really believes in what he proposed when they release their next budget request. Until then, it's just words...
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Doom and gloom people who think we're going to have space-based weaponry are ignoring the fact that we are a signatory to the Space Treaty which prohibits such things.

You and I know that (as well as lots of other people), but Trump doesn't seem to care about that based on the language he is using to describe the reasoning for having the Space Force. According to Trump:

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...it is not enough to have an American presence in space, we must have American dominance in space. So important.

Anyone have a guess what that is supposed to mean? We obviously already have a form of dominance in space for national defense, commercial and NASA, so what is Trump thinking that we need to do in order to meet his desire for "dominance"?

I don't know how involved he is with this stuff. He called for "Gwynne Shortwell" to stand up and said that ULA was building SLS.
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...it is not enough to have an American presence in space, we must have American dominance in space. So important.

Anyone have a guess what that is supposed to mean? We obviously already have a form of dominance in space for national defense, commercial and NASA, so what is Trump thinking that we need to do in order to meet his desire for "dominance"?
This is simple to understand.  Trump uses a bit of hyperbole on most things.  It's Trump-speak that he uses to motivate and encourage people to see his vision and get things done.  It's how he's always operated.  I don't think it's anything more complicated than that.
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Space Policy Discussion / Re: US Space Force - US to Militarise Space?
« Last post by RonM on Today at 08:07 PM »
USAF already has Space Command. Spin it off with some extra layers of bureaucracy and you get the USSF. It won't be cheap to do the reorg.

The USA will need to settle at least the Moon or Mars before creating the United States Colonial Marines.
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I think at some point they said they want to bring the COST down to 200-300$. Can't find a source for that though.
What the PRICE will be - who knows. That will largely depend on their local partners.
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All this is is a reorganization of the military.  No real new mission.  This is because Air Force tends to ignore space assets to spend on things like the F-35.  The hope is that with a separate force upgrading and hardening of space assets will be a higher priority considering so much is dependent upon them.  This discussion started long before the Trump admin.   
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Doom and gloom people who think we're going to have space-based weaponry are ignoring the fact that we are a signatory to the Space Treaty which prohibits such things.

You and I know that (as well as lots of other people), but Trump doesn't seem to care about that based on the language he is using to describe the reasoning for having the Space Force. According to Trump:

Quote
...it is not enough to have an American presence in space, we must have American dominance in space. So important.

Anyone have a guess what that is supposed to mean? We obviously already have a form of dominance in space for national defense, commercial and NASA, so what is Trump thinking that we need to do in order to meet his desire for "dominance"?
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