Kryten Posted January 3, 2015 Share Posted January 3, 2015 How would you accelerate a neutron? It has no charge. Quote Link to comment Share on other sites More sharing options...
Bill Phil Posted January 3, 2015 Share Posted January 3, 2015 You don't. You use isotopes that eject Neutrons naturally.Maybe you get the neutron to decay into a proton and an electron, and accelerate those particles instead? Quote Link to comment Share on other sites More sharing options...
K^2 Posted January 3, 2015 Share Posted January 3, 2015 Free neutrons do decay pretty fast, but you would need them to be ejected at a pretty low energy.At any rate, seems impractical. You would need a huge chunk of nuclear fuel for pretty negligible thrust.Now, if you could work out how to get it to eject neutrons in one direction, you would have an awesome rocket, but I see no way of forcing this. Quote Link to comment Share on other sites More sharing options...
Aghanim Posted January 4, 2015 Share Posted January 4, 2015 (edited) Well, there is this thing: http://en.wikipedia.org/wiki/Fission_sailI think it is a good idea to pin this threadHere is my question:What is the name of that huge thing that is stuck on its head? Is it possible to have that in real life? Edited January 4, 2015 by Aghanim Quote Link to comment Share on other sites More sharing options...
shynung Posted January 4, 2015 Share Posted January 4, 2015 Antlers. Male deers use them to fight each other to gain access to females. Quote Link to comment Share on other sites More sharing options...
N_las Posted January 4, 2015 Share Posted January 4, 2015 What is the name of that huge thing that is stuck on its head? Is it possible to have that in real life?Such huge antlers are possible on animals:http://en.wikipedia.org/wiki/Irish_elk Quote Link to comment Share on other sites More sharing options...
Mazon Del Posted January 5, 2015 Share Posted January 5, 2015 Even Musk can only colonize Mars if he finds people willing to buy tickets to colonize Mars. Which is already a stretch. Only millionaires will be able to afford a ticket, and millionaires don't typically become candidates for colonization.And that is another stretch.And well, a lunar lander is not the same as a Mars lander.Why do you assume Musk is not footing the bill for the colonists he chooses from amongst volunteers? Again, at the estimated costs currently posted for the Falcon Heavy, he can personally out of pocket do something like 40-50 launches. That is assuming he doesn't get more money from his other business ventures or that like minded million/billionaires don't join up with the goal of establishing a colony. Musk has pretty repeatedly stated that he views his money as a means to an end, and that not spending it to achieve his goals makes it useless.It really isn't much of a stretch. You bring up that a lunar lander is not the same as a Mars lander. This is true, but given that from what I've heard about Musks intended Mars lander, it should frankly be easier to land on the moon using the same lander. They intend for the on board rockets to do almost all of the heavy lifting when it comes to slowing down when it hits Mars atmo. Considering the speed the system will have upon engaging in a landing on Mars will be MUCH higher than the speed the same system would have for a Moon landing it seems likely that really the only major change the system would need is a different software profile for a lunar landing. They even lose some carried mass (or at least devote it to more useful means) on the lunar setup, because it won't be carrying the parachutes that the Mars variant is intended to have (which are to only be used in the event of a descent engine failure). Quote Link to comment Share on other sites More sharing options...
Deadpangod3 Posted January 5, 2015 Share Posted January 5, 2015 i think the previous question was answered (sorry if its not!) so im going to ask a question ive got going around in my head.asumming we got a working albecuire drive that bends space and all, its compressing the space in front/back of it, but then either we're creating more space, or space itself is being stretched from somwhere, presumably ahead of the compressed bit, so wouldnt our ship have to cross the "stretched" space too, basically negating the albecuire drives effect? Quote Link to comment Share on other sites More sharing options...
Bill Phil Posted January 5, 2015 Share Posted January 5, 2015 No it would not. Space is moving with the ship in the Alcubierre Drive system. Quote Link to comment Share on other sites More sharing options...
Camacha Posted January 6, 2015 Share Posted January 6, 2015 (edited) Why are the Mercury and Gemini capsule skin panels beaded/corrugated? It is such a distinctive feature, yet it is hard to find definitive information about it. Edited January 6, 2015 by Camacha Quote Link to comment Share on other sites More sharing options...
Bill Phil Posted January 6, 2015 Share Posted January 6, 2015 I think it had to do with the strength of the walls. Apollo used a more advanced structure later in the decade... Quote Link to comment Share on other sites More sharing options...
Skyler4856 Posted January 9, 2015 Author Share Posted January 9, 2015 Why are the Mercury and Gemini capsule skin panels beaded/corrugated? It is such a distinctive feature, yet it is hard to find definitive information about it.Perhaps it may be for reasons of emitting heat from the capsule... Quote Link to comment Share on other sites More sharing options...
gooddog15 Posted January 10, 2015 Share Posted January 10, 2015 Does rocket exhaust in space jet out?Jetting out:not jetting out: Quote Link to comment Share on other sites More sharing options...
Bill Phil Posted January 10, 2015 Share Posted January 10, 2015 You mean if rocket exhaust in space is visible? Maybe inside the nozzle, like in the second picture, but I don't know about beyond that. Quote Link to comment Share on other sites More sharing options...
Nibb31 Posted January 10, 2015 Share Posted January 10, 2015 It was for heat radiation. Corrugated panels expose a larger surface. Quote Link to comment Share on other sites More sharing options...
Bill Phil Posted January 10, 2015 Share Posted January 10, 2015 It was for heat radiation. Corrugated panels expose a larger surface.However much of that surface is oriented towards other surfaces, which doesn't help, really. Quote Link to comment Share on other sites More sharing options...
Nibb31 Posted January 10, 2015 Share Posted January 10, 2015 (edited) Does rocket exhaust in space jet out?In a vacuum, exhaust gasses expand more laterally, because there is no air pressure to keep them in a nice pointy shape. So that first picture (as well as KSP) is inaccurate. This is why upper stage nozzles are much longer than first stage ones.Whether the plume is visible or not depends on the gas and the lighting. If light is not reflecting or shining through the particles, then it won't be very visible. Edited January 10, 2015 by Nibb31 Quote Link to comment Share on other sites More sharing options...
Kryten Posted January 10, 2015 Share Posted January 10, 2015 Kerolox stages tend to have much more visible plumes at high altitude than hydrolox ones. Soyuz in particular is infamous for creating 'jellyfish' UFO sightings whenever it has upper stage flight over a populated area. Quote Link to comment Share on other sites More sharing options...
Robotengineer Posted January 26, 2015 Share Posted January 26, 2015 What would longterm exposure to an RTG do to ones health? Like using it for heat?Like in The Martian? Quote Link to comment Share on other sites More sharing options...
N_las Posted January 26, 2015 Share Posted January 26, 2015 What would longterm exposure to an RTG do to ones health? Like using it for heat?Like in The Martian?If weight isn't an issue, than you can easily shield the generator so that there is no noticable difference to the natural background radiation. At least on earth. The natrual radiation on mars should be more concernable than the RTG. Quote Link to comment Share on other sites More sharing options...
andrewas Posted January 26, 2015 Share Posted January 26, 2015 (edited) Pu238 is mostly an alpha emitter, none of that will get through the RTG shell. There is a little gamma, and the decay products may be more worrying in an older RTG. I'd have to look up the isotopes that occur to be sure.Also, he is only close to it during sirius 4, 18 sols duration. The rest of the time, it's in its hole, in the hab but presumably.as far from his work area as possible, or in the trailer during the drive to the MAV. All Mark has to worry about is a slightly higher cancer risk in later life, and the RTG isn't a huge part of that compared to the time on Mars and on the Hermes. Edited January 26, 2015 by andrewas Quote Link to comment Share on other sites More sharing options...
Nibb31 Posted January 26, 2015 Share Posted January 26, 2015 (edited) There was a project of a militarized Soyuz known as Soyuz VI. It carried Pu-powered RTGs instead of solar panels, which saved weight, increased operational capability and reliability, and provided more power for the military equipment.As you can see on this diagram, the RTGs were on the outside, on extended arms, and angled to minimize radiation on the crew module. The Soviets obviously thought that the risk of irradiating the crew justified the additional complexity that design, so I don't really think it is that benign. Edited January 26, 2015 by Nibb31 Quote Link to comment Share on other sites More sharing options...
gooddog15 Posted January 26, 2015 Share Posted January 26, 2015 What would cheese (or any other food) taste like after a month exposed to the vacuum of space? (if it wasn't irradiated) Quote Link to comment Share on other sites More sharing options...
Nibb31 Posted January 26, 2015 Share Posted January 26, 2015 First of all, it would probably outgas, losing most of its water. It would probably freeze too, so it would end up tasting like dehydrated frozen cheese, whatever that tastes like. Quote Link to comment Share on other sites More sharing options...
Robotengineer Posted January 26, 2015 Share Posted January 26, 2015 Probably like that powdered stuff in boxed mac'n'cheese. Nasty. Quote Link to comment Share on other sites More sharing options...
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