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To Mars and Back in Ninety Days
paltemalte writes "A new means of propelling spacecraft being developed at the University of Washington could dramatically cut the time needed for astronauts to travel to and from Mars and could make humans a permanent fixture in space. In fact, with magnetized-beam plasma propulsion, or mag-beam, quick trips to distant parts of the solar system could become routine, said Robert Winglee, a UW Earth and space sciences professor who is leading the project."
This is fine and well, but how does one meanwhile solves the most pressing problem, that is, providing CHEAP and RELIABLE means to get into earth orbit???
Sign me up, should this ever become a reality. However, the only way space travel will become an everyday occrance is if it is profitable. Don't get me wrong. I'd love to do it for the sake of doing it. But people aren't willing to spend millions/billions/trillions of dollars to do something just because "its there".
/. is a bunch of nerds at a million typewriters. It's not a political conspiracy determined to undermine your beliefs.
Hope they can slow it down when they get there.
/will probably make a small crater...
Check out my sysadmin blog!
What's all this about a "new method" being required for short trips to Mars? What about the 101 old methods we have? Nuclear Thermal, Nuclear Electric, Orion, Laser Lifters, Nuclear Salt Water (this seriously needs to be developed!), Fission Fragment engines, Nuclear Steam ships, etc, etc, etc.
We've got high powered propulsion options pouring out of our ears. It all comes down to getting funding. Wave a plan near congress and they're sure to kill it before breakfast.
Javascript + Nintendo DSi = DSiCade
You could build a rocket with a boiler that burned pieces of the ISS. At least *that* would be putting it to good use...
Oh! Sh!t we shoot the cabin insteed of the sail !
Ceci n'est pas une Signature !
How would you accelerate and decelerate from such speeds without the human inside being crushed?
Too funny
I am very easy to get along with, but I don't have time to waste being nice to people who are being stupid. -Theo
That should be "at what Delta-V?" More Delta-V == faster.
Javascript + Nintendo DSi = DSiCade
What are they looking at in creating particle or at least micrometeorite ablative shielding that can handle the increased velocity these hazards will bring with the increased speeds?
right now our spacecraft are basically beer cans with insualtion and windows, any tiny object at any decent velocity can rip through them like tissue paper. on a long distance mission as a trip to mars would be, we need a craft that is at least 100 times stronger than anything we launch now which would make it more than that many times heavier.
Do not look at laser with remaining good eye.
...this will only work for vehicles that have already arrived at their destination.
I poo-poo your silly idea Philleas Fog.. It's impossible and I'll wager my reputation that you won't make it from the Gentleman's Club in London to Mars and back within 90 days!
but even better if they could figued out a way to keep their site from being /.ed
A bunch of Tech Stuff
"Rather than a spacecraft having to carry these big powerful propulsion units, you can have much smaller payloads,"
.sig, but I'm not going to give it to you.
If the station fails at the remote end, will it take 40 years to get back to earth?
I have a great
A few years ago, there were some [astr|cosm]onauts that were highly trained to resist until a year in space so that they could fly to Mars.
Now the technology evolved to the point of making their effort less worthy...
BTW, I wonder if this propulsion could be of some use on Earth ?
Trolling using another account since 2005.
So, you mean that I could get something to and from Mars in under 90 days? That's better time than the US takes to process my tax return. I wonder when Mailboxes Etc will set up a PO Box service on mars? Could be a whole growth opportunity.
Or maybe I shouldn't post to slashdot before morning coffee.
Event Management Solutions : http://www.stonekeep.com/
Isn't this similar to VASIMR? Variable Specific Magnetoplasma Rocket.
/.ed within 6 minutes of the post :-)
I hate to be a buzzkill, but is there ANY realistic reason why sending people to Mars is good science?
It seems that if we spend the money that it would take to develop the spacecraft & lifesupport required to send people that far on better and more reliable robots, a lot more actual research would get done. Heck, we might even have enough left over to fix the Hubble.
Let's work on practical reasons to send people into space at all... then maybe the moon. Billions of tax dollars shouldn't be blown on a project of little scientific validity just because "it's cool."
In Capitalist America, bank robs you!
I barely got the page to load... here's the article text: A new means of propelling spacecraft being developed at the University of Washington could dramatically cut the time needed for astronauts to travel to and from Mars and could make humans a permanent fixture in space. In fact, with magnetized-beam plasma propulsion, or mag-beam, quick trips to distant parts of the solar system could become routine, said Robert Winglee, a UW Earth and space sciences professor who is leading the project. Currently, using conventional technology and adjusting for the orbits of both the Earth and Mars around the sun, it would take astronauts about 2.5 years to travel to Mars, conduct their scientific mission and return. "We're trying to get to Mars and back in 90 days," Winglee said. "Our philosophy is that, if it's going to take two-and-a-half years, the chances of a successful mission are pretty low." Mag-beam is one of 12 proposals that this month began receiving support from the National Aeronautics and Space Administration's Institute for Advanced Concepts. Each gets $75,000 for a six-month study to validate the concept and identify challenges in developing it. Projects that make it through that phase are eligible for as much as $400,000 more over two years. Under the mag-beam concept, a space-based station would generate a stream of magnetized ions that would interact with a magnetic sail on a spacecraft and propel it through the solar system at high speeds that increase with the size of the plasma beam. Winglee estimates that a control nozzle 32 meters wide would generate a plasma beam capable of propelling a spacecraft at 11.7 kilometers per second. That translates to more than 26,000 miles an hour or more than 625,000 miles a day. Mars is an average of 48 million miles from Earth, though the distance can vary greatly depending on where the two planets are in their orbits around the sun. At that distance, a spacecraft traveling 625,000 miles a day would take more than 76 days to get to the red planet. But Winglee is working on ways to devise even greater speeds so the round trip could be accomplished in three months. But to make such high speeds practical, another plasma unit must be stationed on a platform at the other end of the trip to apply brakes to the spacecraft. "Rather than a spacecraft having to carry these big powerful propulsion units, you can have much smaller payloads," he said. Winglee envisions units being placed around the solar system by missions already planned by NASA. One could be used as an integral part of a research mission to Jupiter, for instance, and then left in orbit there when the mission is completed. Units placed farther out in the solar system would use nuclear power to create the ionized plasma; those closer to the sun would be able to use electricity generated by solar panels. The mag-beam concept grew out of an earlier effort Winglee led to develop a system called mini-magnetospheric plasma propulsion. In that system, a plasma bubble would be created around a spacecraft and sail on the solar wind. The mag-beam concept removes reliance on the solar wind, replacing it with a plasma beam that can be controlled for strength and direction. A mag-beam test mission could be possible within five years if financial support remains consistent, he said. The project will be among the topics during the sixth annual NASA Advanced Concepts Institute meeting Tuesday and Wednesday at the Grand Hyatt Hotel in Seattle. The meeting is free and open to the public. Winglee acknowledges that it would take an initial investment of billions of dollars to place stations around the solar system. But once they are in place, their power sources should allow them to generate plasma indefinitely. The system ultimately would reduce spacecraft costs, since individual craft would no longer have to carry their own propulsion systems. They would get up to speed quickly with a strong push from a plasma station, then coast at high speed until they reach their destination, where they would be slowed by another plasma station. "This would facilitate a permanent human presence in space," Winglee said. "That's what we are trying to get to." Love, Tripptdf
Scotty beam me up
A new means of propelling spacecraft being developed at the University of Washington could dramatically cut the time needed for astronauts to travel to and from Mars and could make humans a permanent fixture in space.
In fact, with magnetized-beam plasma propulsion, or mag-beam, quick trips to distant parts of the solar system could become routine, said Robert Winglee, a UW Earth and space sciences professor who is leading the project.
Currently, using conventional technology and adjusting for the orbits of both the Earth and Mars around the sun, it would take astronauts about 2.5 years to travel to Mars, conduct their scientific mission and return.
"We're trying to get to Mars and back in 90 days," Winglee said. "Our philosophy is that, if it's going to take two-and-a-half years, the chances of a successful mission are pretty low."
Mag-beam is one of 12 proposals that this month began receiving support from the National Aeronautics and Space Administration's Institute for Advanced Concepts. Each gets $75,000 for a six-month study to validate the concept and identify challenges in developing it. Projects that make it through that phase are eligible for as much as $400,000 more over two years.
Under the mag-beam concept, a space-based station would generate a stream of magnetized ions that would interact with a magnetic sail on a spacecraft and propel it through the solar system at high speeds that increase with the size of the plasma beam. Winglee estimates that a control nozzle 32 meters wide would generate a plasma beam capable of propelling a spacecraft at 11.7 kilometers per second. That translates to more than 26,000 miles an hour or more than 625,000 miles a day.
Mars is an average of 48 million miles from Earth, though the distance can vary greatly depending on where the two planets are in their orbits around the sun. At that distance, a spacecraft traveling 625,000 miles a day would take more than 76 days to get to the red planet. But Winglee is working on ways to devise even greater speeds so the round trip could be accomplished in three months.
But to make such high speeds practical, another plasma unit must be stationed on a platform at the other end of the trip to apply brakes to the spacecraft.
"Rather than a spacecraft having to carry these big powerful propulsion units, you can have much smaller payloads," he said.
Winglee envisions units being placed around the solar system by missions already planned by NASA. One could be used as an integral part of a research mission to Jupiter, for instance, and then left in orbit there when the mission is completed. Units placed farther out in the solar system would use nuclear power to create the ionized plasma; those closer to the sun would be able to use electricity generated by solar panels.
The mag-beam concept grew out of an earlier effort Winglee led to develop a system called mini-magnetospheric plasma propulsion. In that system, a plasma bubble would be created around a spacecraft and sail on the solar wind. The mag-beam concept removes reliance on the solar wind, replacing it with a plasma beam that can be controlled for strength and direction.
A mag-beam test mission could be possible within five years if financial support remains consistent, he said. The project will be among the topics during the sixth annual NASA Advanced Concepts Institute meeting Tuesday and Wednesday at the Grand Hyatt Hotel in Seattle. The meeting is free and open to the public.
Winglee acknowledges that it would take an initial investment of billions of dollars to place stations around the solar system. But once they are in place, their power sources should allow them to generate plasma indefinitely. The system ultimately would reduce spacecraft costs, since individual craft would no longer have to carry their own propulsion systems. They would get up to speed quickly with a strong push from a plasma station, then coast at high speed until they reach their destination, where they would be slowed by another plasma station.
"This would facilitate a permanent human presence in space," Winglee said. "That's what we are trying to get to."
Wave a plan near congress and they're sure to kill it before breakfast.
Sure they will. The aliens don't want our crap in outer space at least until we can handle our problems like adult persons instead of reacting emotionally to every single difference between us. So, what's better than keep tabs in the govment of the only country that can fund such stuff?
It's better to be the foot on the boot than the face on the pavement. ~~ tkx Kadin2048
The article mentions having one station here and another on the other side, so that the craft itself need not carry its own propulsion.
However, any sort of malfunction - from the braking side not firing at the right time, to the braking side getting knocked off angle by a micrometeorite at the wrong moment, to the craft itself getting pushed off course - would mean that the craft itself would go hurtling through space with no real chance to be rescued.
The way around this? Keep an on-board propulsion system that's able to slow it down from full-speed back to 0, and then speed it up enough to get back to where you were going originally in a reasonable amount of time.
Which kind of defeats the purpose of the entire method.
That green slime had it coming.
I tried a Coral cache link, but even that times out. But if enough people keep clicking it I'm sure the Coral servers will get through at least once... Worth a try, isn't it?
Unless the server is completely crashed, that is....
.: Max Romantschuk
Whose first thought when they saw "magnetized-beam plasma propulsion, or mag-beam" was "I used that in TIE Fighter 10 years ago!"?
:/
Sadly, mine was.
Just send a diplomat to Mars, establish a trade agreement and an alliance with them and build a road.
Then we can quickly invade when they least expect it. When you play enough Rome Total War these things become soooo obvious.
Do not try to read the dupe, thats impossible. Instead, only try to realize the truth
What truth?
There is no dupe
Trip to Mars using nuclear powered rocket would be extremely slow because all the greenpeace protestors along the way, not to mention dozens of them chained to the hull.
Speed is relative. Meteors (including micrometeors) often travel 100's of thousands of miles an hour w/respect to the EARTH. A measly 20-40 thousand mph difference in ship speed isn't going to make much difference to one of these bad boys.
- The race is not [always] to the swift, nor the battle to the strong. -
Too funny ... it melted down after one reply posted :-)
What we need is a network of servers that mirrors websites as soon as they are mentioned in a slashdot article. It should not be very difficult... existing caching proxy web server software and a bit of scripting. Or perhaps some sort of p2p file sharing could play a role. Something to think about at least.
Of course, google cache might already have a copy also.
The Bolachek Journals
From the article:
"But to make such high speeds practical, another plasma unit must be stationed on a platform at the other end of the trip to apply brakes to the spacecraft."
So, since this is a push-away-only propulsion, i.e. the space station is pushing the space craft, you have to have one at the other end to slow it down when it gets there.
Seems unlikely.
"I don't know half of you half as well as I should like, and I like less than half of you half as well as you deserve."
...of erased magnetic media.
From the article: But to make such high speeds practical, another plasma unit must be stationed on a platform at the other end of the trip to apply brakes to the spacecraft.
And if the braking unit malfunctions the mission is going to last a wee bit longer than planned, it seems... Unless they just crash and burn into the planet that is.
.: Max Romantschuk
It sounds all well and good... until the plasma beam at the other end breaks down and you have no way of slowing down or stopping. Then the 90-day roundtrip becomes and endless journey blazing past mars at 20km/sec.
Where do I sign up?
"Under the mag-beam concept, a space-based station would generate a stream of magnetized ions that would interact with a magnetic sail on a spacecraft and propel it through the solar system at high speeds that increase with the size of the plasma beam. Winglee estimates that a control nozzle 32 meters wide would generate a plasma beam capable of propelling a spacecraft at 11.7 kilometers per second."
Would not it also push the space-based station the other way? The whole action-equal-reaction thing they teach in physics?
no but it will make a difference in relation to the ones that were going slowly and we did not have to worry about.
and how about the number of micrometeors this "plasma beam" will fling at the spacecraft?
Has anyone gleaned from the article how the beaming stations are maintained in place?
I got that nuclear and solar power would be used to generate the beam, but generating the beam would impart thrust to the station.
Did I miss something?
The REAL jabber has the user id: 13196
What you do today will cost you a day of your life
..or at least the brakes. It's not a new plan, though it might be a new flavor. Nivens was talking about laser-based launching stations back in the 70s and he was just taking the most probable solution.
Of course Newton's laws interest me. If you fire an energy beam able to move a 1000kg probe at 11.7km/s, your 10,000kg station is going to be moving 0.117km/s. (261mph)
Then there's the power issue. Exactly what are these orbital launcher going to use for power? I don't see the green club letting enough fissionable materials get up there and otherwise we're looking at a biiiiig solar array tied to some form of energy storage (water/hydrogen/fuelcell?)
I've been on slashdot so long I'm starting to get out of touch with the cool stuff if it ain't on slashdot.
Smile.
there's particles travelling high speed that might hit you, no matter what speed you're going yourself.
and as such, high speed in this case wouldn't necessarely be 'increased risk'.
if anything, it would be less risk of that(because the trip itself would take less time..).
though, with this and the gazillion other "how to get to mars" plans there's holes in it that haven't been filled.
world was created 5 seconds before this post as it is.
Another way to go somewhere.. Now only if we have a reason to go.
Faster than a speeding mag-beam, the server goes titsup.
A copy of the article text or htm:
text
html
Join the Slashcott! Feb 10 thru Feb 17!
Well, either that, or we stop worrying about profit so much, and prioritise what's important.
Forward shields at full stregth captain.
That should be "at what Delta-V?" More Delta-V == faster.
If, by "Delta-V" you mean "change in velocity," then that would indeed be acceleration -- which doesn't necessarily mean faster.
Think about it: I drive my car from 0 to 60mph in 3 seconds, while yours only goes from 0 to 60mph in 12 seconds. At the end of that time, we're both going the same speed (assuming we stop accelerating once we hit 60mph), but my acceleration was much quicker than yours (4 times as fast, in fact).
Can anyone tell me how the "pusher" satellite in the picture is supposed to work? I see one beam of energy with enough force to accelerate a spacecraft with a lot of force. Either there's an invisible other beam balancing this out, scorching the Earth underneath, or the satellite is doing a much better job of propelling itself out of the solar system than it is pushing the distant spacecraft where it's supposed to go. Or has someone figured out how to suspend Newton's second law?
The big "breakthtrough" here is to decouple the propulsion system (the plasma beam) from the spacecraft. That makes the craft smaller and lighter since it doesn't have to move all that fuel around.
HOWEVER...
This system requires having another plasm beam generator to "catch" the spacecraft and slow it down with another plasma beam. That means not only sending the generator platform to Mars, but also all of the material from which to make the plasma (most likely nitrogen or one of the heavier noble gases). The generator platform needs a power source capable of sustaing the creating and acceleration of the plasma beam, which means nuclear, and a fission nuclear reaction, not radiothermic generation. All of that means a technically complex space station, with people to keep it running. To have such a system in Earth orbit would be tough enough. The cost and difficulty of shipping all of that material out to a Mars orbit, and maintaining it so it will be ready to deccelerate an incoming spacecraft would be Absolutely Enormous.
The man who does not read good books has no advantage over the man who cannot read them. - Mark Twain
Traveller by GDW had all sorts of formulas.. you go half way balls out, turn the ship around half way and throttle back up again... you get a nice quick trip, and arrive at orbital speed.
meh
And no, spacecraft right now are NOT beer cans. They contain an outer shell, and several layers of different material to prevent micrometeriods from penetrating the pressure hull. Windows are specially designed, and if you pay attention to photographs from spacecraft you would see tons of scratches on the outer surface.
Guess what they are from?
"Learning is not compulsory... neither is survival."
--Dr.W.Edwards Deming
It's all about weight.
The reason our spaceships are tin cans is because nobody can afford the weight for shielding. When 99+% of your mass is thrown away, carrying an extra kilo at the end means an extra hundred kilos at the start.
But, if you have a good enough fuel that you only need 10 times your ultimate mass in fuel, suddenly you can carry shielding. The better your specific impulse (I_sp = pounds of thrust per pound of fuel used per second), the better your chances for shielding. An I_sp of 200 (about what http://armadilloaerospace.com/ hoped to achieve) means you're just barely cutting it. An I_sp of around 300 makes life a lot easier, but that pretty much requires liquid hydrogen/liquid oxygen.
Anything higher than that is just pure nirvana for the rocket guys. I have heard of I_sp of over 1000 from a cesium ion drive, but that had just a teensy thrust, making it useful only for satellite station keeping.
So, in conclusion, if you can get a high I_sp and a high thrust, then shielding is a piece of cake.
----- Why sig when you can sign? PGP key id 7675D05E
BTW, there's more information on UW's space research here, and more info on this program here. And for a final bit of karma-whoring, Winglee's page can be found here (he's got movies, too!).
Carousel is a lie!
but you are overlooking one thing.
most meteorites are made of????? iron.
a magnetic plasma "ray" to push the spacecraft that will have a higher mass than a 100 gram solid iron meteor.
what will happen when the force applied to the ship hits that errant meteor that wanders into the "beam"?
it becomes a nice fresh bullet to hit you from the rear.
now we no longer have to worry about a small craft in space but the entire swath the beam makes in space and every second it is on, is that much more acceleration DIRECTLY at the spacecraft tons of micrometeorites and other nasties have.
we have yet to invent a magical "push only spaceships" beam. this thing works on magnetics and plasma... and it will have a more efficient effect on small light metal objects that will have no trouble tearing through a thin aluminum ship.
>Winglee envisions units being placed around the
>solar system by missions already planned by NASA.
>One could be used as an integral part of a research
>mission to Jupiter, for instance, and then left
>in orbit.
This ignores Newton's law that for every action there is an equal and opposite reaction.
According to Newton if the transitter unit isn't fixed to something big and heavy (i.e. a planet) it would also propel itself backwards (and out of position) at an inversely proportional acceleration rate to the spaceship.
In your example, both cars had a deltaV of 60mph. One had an acceleration of 20mph/s, the other 5mph/s.
"I do not agree with what you say, but I will defend to the death your right to say it"
For perspective, to the Moon and back in a day with plenty of time to have a picnic.
How about carbon nano shields ? they are claimed to be 100 times stronger than steel at 1/6 th the weight.
Yes, I agree. I could never see that coming. But, fact is: NASA sold out to the real-life equivalent of Vulcans, yes.
It's better to be the foot on the boot than the face on the pavement. ~~ tkx Kadin2048
You are in error. No-one is screaming. Thank you for your cooperation.
EXACTLY.
unfortunately a safe ship for an interplanetary would have to be many metric tons just for shielding. and getting that out of our favorite gravity well is still near impossible.
creating a space propulsion system is great, we need a takeoff and landing system that will do heavy lifting.
\and for the armchair rocket scientists, no 10 saturn 5 rockets strapped together, while a really fricking cool idea, is not doable.
Do not look at laser with remaining good eye.
Was the Parthenon built because it was profitable? The Great Pyramid of Egypt? Did Beethoven write his symphonies for lavish fortune? Did Leonardo da Vinci paint and tinker for this profit of which you speak?
Not much has happened in this world since profit became the guiding motive of life. You will find, at some point in your dreary life, that the accountants and financiers cannot possibily understand what it means to be truly human. Those qualities that propel mankind to challenge the limits of existence are beyond the realm of a ledger or spreadsheet.
Before any great change can take place in this world, the tyranny of international finance must be broken. We must have leadership from aesthetic ideals, not bullshit financial numbers.
NOTHING great will become a reality as long as your attitude is the guiding principle of our civilization.
Strive for greatness, no matter what the cost, even if death. Any other path is for the weak.
I don't read or respond to AC posts
they need to adapt the high voltage tank armour they have in the works. Just run enough current through the outside of the ship so that anything that touches it gets vaporized before it plows through. :)
No I didnt spell check this post...
If that goes down, here's the cache of those two working links...
Text
Html Article
You're always going to be hit by micrometeors, trying to avoid it is pointless. All you can do is minamize the amount of time your vulnerable to being hit by meteors (eg, faster trips so you're outside the earths atmosphere for less time) and design a mechanism for absorbing impactrs, and repairing the damage that they do. Its not really that ahrd. Ever heard of those self patching tires? Well a ships hull should be designed to do somthign similar.
Life isn't like DS9 (ablative shielding? micrometeoroid impacts?). I wouldn't say spaceships need to be 100 times stronger - where did you get that number? I believe that scientists have a pretty good idea what kind of hazards are out there, although more work still needs to be done.
The first thing I'd do with a working model is launch a satallite toward mars with this engine. The amount and rate of dust impacts can be measured along radiation intensity and other hazard checks.
It is impossible to enjoy idling thoroughly unless one has plenty of work to do.
- Jerome Klapka Jerome
For real perspective, running into all the space debris at this speed would be like hitting a brick wall in an F1 car.
We're going to need some kind of shielding.
1) quit my job
2) enjoy a round trip fly to Mars
3) jump on a new job
I got 6 month unemployment paychecks. B-)
^(oo)^pig~
How about another question:
What if the idiot running the magnet gun doesn't get his aim right? If they don't put any alternate propulsion source on the craft, how would they make course corrections? Careening off into space at 26000 miles an hour doesn't sound very fun to me.
You could always RTFA, but you just wanted to get a post in, didn't you?
These spaceships have no onboard engines.
Do not trust the pusher satellite. Pushing will protect you from the terrible secret of space. Do you have stairs at your house?
Stop learning! Only you can prevent esoterrorism.
Scientists have come up with a cheap and reusable method of getting to orbit and traveling about the cosmose. Utilizing the effect of slashdotting a website, we beam those hits against a reflective matterial on the space craft that will allow network packets to propell it in to orbit and beyond. To slow down a craft ariving at it's destination, a special set of mirrors will be setup to redirect traffic to the front of the ship where another reflector will slow down the craft...
~~ Behold the flying cow with a rail gun! ~~
A NERVA, starting from LEO could match that speed with a mass ratio of 2.7 or thereabouts.
In other words, it's not really terribly fast by the standards of the solar system.
"I do not agree with what you say, but I will defend to the death your right to say it"
What happens if you're jetting at 26,000 mph, and the braking system fails. You'll be doing a David Bowie - "Major Tom, it's been nice knowing you!"
Hmmm... according to my calculator, 26.000 miles per hour times 24 equals 624.000 miles per day...
:-)
But I might be wrong
Phileas Fogg bets half his fortune against other members of the Reform Club he can travel to Mars and back in 90 days or less. He leaves with his valet, is followed by a detective who believes Fogg robbed the Bank of England, and picks up a lunar Princess along the way. He believes he lost the bet (and spent the other half of his fortune during the journey), but forgot that since that was martian days, he picked up two day and half. He arrives at the Reform Club with seconds to spare, and wins his bet.
If the platform spew forth this plasma from a 32 meter nozzle, wouldn't this create a force on the platform that pushed it away from the direction the ship is supposed to fly? Did I overlook something? Can someone enlighten me, please?
___
No power in the 'verse can stop me
They've got to have a serious stash of fuel on board for the "Holy $@%^%$%! There's an asteroid at 12:00" times. You can't expect to cruise through space and not come across some floating debris, can you?
Life isn't like DS9 (ablative shielding? micrometeoroid impacts?). I wouldn't say spaceships need to be 100 times stronger - where did you get that number?
can we be a bit more dismissive and insulting?
abatave shielding, cince you do not understand what he is talking about is a type of shielding or "armor" that noneducated types call it. it sacrifices it's self to convert impact energy away from the target and is extremely common in many places espically military.
as for 100 times stronger number he quotes.
if the space ship can not take machine gun fire at it without damage, then it has no chance in interplanetary travel where you have to cross an asteroid belt, so I would say that 100 times stronger is a bit low.
think the strength of a troop carrier. that is the MINIMUM I would suggest for a space ship going to another planet. why? because you cant say "oops, got a problem, can you help?" nope.. one problem and you are 100% toasted.
The kinetic energy of the plasma beam would be negligible -- we're not talking about accelerating a ship by firing cannon balls at it. Energy being imparted to the vehicle comes from the electrical charge on the plasma -- heance the magnetic sail. If it were simply kinetic impacts, a plain old fashioned canvas sail would do the job.
OK, this 90 day thing sounds nice on paper, but I don't think it's possible. I seem to remember reading an article a few years back (Sorry, it would take me days to dig it up) that even if we COULD travel that fast, the acceleration/decceleration would kill whoever was in that spacecraft.
The article that I read said that if we accelerated subjecting the occupant to a force of 1 G, then decelerated at that same rate once we reached the halfway point it would still take 3 years to reach Mars at the shortest distance. I know someone here will check the math, and maybe I'm wrong, but 90 days seems like an impossible dream without inertial dampeners.
-Arthur
Cave ne ante ullas catapultas ambules
A change in velocity is a result of acceleration. Acceleration as a measurement is a rate of change in velocity.
The cars, assuming lack of friction, did not have a deltaV. They had a V of 60 mph. They had a deltaV if they were turning, slowing down or speeding up, each of which is a result of acceleration.
Reality has a conservative bias: it conserves mass, energy, momentum...
I'm sure we all remember this episode where some scientists did pretty much the same thing, except they used a "soliton wave", and the ship went at warp speed.
I think this episode underscores the dangers of this sort of technology -- the receiving planet, the test space-craft, and Alexander (Worf's son) almost got demolished!
-S
Transport up to space (Earth orbit) all the equipment to build a MASSIVE transport. Enough to hold say one thousand people, and enough supplies for one - two years. Start transporting people to mars - one thousand at a time. Build more ships like this, have nice routes...give me a laptop - Counterstrike, PS2 - FF X-2, a gym, and PLENTY of Netflix DVD's and I can be set for a 90 day journey to Mars...with luck I will find myself a girlfriend on the trip :D
Build bases on Mars..wash rinse and repeat. If done properly (maybe not have the gov't contractors get a super outrageous payroll) it is feasible.
I mod down so you can mod up. Your welcome.
Google news search for "mag-beam" returned http://www.newswise.com/articles/view/507649/ and http://www.universetoday.com/am/publish/mag_beam_p ropulsion_system.html?14102004 with a sci-fi looking picture.
Froogle search for "mag-beam" did not match any products. :)
Guess what they are from?"
UFO punk alien kids. Their vandlizing our ships! Where's the men in black when you need them.
I'm not a doctor, but I play one in bed.
We've got a world full of nerds excited about spending months in a can to get to a world with no water and no air and no life that we know of, hoping to use the information gained on the trip to hop in another can to go to other worlds which will most likely have no air and no water.
Meanwhile, we're on a planet that our bodies have been custom built over billions of years to live on (with both air and water-perfection for us by definition) and we are so expectant at our own ability to screw the place up that we are trying to plan on the day when we'll have to leave this place because of what we've done to it.
Doesn't it seem a whole lot EASIER to just change our planet screwing habits than it does to attempt to terra-form a dry, red rock-which we would inevitably screw up in our same unlearned fashion?
This is a waste of money that would better be spent trying to figure out why we screw things up for the world around us so much better than we fix them. We have great success at helping our own species in specific fashions while screwing every other form of life up in general. Our myopic vision does not allow us to see big pictures, those that are more than 2 steps away from any cause or cure we undertake.
Any other planet with life on it out there would undoubtedly regard us as the trailer-trash that devalues the neighborhood. "Welcome!" signs are not in our future...
This reminds me of an idea from Larry Niven's Known Space stories. He thought that intrasystem transport would go through a phase in which photo-sail craft would receive an additional push from orbiting lasers sitting where they have access to high-density power supplies, making the light and simple vehicles fast enough to be practical for routine use.
:-)
:-/
(This plan figured interestingly in the first Man-Kzin War. Kzinti planners had not used reaction drives in so long that they failed to realize what a fleet of exawatt laser stations scattered all over a star system could do to an incoming force.
Come to think of it, long-range focused plasma beams could have military uses, even if they aren't dense enough to instantly zap the other guy out of existence. So, funding should be assured.
If, by "Delta-V" you mean "change in velocity,"
Yes.
then that would indeed be acceleration -- which doesn't necessarily mean faster.
No. Delta V is the desired change in velocity. How fast you accelerate has nothing to do with that. So I could thrust toward Mars at 1/100 gravities and still obtain the same Delta-V (for the same fuel!) as someone who thrusted at 2 gravities.
In other words, Delta-V for rockets is all about the final velocity obtained. Thus a slower thrusting craft that obtains a higher delta-V over time is still likely to beat out a high-thrust craft that only burns for a few minutes.
Javascript + Nintendo DSi = DSiCade
Acceleration is the rate of change of velocity with respect to time (instantaneous), OR the change in velocity for a given period of time (average).
If an object has a velocity function V(t), the derivative of that function with respect to time, dV/dt, is the instantaneous acceleration of that object with respect to time.
"deltaV" is the change in velocity, and thus acceleration. In the given example, 20mhp/s and 5mph/s are average accelerations only.
=Smidge=
Just do 'J' for jump ;)
Otherwise there won't be any slowing down at Mars , just a big splat. Unless the ship carries conventional thrusters too of course, but the fuel required to slow down would be immense and then we're back to square one.
The kinetic energy still has to go somewhere, even if the item carrying it is vaporized.
Reality has a conservative bias: it conserves mass, energy, momentum...
Does that picture remind anybody else of the sail ship that they used in the movie Tron? Were they ahead of the game -again-?
The (average) acceleration is DeltaV/DeltaT. You don't want to tell us that always DeltaT=1, do you?
The Tao of math: The numbers you can count are not the real numbers.
After 20 years of making patches to the road, since nobody want's to do proper repair work to infrastructure, the subsurface will be in great need of repair. Just like in many places in Wash D.C.. This results in a severely warped road, with many potholes that bend and dent your spinning Twenties (Twenty Decimeters). The resulting lack of spin on your rims causes your space shuttle to have to pull over in a bad neighborhood, and you are jacked for your Bling Bling (dilithium crystals)
If I were designing a mission using this system, it would be as an additional boost, rather than the only propulsion. Deceleration would probably be a combination of traditional rockets and aerobraking.
In a serious emergency, you'd be able to use the systems designed for getting you home to get you to mars itself. Once there, you'd be forced to use Zubrin's techniques to actually make yourself comfortable while you wait for Earth to figure how exactly they're going to mount a rescue operation. The mission would be carrying equipment for extracting oxygen & water from Martian minerals in order to enable an extended stay there anyway; I'm not sure what you'd do for food supplies, though.
There's a nice pdf on the Nasa site by Winglee:o ns/3l_wing l.pdf
http://std.msfc.nasa.gov/ast/presentati
What kind of propulsion is next, the Infinite Improbability Drive ?
"Ford, you're turning into a penguin. Stop it."
If a plasma beam can push a spacecraft at 11.7 km/sec, what keeps the plasma cannon from shooting off at 11.7 km/sec in the opposite direction?
ftp://ftp.hq.nasa.gov/pub/nickname/
Perhaps someone can start a chain letter to help NASA get this funded?
Speaking of Ablative Shielding, one has to wonder if reactive armor might be an effective counter to micro-meteorites. It would certainly be lighter and cheaper than trying to construct the hull like that of an iowa class Battleship.
The biggest downside is that as the impacts accumulate, the armor would develop a variety of weak points. The crew would then need to either replace the panels, or hope that lightning doesn't strike twice in the same spot.
Javascript + Nintendo DSi = DSiCade
duh!
This is completely false. This is not a sig.
It'll be a long time until any of the (former) X Prize teams get anything into orbit, and when they do it won't be very similar to the purpose-built vehicles they've been working on up until now.
You're forgetting that Scaled Composites (Burt Rutan's company) was heavily involved with both the McDonnell-Douglas Delta Clipper and Lockheed Martin Venture Star programs. Though these programs were not complete successes, it does mean Scaled Composites has actual experience in building real spacecraft and that means Rutan has a pretty good idea of the engineering needed to build a spacecraft to reach low Earth orbit (LEO) at reasonable cost.
...where is that break????
unsig
Sorry, link on reactive armor.
Javascript + Nintendo DSi = DSiCade
Imagine when 80 days around the world was an extraordinary and unbelievable accomplishment, now it seems that something as odd as 80 days around the solar system may be laughed at in a 100 years time.
In todays world, I cannot imagine how restrictive travel must have been, in tomorrows, they will pity us with our cars and segways!
#hostfile 0.0.0.0 primidi.com 0.0.0.0 www.primidi.com 0.0.0.0 radio.weblogs.com
Sorry, just having a bad week. I apologize.
I know what ablative shielding is. Every space capsule used it. Tanks use it. I mentioned DS9 since the terms, "ablative armor" and "micrometeoroids," are common in Trek.
Didn't all of the probes and satellites sent beyond Mars travel through the astroid belt (and are still traveling through the Ort cloud)? They didn't seem to be damaged much.
Besides, I'd think that there would be more dust and other micrometeoroids around planets and in Lagrange points than in the interplantary regions of space. I am skeptical of this risk without evidence.
Well, that argument applies to everything, really. One blown tire on the highway, and your car rolls or bike crashes. One mistake crossing the street and I'm roadkill. The best you can do is calculate the risks and prepare for the most likely senerios, but I am skeptical that the micrometeoroid density between the planets is risky.
Perhaps I am being a hostile student, but I ask for some studies or evidence before I accept your conclusion.
It is impossible to enjoy idling thoroughly unless one has plenty of work to do.
- Jerome Klapka Jerome
once"
..
"Beam me OUT, Scotty..."
Or,
"ENERgize!"
Previously: "Linux... Toward the Sunrise..." Now: "Linux... Toward the-- No, now, part of Every Sunrise"
Actually, that's very close to how current space armour works. First, there is a thin outer layer that is hit by the high speed object. Because of the insane speeds involved, approximately equal masses of the shield and object are turned into a vapor. That vapor is allowed to expand a bit (as in there is a gap between the inner and outer shields), and then it hits the inner sheild. But now the inner sheild only has to stop a rapidly cooling gas, spreading the energy over a much larger area.
Of course, if the rock is big enough, it won't totally vaporize - then you are toast!
while (sig==sig) sig=!sig;
WTF am I missing?
Round trip is both ways - so make that
Quidquid latine dictum sit, altum videtur
If there is anywhere in the world I would go to hear useful information about something computer-related, I would go to slashdot. But when it comes to space, you guys are about as dumb as the people on Fark.com.
"When will we have warp drive? hehheaha (nerd cackle)"
"Will my linux box work in the Van-Allen belts?"
"I bet if the Klingons made a linux distro, it'd be called KlAch`TlaCH!"
Sheesh...
Because we all know the delicate, fragile probes with these large, gossamar solar panels we send all over the solar system are shredded to bits within a week of leaving the atmosphere.
You've been watching the Empire Strikes Back too many times.
You can tell a great deal about the character of a man by observing those who hate him.
1. Because of human curiosity. From the very beginning of human existance, we've always asked what is out there in the whole wide world. It's this curiosity that has driven humanity to explore the Earth's surface, the oceans and into space. What you're suggesting effectively kills human advancement.
2. The enormous scientific spinoffs from the science and engineering developing a spacecraft flying to Mars and back. Indeed, the computer you're using is one of the major spinoffs from the US space program, and medical sciences have advanced tremendously because of the need to study the unknowns of humans travelling for long periods of time in space. The scientific spinoffs from the engineering and science needed to develop a manned Mars mission could be just as big as what we got from the US space program of the 1960's.
No. Reread the grandparent. The cars started at 0, and accelerated to 60mph. The deltaV (change in velocity) was 60mph. The acceleration was as listed.
"I do not agree with what you say, but I will defend to the death your right to say it"
I don't think going faster will help you avoid more meteors, and going slower will not have any effect (unless you plan on trying to dodge them).
Saying that by going faster you will spend less time travelling and reduce the amount of meteoroids hitting you sounds flawed. If you have to travel 10 million miles you have to travel 10 million miles...the amount of time it takes you to get there is irrelevant...any objects in your way will be there and we do not have any current way of calculating the best speed to avoid the countless debris in space.
I mod down so you can mod up. Your welcome.
Three things you're overlooking:
1. A small, light object will also have a much smaller surface area for the beam to push against, so it will pick up much less accelleration (the article mentions that the speed applied to the ship is very dependant on the width of the beam).
2. The beam is only planned to be on for a short time.
3. Any items wandering into the beam will have a velocity of their own to start with, which would cause it to travel off at an angle. The further away the craft is, the lower the chances of anything being able to enter the beam at the proper angle and speed to be pushed towards the ship.
...the reasons mobile phones can't get any cheaper is that one part requires an obscenely expensive metal for the tuner.
Recyle from older phones and improve!
Grundgesetz * 23. Mai 1949 - 30. November 2007 - http://www.vorratsdatenspeicherung.de/
Just a few nits - the Space Shuttle Main Engine has an Isp of ~430, and still throws away a lot of stuff! Most Hydrogen/Oxygen engines have Isp in the 400 range, while the 300 range is typically hydrocarbon such as kerosene. I would have difficulty believing that a 200 Isp engine would make it to orbit, if it hadn't already been done. (Pretty amazing engineering, that!) The mass ratio required goes up exponentially with Isp, and at 200 it is ~90:1 (so for every kg in orbit, you launched with 90 kg!).
As for your other comment, about how high Isp devices seem to always have low thrust, that is because to a first approximation we are limited by the power available. Engine power is proportional to thrust x Isp, so assuming the same power source increasing Isp decreases thrust. Going from a dense power source (chemical fuel) to a non-dense power source (solar panels) only makes that worse!
while (sig==sig) sig=!sig;
No. DeltaV is change in velocity. Acceleration is NOT change in velocity. Acceleration is change in velocity per unit time.
Please note that deltaV is measured in units of m/s, NOT in m/s^2, as acceleration is measured.
"I do not agree with what you say, but I will defend to the death your right to say it"
Unless, of course, the numbers are reported to 3 significant digits. Then the "real" speed could be slightly higher, like 26,049 mph, in which case, the miles per day would be 625,176 ... which, when rounded to 3 significant digits is 625,000
There are no tiger attacks in my area and it's all because this rock I'm holding keeps the tigers away.
If I Remember Correctly, Kirk would slingshot around the sun, break the speed of light, and travel back in time to the 80's where he could invent transparent aluminum and (naturally) pick up a spicy little local female.
"Wait, that's not right! _I'M_ the one who told the 20th century about transparent aluminum."
"Ha ha ha, Kif you're a riot. Go wash the sheets on the space bed."
"My name is 'Scotty'."
Exercises for the reader:
Spock learns to breakdance
Data sings "Mr. Roboto"
'The Physics of Star Trek' is actually pretty lame
I just got locked into this Russian capsule for 500 days. Well, at least I get cable in here.
"DeltaV/DeltaT" is not the same as "dV/dt". I also don't know where you got DeltaT=1 from. Have you had your coffee yet today?
The average acceleration is DeltaV/DeltaT. If you drive feom 0 to 60mph in 3 seconds, that's (60-0)/(3-0) = 20mph/sec average acceleration. But that is no instantaneous acceleration, unless your car actually does accelerate uniformly from 0 to 60. Chances are your car accelerates at a faster rate early on, tapers off as you reach the high end of first gear, increases when you shift into second gear, then tapers off again, etc.
And that still doesn't change the fact that "DeltaV", which is a change in velocity, is an acceleration. You simply cannot determine the magnitude of that acceleration without a corresponding DeltaT. By definition: your velocity can not change unless you accelerate.
=Smidge=
Have you ever read Henry Ford's writings on business organization? He was a far more ardent critic of international finance than me.
From what I know of Ford, I can only assume that "international finance" is a code-word for "The Jews".
--grendel drago
Laws do not persuade just because they threaten. --Seneca
As I understand it, VASIMR and other plasma based systems require megawatts of power. I wonder where they are going to find a dense energy source that can provide that much power. Consider that the space shuttle only requires power on the magnitude of kilowatts. It would be interesting to see a nuclear powered (think submarine, not actomic bomb) spacecraft because that might be the best way we can put a dense enough energy supply on a craft.
Here's my equally viable idea - the astronauts could jump straight up from the top of a mountain, fart and flap their arms!! They could get to mars and back in two weeks, or a long weekend if they "bean up" just before lift off. Another fine example of your tax dollars pissed away.
Nothing says this has to happen in an afternoon.
emt 377 emt 4
Here is an application just waiting for a technology that can produce sustained thrust for a long time.
How about cleaning up all the space junk?
You only have to boost the janitor-bot into orbit once. It then docs with a large piece of junk, such as a dead but highly radioactive Russian satellite, starts pushing it, even gradually such that it will de-orbit. Then the bot un-docs, gently kicks away, imparting even more momentum to the junk. Then the bot calculates the next orbital change and goes after the next piece of junk. After days of time to dock up with the new piece of junk, the process is repeated.
Eventually, the bot could go after smaller and smaller junk.
Would it be possible to build a second janitor-bot that goes after dead geosynchronous junk? Push the junk outward from earth, and anti-spinward, thus putting it into an orbit with extreme difference in apogee and perigee. Ideally a parigee that grazes the earth's upper atmosphere so that after a number of orbits it finally de-orbits. As the bot and junk together begin to cross the orbital height of geosynchronous objects, the bot undocks, and begins applying thrust to go after the next piece of junk.
Doesn't such a cleanup bot just beg for a technology that can offer sustained thrust, many times, over a long period of time.
Finally, the bot de-orbits itself.
I'll see your senator, and I'll raise you two judges.
Of course you need some kind of shielding, this is space after all. But your velocity has little to do with the danger of the debris that you will encounter. Speed is relative. Chances are that the debris that impacts your ship will be moving at 200,000mph. Even if you are motionless, you have the same type of impact. All space debris is not just sitting out there motionless waiting for some ship to fly into it.
"The first thing I'd do with a working model is launch a satallite toward mars with this engine."
Or, to quote the movie "Contact":
"Why buy one when you can get two for twice the price?"
Space Elevators would do the trick until we can master electromagnetics and locally invert/trick the Earth's gravity in regards to a specific collection of objects. It's only a matter of time before a Slashdotter gets the grant money he/she needs to do the research and get the job done.
The dangers of knowledge trigger emotional distress in human beings.
Look, when is NASA going to get it that public, mass transit just doesn't work for Americans? I mean, hell, if I want to hit the 7-11 on the way home from work, I don't want to have to jump six space buses to get there! Traffic is bad enough as it is without waiting for overcrowded buses stopping at every damn planet just to get home!
no, because all those probes we send out do NOT have those large, gossamar solar panels .
they have nuclear reactors. the deep solar system probes are the size of a Greyhound bus and are built like a brick shithouse.
i suggest you actually learn about those "probes" by looking at their designs online.
Lumpy is right.... and to take your idea of it.. how many mars probes have we lost??
get a grip, space is not a nice clean empty playground.
I would suggest we make the Mars trip one way only. This solves a host of problems. Any volunteers?
You get here by Mag-Beam, take the Space Elevator down the gravity well, then you take a RamJet, catch a Mag-Rail from the airport to your arcology, and then... uh... Segway straight to your apartment.
And lookee here - HL2 still preloading!
cool concept, but one thing i'm left wondering after reading is what do they use to stablize the generating station. law of conservation of momentum says that it has to push back. what form of thrust will these space based station use?
will they have a land(lunar/earth) based mag-beam to keep it in position?
a little more over all detail would have been nice.
Others have responded with good info. If there were a counter beam, consider that it would not *have* to be aimed at earth. It might be such that both jets form a tangent to the surface of the earth below.
Also, multiple beams at angles to the propulsive beam could be used to keep the attitude adjustment beams from being pointed at earth.
*And*, who says these things need to be in earth orbit? Put them in a Lagrange point somewhere, and let them work from there. Some work would need to be done to keep the beam from pointing at things we want to keep, but it seems that that wouldnt be too hard.
Mix and match as needed.
emt 377 emt 4
... because it could be used as a weapon.
This is my post. There are many others like it. If you don't like what you read here, go try one of the others.
The article mentioned that if you dont have a partner station to slow down the craft at the end of the voyage, you simply dont push it up to full speed. Just fast enough to get it there, without it being "catchable" by gravity or the resources available in the craft ( ordinary rockets, or whatever ). Use this "slow mode" to get enough out there to build a catching/relaunching station, then go to full power.
emt 377 emt 4
It seems the Slashdot effect has already sent the UW server into an orbit!
I am the unwilling control for my Origin.
I see a series of technical problems with this propulsion method. To summarize, the method is a variation on ground-laser-assisted flight. It envisions a space station shooting a beam of magnetized particles towards the ship, which are caught by a sail and used to boost the ship's velocity.
1. NO ACCELERATION TOWARDS THE STATION. This only works in one direction, it will not help the astronauts REETURN HOME.
2. No Acceleration during critical orbital adjustment maneuvers. This includes slingshot trajectories behind another body in space like a planet.
3. No mention of effects of beamed particles on astronauts on the ship. Is this beam a significant plasma stream? If so, when it hits the spaceship, it will kick out some nasty E-M (gamma, Xrays), heat up the ship perhaps radiologically, and do ugly things to any electronics that are hanging off the side of the ship.
4. If the beam is magnetic particles, this would have to be Iron, right? Tell me you're going to boost IRON into orbit to propel a ship. MV^2 says that's a bad bang for your buck, methinks.
5. If the beam is statically charged particles, are you going to accumulate a static charge on the ship? Won't that do nasty things to the electronics and possibly kill people who accidentally remain ungrounded for a time period?
Call me and tell me if they actually put this charged-particle gun on a moving surface to use the mv^2 for propulsion instead of Grand Space Gun theatrics instead of solidly reliable engine designs that start, restart, re-re-start (ad infinitium), when, where, how, you need them, with a variable thrust vector.
Unitarian Church: Freethinkers Congregate!
True enough, but the likelyhood that you will encounter some form of debris increases with the distance that you travel. Sit in one spot, not a big deal. We know where a lot of that is and where it's going. Go rocketing around the solar system, Whoo-boy!
"is there ANY realistic reason why sending people to Mars is good science?"
Science? You've got the wrong idea, buddy. We're talking PENAL COLONY!!!
Yeah! Think of the benefits!
1) Prison Overcrowding? Pshaw!
2) Cool action movies a la Riddick!
3) In couple hundred years when Australia mellows out we've got a ready replacement!
All you have to do is reroute power from the phaser bank to the deflector array.
I remember reading about another 90 days to Mars proposal (acutally 120 days there and back, in Scientific American or IEEE Spectrum) that used a plasma beam over a year ago (maybe two). This one kept the beam generator on the ship and was nuclear powered (horrors!!!). That seems a lot more reasonable than building two power supplies and positioning them prior to a launch. Not to mention all the problems that could occur if you lost your deceleration beam on the way out.
I've read a few of these laser, plasma beam propulsion ideas and I'll just never be comfortable unless I can reach back there and check the spark plugs myself.
Mirrors are available at MirrorDot.
~Jay
Hypersonic Ramjet technology would be able to use the atmosphere to compress a fuel/air mixture for produce thrust into near earth orbit. You wouldn't have to take as much fuel - which would increase your payload potential.
Lodragan Draoidh
The more you explain it, the more I don't understand it. - Mark Twain
http://www.ess.washington.edu/Space/magbeam/
let's not confuse "cost" and "value".
Just because those materials wouldn't be quite as expensive (per MT) as they were, does not mean that they wouldn't remain just as valuable.
Valuable for processes, R&D, manufacturing... Not to mention that when "expensive" materials become cheap, it opens up whole new uses for those materials.
also deBeers can go suck an egg. nobody needs their dirty diamonds.
-tom
It breaks my pluginses, my precious!
and it's modded information.
It breaks my pluginses, my precious!
But unless this tech can also aid in launching craft out of Earths gravity well, travel to more distant parts of the galaxy will not be routine.
I would read the article, but it appears slashdotted at this time. Unfortunate.
It would be intresting to see if this propulsion can work inside of earths atmosphere.
END COMMUNICATION
The station is propelled backwards a small amount due to the KINETIC energy it imparts to the plasma beam, but that level of energy is INSIGNIFICANT. The station also imparts MAGNETIC energy to the plasma beam, but that does not propel the station backwards at all.
The ship is propelled forwards primarily due to the MAGNETIC energy in the plasma beam, not the KINETIC energy. It does this by creating an electromagnetic shield that repels all magnetically charged particles. This force is much stronger than the KINETIC energy.
Newton's 2nd law is preserved. The shield pushes the magnetized plasma particles away with enough force to accelerate the ship to high speed. Turn the shield off, and it won't go very far.
And anyone who thinks this plasma beam could scorch the Earth doesn't realize just how much energy the Sun blasts the Earth with constantly. The Earth has its own magnetic shield, and what little of the solar wind does get in is scattered in the upper atmosphere (i.e. auroras). Even though it's a more focused beam, the beam would be spread thin before it came close to the ground.
The biggest problem with this method is not being able to slow down if there's a problem at the other end. Even if there's not a problem at the other end, it would be like trying to throw a rock from here to Mars and expecting to hit a very small target precisely when it got there. Without course corrections on the way, it will miss by hundreds of miles. Even with corrections, it will very likely miss on the scale of hundreds of yards.
IMHO, they should use this only for acceleration. Add ion thrusters to the craft, and it can help accelerate the craft as well as decelerate it as it approaches Mars (making continuous course corrections if necessary). The last step would be a gravity-assisted deceleration to put the craft in orbit. It can meet up with the mag-beam station later, which will help to send it back to Earth quickly.
The ion thrusters would also be insurance against the station on the other side breaking down. It may take a few extra months to get home, but ion thrusters can provide continuous acceleration for years. You could put extra rations in the station itself. If and when it breaks down, the rations can be transferred to the ship for the longer ride home. If it doesn't break down, then the ship remains lighter and will be easier to send home.
These aren't the only guys working on such things.
Dr. Bering working on variable specific impulse magnetoplasma rocket
Since the server is slashdotted. Here it is:
A new means of propelling spacecraft being developed at the University of Washington could dramatically cut the time needed for astronauts to travel to and from Mars and could make humans a permanent fixture in space.
In fact, with magnetized-beam plasma propulsion, or mag-beam, quick trips to distant parts of the solar system could become routine, said Robert Winglee, a UW Earth and space sciences professor who is leading the project.
Currently, using conventional technology and adjusting for the orbits of both the Earth and Mars around the sun, it would take astronauts about 2.5 years to travel to Mars, conduct their scientific mission and return.
"We're trying to get to Mars and back in 90 days," Winglee said. "Our philosophy is that, if it's going to take two-and-a-half years, the chances of a successful mission are pretty low."
Mag-beam is one of 12 proposals that this month began receiving support from the National Aeronautics and Space Administration's Institute for Advanced Concepts. Each gets $75,000 for a six-month study to validate the concept and identify challenges in developing it. Projects that make it through that phase are eligible for as much as $400,000 more over two years.
Under the mag-beam concept, a space-based station would generate a stream of magnetized ions that would interact with a magnetic sail on a spacecraft and propel it through the solar system at high speeds that increase with the size of the plasma beam. Winglee estimates that a control nozzle 32 meters wide would generate a plasma beam capable of propelling a spacecraft at 11.7 kilometers per second. That translates to more than 26,000 miles an hour or more than 625,000 miles a day.
Mars is an average of 48 million miles from Earth, though the distance can vary greatly depending on where the two planets are in their orbits around the sun. At that distance, a spacecraft traveling 625,000 miles a day would take more than 76 days to get to the red planet. But Winglee is working on ways to devise even greater speeds so the round trip could be accomplished in three months.
But to make such high speeds practical, another plasma unit must be stationed on a platform at the other end of the trip to apply brakes to the spacecraft.
"Rather than a spacecraft having to carry these big powerful propulsion units, you can have much smaller payloads," he said.
Winglee envisions units being placed around the solar system by missions already planned by NASA. One could be used as an integral part of a research mission to Jupiter, for instance, and then left in orbit there when the mission is completed. Units placed farther out in the solar system would use nuclear power to create the ionized plasma; those closer to the sun would be able to use electricity generated by solar panels.
The mag-beam concept grew out of an earlier effort Winglee led to develop a system called mini-magnetospheric plasma propulsion. In that system, a plasma bubble would be created around a spacecraft and sail on the solar wind. The mag-beam concept removes reliance on the solar wind, replacing it with a plasma beam that can be controlled for strength and direction.
A mag-beam test mission could be possible within five years if financial support remains consistent, he said. The project will be among the topics during the sixth annual NASA Advanced Concepts Institute meeting Tuesday and Wednesday at the Grand Hyatt Hotel in Seattle. The meeting is free and open to the public.
Winglee acknowledges that it would take an initial investment of billions of dollars to place stations around the solar system. But once they are in place, their power sources should allow them to generate plasma indefinitely. The system ultimately would reduce spacecraft costs, since individual craft would no longer have to carry their own propulsion systems. They would get up to speed quickly with a strong push from a plasma station, then coast at high speed until they reach their destination, where they would be slowed by another plasma station.
"This would facilitate a permanent human presence in space," Winglee said. "That's what we are trying to get to."
From the article: The mag-beam concept grew out of an earlier effort Winglee led to develop a system called mini-magnetospheric plasma propulsion. In that system, a plasma bubble would be created around a spacecraft and sail on the solar wind.
I'm not sure at all just how practical this technology would be for propulsion in practice, since it involves having to transport the breaking beam generator to the other end of the journey before regular trips can beginn, and, as a collollory, it would mean that huge power generators would have to be moved to the outer solar system to enable trips there.
The dangers from a stations balancing beam shoud also not be ruled out.
Given that there are already means, and a planned mission to Jupiter, of using nuclear power reactors with ion electric engines, I think that it would be both safer and more practical to equip the spacecraft with a small nuclear power station and use ion engines, at least until the infrastructure is better thought out.
BUT, there is one very good idea, taken from the above quoted paragraph, and that is that by enveloping a spacecraft in a plasma bubble, you can provide it with a shield against charged particles, something that is today, still a major headache when planning long distance human spaceflight. Solar storms send out huge bursts of very deadly chared particle clouds into space and up until now the idea to have heavy and somewhat ineffective metal shielded areas has been the way to go. With a plasma bubble around a spacecraft, one would be giving it a minature magnetic field, so to speak, and the spacecraft could go to places which, have, until now, been decidedly unhealthy for humans, such as the radiation belts around Jupiter and Saturn.
Or do I misunderstand this totally?
NASA has this page explaining the physics and why it granted the money to the UWash research team. And the NASA page responds...The UWASH page pointed to by the article is somewhere behind a cloud of smoke coming out of their poor slashdotted server. 350 comments later, I still cant raise it.
SLASHDOT: news for people who can't concentrate on work or have no life at all and got tired of yelling back at the TV.
were it those damn space kids keying mah ship again?
I think I see the problem here... You are using the term "DeltaV" to describe a velocity, which is incorrect. It CAN be used to describe a "change in velocity" (eg: "When the object hit the water, it's velocity decreased by 10m/s, therefore the DeltaV was -10m/s."), but that is useless when discussing things like travel times (eg: "How long will it take to get there if I have a DeltaV of 10m/s?" - "That depends, how fast were you going before your velocity changed?") It can only be used to compare two velocities of the same object at two points of reference: DeltaV = (V2-V1)
This implies a necessary acceleration, because velocity cannot change instantaneously, and if DeltaV is anything other than 0 then there must have been an acceleration to change it.
In other words, this really tells you nothing useful about how long a space ship will take to get to Mars since you have two unknown velocities... or are you assuming something that I'm missing?
=Smidge=
Just not slowing down when you get to Mars?
keep the ship in orbit and it still has all that energy for the return trip. Use a lander-style smaller vehicle for itra mars-orbit travel.
The only problem you have is the energy still required to slow down from and catch up again to the orbiting ship.
Hey, what about equal and opposite forces? If the beam generator was mounted on a space station like they say it could be, wouldn't the space station need to be much more massive than the object it is propelling?
I am only asking because I would think that if the beam is as powerful as they say it is, then I think it would push the two bodies apart, which is fair enough for the spacecraft, but you really don't want your space station being pushed out of orbit. Is there any chance of this technology being used for anything other than the propulsion of tiny spacecraft?
I'm an engineer.
If you put me in charge of a Mars mission here's the only proper way to do it.
#1 what we did in the sixties, whistle stop one pass visits, are pointless, if you're going to go then go, don't fuck around.
#2 we have the perfect platform for solar system operations right on uor doorstep, Luna, that and the L1 and L2 largrange points in lunar orbit for stuff that the moon's 1/6th gravity will make difficult or expensive.
#3 all space vehicles will need enough delta vee to decelerate to matching velocity with the target, whether that target is Mars, another planet, or an asteroid, that's no big deal we can use MHD which will efficiently generate low braking thrust for long periods.
#4 all space vehicles and this includes "materiel" of any kind, including "lego" style construction sets and so on, can be given practically any velocity you like by launching from a lunar linear accelerator, these work REALLY well in a vacuum.
SO top priority will be getting mebbe 500,000 tons of mass up to the moon to buind a nearly self sufficient base.
Best way to do that is a two pronged approach.
1/ Develop REALLY heavy lifters, nuclear salt water is cool as a starting point, first step need to be throw everything at perfecting Fusion until it's as doable as fission power plants.
2/ Develop (materials) for the space elevator.
The united states spends 450 BILLION dollars every year on the military, if that lot was thrown at this project you could adopt a JFK / Apollo sort of timescale and we'd have a viable and working moonbase by 2020 AD easy.
If the USA doesn't do this, there will be a moonbase by 2050 at the latest, and it will be Chinese.
When that happens the entire might of every military on the planet, IN CONJUNCTION, will be as effective as wet toilet paper agauinst a
Who knows, I may even live long enough to see it.
http://slashdot.org/~GuyFawkes/journal
Thus a slower thrusting craft that obtains a higher delta-V over time is still likely to beat out a high-thrust craft that only burns for a few minutes.
Plus there's none of that pesky drifting off into deep space. That tends to make your flight a little depressing.
No, you got it about right. See the picture at the NASA page on the original grant to UWash...it looks just like a mini version of earth.s magnetospheric sheilding of the solar wind.
SLASHDOT: news for people who can't concentrate on work or have no life at all and got tired of yelling back at the TV.
we need a craft that is at least 100 times stronger than anything we launch now
Two words: Force Field
Software Wars
I saw a talk, by this group, when they ventured across the state to my University. Despite the fact that all researchers are convinced that their new way of doing something is so much better than the other ways, this group really seems pragmatic about the whole thing.
They admit that the difficulties in getting this to work are tremendous. But from a cost standpoint (as opposed to nuclear methods, the only other energy source we can work with right now that provides enough energy density -- antimatter has a much higher energy density, of course, but we haven't any way of carrying it with us!), the UW method is the best I've seen so far, and it doesn't really screw around with the tricky issues of getting a nuclear source up in the atmosphere, where a problem can cause BIG problems for those of us on the ground. His charts showed that among all the methods out there (including some -- I don't remember seeing some of the parent poster's suggestions -- of Orion, Nuclear Salt Water, etc.), this dealie from his group sort of lies on a critical line between expense, availability, and ability to develop it to a useful stage.
Technical, very tricky engineering is required to get their "induction coil" out there, and have it be strong enough, but once it's deployed, the basic physics behind the thing is really pretty foolproof (as far as I can see).
I *did* ask him during the colloquium whether the accelerations provided would be enough for a long manned spaceflight -- they're SO much less than 1g. He said that for (far-in-the-) future flights, they have found a way to couple the fields' angular momentum to the "sail", thus spinning the spacecraft about the axis of translation, so that you could essentially have a spinning ring of which sci-fi writers are so fond. However, the efficiency of this is pretty low, so to spin the thing up, you might want to use chemical rockets, and let the plasma thingy do its job in the other direction.
This picture actually shows a Stars Destroyer killing off a rebel satelite.
George Lucas is a huge visionaire.
Anyone have a mirror, since it appears that the Microsoft IIS server they're using couldn't handle the slashdot load.
Don't Vote for Norm Dicks! http://www.nodicks2008.com Another nutless dirtbag that voted for the FISA bill!
Why don't we just use the inflatable habitat technology for shielding? Fill it with the most compressable gas available. If something hits it hard enough to hole it then the gases escaping should slow it down, right? A multicellular inflatable armor design should behave like reactive armor in a vacuum.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
There is a corridor through which you travel. Over time the odds of chunks of dangerous stuff (anything solid with mass) passing through this corridor increase. Reducing the amount of time reduces the odds. I think that pretty much sums it up...
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
OTOH, I guess it's perfectly secure now, as it's crashed and not responding to requests.
Way to go, University of Washington!
And remember kids: Never trust a computer you can actually lift.
exactly! and that's why there is no way around dense power sources, which are inherently dangerous. Therefore, if we plan to rely on the rocket principle (as opposed to elevator or plane schemes) there is no way around nuclear propulsion if we want a reasonable mass ratio.
BTW, following the instructions on the error mesage got me back to the same error mesage.
SLASHDOT: news for people who can't concentrate on work or have no life at all and got tired of yelling back at the TV.
"Guess what they are from?"
Careless orbiting window cleaners?
Correct me if I happen to be mistaken, but what physics and maths I attended state that the greek Delta translates in equations as the phrase "change in".
So, therefore, Delta-V = change in V (or change in Velocity).
If, "Delta-V for rockets is all about the final velocity obtained".
Why is the symbol Delta used instead of one for maximum?
"Secrecy is the keystone of all tyranny. Not force, but secrecy
Okay, so here is an idea to get this whole system set up...
1) Send materials up into orbit, assemble 2 of the "stations" there, with nuclear reactors, plenty of fuel, and a plasma generator on both ends
2) Use the engines to move these stations out of earth orbit, put them in a stable orbit around the sun but near the earth
3) Use 1 station with both engines on to push the other to Mars while maintaining its own position
4) The station en route to Mars slows itself down
5) Now, you have 2 stations in position and travel may commence.
Figure it would take 10 times as long to send a whole station out via this method as it would to send the ship later, and you are looking at, what, maybe a year or two to get it to Mars, on top of a few months to a year to get the stations safely away from the Earth where the plasma wouldn't be a danger, plus several years for design and construction, plus a lot of money both for that and for sending the parts into orbit - it would take a decade or two and several billion dollars, but the payoff to having a stable (relatively) and reusable system could be enormous...
William George
So here's an idea. Put a captured asteroid into an elliptical orbit. Perigee is at about 200 miles, going about 10 km/sec, apogee is at about 18000 miles going about 1900 km/sec. As the asteroid approaches perigee, it lowers a cable (made of space-elevator rope) into the upper atmosphere. As the cable gets into the atmosphere, the asteroid starts paying it out very fast, so that the end moves slow enough to be grabbed by a high-altitude airplane and attached to a spaceship. Once attached, the asteroid pays out cable slower and slower, accelerating the spaceship to the asteroid's velocity, and very slightly slowing the asteroid in its orbit. Eventually the asteroid starts reeling in the cable faster and faster, accelerating the spaceship further.
The spaceship only needs to be accelerated a little past the asteroid's velocity to reach escape velocity. There are a few possible ways to correct the energy loss of the asteroid's orbit. The simplest is for the airplane to attach a fuel tank to the cable along with the spaceship so that after the spaceship detaches, the asteroid can reel in the fuel and do a burn to pump its orbit back up.
Of course there's a big PR battle to be fought, to make people feel good about a big rock in a relatively low orbit over the earth. But if it worked, it would use a lot less rope than the space elevator, and it would get you into space quicker.
WWJD for a Klondike Bar?
Obviously, over time the "road" you take will have more objects passing through it, however, we are only concerned about our space ship at a given location at a given time. Since we cannot calculate where a random debri will be at any given time, it is impossible for us to figure out if its better to send the ship faster or slower. In the end, the ship will remain in space until it is decomissioned and sent hurtling to some planet. Now going faster is better because it will save time--- now what we need to figure out is some kind of shield (i.e. star trek) to help deflect these objects from hitting the ship. I would imagine that a rock the size of a fist going at high velocity towards a ship would be detrimental.
I mod down so you can mod up. Your welcome.
Ah, ok. Allow me to explain. If I want to go from Low Earth Orbit to the moon, it will take a minimum Delta-V of 4.4 m/s. That means that from my starting velocity in LEO (~8 m/s) I must increase my velocity by 4.4 m/s to reach the moon.
If I want to get to the moon faster, I need to adjust my velocity by a much higher Delta-V. So obtaining a Delta-V of 7.2 m/s would allow me to get to the moon way faster than my 4.4 m/s friend. (Actual time differences are only determinable by orbital mechanics.)
So yes, Delta-V for rockets is about the change in velocity. But it's about the amount of change necessary to move from point A to point B at travel time C. Does that clarify it?
Javascript + Nintendo DSi = DSiCade
Not really. Micrometorites would be on the surface of the Earth.
In that case it seems like something to be INSANELY worried about...
If you have to travel 10 million miles you have to travel 10 million miles...the amount of time it takes you to get there is irrelevant...
Try this next time it rains:
Run as fast as you can ten feet, unprotected, through the rain, then turn around and walk very slowly back the same ten feet. Which direction got you more wet, going fast or going slow?
void beamStation::propelShip()
// Should be facing ship again now
{
while(m_PushOnShip)
{
fireBeam();
waitForHalfEarthOrbitOfStation();
}
}
As an answer to this and other posts, the pusher satellite which is in orbit around the earth may BENEFIT from the force it is imparting to the probe. Since it is (presumably in an equatorial orbit) circling the earth, half the time a force directed "out" (away from the sun for example) would slow the satellite causing it to de-orbit but half the time it would actually lift the satellite by imparting momentum in the direction of orbital motion. Of course if the satellite was in polar orbit or sun-synchronous orbit the there would be no effect because the force would be perpendicular to the orbital plane.
As for decceleration around the target body (Mars), if the body is large enough (deep enough gravity well), the probe could be slingshotted back facing earth. In that case it will be facing the pusher beam which can deccelerate it. (This idea is from interstellar solar sail designs). Honestly though, unless the plasma beam can be kept very tight over interplanetary distances(!) I can't see how a reasonable amount of thrust could be generated for this to work. Aerobraking (see "2010") would probably be much more practical.
As pointed out elsewhere the energy needs are likely to be very high and only a nuclear reactor (not just radioisotopes) could generate it. Presumably these needs could be taken care of by NASA's "Prometheus" program which is developing nuclear reactors for energy hungry missions (like JIMO). On the other hand, I'm not sure if the energy needs to accelerate a probe are THAT high, remember that you are only accelerating the probe (and not its fuel!) which is a much smaller mass than you might think. Manned missions are much heavier though.
Yeah, I remember when that asshole Skylab used to post on slashdot- posts filled with drivel and racial attacks. Let this be a warning to everyone on slashdot- trolling & flamebait posts can kill your karma, and this bad karma can follow you offline as well.
You've been warned...
Thats a great point that I did not think of... however, I do not know if it will apply to our situation. We are talking about travelling through space - a place that is fairly barron. The rain example seems more apt if we were running through a meteor shower, or an astroid belt (one moving fast enough to make it impossible to dodge individual rocks).
I mod down so you can mod up. Your welcome.
The thought that immediately sprung to my mind is if you have some satellite spewing a huge stream of charged particles, that's called an ion drive, a rather big one in our terms.
What keeps this base propulsion station from rocketing off into the nether parts of the solar system ?
-- Pat
The biggest problem with communication is the illusion that it has occurred
And *who* will keep the satellite in place while it's pushing Spaceship 1e-5 to space ? Another space beam jerking station ? Because *cough* tell me if I'm wrong *cough* but my modest physics classes make me think that the blowing satellite will be subject to the same force - well, greater in fact, since the sails will not receive all the beam's thrust - than Spaceship, but opposite in direction...
A solution could be placing a thrust engine opposite to the first one and blowing exactly the same amount of ionized things as the "pushing" thrust engine. But that's already putting a theoretical limit on efficiency of 50% !
That's got to be the first seriously original though on how to get things into orbit that I've heard in a long time. Definitely worthy of a place in science fiction, if nothing else. It would take quite a bit of work to figure out the physics behind it, how low the rock would have to dip to make it possible, etc. Nonetheless, one of those thoughts that gets imaginations going.
Wake up - the future is arriving faster than you think.
Why would greenpeace care about people mining asteroids? I would think they'd rather see a lifeless rock stripmined than the living earth.
It seems like 26,000mph should be easily achivable with conventional methods. How fast do current mars missions travel?
In other words, this really tells you nothing useful about how long a space ship will take to get to Mars since you have two unknown velocities... or are you assuming something that I'm missing?
For rocketry, Delta-V does indeed determine flight time. The reason is that there are different ways of achieving an orbital transfer. Slower methods require a lower Delta-V, while faster methods require a greater Delta-V.
Here is a list of orbital transfers and Delta-V requirements.
The cheapest maneuver used to be the Hohmann Transfer, but it has recently been supplanted by an even more efficient (and slower) transfer called the Interplanetary Superhighway.
Javascript + Nintendo DSi = DSiCade
Therefore DeltaV is a relevant, indeed, a vital, statistic for any spacecraft. If you are in LEO, with a deltaV Note that this is a bit fuzzy. Very low acceleration spacecraft require rather more deltaV for a given maneuver than high acceleration spacecraft. How much more depends on the local gravitational fields, and the extent to which they are aiding your velocity changes. As an example, normally, with a high acceleration (>1m/s, say) spacecraft, deltaV required to reach escape speed from a circular orbit is considered to be ~.4142 orbital speed (Sqrt(2)-1). with a very low-acceleration spacecraft (0.01m/s, say), deltaV required for the same maneuver is ~1.0 orbital speed.
"I do not agree with what you say, but I will defend to the death your right to say it"
One blown tire on the highway, and your car rolls or bike crashes. One mistake crossing the street and I'm roadkill.
actually, cince in all those situations you are in a life support environment, even if you suffered major damage and are barely alive, you have a much greater chance than the space crew with a minor pinhole leak 1.2 million miles away from home in the most hostile environment possible.
your basic body functions can still work as you lie paralyzed and bleeding on the shoulder of the highway, and can easily survive until help arrives in most cases.
in space, there is no help that will arrive. and a tiny boo-boo is your death knoll.
Space probes have many redundant systems and REQUIRE them on a regular basis. and most space probes sent to mars never made it. Voyagers had heavy armor and shielding, ran on nuclear power and had MASSIVE antennas that would still do their job even if 1/3rd destoryed. most of pioneer's and voyager's instruments failed and they had to rely on the backup systems by the end of the missions. were they simply bad products with manufacturing defects or were they damaged by debris?
we do not know because nothing has ever been brought back from space outside the protection of our moon and planet's gravity well.
I'm betting that voyager I is beat to hell.
Here's a nice story how to achieve that.
It's fiction but the facts are solid. NASA remains clueless and SS1 is really just a toy. The Rocket Company story gives you robust design and even a business plan to start with. Some billionaire should make this into reality (and in the process himself/herself into world's first trillionaire!).
Please insert "less than 3000m/s or so, you CANNOT escape from Earth's gravity, no matter how that reaction mass is expended. If you are in GEO, you require a deltaV of ~1400 m/s to re-enter the Earth's atmosphere. With less deltaV than that, NO amount of acceleration will be sufficient to change your orbit to an atmospheric entry orbit." before the word "Note" in the above post.
"I do not agree with what you say, but I will defend to the death your right to say it"
great! you going to build it?
because you are talking like it exists.
oh wait? you are offering solutions that dont exist?
then why not a artifical black hole in front of the ship? you would move faster and it would vaccuum the way clean.
I prefer ripping space time and traversing the 7th dimension.
come back with a real solution.
Yes, this was another rejected story you won't hear about.
We will bankrupt ourselves in the vain search for absolute security. -- Dwight D. Eisenhower
Having been corrected on this, I often feel a need to pass it on.
The moon is:
just over 1/4th of earth's diameter (27%)
roughly 1/6th of earth's gravity, (17%)
roughly 1/81st of earth's mass (1.2%).
roughly 3/5th of earth's density.
The mass part is one of the highest in the solar system, but I believe that Pluto/Charon have us beat by a comfortable margin. Of course, a lot of people want to have Pluto rescheduled as something besides a planet, but that's an argument for another thread.
Wake up - the future is arriving faster than you think.
With less deltaV than that, NO amount of acceleration will be sufficient to change your orbit to an atmospheric entry orbit
;-)
That's not quite 100% correct. It is possible to lose *more* velocity in an acceleration maneuver rather than a deceleration maneuver. The trick is to modify your orbit such that it becomes an ellipsoid with the Earth at one end. With such an orbit, you could theoretically reenter the earth's atmosphere on an orbital flyby. The temporary reentry would result in strong aerobraking which would reduce your speed *without* reaction mass. Of course, you're quite likely to burn to a crisp in such a maneuver, but that's just minor details.
Javascript + Nintendo DSi = DSiCade
It is to big, and affects earth to much (1/3 the size of earth) to be considered a satalite.
You would be much more credible in your wild claims if you could spell the word "satellite" correctly, you know.
But, then again, if you knew how to spell it, you might know the definition of it: "a celestial body orbiting another of larger size"
And since you mention that the earth is, in fact, larger than the moon...
You can't take the sky from me...
After reading the article the first thing I did was to scroll through the posts looking for somebody to mention this very thing. Yes you could compensate for the thrust, but the article doesn't mention it at all, which I think is a big omission. Either the station would have to have twice the plasma generation capacity and a second emitter, and a way to ensure that the backwards beam didn't hit anything important, or it would have conventional thrusters of some sort and would need a constant supply of fuel shipped up to it.
These things might not be germaine to getting the basic concept across, but they get important fast when you start to translate the concept into a practical design.
Rocheworld
I drank what? -- Socrates
He'd make a plan and follow through, that's what
Brian Boitano'd do!
The brake is a remote emitter that has to hit a small craft going 26,000 miles an hour with a stream of magnetized ions. Granted, the craft will hopefull be coming straight at it, making targeting easier, but I be the military would love to be able to hit a target that well.
I hope the craft will have at least some small thrusters for adjusting its course, because you're going to have to be headed straight at that "receiving" emitter or it will just will just slow you down a bit and alter your trajectory.
I'd hate to be on the ship when the remote emitter either misses or simply doesn't work.
Deep space, here we come!
I am ignorant of the forces used in this technology, but if I am correct...
You have a space plasma generator orbiting the sun that will push payloads into a Mars-intercepting trajectory. OK, fine and dandy.
Now, if it's shooting all this high energy plasma out one end, won't there be a reaction of its own in the opposite direction, effectively causing the force on the payload to be cut in half, while also shooting itslef way the heck out of the original "stationary" orbit? I'm sure someone smarter than me has already thought of this, I just can't see the solution.
I'll pass on this for now.
Just the idea that the only thing keeping me from a neverending journey into space is that a remote mag-beam emitter will be exactly where it needs to be at exactly the right time and be fully functional...
Sounds to much to me like being shot out of a rifle and hoping your aim is good enough that you will go straight down the barrel of the "receiving" rifle millions of miles away.
My mind is just boggling at the distances and the accuracy required for this to work. I assume that just because they won't carry "big powerful propulstion units" doesn't mean the won't have some darn good navigational units to adjust their course.
That's a good start, but a whole lot more would be needed. What we'd really need to look at is the amount of drag it would incur by dropping a cable a few miles into the atmosphere, then pulling the cable and passenger (and fuel for the rock) up out of said atmosphere. Unfortunately, my understanding of the math behind friction is poor.
How big a rock would you need to make sure that the rock pulls the passenger out instead of the passenger pulling the rock in? How much thrust would it take to put the rock back into its original orbit? Would it be less fuel than to just to push the passenger in the first place, accounting for drag on the cable? Could this be offset by being able to use an ion jet on the rock instead of chemical rockets on the passenger? Like I said, lots of math.
Wake up - the future is arriving faster than you think.
Time to start saving money for that ticket to.... Pluto! (bet you thought I was going to say Uranus)
Could one be built that could hurl payloads into orbit from the moon's surface?
"I'm not impatient. I just hate waiting." - My Dad
If you have a satelite capable of accelerating a spacecraft that fast, shouldn't the satelite move too? Thus you either need a very strong gravitational field to pull you back or you need to blast yourself the other side comsuming twice the amount of fuel...
i liked stonekeep because the monsters wouldnt go through the doors and you could just shoot them through the doors and it was mad fun.
Buy Steampunk Clothing Online!
he wants to hire goons to push you down the stairs because your selling drugs?
It's there in 90 days and another 90 back. The reason that they want a 3 month trip is that they realize the astronauts will probably kill each other otherwise. They have a big program about this where they built a replica of the proposed ship and are trying to figure out ways to force people to live together this long without having the first 'space murder' Discovery I think it was had a great special on the program.
I tend to agree with the rain guy. The amount of space debris and it's speed and direction is something that you cant control. Assuming that you know nothing about where the debris is, the only thing you can control is the amount of time that you expose the ship to it.
Not everything is analogous to cars. Car analogies rarely work.
Found in the link:
"In the past year, astronomers have reported finding such objects around Uranus."
Ricardo da Silva Lima
I think the inflatable habitats are the best way to accomplish that. Plasma won't do much for projectiles almost any way you energize it. There was a /. story a while back about a new way to "cheaply" make cold plasma... Be nice if we meet someone with energy weapons I guess :)
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
I lot of concern has been expressed about missing the stopping ion beam and hurtling into the great unknown. The trajectory could be optimized such that, in the event of an ion beam failure at the target, a gravitational slingshot around Mars could be used to bring the ship back to Earth. The mission to explore Mars would be a failure, but the astronauts would live to try again.
> With an energy model (e.g. you must climb to height X and introduce "potential energy" Y--escape velocity is derived from a kinetic/potential energy model anyway), it becomes unambiguous about how energy you've spent so gains you, and you can now integrate issues of energy lost to drag from doing anything other than flying straight up, and the validity of shooting straight up is clear.
In theory, you're correct, but there are other factors with the "space plane" design that change the balance. The first is that using a space plane means you only need to lift a portion of your craft out of the atmosphere, leaving the plane part behind, so you need less fuel on the "space" part of the plane. Second, the "plane" part of the space plane can incorporate an air-breathing engine, so you don't have to carry all of the oxidizer with you from the launch pad, like the shuttle does. This lowers the amount of total weight you need to lift, which (using proper mission design) could offset the extra energy you're using in a not-straight-up flight. Whether the savings from less oxidizer/less to-space weight can make up for the extra wasted energy remains to be seen, but I have high hopes that it can be.
Virg
I guess the problem would just be at launch. How hard would it press you?
Based on your idea, you'd only need a working design for a space elevator and a solution to the Grand Unified Theory that allows for harnessed gravitics.
Keep working on it.
Virg
Sounds like the same old to me, just turned around backwards with the propultion system pushing the craft from somewhere else, but having to magnitize the beam so that it can be "caught". JHU APL designed and tested an ion plasma engine before, just the other way around where we did not have to "catch" the beam on the other end (requiring yet more energy), but we did have to carry our own "fuel" (light weight plastic for generating non-magnetic ions). Their propulsion "plasma" station will need more/heavier fuel (to be magnitized) and also have to worry about the "reaction" to the ion plasma's origional "action" which is slightly more than the net action pushing the craft to Mars. Isn't that (1.x + 1.y >= 2) like twice the energy? This higher level math always gives me problems. ;}
But think about it for a sec, would you want to sit *behind* a saturn 5 booster? Not me, in front is fine. A plasma beam is energy, *ionizing* energy. I would not want to sit in a craft receiving a direct hit by a plasma beam powerful enough to push it around the solar system any more than I would want to sit inside a microwave wrapped in tin foil.
Ok, so I won't burn up with the right shielding around me, and you've driven this thing all the way to Mars. How do I put that beam in reverse to go home again? Turn your sail around the other way? Keep an extra set of horse shoe magnets in the glove compartment? (lol)
In a vertical lift-off, the person(s) would have to endure a greatter amount of G-force due to the amount of force unleashed in a fraction of a second to achive the inertia needed to start lifting and contiune accelerating toward achiving proper amount of velocity(ies)...etc
In a horizontal lift-off, the person(s) wouldn't have to endure the same amount of G-forces, as in a 1st stage one would only have to achive the inertia to overwin the air/frition-resistance, and sure at a 2nd stage one would still have to overwin the Gravity-force that's keeping us so firmly on the ground to achive orbitit - but the main difference in this take-off method is that one can/could adjust the amount in inclination and therefor be able to control the amount of G-force the person(s) would feel/endure. (btw, yes one would also have to achive a proper amount of horizontal velocity (aka, orbiting velocity) o achive the destined orbit...).
So basic knowledge of physics and mathematical skills in doing x-axis/y-axis component calculation is needed to start calculaning out the scenarios... nothing fancy. (NOTE: Though, greater skills are required at calculating with/at pin-point accuracy! - thats start sending ppl to space... - but for theories, basic skills are enough)
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Now one has to start to dissect the +positives/-negatives of both methods, and look at what is possible to achive with the available resorces at hand. One good thing to note is that just because one has used one method at a period doesn't mean that that has to be the defacto standard for all comming time either - that that lator in life a method prior thought unusable might become our next new 'best thing since sliced bread' :)
We evolve, we improve ourselfs and our capabilites (technologies, etc...), we uncover xor learn of new things, and as a consecvence we change over time. So our understanding of a matter can't be 'put into stone' for an indefinite period because of our nature - constans 'state of flux' we humans are in.
I don't claim I know more than I know, and if you know you know more than I know, then by all means, let me know.
The parent probably means that the Micrometoriods that hit the surface of the Earth are called Micrometorites and since they are already on the surface of Earth they should pose no threats to spacecraft in space. :)
I just want a one way trip taking only 45 days for a poor anti-Fascist American Self Employed/Unemployed Computer Scientist.
I seriously question the sanity of anyone who says that a space elevator can acheive a "reasonable mass ratio!"
Theoretically it could be done. I say we get to work immediately.
Of course, we'd be exposing our astronauts to a one time acceleration that would disintigrate the human body, but hey no pain no gain right?
Yes, thank you.
It's not the final velocity attained, but the rate at which that velocity is obtained.
So, to paraphrase, for Rockets it's half about Acceleration and half about maximum Velocity.
For example a rocket that accelerates up to 100m/s in a minute but then can not accelerate further is a worse choice than a rocket that constantly accelerated at a speed of 1m/s2. Only if, the former rocket would not have reached it's goal before the later rocket reached a speed high enough to negate the inital gain of the first rocket.
"Secrecy is the keystone of all tyranny. Not force, but secrecy
I must have missed something in the article. I seem to remember Newtonian mechanics requiring that any force have an equal and opposite force. So, if this beam is going to push a craft, something must push the beam. And, if the satellite is pushing the beam, then something must be pushing the satellite. Now, if the satellite is sitting out in space, what's pushing on it? Isn't the satellite just going to fly backward (at a rate dependent on the ratio of its mass to that of the craft)? What did I miss in the article?
...acceleration and deceleration...
I know what acceleration is, but what is deceleration? If you meant negative acceleration, than I understand what you are talking about. A fact that nobody seems to understand is that de means opposite. There is no such thing as the opposite of acceleration, but only acceleration in a different direction, usually behind you. This is negative acceleration, and nothing else. In my physics class you would be reprimanded for saying the d word.
i went, and checked...
first, that link don't work.
second, digging, a bit further, i found this link -- look at #62, specifically:
So I guess the line "First Mars, then: THE WORLD!" doesn't quite fit here.
But what does come after Mars? The potentially lively moons of Jupiter? Saturn? Uranus? Neptune? You know, because walking on Neptune is so critical for the continuation of our species.
How about we send robots to Mars and invest the savings into education in the United States?
There's nothing cold and lifeless about amazing photography from another planet. A good motion picture is also very good at stirring up excitement.
Spoon not. Fork, or fork not. There is no spoon.
WRONG WRONG WRONG.
*Bzzzzzt* and thanks for playing. 1 G constant accelleration is 32ft/sec/sec. That's the same force you feel, standing up on Earth. 3x that is what the pilot(s) of SpaceShipOne experienced, both rocketing skyward, and on their return.
Your post shows a complete and UTTER lack of understanding.
To help your understanding along.. 165 seconds of 1 G accelleration brings you up to a speed of 1 mile/second. To put that in perspective, that's 19 minutes thrust, at 1 G, to achieve escape velocity... WITHOUT disturbing a hair on your pretty little head.
If that doesn't put the give you the scope we're talking about, two days of 1-G acceleration, and you've traveled almost 1 AU -- so if you then decelerate at the same rate, you've crossed the diameter of the Earth's orbit in 4 days flat. Earth orbits the sun at 1 AU, and Mars orbits at 1.5 AU. I do not see a 1 G acceleration trip to Mars taking anything like 3 months, much less 3 years.
* Disclaimer... All calculations were done back of envelope, with a standard #2 pencil, and my overworked brain, on a friday afternoon!
-- All That's Evil in the Geek Space
Jiggity
The first test of speed would require your standard long distance travel time measurement.
Buy a Big Mc(TM) from a drive through on Earth and kept the receipt. Get over to Mars as fast as possible and get another Big Mc(TM) at a drive through.
Compare times, throw out Big Mcs(TM).
DeBeers has warehouses of bins, floor to ceiling of diamonds they keep off the market to artificially inflate their value.
11 Harrowhouse
gewg_
How bulky does this beam station have to be in order to stand still when it's shooting out this beam (Newton #3)? How does this station keep its spaceship within its line of sight (high orbit to avoid long earth "nights"), and is the direction of thrust always in the direction of the stations line of sight? Maybe the article could have been a bit more detailed.
For generating the plasma, Focus Fusion looks like a real possibility. Could even be light enough to carry onboard for power and backup propulsion.
ok now all I'm going to need is a good strong hot cup of tea, a finite improbability drive and protection from the physicists...
the only problem with this are all the petunias and whales dropping from the sky and the increased chance of your turning into a cherry pop-tart...
yes...I am rereading the trilogy...
Did you know you can be apathetic to apathy? Not that I give a shit...
I believe the proper design for the beam projector is a sphere the size of a small moon.
This whole project seems idiotic. Did somone know a senator or somone "connected" to funding?
Why put two "huge" space station (huge so they have enough mass they don't push themselves out of orbit)in space, one around Earth & one around Mars, when you can put the drive on the ship? Launch the ship and let it push itself 1/2 way to Mars with the plasma drive, turn around and fire the drive in reverse to break for Mars orbit, then later reverse the process. Why not just use the huge plasma generator as a ship drive?
"As for the future, your task is not to foresee it, but to enable it." - Antoine de Saint-Exupery
It is important to remember the difference between deterministic effects (the minimum dose needed for depilation, skin burns, marrow suppression, death) versus stochastic effects (relative risk increases in cancer). From what I understand, there doesn't seem to be a risk of death, but there may be a relatively increased risk of fatal malignancies in the future.
Personally, for me, the trip would still be worth it (though I would probably bank my sperm). Also, someone can probably help on this, I understand that there are transient increases in ionizing radiation levels, from solar flares, and from some deep space sources that have screwed up satellites from time to time. I don't know if unshielded exposure to these sources would be 'deterministically' fatal.
Are they gonna name it the Lyle Drive?
How much time would a mars round trip take with current technology?
So, we have this SPACE SAILBOAT.
And at Earth we have a GIANT FAN.
And we use the GIANT FAN to push the SPACE SAILBOAT.
And since the SPACE WATER is so smooth, the SPACE SAILBOAT goes faster and faster and faster.
And so the SPACE SAILBOAT doesn't sail right past Mars, we put another GIANT FAN there, too, that blows in the other direction.
Is that about right?
since they are already on the surface of Earth they should pose no threats to spacecraft in space.
I beg to differ... A huge planet rushing towards you poses a GREAT threat to a spacecraft.
Thats a great point that I did not think of... however, I do not know if it will apply to our situation. We are talking about travelling through space - a place that is fairly barron. The rain example seems more apt if we were running through a meteor shower, or an astroid belt (one moving fast enough to make it impossible to dodge individual rocks).
It shouldn't matter. Say an asteroid crosses somewhere along your path once every ten minutes. If you took only ten minutes to travel the complete distance, then only one asteroid could have crossed and the chances of it having crossed rigth where you were at the time is fairly low. But if it takes 1000 minutes to cross then 100 asteroids have crossed your path... The chance that one of them crossed a the same place you are is 100x times higher, right?
800 miles length of pinwheel arms
13422.3 MPHs ground speed of pinwheel
2.9529 seconds to grab the cable
11.2347 minutes riding the pinwheel
8.96209 MPSs speed when leaving the pinwheel
5 pinwheel rotations til next try
112.347 minutes til next try
231.425 miles to next try
If you miss the 2-second capture window, you can wait for the next try. As previously noted, the pinwheel requires as many landings as launches to avoid orbit decay.
WWJD for a Klondike Bar?
I haven't even googled it, but how aould solar sails work headed toward the sun? Unlike sailboats, there's nothing to resist the thrust (like water), so there's no way to "tack".
Maybe you should drink your coffee :-)
You said that DeltaV = acceleration. Noe DeltaV/DeltaT is average acceleration (other than average doen't make sense with Delta).
Now if DeltaV = acceleration and DeltaV/DeltaT = acceleration, then DeltaV/DeltaT = DeltaV, which implies DeltaT = 1.
DeltaV != 0 implies that there is/was an acceleration. Bit DeltaV is not an acceleration. It doesn't even have the correct units for an acceleration.
And no, you don't have to explain me the difference between average and instantaneous acceleration (nowhere did I even mention the latter). I know that very well.
The Tao of math: The numbers you can count are not the real numbers.
with all those financial firms with German-Jewish names...
I don't think even Jews are unwilling to admit that they founded a large number of powerful investment banks.
Further, today we call Internationalism "Globalism" specifically for this reason. This is a debate about international economic control, in which Jews play a dispproportionate role as a comparison to their overall population, but which is now primarily a gentile activity.
Jews started it a century ago, but they are an increasingly minor role.
So, do we stop fighting this system simply because Jews founded it? And a few brave men generations ago tried to fight them in a World War?
The past is the past. Ford funded the research behind "THe International Jew". His criticisms of international economic power is not necessarily related.
So are most of our PCs.
I'm quite aware of the use of aerobraking in reentry, and the limits of it (you have to hit atmosphere before it can work).
"I do not agree with what you say, but I will defend to the death your right to say it"
You're about 4 orders of magnatude shy of the engergy involved.
But with the same result.