understanding the behaviors of space travel

8/13/2019 Understanding the Behaviors of Space Travel

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anutensilKyldeThe JanitorTheSkyNet...and 5 more 6467Possibly MisleadingThe VASIMR Plasma Rocket: Breakthrough in rocket technology can make the trip to Mars in just 39 days instead of 300 days (spaceindustrynews.com)submitted 18 hours ago by slavecrud2021 commentsshare


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top 200 commentsshow 500sorted by: best[]001100010010 993 points 16 hours agoI expected this to be here and it wasn't.Video of VASMIR at Full Powerpermalink[]WITHYOURASSHOLE 1070 points 13 hours agoIt even "burns" with the same luminescence and color as science fiction space engines. Makes my science penis hard.permalinkparent[]NerdRaeg 144 points 12 hours ago"Man, that looks like it came right out of Homeworld or something" was the firstthought I had after watching that video.permalinkparent[]Monstertelly 131 points 12 hours agoMy first thought was this.permalinkparent[]arcticlynx_ak 42 points 10 hours agoMy first thought was the Millennium Falcon. Of course I AM a good guy though.permalinkparent[]skabbo 52 points 10 hours agoMan, the Empire was just preppin for the Yuuzhan Vong "planet ships".23 trillion deaths were ensured the minute that second Death Star was destroyed.permalinkparent

[]Charwinger21 62 points 8 hours agoWorldships, but yeah.At the same time, while the Empire was preping for the Yuuzhan Vong (especiallywith their expeditions out to the Unknown Regions and their work with the Chiss), the Emperor was still being evil.Honestly, the 23 trillion deaths were more ensured the moment Thrawn died, not the moment the Death Star was destroyed.Yes, the Death Star would have gone a long way towards defeating the Yuuzhan Vong, however Thrawn was such a great strategist that even without any "superweapons" he would still have been capable of stopping the Yuuzhan Vong at the Outer Rim..Not to mention that you have to ask if the galaxy would actually have been bette

r off without the Yuuzhan Vong invasion (which led to tremendous technological leaps forward, as well as future thought towards populating other galaxies, as they proved that extra-galactic travel was possible), and you cant forget that the23 trillion figure doesn't include Yuuzhan Vong deaths. And you've also got everything that Zonama Sekot brought to the galaxy, including the entirely new mindset that came with the peace with the Yuuzhan Vong and the settling of Zonama Sekot.And I haven't even read a Star Wars book in years...permalinkparent[]skabbo 15 points 8 hours agoAh, love me some Starwars EU.permalinkparent[]WitherSlick 15 points 3 hours ago

I just spent three hours on the starwars wiki you linked...permalinkparent[]Fojus9000 6 points 2 hours agoIm glad im not the only one, i had no idea of the depth of star wars!permalinkparentload more comments (1 reply)load more comments (11 replies)load more comments (1 reply)load more comments (1 reply)load more comments (8 replies)


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[]Humbledung 28 points 11 hours agoBut will it sound as cool as the methane rocket?permalinkparent[]Karakanov 13 points 6 hours agoPretty sure it wont make any sound in space.permalinkparent[]Humbledung 12 points 5 hours ago|But will it sound as cool in a non vacuum setting as the methane rocket does?Better?permalinkparentload more comments (4 replies)load more comments (5 replies)[]DaveBowman 65 points 13 hours agoWhich is my normal penis for me.permalinkparent[]cafezinho 22 points 12 hours agoI'm sorry, Dave. I'd do anything for love....permalinkparent[]pobah 11 points 7 hours agoOpen her pod bay doors Hal...permalinkparentload more comments (1 reply)load more comments (2 replies)load more comments (2 replies)

load more comments (12 replies)[]l1ghtning 346 points 13 hours agoWhat you are seeing here is a vacuum test chamber. That means a chamber made ofstainless steel which has had almost all of the air molecules pumped out of it,to come close to simulating outer space environment (difference being that in space there will be a slightly better vacuum and nil gravity).What you see is the thruster installed in the side of the chamber expelling itspropelled argon ions into the chamber. What you are seeing (blue) is the plasma(sometimes considered the 4th state of matter) which you could casually say is like a cloud of charged ions. In this case argon gas ions or whatever inert gas was used. Other well known examples of plasma include lightning strikes and any light bulb that does not have a filament (eg. neon signs and all fluorescent lamps).

There is most likely lots of instrumentation in the chamber to take measurementsof what is happening.You can see that towards the end of the test there is a highly stable blue cone.I am going to assume this is the 'full power' stage of the test. The other brief times you see different looking plasma is probably to do with ensuring protection of the electrically charged components, ie. processes that have been found to reduce wear, or, they are just parts of the test where the plasma is not yet stabilized.Because its in a vacuum, you are not actually 'hearing' the 'rocket', because asyou should know sound is not conducted well in a vacuum. What you are hearing sounds to me like the vacuum pumps on the chamber which would be quite loud. Youare not hearing anything going on inside the chamber. Other sounds will be the cooling and gas handling for the system, perhaps some cooling fans on some of the

power electronics of the thruster too.permalinkparentload more comments (49 replies)[]urgehal666 136 points 14 hours agoLadies and gentlemen, I present to you the caravel of the age of galactic exploration!permalinkparent[]BearDown1983 230 points 14 hours agoHonestly more like the first unfurled sail.permalinkparent


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[]Ice-Z 42 points 9 hours agoWell... even if we can't sail around the world on a few ships like the Europeansduring the Age of Exploration did, we can still do things the island-hopping Polynesian way until we can.permalinkparent[]Haddock 8 points 5 hours agoIsland hopping? The Polynesians straight up crossed thousands of miles of fullyopen pacific regularly. You're thinking more of European style 'coast hugging'.permalinkparentload more comments (1 reply)load more comments (1 reply)[]ColnelCoitus 17 points 13 hours agoI mean... that was like a couple pounds of thrust, very efficient fuel wise though. You could set of an estes model rocket that has a higher momentum change. Over a long time, (40 days) those couple pounds of thrust could send you to a veryhigh velocity, however in most gravity fields you want an almost instantaneousthrusting period, any extra thrust is an inefficiency. This, and the fact that electron thrusters have extremely large power requirements means your tiny spacecraft will be appended with a huge easily damaged and heavy solar cell.Sort of an ok idea, but probably not going to cut it for a majority of martian missions.permalinkparentload more comments (14 replies)load more comments (4 replies)

[]IndoctrinatedCow 42 points 14 hours agoWhat exactly am I watching here?permalinkparent[]purenitrogen 199 points 13 hours agoIt's turning argon to plasma and ejecting it.permalinkparent[]zangorn 51 points 13 hours agoThat's the best damn summary on here.Now, the article fails to mention how much argon is used for such propulsion. Any idea how much more thrust power this yields compared to current rocket fuel, by weight?permalinkparent[]Innominate8 57 points 12 hours ago*

Any idea how much more thrust power this yields compared to current rocket fuel,by weight?Chemical rockets tend to produce very high net thrust, but only for short burns.The net thrust of these kind of rockets is VERY low, but they make up for it bybeing designed to run for long periods. What's most important is specific impulse, effectively how much thrust you generate with unit of fuel.The specific impulse of a hydrogen/oxygen rocket is on the order of 450 seconds.The specific impulse of the vasamir in testing appears to be on the order of 5000 seconds.VASIMIR is quite a lot better in terms of mass efficiency, though that doesn't include the problem of generating a steady 200kw+ of electricity to run the engine.permalinkparent

load more comments (24 replies)load more comments (2 replies)load more comments (2 replies)[]xcvbsdfgwert 162 points 13 hours agoA blue LED. At full power.permalinkparent[]SirPrize 62 points 13 hours agoFull power? What are they thinking?permalinkparent[]TThor 40 points 13 hours ago


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NEVER turn your blue LEDs to full power.permalinkparent[]skribzy 16 points 13 hours agoNo, its ok to run blue LEDs at full power because they run cooler than the red ones.permalinkparent[]manowar2324kenshin 11 points 11 hours agoBut if you have red lights, a ping-pong ball, and white noise, you can trip outa little and hallucinate.permalinkparentload more comments (2 replies)load more comments (8 replies)load more comments (7 replies)load more comments (4 replies)load more comments (36 replies)[]ADickFullOfAsses 572 points 16 hours agoI've been following VASIMR for a few years, I'm glad to see there's still progress being made. It's my understanding that NASA will be implementing a few of them on the ISS (in 2014 last I read) to boost its orbit.permalink[]SPARTAN-113 217 points 16 hours agoI have been looking for news about the VASIMR for several years as well. I was under the impression that there were supposed to be test flights in the form of collecting space debris in Near Earth Orbit by now, but I don't think it ever hap

pened.permalinkparent[]letsgoiowa 306 points 15 hours agoAs SPARTAN-113, you must be pretty excited about this plasma tech.permalinkparent[]SPARTAN-113 386 points 15 hours agoWe need every advantage we can get.permalinkparent[]Link941 89 points 15 hours agoIncluding augmentations and Mjolnir armorpermalinkparent[]TThor 60 points 13 hours agoMjolnir armor?

permalinkparent[]HazzaMuzza 64 points 13 hours agoIt's a Halo (game) referencepermalinkparent[]TThor 152 points 13 hours ago*Nobody ever references my hammer...permalinkparent[]tjberens 56 points 13 hours agoMeow meow? What's meow meow?permalinkparent[]Dramatic_Explosion 13 points 8 hours agoI do! I understood that reference.permalinkparent

load more comments (2 replies)load more comments (18 replies)load more comments (3 replies)[]in_dog_we_trust 7 points 12 hours agoHey buddy. Sorry no one got your joke.permalinkparent[]TThor 15 points 11 hours agoThe eternal shame of being unfunnypermalinkparentload more comments (9 replies)


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load more comments (1 reply)[]L3R 34 points 13 hours agoOrbital Drop Shock Troopers are in the immediate future.permalinkparentload more comments (4 replies)load more comments (2 replies)[]-Alexander- 35 points 15 hours agoIs it a spider?permalinkparent[]darkh4ck3r 29 points 15 hours agoNo. Its more like a glowy pulsating thing.permalinkparent[]AmadeusMop 25 points 14 hours agoThat doesn't sound much better than a spider...permalinkparentload more comments (3 replies)load more comments (10 replies)load more comments (4 replies)[]staticquantum 18 points 16 hours agoThey are still active however, they have been testing their prototypes. I guessit is a matter of patience as with all the good thingspermalinkparent[]xDrRed 25 points 13 hours agoHow do you measure thrust in horsepower? Horses can't fly.

permalinkparent[]EPICHEADBANG 25 points 9 hours agoNot with that attitudepermalinkparentload more comments (1 reply)[]CartoonPiranha 6 points 8 hours agoThrust is force, while power (in the sense of a car engine) is Force x (distance/ time). So:P = F (d/t) and T = FP = T (d/t)Since distance over time = speed, we can write:P = TvSo thrust is equal to power times speed. This does mean jet engines get more pow

erful the faster they go, curiously.permalinkparentload more comments (1 reply)[]MUMHATESME 6 points 12 hours agoxDrRed asking the important questions.permalinkparentload more comments (2 replies)[]SPARTAN-113 10 points 16 hours agoBut they tested a prototype a couple years ago. Not in flight of course, but they knew it worked. Well, in the conditions they created. I'm just disappointed that no craft have tested even a small scale thruster or something.permalinkparent[]staticquantum 10 points 15 hours ago

I am also following them but don't know their milestones and project charts. I know that they were looking to get the proper permits to test in the ISS and thattakes time, they were approved mid-year. IIRC the tests are set for 2014/2015(not sure)So its definitely moving forward but not at 'Internet hype' speed standardspermalinkparent[]downvotethiscontent 46 points 15 hours agoMilestones?2001: http://i.imgur.com/2ctsMkP.jpg2010: http://i.imgur.com/tsPjCuo.jpg


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permalinkparent[]staticquantum 17 points 15 hours agoGreat charts, so we are really at the beginnings of this journey. What this shows is that real breakthroughs take a lot of testing, time and effort. At least ifall goes well by 2030 I will still be around to see VASIMR in full.permalinkparentload more comments (5 replies)load more comments (10 replies)load more comments (1 reply)load more comments (2 replies)[]Exodus111 42 points 15 hours agoCorrect me of I'm wrong, but from my understanding this runs largely on electricity, and the size needed for a manned mission would probably require something like an atomic reactor.permalinkparent[]LazerSturgeon 54 points 14 hours agoIt is not as much as you might think. Plus modern reactors can be made quite small. The reactors used in power general for cities is comparatively old tech.NASA and other space agencies designed small reactors for spacecraft as far backas the late 60's. At one point they built ones small enough to be used in nuclear thrusters.permalinkparent[]fillydashon 5 points 7 hours agoMy understanding is that the largest part of a reactor is the cooling system, an

d that cooling systems are a rather more complex problem to solve for spacecraftintended for human habitation.permalinkparentload more comments (3 replies)[]-------------------0 3 points 5 hours ago*Don't confuse a boiling water reactor with a radioisotope thermal generator.The reactors used in power general for cities is comparatively old tech.No, they're newer tech than the RTGs. RTGs are very simple, old school reactors.It's basically a thermocouple attached to a heat source. They're very inefficient (under 10%) but simple and reliable.RTGs also produce very low power, usually only a couple hundred watts. This is less than a third of a horsepower.permalinkparent

load more comments (1 reply)load more comments (11 replies)[]definitely_in_doubt 45 points 15 hours agoSome submarines have atomic reactors.permalinkparent[]SomewhatIntoxicated 64 points 15 hours agoI think a bigger problem would be dissipating that much heat... In the ocean youliterally have an ocean of water to run through a heat exchanger.permalinkparent[]Zbow 150 points 13 hours agoThen it's solved then, surround a space ship in an ocean of water while in orbit. Simple enough.permalinkparent

[]ItsDijital 97 points 12 hours agoYou should probably apply at NASA.permalinkparentload more comments (2 replies)[]manowar2324kenshin 41 points 12 hours agoI'm always thinking we have too much water doing nothing but sitting there. Minus an ocean or two and we'll have so much more room for activities!permalinkparentload more comments (3 replies)load more comments (5 replies)


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load more comments (66 replies)load more comments (8 replies)load more comments (31 replies)[]JellyMule 12 points 13 hours agoWhat do you mean by boosting it's orbit if I may ask? Is it not far enough currently from earth?permalinkparent[]Ilerea_Kleinokitz 36 points 12 hours agoDue to friction its orbit is continually getting lower and lower. So it has to be lifted up once in a while. Usually this is done by rockets that are resupplying the ISS.permalinkparent[]ANGRY_BASTURD 18 points 8 hours agoBy burning prograde on the apoapsis to increase the height of the periapsis. Ehehe look at me sneaking in here with my video game knowledge.permalinkparentload more comments (3 replies)load more comments (6 replies)load more comments (1 reply)load more comments (8 replies)[]jemtallon 746 points 15 hours agoHunh. So now it's quicker to go to mars than to receive a rebate check for my microwave. I'm filled with a mixture pride and shame.permalink

[]Aboot_ 89 points 14 hours agorebates are like vacuum cleaners. They suck.permalinkparent[]tjberens 52 points 13 hours agoThat's basically the point of them. Companies figure that most people won't go through the hassle of sending in for their rebate. That and the fact that most, if not all, rebates waive your right to a refund.permalinkparentload more comments (12 replies)load more comments (8 replies)load more comments (2 replies)[]PixelBlock 1551 points 17 hours agoTo think that the journey can be cut down so much by such an innovation ... we m

ight actually see some proper interplanetary travel in the next decade or two !Exciting !permalink[]herrohkitteh 661 points 15 hours agoSadly, saying that VASIMR will reduce the to Mars time to 39 days is a bit of astretch, especially going off the concept of a solar powered unit.Plasma rockets take massive amounts of power to work and provide very little thrust. I believe the thrust is typically in the range of a few pounds. So you needhundreds of KW of electricity to provide a tiny bit of thrust. The trick to them and their real value is that they provide that very small amount of thrust extremely efficiently.permalinkparent[]insertAlias 338 points 15 hours ago

What kind of efficiency do you mean? It sounds like it would be inefficient if it takes lots of electricity to produce little thrust.permalinkparent[]TheKingsJester 292 points 15 hours agoFuel, the electricity is essentially infinite if you're doing small amounts of thrust (due to constant solar energy).permalinkparent[]03Titanium 448 points 14 hours agoSo is it like an ion thruster?Honestly I've only blasted a few rockets into deep space in Kerbal space program


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so my knowledge ends there.permalinkparent[]DishwasherTwig 404 points 14 hours agoIt was a thing in fiction at least 35 years before KSP as well.Twin Ion Enginepermalinkparent[]sargent610 44 points 13 hours agowhats funny is with current ion engine tech the TIE fighter wouldn't be able toaccelerate for shit.permalinkparent[]DishwasherTwig 54 points 13 hours agoThey'd have to start out as TIE cruisers then work their way up.permalinkparent[]sargent610 7 points 13 hours agomore like they just start idledpermalinkparentload more comments (1 reply)load more comments (1 reply)load more comments (3 replies)[]LetsPlayK 77 points 14 hours agoThats what tie fighters are right?permalinkparent[]ColdIceZero 24 points 13 hours agoIndeed.

permalinkparentload more comments (4 replies)[]mypantsareonmyhead 18 points 11 hours agoHoly shit. Saw it in 1977 on the big screen, and only today learned what TIE actually stands for. Astounded.permalinkparentload more comments (4 replies)load more comments (1 reply)[]dopey_giraffe 178 points 14 hours agohttp://i.imgur.com/C4buo.gifpermalinkparent[]sithjustgotreal 300 points 12 hours agoSomewhat more relevant version

permalinkparent[]animesekai 3 points 6 hours agorelevant user too!permalinkparentload more comments (3 replies)[]mikeypuff 24 points 13 hours agoOk can someone out there explain where this beautiful gif is from? I've been wondering for probably two years now.permalinkparent[]edgeofthedesert 65 points 12 hours agoTim and Eric Awesome Show! Great Job!permalinkparent[]Pfmohr2 7 points 8 hours ago

SPAGHETpermalinkparent[]All_Hail_Dionysus 5 points 12 hours agohttp://www.youtube.com/watch?v=NFTaiWInZ44Around 2:15permalinkparentload more comments (7 replies)load more comments (10 replies)[]Migratory_Coconut 94 points 14 hours agoYeah, pretty much an ion thruster to KSP. Imagine sending a manned mission to Du


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na with only ion engines. That's pretty much this proposal.The ship would need a truly giant solar panel, or some other means of getting electricity. One other option is nuclear power, and another is microwave power beamed from a solar array around earth, or even a nuclear power plant around earth(moving such large power plants is heavy and takes energy, which is why it makessense to leave them behind and use microwave lasers to transmit the energy)permalinkparent[]Best_Towel_EU 5 points 14 hours agoExcept ion thrusters in ksp are awesome, burning for a few hours doesn't reallymatter if timewarp wasn't available.permalinkparent[]Migratory_Coconut 13 points 14 hours agoTrue, but that just proves the point. Getting a manned mission to Duna on a kspion thruster is not fast. Real ones are even worse, so a mission to mars is evenmore impractical.The above is true unless you have a giant thruster with a crazy power source, ofcourse.permalinkparentload more comments (12 replies)[]Elukka 6 points 11 hours agoanother is microwave power beamed from a solar array around earth, or even a nuclear power plant around earthThese are completely unrealistic in the foreseeable future.microwave lasers

Masers are not very efficient at all.permalinkparentload more comments (1 reply)load more comments (11 replies)[]Pillagerguy 22 points 14 hours agoYeah, it's a lot like that from KSP.permalinkparent[]alexkh150 4 points 14 hours agoExcept even slower to accelerate than in KSP.permalinkparentload more comments (7 replies)load more comments (13 replies)load more comments (15 replies)

[]herrohkitteh 43 points 15 hours agoBecause the efficiency is measured in terms of the mass used as fuel.It takes very little fuel in the form of mass but a lot in the form of electricity.It's all about Specific ImpulesCopy pasted from another reply I just made to a very similar question.permalinkparentload more comments (1 reply)[]CheeseNBacon 25 points 15 hours agoIt's a matter of how much fuel it needs to run. Fuel adds weight. You can provide a huge amount of thrust, but it takes a lot of weight and uses it real quick.This provides a small amount of thrust, but also uses very little fuel and as long as the electricity is coming from solar or some other renewable source you en

d up saving a lotpermalinkparent[]candygram4mongo 45 points 14 hours agoFuel is a bit of a misnomer here. What we're really talking about is reaction mass.permalinkparentload more comments (4 replies)load more comments (2 replies)[]Richardcj 4 points 15 hours agoefficiency


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Its efficiency of mass (fuel). Electricity is renewable with solar/nuclear but no places to pick up extra fuel.permalinkparentload more comments (12 replies)[]ChucktheUnicorn 104 points 14 hours agoa few pounds exerted constantly can add up pretty quick in a friction-less environment like spacepermalinkparent[]herrohkitteh 30 points 14 hours agoVery true, and that is their value. The problem is trying to propel crew carrying vessels with that low amount of thrust kills it off pretty quick, I'd imagine.A couple hundred pounds of human, a couple hundred pounds of structure, and then however much for food, water, waste storage. 4 plasma rockets each putting out5 newtons, or about 4.5lbf, vs all that mass isn't going to get any where in ahurry.I'm not a physicist though so I could be misunderstanding something.permalinkparent[]krevency 45 points 14 hours agoI think that the idea is (bear with me, also non scientist) if it makes you go ten miles an hour faster per day, after a month you're going 300 miles an hour. So even if it's not adding that much speed, it's always adding it, and there's nodrag to take it away.permalinkparent[]Pandarandrist 329 points 13 hours ago*

Hey guys! I'm a scientist! The problem here is that, while you do get small thrust that adds up over time, it's not as simple as traveling in a straight line and accelerating at a constant rate. The fact that everything is in orbit around the sun complicates things quite a bit. Basically, it is much, much worse than you think. I can provide some examples for earth orbiting satellites if you like.edit: So, examples, because why not. This is the simple case of a low thrust continuous burn vs. a pair of impulsive (high thrust, short burn) maneuvers.So, I guess I'll just do the case of LEO (Low Earth Orbit) to GEO (Geostationaryorbit). What I will give you is the Delta V (change in velocity) you need to gofrom one place to another. These are the numbers you would use to find out howmuch acceleration you need for how much time, or similarly how much propellant you need to expel.First of all, the orbital velocities:

ISS altitude (370 km) - 7690 m/sGeostationary orbit (35786) - 3075 m/sDelta V using low thrust continuous burn - 5928 m/sDelta V using 2 impulsive maneuvers (Hohmann transfer) - 3866 m/sThis really highlights several of my points. First, you are forced to use less efficient trajectories when you use low thrust, continuous burns. This, overall,tends to hurt your performance. However, what is low thrust is relative to the other forces acting. In this case, the acceleration due to the thruster must be very small compared to the acceleration due to gravity of the craft at a certainaltitude.Second, in orbital dynamics, the change in velocity is NOT NEARLY AS SIMPLE AS YOU THINK. The article says VASIMR will accelerate a craft to 35 km/s. This is anabsurd statement without context. If VASIMR is able to achieve a minimum escape

trajectory from earth it will travel at the same speed with respect to the sunas the earth does. The earth is orbiting the sun at ~30 km/s. If I do a burn toSLOW DOWN, I will fall towards the sun. If I plan to get to mercury, by the timeI get there, I will be going 42 km/s, just from falling. Orbital mechanics doesnot work like accelerating in a straight line without other forces acting likein freshman physics. If the gravitational forces are relevant (Hint: they almostalways are), then they complicate things quite a bit.Silver LiningThe reason the Mars trip takes 300 days is this. The (simplified) plan: Do one really big burn to put you on a path to Mars, then coast, and let the sun do all


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the work. At this point, you are just in an orbit, and you let it happen. Then,when you get there, you do another burn to insert into Mars orbit (otherwise, you end up back where the Earth was when you left, but it's not there anymore!). Then, you chill at Mars for awhile, do your shit, and then do it all in reverse.The reason this takes so long is that your burns are short, and you're really just in orbits the whole time. Half of the trip you're almost doing what the earthdoes, and you're doing it for half an orbit (read, half a year).To make these trips better, what we need is a thruster we can leave on for longer periods of time without using too much propellant, and whose thrust is very large compared to influences from the Sun. For some frame of reference, the Sun exerts about 6 Newton's of force for everyone 1000 kg of mass at 1 AU from the sun. That means you don't need much force!However!! The VASIMR engine produces 5 N of thrust, at a specific impulse of 5000s. This means that you expel 100 mg of fuel every second that it's running. Fora continuous 40 day burn, you'd burn 345.6 kg of propellant, and with an initial craft mass of 4000 kg, you'd get a Delta V of 4432 m/s (Not even enough to gofrom LEO to GEO, although, again, this can be a misleading comparison).For those who are familiar with orbital dynamics, I have simplified many thingsin my explanations intentionally. If you feel I have made a real error, let me know. Otherwise, please don't bother me about how it's not really half a year orthis and that. I know.Tl;dr Orbital Dynamics is more confusing than you think, because gravity does most of the heavy lifting (irony!), and low thrust burns are less effective than impulsive maneuvers.

permalinkparent[]mr_stagger_lee 18 points 10 hours ago*Fabulous. Assuming you are the kind of authority that you sound like you are, I've learned more about the intricacies of space manoeuvres from your comment thanI have from all of the sci fi I've ever consumed.Edit: can you explain specific thrust? Does the 's' mean specific?permalinkparent[]Jedimushroom 11 points 8 hours agoSpecific impulse is a measure of the energy-efficiency of your rocket. Impulse is the force your rocket produces multiplied by the time you can produce it. If you divide that number by the weight of the fuel at earth surface gravity (because that will also be a force) you end up with a quantity measured in seconds thatis helpfully independent of your unit system. This is very important because NA

SA still hilariously uses foot/lbs and other bizarre measurements.permalinkparent[]Swiggles_ 5 points 9 hours agoSpecific impulse is measured in seconds. s = secondspermalinkparentload more comments (2 replies)load more comments (4 replies)[]Get_a_GOB 9 points 7 hours agoAs an orbital mechanics guy, reddit can be an extremely frustrating place. Yoursmay literally be the first post I've ever read here that is both explanatory and not full of unacknowledged wild inaccuracies or oversights. As soon as you listed the orbital speeds in LEO and GEO I thought, "here we go again," but my surprise as I kept reading was unexpectedly pleasant.

Wild applause.permalinkparentload more comments (3 replies)[]Soddington 5 points 7 hours agoThanks to Kerbal I actually have the vocabulary to follow this.permalinkparentload more comments (38 replies)[]IICVX 18 points 13 hours agoThe problem is it doesn't make you go ten miles faster per day, it's more like half a mile faster if we're talking about moving all the infrastructure necessary


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to keep humans alive.VASIMR is awesome sawsum for unmanned probes and satellites and stuff that's either super light, or that we don't care how long it takes to get where it's going. Unfortunately, people fall into neither of these categories.permalinkparent[]SinkHoleDeMayo 33 points 13 hours agoYou callin me fat?permalinkparent[]mrducky78 31 points 12 hours agoWe are calling most of you as non essential.permalinkparentload more comments (8 replies)load more comments (7 replies)[]McWut 8 points 14 hours agoSay the vessel is 2000 kg (4,400 lbs). I think 20 Newtons would accelerate it by0.01 m/s2. That's still 864 meters per second per day. Give it 4 weeks and it will reach Curiosity's average speed.How long can these things accelerate?permalinkparent[]Stingray88 4 points 14 hours agoProvided it's still getting sunlight, indefinitely.permalinkparent[]ObeyMyBrain 11 points 13 hours agoOr until it runs out of Argon

permalinkparent[]Soul-Burn 31 points 12 hours agoSo it's until all the propellant particles Argon.permalinkparentload more comments (6 replies)load more comments (4 replies)load more comments (10 replies)[]bowdenta 7 points 14 hours agoYep and a sustained "burn" for 39 days has to be far geater than a conventionalthruster for a few minutes. Slowing down has to be the biggest challenge for atmospheric entry in this scenariopermalinkparentload more comments (4 replies)

load more comments (2 replies)[]Theeedill 8 points 14 hours agoI did some searching on google and found that they would pair two of these engines requiring 200 kw of electricity. However, I couldn't find an output for the solar panels that would be located on a space craft. I was wondering if anyone had the output per area unit on one of these solar panels to understand how feasible it could be to power these.permalinkparent[]dgriffith 23 points 14 hours agooutput per area unit on one of these solar panels to understand how feasible itcould be to power these.*Solar output from the Sun when you're in Earth orbit is approximately 1300W/square metre.

Fancy-ass (read: expen$ive) spacecraft grade solar cells are 30% efficient.200kW / 1.3kW.m2 * (1/0.30) = 500 square metres of panels, or about 25 x 20 metres of panels.That's at earth orbit. Going out to mars significantly drops the power available.permalinkparentload more comments (3 replies)load more comments (5 replies)load more comments (96 replies)load more comments (183 replies)


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[]scott123456 64 points 15 hours agoI'm a little confused by this bit:"radio waves in the form of light"permalink[]Silpion 54 points 15 hours ago*Me too. This is where I stopped reading, because the author didn't seem to knowwhat he was talking about.permalinkparent[]Beer_in_an_esky 22 points 13 hours agoThere are lots of points in that article that are just weird to anyone who has more than a HS science education. It really just reads as if he had taken a pressrelease, and then tried to spin it out into a proper article.permalinkparentload more comments (1 reply)[]kawfey 18 points 14 hours ago*I think they mean solar flux. And by that I mean light from the sun. And by thatI mean they'll use antennas to capture the signal from the sun..By that I mean solar panels.Edit: What they really meant to say was that gas is ionized into plasma by meansof RF. Sort of like microwaving grapes. The actual craft would likely be nuclear powered.permalinkparentload more comments (1 reply)[]Demos181 13 points 14 hours ago

Technically every wave on the electromagnetic spectrum is light, only they are each at different wavelengths and we can see only a specific band.permalinkparentload more comments (3 replies)load more comments (4 replies)[]EvanDaniel 108 points 16 hours agoThis is a really awesome approach to ion thrusters, and it's cool to see it getting research and making progress.But without some serious upgrades to power sources and power electronics, the thrust level available won't be that much higher than other ion engines, which means you won't see any 39 day Mars missions. Multi-megawatt power systems on spacecraft are just plain hard.permalink

[]Raed-wulf 15 points 15 hours agoYeah, I agree. This article made VASIMR seem like a TIG welder attached to a solar panel. While I'm sure it's a lot more complicated than that, I imagine the power source for this will be incredible.permalinkparent[]cryptorchidism 41 points 11 hours agoThe "39 days" figure assumes a 200 MWe space nuclear reactor weighing 110 tonnes, or 1800 W/kg. They propose using a Closed Cycle Magnetohydrodynamic reactor.That's a tall order. By comparison, the best nuclear space power system ever flown achieved 5.4 W/kg.permalinkparent[]sam712 23 points 10 hours agoClosed Cycle Magnetohydrodynamic reactor.

If Captain Kirk said, "Scotty, fire up the Closed Cycle Magnetohydrodynamic Reactor!" I'd have laughed at what I thought was After Earth level technojargon.permalinkparentload more comments (1 reply)load more comments (12 replies)load more comments (1 reply)[]generalCrozier 10 points 15 hours agoYou really should have more upvotes. EP systems would have to be on the order of10s of megawatts; for perspective large modern day satellites operate up to 18kW. The specific power of the power source and the power system are basically dea


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d weight working against the efficiency.I also have a problem with argon as the main source of fuel. For hall thrustersat least argon is much less efficient than xenon and krytpon as it is lighter and requires longer acceleration channels.From what I think I know, the promises of VASIMR seem a bit exaggerated.permalinkparent[]MrMooMooDandy 8 points 12 hours agoAerospace engineer/astrodynamicist here -- it has definitely been oversold by its developers. It's a promising technology from a conceptual standpoint, at least, but the above poster is correct in that it will not be cost effective any timein the near future unless there's some drastic several-orders-of-magnitude-breakthrough in power generation. With that said, you can simulate a lot of interesting optimal trajectories to various places in space using a variable specific impulse engine model, but they are purely academic exercises at this point, and will remain so for many decades to come.permalinkparentload more comments (35 replies)[]hadronshire 76 points 14 hours agoTo answer many of the questions in this thread.Start with the wiki page: http://en.wikipedia.org/wiki/Variable_Specific_Impulse

_Magnetoplasma_RocketAdAstra, the guys who make the thing. http://www.adastrarocket.com/aarc/VASIMRA rather in depth and technical explanation of the potentials of these thrustershttp://www.adastrarocket.com/VASIMR_for_flexible_space_exploration-2012.pdf

Power: Many people expressed concerns and questions regarding powering these thrusters. The current module being placed on the ISS in 2015 (according to currentplanning). Is a 200kw unit. The ISS produces 84kw of nominal power (http://www.nasa.gov/mission_pages/station/main/onthestation/facts_and_figures.html#.UqK3jPRDtfY) They will trickle charge the thruster's battery so that it can operate for15 minutes at a time.This means that we can easily power one of these thrusters with technology thatwe have today (it wouldn't be a stretch in regards to technology to build/launcha larger solar array in/into orbit).Now the bad news. To do any of the larger weight missions the power needs go quite a bit higher. Proposed Mars missions require in the range of 1-2MW. This is an amount of power not currently feasible with solar arrays on a space ship, notto mention the reduced efficiency of the arrays as the distance from the sun inc

reases. For these missions AdAstra is banking on using nuclear power. The energydensity of a nuclear reactor is about the only thing we have today that would allow us to power a bank of these thrusters powerful enough to get a ship anywhere near the velocity discussed in this news article.Summary: Pretty cool system for unmanned lightweight ships, station keeping bursts of thrust in LEO and potentially really cool if we can get enough power up there. As it stands, the thruster is probably good to go, but the power systems need a ways to catch up.TL; DR Really cool system with tons of potential, but its being way oversold compared to what it can do now. Maybe one day.permalink[]johncipriano 7 points 12 hours agoWhy is a nuclear reactor currently not feasible today?

permalinkparent[]hadronshire 8 points 4 hours agoThe short version is that the weight of a reactor is too heavy for current liftsystems and we haven't developed a miniaturized/lightweight reactor yet. Development time ranges in 10+ years for new designs and a design like this would needto be tested prior to launch, so you are looking at more like 20 years+.permalinkparentload more comments (3 replies)load more comments (5 replies)[]g0_west 4 points 7 hours ago


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If we can cut down earth to mars to 40 days, does that mean earth to moon will be like 20 minutes?permalinkparentload more comments (1 reply)load more comments (11 replies)[]Shandlar 19 points 14 hours agoI've gone back and read everything I could find on all the competing forms of ion drives a few times over the last several years, and this article could have been written at any time in that span its so lacking in detail. We've had magnetically accelerated argon rocket drives in the lab for a decade, what breakthroughwas made in its improvement?The extreme lack of numbers is extremely upsetting.To what fraction of c is the argon accellerated to (fuel/mass efficiency)?What amount of power is required (last I heard, these things sucked down a fullmegawatt, an extremely high sum of energy in space for us currently.)?If the power requirements can be met, what amount of thrust can be obtained (again, last I heard 1 megawatt resulted in only around 200 newtons of thrust.)? A reasonable mars mission capsule could be 25,000 kilos or more. 200 newtons wouldonly be 0.008 m/ss. Thats over 80 days to acheive the 35 miles per second quoted, and decelleration would be needed to acheive orbit of mars.What shielding was developed to prevent the corrosion of the components exposedto the ionized gas? How many hours of continuous thrust can we acheive before failure? Last I had read was 10,000 tops, which is cutting it very close for a manned mars mission, although we could just waste some mass and place a second unus

ed backup engine on a craft.Has anyone found an actual scientific write up on this breakthrough I can peruse? I would be eternally grateful.permalink[]sdavid1726 4 points 11 hours agoExhaust velocity is 9.806 * I_SP, so you can expect the argon to be acceleratedto around 25,000 to 100,000 m/s (.0001 to .0003 c).permalinkparentload more comments (1 reply)load more comments (5 replies)[]jkonine 261 points 16 hours agoSo this is like, kind of a GIANT FUCKING DEAL no?My dad talks about the impact seeing men on the Moon had on a society that was l

osing faith in the world.I think we need something like that again.permalink[]morocco36 30 points 15 hours agoYour dad is right we all could use a boost right now.permalinkparentload more comments (1 reply)[]Very_subtle 95 points 16 hours agoWordpermalinkparent[]qdhcjv 154 points 15 hours agoExcelpermalinkparent

load more comments (24 replies)load more comments (5 replies)[]bearadox 5 points 14 hours agoNASA is fond of making big, bold announcements, though. This is a wait and see kind of thing, but I certainly hope it works out.permalinkparentload more comments (1 reply)load more comments (50 replies)[]awFirestarter 30 points 15 hours ago*VASIMR Debate/The VASIMR Hoax


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Did they solve some of these fundamental problems?*Edit* Video has two speakers: 30min + 15min + Q&A. Watch both if you are interested but the first is the main part.permalinkload more comments (9 replies)[]Tommothy 316 points 16 hours agoIt pisses me off beyond belief that we are cutting NASA's funding. And this is why...permalink[]Scarecrow398 147 points 16 hours ago"Hey NASA... heard you could use some funding, in return we'd like a few things"~Elon Musk.permalinkparent[]wooddraw 130 points 16 hours agoYeahhh, in reality, it's the other way around.permalinkparent[]chknh8r 22 points 15 hours agoThey cut the Constellation program, just like the Saturn Program was cut for theAres Program. They are moving onto bigger and better things, which is this plasma shit.permalinkparent[]con247 17 points 15 hours agoSaturn was cut for STS. STS was cut (thankfully, the shuttle flew way too long imo) for the constellation project which included the Ares launch vehicles among

other projects like Orion, Altair, and the proposed Mars transfer stages. Constellation was cancelled aside from Orion and now we have SLS which might actuallyfly before it gets cancelled.permalinkparent[]M129k 12 points 11 hours agoThe US space program should get a kick in the nuts for operating Heavy Lift Vehicle technology, powerful enough for an Apollo-repeat, for 30 years without evergoing beyond Low Earth Orbit with it. The Space Shuttle, without the orbiter, could get over 70 metric tons to Low Earth Orbit, with an upper stage that would've been enough to send the Apollo CSM to the moon in a single launch.What I love about SLS is that finally, the HLV technology developed for the Space Shuttle is finally being evolved into an actual HLV rather than being used togo in circles.

permalinkparentload more comments (9 replies)load more comments (1 reply)load more comments (1 reply)[]bob000000005555 7 points 13 hours ago"Hey SpaceX, we heard you could use some of our decades of research" -NASApermalinkparentload more comments (1 reply)load more comments (3 replies)[]Strangely_Calm 11 points 15 hours agoRoyce: That's the miracle of the franchise. You get all the equipment and know-how you need, plus a familiar brand-name people trust. You'll be on a rocket-rideto the moon! And while you're there, would you pick up some of that nice, green

moon money for me Royce McCutcheon!Homer: No deal, McCutcheon, that moon money is mine!permalinkparentload more comments (1 reply)load more comments (5 replies)[]OllieMarmot 89 points 15 hours agoIt pisses me off when people keep repeating this without actually bothering to verify it for themsleves. Look here. NASA is not, in any way being gutted. It's funding has remained essentially steady, and is significantly higher than it was5-10 years ago. I see these comments on reddit every day, and I really do think


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it is damaging to the organization when people are always claiming (falsely) howmuch it has been gutted and what a joke it is now.permalinkparent[]PastyPilgrim 86 points 15 hours ago*It's grown a few billion over 10 years, but at less than half of one percent ofthe total budget it's a fairly insignificant amount (a percentage that has shrunk every year). The amount is barely staying ahead of inflation. So I think mostpeople that complain might be upset that NASA gets half a penny, whereas defenseis getting fists full of paper. Amidst the controversy surround things like theNSA, TSA, etc., I'd like to see a bit more of my tax dollars migrate over to NASA.permalinkparentload more comments (16 replies)[]TheKingsJester 34 points 15 hours agoAdjust for inflation, it was highest in the 90s.permalinkparentload more comments (2 replies)[]yukisho 9 points 14 hours agoIn the eye's of the government "After several trips to the moon we can verify there are no resources to exploit. Space has been explored. GG"permalinkparentload more comments (5 replies)[]JohansenTurbo 7 points 12 hours agoNASA should open a donation page where people can donate monthly to them.. I wou

ld drop 10-20$ per month to help them (And I'm not even American..), they mightbe able to get alot of money this way!permalinkparentload more comments (11 replies)[]RobNoxious 12 points 7 hours agoIt made the Kessel run in less than twelve parsecs.permalink[]tuckertucker 96 points 16 hours agoAt the speed of 35 miles/second, it should reach the moon in 113 minutes, if themoon is an average 238,900 miles away. Did I do that math right?permalink[]Lurking4Answers 224 points 16 hours agoDid you account for slowing down?

permalinkparent[]la_Brea 648 points 16 hours agoSlowing down is for pussies. Besides it'd still slow down, it would just do it all at once.permalinkparent[]alextk 218 points 16 hours agoI am a seasoned Kerbal Space Program player and I confirm that slowing down is for pussies, even if Jebediah disagrees (he's a pussy, of course he'd say that).permalinkparent[]herrohkitteh 148 points 16 hours agoA seasoned KSP player should recognize that Jeb is the last Kerbal you could ever accuse of any form of cowardice.That little green bastard would be loving every second of his upcoming high spee

d impact.permalinkparent[]CUNTBERT_RAPINGTON 40 points 15 hours agoA seasoned KSP player will do anything in their power to ensure the survival ofJeb. You can't just throw away an orange suited kerbal like that.Bob does all of the hazardous testing first to make sure things are safe for Jeb, and is usually replaced with Bill when there is a catastrophic failure.permalinkparentload more comments (1 reply)[]Televisions_Frank 65 points 15 hours ago*


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What people didn't see in Gravity was Jeb on the other side of the space stationenjoying every minute of it.Apogee starring Jeb Kermanpermalinkparentload more comments (3 replies)[]gdeadfan 40 points 15 hours agohttp://i.imgur.com/t1FXu.pngpermalinkparent[]Gunnmitten 13 points 15 hours agoI never liked Jeb, too much stupidity to overcome what courage he had. But the day he died was a sad day indeed. I attempted to erect a shrine and flag on Eeloofor him- I did, but it was burning in a fifty foot crater last I saw.permalinkparent[]32Dog 16 points 14 hours agoJust how he would have wanted it to bepermalinkparentload more comments (1 reply)[]Scarecrow398 29 points 16 hours agoShitty Kerbal Space Program player here, can support his confirmation of slowingdown being for pussies, I never slowed down while approaching the Mun and managed to glitch through it...permalinkparentload more comments (1 reply)[]la_Brea 10 points 16 hours ago

Ahhh yes! I just started playing that game yesterday and I find it insanely hard.permalinkparent[]ajh1717 15 points 15 hours agoIt is actually pretty realistic.I have a harder time landing on the mun than other planets because of the (essentially) no gravity.Give me parachutes. I can't land for shit with reverse thrusters for my life.permalinkparent[]Dagon 11 points 15 hours agoZero your horizontal speed nice and high - like, start zeroing it out at 20,000mup, so that by 10,000m you just have to fall straight down.It means your fuel expenditure is higher, but it makes it MUCH easier to learn h

ow to land. Fuel efficiency can come later when you've got the landing thing figured out.permalinkparentload more comments (10 replies)load more comments (13 replies)load more comments (2 replies)[]Volentimeh 13 points 14 hours agoLithospheric braking.permalinkparentload more comments (15 replies)[]acini 10 points 16 hours ago2 hrs.permalinkparent

[]ComradeCube 48 points 16 hours agoThe inflight movie will be apollo 13.permalinkparent[]KMFDM781 6 points 15 hours agoWhat's the matter Colonel Sandurz? Chicken?permalinkparentload more comments (32 replies)[]bowlthrasher 26 points 16 hours agoThat doesn't take into account acceleration and (hopefully ) deceleration times.You don't want it to look like the scene in spaceballs where they come out of l


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udicrous speed too soon.permalinkparentload more comments (3 replies)[]THE_ISENGARDNER 23 points 16 hours agoI believe that the 35 miles/second is the max speed, so it would need time to get up to speed (if it can even do that in the short distance from here to the moon), and then turn around and slow down as it approaches the moon, so it would probably take longer than your 113 minutes.permalinkparent[]ExogenBreach 48 points 16 hours agoActually its max speed is 186,282.4 miles per second.permalinkparent[]FredeJ 20 points 14 hours agoSo he was pretty close.permalinkparentload more comments (29 replies)load more comments (7 replies)[]b1122 6 points 16 hours agoFree return trajectories are preferred for crewed lunar missions, so going faster is not an option.permalinkparentload more comments (3 replies)load more comments (9 replies)[]neuromorph 128 points 18 hours ago

Saw a prototype at JSC. And talked with Dr. Chang. It was amazing to see it bothunfired and in low thrust tests.permalink[]otter111a 208 points 16 hours agoHumblebragpermalinkparent[]NoNeedForAName 28 points 16 hours agoThe fact that it was made a separate sentence makes it plainly obvious, no? A standard compound sentence would have sounded much better.permalinkparent[]asimpleguy 20 points 15 hours agoThe subtleties of languagepermalinkparent

[]bruffed 35 points 15 hours agoSubtleties is a strange looking word.permalinkparentload more comments (7 replies)load more comments (1 reply)load more comments (1 reply)load more comments (4 replies)load more comments (1 reply)[]UmamiSalami 59 points 16 hours agoThere really isn't anything new here. VASIMR has been around for awhile, and hashad its fair share of criticisms.In my opinion, nuclear thermal rockets show more promise right now.permalink

[]John-Garrison 43 points 16 hours agoI think the whole "ready for testing in space" is the new part. It would be interesting to see if any of the past criticisms are no longer relevant for the current state of the technology.permalinkparent[]Great_Gig_In_The_Sky 6 points 15 hours agoI thought it had been slotted for a test in 2013 but I guess I was mistakenpermalinkparentload more comments (3 replies)load more comments (3 replies)


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[]SadAttemptAtPun 13 points 15 hours agoAdditionally, the magnetic field created by the rocket is thought to create a protective shell for the spaceship, which would help protect it against the radiation in space.IIRC, wasn't this the main thing preventing NASA from performing Manned Exploration of the solar system? Isn't this just as important as the new propulsion method?permalink[]Volentimeh 7 points 13 hours agoMagnetic shielding only protects against charged particles, a proportion of ionizing radiation is electrically neutral (high energy neutrons) and is unaffectedby a magnetic field (our atmosphere protects us from those particles).permalinkparentload more comments (1 reply)[]imfineny 11 points 16 hours agoI think VASMIR certainly has potential, but I from what I understand its simplya a higher thrust engine in the ion series, that's less efficient than most ionengines, but not too much so. It will also require a tremendous amount of power,such as an advanced nuclear reactor to power. So I am not sure why we would usethis over regular nuclear engines.permalinkload more comments (5 replies)[]factorV 8 points 8 hours agoJust a matter of time before we see 30 seconds to mars.

permalink[]Pykoh 9 points 5 hours agoThat would be 14-60 times the speed of light, but sure!permalinkparentload more comments (4 replies)load more comments (1 reply)[]Olasana 6 points 15 hours ago*I work with optical emission and mass spectrometers that use this principle to atomize samples. Argon stream passes through an open ended torch, surrounded by aload coil that carries radio frequency oscillating electrical current. This current produces an oscillating magnetic field inside the torch. Argon atoms (someof which have been ionized during an ignition spark) slam into each other, electrons are lost and accelerated, colliding with other Argon atoms. This magnetical

ly induced process generates an electric current inside the argon gas. Ionized argon is such a poor conductor of electric current that the resulting ohmic heating yields a plasma hotter than the surface of the sun, typically about 10,000 Kelvin in analytical applications (but can be made much hotter, such as in VASIMR). It's extremely simple, the fundamental concept has been around for over a century, and the prototypical atmospheric pressure inductively coupled plasma for nearly 70 years.permalinkload more comments (3 replies)[]Palmettojcm 12 points 16 hours agoIf technology will take a question: Can this be used to propel from earth or just for use once in space?permalink

[]garrydanger 13 points 16 hours agofrom what the article says, it would only really be useful in space.The main difference with this type of rocket is being able to use mostly renewable energy in the propulsion system, which gives the rocket a greater lifespan than similar, modern-day rocket technologies.permalinkparentload more comments (1 reply)[]Metlman13 19 points 16 hours agoI think it would be one of those things assembled in space, and then used from there.


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Either way, I hope to see someone, government or private group, use this to reach Mars. It would be nice to see some research facilities (or small settlements)supported by VASIMR ships.permalinkparentload more comments (14 replies)[]elasticthumbtack 5 points 16 hours agoI believe it is very low thrust, but very high speed and efficiency. You probably couldn't feel the force of it accelerating you, but it will just keep accelerating way past the top speed of other rockets.permalinkparentload more comments (2 replies)load more comments (23 replies)[]KingHiramismypapa 13 points 15 hours agoMaybe its just me but stuff like this is freakin awesome. Why CNN insists on exaggerating on random ass stories when stuff like this is out there, I will neverunderstand.permalink[]Lars0 21 points 14 hours agoThis is another one of those exaggerated stories.Here is an op-ed by a former lockheed space system engineer.http://www.marssociety.org/home/press/tms-in-the-news/thevasimrhoaxpermalinkparentload more comments (6 replies)load more comments (2 replies)

[]Nyarlathotep124 11 points 16 hours agoThe article doesn't list the estimated acceleration. Would this be something comfortable for humans? Survivable for humans? Or would it only be usable on unmanned flights?permalinkload more comments (14 replies)load more comments (460 replies)aboutblogaboutteamsource codeadvertise

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understanding the behaviors of space travel

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