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SciFi movies and pathetic misconceptions of tech failing for the story line.
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tszaboo:

--- Quote from: Kim Christensen on April 18, 2023, 10:34:38 pm ---
--- Quote from: tszaboo on April 18, 2023, 10:03:59 pm ---So if you just burn radial out, this doesn't work at all, and you fall back to earth, quite fast.
--- End quote ---

You can, if you reach escape velocity, then you won't fall back to Earth. Less than escape velocity, then yes, you'll fall back.
So as long as you are traveling at more than 11.2 km/s away from Earth, it doesn't matter which direction you are going*. But this is not what we do when launching a satellite which we want to orbit the Earth. Then we need to lean the rocket into a gravity turn to give it horizontal velocity in addition to getting it out of the atmosphere. Ideally a satellite, in a perfectly circular orbit around a perfectly spherical Earth, has zero vertical velocity relative to the surface of the Earth.

*  Well, you might come back in a few years if your new solar orbit intersects that of Earth's orbit around the Sun. (That's why Elon's Tesla will pay us a visit sometime in the future)

--- End quote ---
Well, you are the one who is insisting into launching satellites with only radial out burns. And yes, of course if you leave the spere of influence of earth you don't fall back, but that's also a bad strategy to go into an orbit now, isn't it?
Kim Christensen:

--- Quote from: tszaboo on April 19, 2023, 09:21:18 pm ---
--- Quote from: Kim Christensen on April 18, 2023, 10:34:38 pm ---
--- Quote from: tszaboo on April 18, 2023, 10:03:59 pm ---So if you just burn radial out, this doesn't work at all, and you fall back to earth, quite fast.
--- End quote ---

You can, if you reach escape velocity, then you won't fall back to Earth. Less than escape velocity, then yes, you'll fall back.
So as long as you are traveling at more than 11.2 km/s away from Earth, it doesn't matter which direction you are going*. But this is not what we do when launching a satellite which we want to orbit the Earth. Then we need to lean the rocket into a gravity turn to give it horizontal velocity in addition to getting it out of the atmosphere. Ideally a satellite, in a perfectly circular orbit around a perfectly spherical Earth, has zero vertical velocity relative to the surface of the Earth.

*  Well, you might come back in a few years if your new solar orbit intersects that of Earth's orbit around the Sun. (That's why Elon's Tesla will pay us a visit sometime in the future)

--- End quote ---
Well, you are the one who is insisting into launching satellites with only radial out burns. And yes, of course if you leave the spere of influence of earth you don't fall back, but that's also a bad strategy to go into an orbit now, isn't it?

--- End quote ---

Nope... Just taking issue with the line highlighted above.
Of coarse, launching satellites meant to go into Earth orbit using that method would be a failure.
But you could go to Mars that way, instead of going into low Earth orbit first, but it's not done that way for various reasons.
CatalinaWOW:
There are a great many ways to move around in space when you have essentially unlimited energy and "magic" propulsion systems.  And orbit is as good a word as any to describe what they are doing.   No one gets particularly upset when a pilot comes on the intercom and says "We are going to be orbiting the airport for a while waiting for a landing slot".
MathWizard:
There's some disaster movie where they literally "fly" something like a Star Trek shuttle craft, into the CORE of the Earth, in modern times. There's sci-fi that does crazy stuff, but this is something else. It's not some tunnel boring machine either. I don't think it has lasers  or anything vaporizing the rock in front of them either. Maybe it did, but still.
coppercone2:
that kind of technology is attributed to a plasma drill, the idea is there is a strong hot plasma made infront of something that melts the rock and thermal design so that the rock is solidified after the craft to form a tunnel.

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

I would say it more like.. swims through rock rather then flies. If you superheated everything to make a gas bubble you could fly like cavitation craft, but that is technology... 10m years in the future maybe lol

If you want it fast you would need some kind of chiller to solidify the rock fast enough so there is not a bunch of lava behind the craft (different thermal conductivity and specific heat of lava), also possibly some kind of thermionic cooling effect would need to be used for that

But IMO not that crazy, its kind of like cutting through ice with a string, Just very hard.

Often done with plasma cutters to put holes in metal, but its not that good because usually the hole is hardened as fuck (nitrided), so its hardly a good pilot hole, I would prefer virgin steel (but it could serve as a OK pilot hole for an annular cutter center shaft if you got that)... if you deal with plasma cutter you know how much of a bitch hardened steel on the edge can be, thats what they hide in the brochures about productivity, it seems much worse then oxyfuel cut steel. Best way is to smack it with a hammer and chisel if you don't mind deformation to crack it of, then grind.

A combination approach is interesting too, if you have the power, to crush the rock with carbide cutters then melt it on the back 'exhaust chute' to make a glassy tunnel
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