Ultimate Steve

I am aware of that, I was using that as an example. Like how progress altered mirs course by hitting it, exhaust would alter the course of a deflector by hitting it. However, since the deflector is attached to the engine providing the exhaust, there would be no net thrust. I said that if Mir had launched the progress into itself there would be no velocity change, like in his engine. Sorry for not being clear.

I do not believe it is a myth, but it doesn't protect against radiation everywhere, just one crucial place. Iirc, your thyroid loves iodine. It will suck up as much as it can get. However, in many nuclear reactions, a radioactive type of iodine is created. If this gets spread out in an explosion, it can get into your thyroid and cause cancer and sickness. The solution is, as soon as possible after the explosion, take lots of non radioactive iodine so it will overwhelm your thyroid so for some time, it will not be able to absorb any more. When it encounters the radioactive iodine it will not absorb it. This gives you enough time to get out before getting thyroid cancer. Edit: mobile typo made me say the opposite of what I wanted to.

If you push down on the center of a table the force goes downwards into the legs. However, assume you are stuck in space with just a table. If you hold on to the table, pushing against it isn't going to do anything. Replace table with spaceship and push with fire engine at. The force would go into the y axis of the craft. And yes, if you send a Progress crashing into Mir, Mir would have altered velocity. However, in your engine, Mir launched Progresszt itself, and the energy spent to accelerate Progress (accelerating Mir in the opposite direction) went straight back into decelerating Progress (and decelerating Mir in the opposite direction). Basically, we have a gun shooting a bullet, but the end of the barrel is blocked, and to simplify we have a spring instead of gunpowder. The spring, attached to the gun, accelerates the bullet down the barrel, and also accelerates the gun in the opposite direction. When the bullet hits the blocked barrel it transfers it's energy back into the gun. No net change in velocity. If you don't permanently expel something backwards, or push off of something in the environment, you will not gain velocity. If you recapture what you expel, you are by definition not expelling it permanently.

So your design has two parts where forward thrust is cancelled out. The slow down part is fairly easy to explain. The energy from the propellant goes into the magnets/slow down devices and assuming the magnets are attached to the craft, the energy goes into the craft. If you do not get this I cannot help you. The second part is a bit more difficult to explain. Say you have 500kn coming into the redirector. Assuming the redirector is perfect, this 500kn will be absorbed by the deflector and into the craft. redirected sideways, 250kn in each direction. You can't get more than 500kn from 500kn. It may seem intuitive that there would still be a 500kn force downwards, but due to deflection it's absorbed by the craft. It involves a bit of vector math that I have forgotten to do, but it works out, and there is zero net vertical thrust. However, you still have 500kn of thrust to work with as you are expelling the exhaust rather than capturing it, the same amount you would have had if you didn't deflect it at all. You have decided, for some reason, to deflect it in a way that has no net thrust (the two nozzles opposite each other).

1. The thrust is 100 percent after the propellant exits the nozzle. 50 percent is taken away by the slow down device and 50 percent is taken away by the redirector (well actually converted from vertical to horizontal force, but that remaining vertical momentum is still transferred to the craft). 2. Yes, if one axis had a non zero energy then it would accelerate along this axis. However, your design has zero net energy in either axis. The y axis energy is all absorbed by the craft/redirected and the x axis nozzles cancel each other out.

Well, because the exhaust is slowed down before the redirection, there would be half as much thrust coming out if the side exhausts than without slowing it down by half before the redirection. But what I was saying is that it doesn't matter how many stages you use to show down/redirect/remove y axis velocity from the exhaust, it will always add up to 100 percent if you slow it's y axis velocity to zero, and that energy goes into the craft.

So you are slowing the exhaust down before you deflect it sideways. If you slow the exhaust down by 50 percent with the slow down device and then redirect it later, that energy (50 percent) would be absorbed by the slow down device and transferred to the craft. The other 50 percent of the energy in the y axis will be absorbed by the redirection device, and then transferred to the craft.

Like E1 ^ <E2 E3> You are correct. If you have three engines firing in a T shape like that, it will produce thrust. However, if you get that configuration by taking the exhaust from engine 1 and redirecting it into two nozzles (2 and 3), which is what I believe you are getting at, you will not produce forward thrust. That is like having a jet engine, set vertically, blow its exhaust out of two horizontal holes. It will not produce vertical thrust because the thrust has been redirected sideways. That redirection cancels out the propellant's vertical momentum, which goes back into the craft.

Forgive me, I am unsure what any of this means. Some labels would help. Going back to your earlier drawing, assuming you were decelerating the propellant to a speed of 0 in order to pipe it back up to the reactor/fuel tank to re-use it, the momentum of the fuel would be transferred into the magnets into the ship, canceling out the thrust gained from the engine in the first place, like having two engines firing in opposite directions pretty much. If you just slow down the exhaust, say by 90%, but any number works, and then expel it, then you do get a net thrust. However, because you absorbed 90% of the momentum of the fuel, you in effect have an engine opposite the main engine at 90% power, meaning your effective output is 10% of your input. Just now saw your next quote, but I'm on page 3 so I can't quote it, so here it is. "The magnetic field isn’t just supposed to stop it just slow it Down I just need to take energy out of the system." Okay. So we slow the propellant down, taking energy out of the propellant. This energy then goes into whatever you used to slow it down. If the propellant is then expelled at a reduced velocity/energy you have effectively eaten some percentage of your engine's efficiency/thrust. If it is then recaptured, you have to slow it down the rest of the way to zero, and that energy goes into your craft.

Redirecting the force to the x axis still requires absorbing its y axis momentum. So if I'm correct, it's sort of like this: Propellant, heated by reactor | | | | | \____________ -> out sideways ^Magnet/deflector But mirrored on both sides, with one deflector going left. That would be a 45 degree angle though and you said 90. If it was a 90 degree angle you would push the propellant sideways a bit but you wouldn't change its y axis velocity. So talking about 45, when you redirect the propellant sideways, you are still absorbing its y-axis momentum. It would be like firing a bullet at a 45 degree wedge and expecting the wedge to not move backwards. What you've basically done here, if I'm right, is created a rocket engine which diverts its exhaust so it cancels itself out, even if you then expel it instead of recapturing it.

If you slow the exhaust plume down, it has to speed something else up in the same direction that the exhaust was moving. It takes an equal amount of energy to speed it up as it does to slow it down. If the thing that slows the propellant down is connected to the craft, then the craft will accelerate backwards the same amount it accelerated forwards when it expelled the propellant. Magnets as a catching mechanism are not immune from this rule, momentum is transferred to and from magnets the same as momentum is transferred to and from normal objects, just from far away instead of through direct contact.

Kind of off topic, but I want to let you know that whenever I get a notification that you've posted in a spaceflight thread that hasn't had activity in a few hours, I usually light up because it's probably a space update.

I might get back into Whirligig once 1.0 is out. The reason I stopped is because I wanted my Kerbmun base to have a realistic temperature, so I moved it after the update, but then there was another update that messed with the temperature, I think, and I just kinda burned out. I still need to finish that Typoball mission... Once 1.0 is out, though I can expect a bit more stability, and I can hopefully continue.

IIRC the crew couldn't trigger it manually and the mission control abort wiring had burnt through. They had to get the radio activated abort to work and that took several seconds.

And yet, few people know who Vladimir Titov and Gennady Strekalov are.

If you remove momentum from the fuel, the momentum will go into whatever you slow it down with, in the same direction that the fuel was travelling. So if you decelerate the fuel, you decelerate the craft.

When you slow something down using a magnet, the force goes to the magnet. Like if you had a piece of iron and a magnet, not only would the iron be pulled towards the magnet, the magnet would be pulled towards the iron.

There is no reaction mass going backwards, then. The force of the engine would be exactly undone by the force the exhaust imparts on the catcher/condenser and you would get no net force. Sort of like how it takes the same amount of energy to accelerate something as it does to decelerate something. unless there is something I am missing.

So you heat up air, expel it, capture it again, and repeat? I'm not sure if I'm getting what you're saying. What exactly would the air then power? If you catch the propellant you just expelled, you get no net force.

So you take in air and don't expel it? Then what's the air for? In order to create thrust, you need to throw something backwards (unless you are talking about solar sails or something). Planes throw air backwards, boats throw water backwards, cars "throw" the road backwards (you don't notice because Earth is so huge), rockets throw exhaust backwards, etc. The same rule holds true for nuclear, you need to throw something backwards, be it hydrogen or air. Now, you can get creative, though. You can use the fission fragments from the reaction as your throw backwards material. This is called a fission fragment rocket and can get efficiencies of over 100,000 seconds. However it is also not good as you are basically spewing nuclear waste everywhere directly. I believe it is also fairly low thrust. You can also go Orion style and blow up nukes behind you to push you forwards. That's also not a good idea in most cases.

You can still get really good efficiency with closed cycle. Harnessing the air, that's a nuclear jet engine, and the USSR actually flew a nuclear jet engine powered aircraft once. Uses no propellant other than the nuclear fuel. Unfortunately it was open cycle though. Yes.

Technically you can use anything, but hydrogen is the most efficient. I like the idea of a water powered engine, you can refuel at a lot of places that way.

Yes, that is usually how nuclear engines work. Open cycle, you basically flow the fuel straight through the reactor, closed cycle, you have heat transfer devices that heat the fuel indirectly. Closed cycle is safer, but open cycle is more efficient. This way you can get specific impulses of around 1000, plus or minus some, depending on how far you push it.

If it is an actual nuclear engine, I would at first be happy that they are trying to do this, but after this accident, if it becomes very public, this may set back nuclear engines by years. However, it is Russia. I wouldn't be too surprised if they just continue.

Nuclear electric propulsion maybe? It does specify liquid propellant, though, so that's unlikely. This is almost certainly wrong and would make no sense, but maybe a nuclear reactor driving the pumps? I don't think that would be worth it at all though. If the article is correct, it certainly sounds like a nuclear engine. But it says "isotope" power source, which makes me think more of an RTG... But the word *can* be used to describe both. Maybe it's a Russian translation thing. Maybe they use the word for both over there... Maybe they were doing tests on a spacecraft that had both a liquid engine and an RTG on board.