To Mars and Back in Ninety Days 812
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... (Score:5, Insightful)
Re:This is fine and well, but... (Score:5, Insightful)
Re:This is fine and well, but... (Score:4, Interesting)
Re:This is fine and well, but... (Score:4, Funny)
So you were at that party too?
Re:This is fine and well, but... (Score:5, Informative)
http://www.space.com/scienceastronomy/solarsyst
Passing on a correction... (Score:4, Informative)
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 [slashdot.org].
Re:This is fine and well, but... (Score:5, Informative)
The first moon is the largest, aka Luna.
The second moon is named Cruithne and has roughly a 5km diameter.
The third moon hasn't gotten a cool latin/celtic name name and is known as 2002AA29. It's only about 100m in diameter.
My thinking is that we could move Cruithne into an orbit that would suit our needs for a space elevator.
Getting to LEO (Score:4, Interesting)
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.
Re:Mod parent up, please (Score:4, Informative)
I've gotten curious enough about this stuff that I've started learning a little bit about orbital mechanics. I've written some Python code to do the calculations for this stuff. Here's the asteroid's orbit:
This needs my libraries for physical units [willware.net] and orbits [willware.net], and produces these results:Re:This is fine and well, but... (Score:5, Insightful)
Spaceship One has no chance of surviving re-entry at orbital velocities. Tier Two is going to need to be a totally new craft. I'm also betting its body shape will be closer to Buran or the STS than Spaceship One's. You need some bulk to carry the required heat shielding. You can't "feather" your way out of orbit, since there's no atmosphere for the feathers to work on.
That isn't to say that I don't think that Scaled can do it, eventually. I'm just not willing to pee my pants in joy over their relatively minor accomplishments so far.
Re:This is fine and well, but... (Score:5, Insightful)
Re:This is fine and well, but... (Score:3, Informative)
Re:This is fine and well, but... (Score:3, Funny)
Re:This is fine and well, but... (Score:5, Insightful)
Question: which weighs more, the heat shielding and structure required to survive re-entry at orbital velocities or the fuel required to brake then re-enter at a low velocity?
(Another question, at high altitudes, does the atmosphere rotate with the Earth?)
Re:This is fine and well, but... (Score:4, Insightful)
Now imagine how much fuel would be required to decelerate the craft (a fairly hefty piece of mass) by even one Mach number. Now multiply that out to orbital velocity...
Re:This is fine and well, but... (Score:4, Interesting)
Heh... Imagine catching a marlin with the same line.
Anyway, we still have some things to do, but we may be getting close to the point where we're not trying to peer over the horizon because the next major port is in view.
Re:This is fine and well, but... (Score:5, Funny)
That's not what I heard.
I wouldn't bet against Burt Rutan, though. (Score:4, Informative)
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.
Re:This is fine and well, but... (Score:4, Insightful)
Surely our biggest problem is getting to the point where most, if not all of solar system and beyond voyages are launched from the moon, with a spaceship that is made on the moon (or in the surrounding space). Whilst getting off earth will become cheaper as better methods are found, getting a fully functional industrialised moon base will make launches like this a thousand times more doable. Eventually you want the only thing coming off earth to be astronauts returning from a family holiday.
Re:This is fine and well, but... (Score:5, Funny)
Oh SURE. Outsource that TOO.
Re:This is fine and well, but... (Score:4, Funny)
Re:This is fine and well, but... (Score:4, Interesting)
As I understand things, from (among other books) Zubrin's "The Case For Mars" as well as ample proof from the ISS and our own Apollo moon missions, merely being in space does not mean fatal radiation doses are inevitable.
Rather, space travel does involve higher doses than one would receive on the ground, or (say) in a mineshaft. But that doesn't mean these doses are fatal, or even that they significantly impact long term health.
I remain interested if ANYONE can cite specific data (hopefully from a reputable source) saying that radiation doses in space are near fatal in the time frame envisioned for a Mars mission or, or any other popularly conceived-of mission aside from a manned mission to Jupiter, which does have significant radiation belts.
Re:This is fine and well, but... (Score:5, Informative)
I'm not sure where this idea comes from.
Any given acceleration requires the same amount of force no matter how fast you're going. F = ma.
When you're moving in an atmosphere, you have to add force to counter air resistance as well, which goes up roughly as the square of airspeed.
The shuttle boosts upwards to get out of most of the atmosphere as fast as it can. Then it thrusts sideways, because it's sideways velocity that puts you in orbit. Taking off at an angle would just mean there'd be that much more atmosphere to plow through.
Aerodynamic craft with air-breathing engines _might_ be able to derive benefit from being in the atmosphere, but the shuttle's a brick strapped on to a bigarsed rocket booster, so it doesn't.
Re:This is fine and well, but... (Score:5, Informative)
That would be true if it wasn't for gravity and aerodynamics adding to F. Imagine a spaceplane with wings and with engines that can indefinitely deliver 1G of acceleration: If it tried to launch straight up, it would never make it off a launch pad, but taking off from a runway it could reach orbit, because it's lift to drag ratio (even hypersonically) could be much larger than 1.
This doesn't apply to the shuttle, though; the shuttle's L/D ratio is larger than 1, but the L/D for the stack as a whole is pretty much zero.
Re:This is fine and well, but... (Score:5, Informative)
Actually, thrusting horizontally is the perfect way to reach orbit (and this is largely what the shuttle does now). Orbital velocity is tangential; an escape trajectory is a very different beast (can be thought of as the limiting case of a parabola or a hyperbola as perigee (backtracked along the course) approaches the centre of the earth).
What puzzles me is people who think flying horizontally is free, or lets you climb for free, or magically reduces by some large fraction the delta-v required to reach orbital velocity.
Re:This is fine and well, but... (Score:5, Insightful)
It's also a matter of the fact that rocket propulsion using a C-D nozzle accelerates a vehicle much more quickly than standard turbo jet aircraft are capable of accelerating. As a result you don't really deal with the extra drag nearly as long. That drag equates to friction which in turn equates to heat on the skin of the vehicle. If you used a rocket engine in a horizontal position you'd have higher drag for longer and therefore higher heat loading on the vehicle.
The vehicles that launch from a horizontal position are almost always carried to 50,000 feet by a conventional aircraft. Examples include SpaceShipOne being carried up by White Knight and a Pegasus booster being lofted by a B-52 for a satellite launch.
Daniel
(Aerospace Engineering major.. Senior year finally.. I love my high-speed aero class.)
Sign me up... (Score:5, Insightful)
Re:Sign me up... (Score:5, Insightful)
Re:Sign me up... (Score:3, Insightful)
The tourism industry proves that people will pay money to send themselves someplace because "it's there".
But the existence of the tourism industry is insufficient to prove that people will pay money to send someone else someplace because "it's there".
Re:Sign me up... (Score:3, Insightful)
Your idea only holds for a "cruise ship" type experience: see Jupiter and Saturn's Rings!
Re:Sign me up... (Score:3, Funny)
Will they have big, yellow billboards along the way there?
Re:Sign me up... (Score:3, Insightful)
Re:Sign me up... (Score:3, Interesting)
Re:Sign me up... (Score:5, Insightful)
Re:Sign me up... (Score:5, Insightful)
This is precisely why DeBeers are so keen to differentiate between 'real' (ie. they dug them out of the ground and make a fortune out of) and 'fake' (manufactured, potentially dirt cheap) diamonds - even though you need an electron microscope to actually tell the difference.
Re:Sign me up... (Score:5, Informative)
Diamond is one of the most common gemstones in the world. It would have virtually no value if a) DeBeers hadn't pulled the greatest marketing spinjob in history convincing people today that diamond rings are a centuries old wedding tradition, not a decades old one and b) they didn't warehouse them.
DeBeers has warehouses of bins, floor to ceiling of diamonds they keep off the market to artificially inflate their value. By controlling access to virtually all the mines that are econimical to exploit, they ensure competitors with access to diamond deposits will not flood the market with cheap ones.
Re:Sign me up... (Score:4, Informative)
If the rockets bringing the material to us match Earth's velocity before dropping the material off, an infinite amount (or at least, up to 10-20% the mass of the _Sun_, before the center of mass of the Earth-Sun system changes enough to affect our orbit).
You could pile on at least the current mass of the Earth before gravity increased enough to be a serious problem.
If you're asking "how big an object could smack into earth before its orbit is affected", the answer is "more than big enough that far smaller objects would reduce the surface of the earth to a magma field and maybe give us a new moon or two in the bargain". Motion induced by Earth's gravity doesn't count, because the centre of mass of the system is still pretty much the same - this refers to something plowing into Earth from an asteroid belt transfer orbit without being slowed down first. Nobody's going to do that, because we don't want to reduce the planet's surface to a magma field. The actual amount of mass you'd need depends on the impact velocity, but is at minimum comparable to the mass of the moon (about 1% Earth's mass).
In summary, for any reasonable asteroid-recovery scheme, there is zero effect on Earth's orbit.
Re:Sign me up... (Score:5, Insightful)
Now the adventures and scientists always had a hook they sold to their Queen or benefactors.
- "A path to Asia"
- "Enhanced Missile design"
- "Ermm, *cough* *cough* commercialization of space"
The fact is, there is no predicting what fruits pure science will yeild, antibiotics, electricity, a new propulsion system, or different way of computing. The only guarantee is that if you throw enough money at them they will and it will pay off.The minute a nation forgets this fact and neglects the pure sciences in lieu of the sure thing, is the minute they begin to decline.
Re:Sign me up... (Score:5, Funny)
Re:I am so tired of this ridiculous logic (Score:5, Insightful)
Re:I am so tired of this ridiculous logic (Score:5, Interesting)
But the Printing Press? Did you think this through? Do you really think Johann Gutenberg's motivation was profit??? Have you ever read Henry Ford's writings on business organization? He was a far more ardent critic of international finance than me.
I think you need to read a little more about the people who invented the items you are discussing. Most were invented by men who followed their dreams and were hardly concerned with financial gains. More importantly, financial concerns did not dictate whether or IF they pursued that dream.
New Method? (Score:5, Insightful)
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.
Re:New Method? (Score:5, Funny)
Press 'H' to jump into hyperspace.
Waving (Score:4, Interesting)
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?
Re:Waving (Score:5, Funny)
Re:New Method? (Score:5, Informative)
I had to look it up. Looks like a good candidate for in-space propulsion. If its as cheap as it is simple, then its definately worth looking into. I doubt it'll get the go-ahead for launchpad stuff... all that plutonium spewing out the back would freak people out.
A nuclear salt-water rocket is a type of rocket designed by Robert Zubrin that would be fueled by water bearing dissolved salts of plutonium or U235. These would be stored in tanks that would prevent a critical mass from forming by some combination of geometry or neutron absorption. The rocket would be powered by a nuclear-thermal reaction when the water was injected into a reaction chamber.
Calculations show that this rocket would have both very high thrust and a very high specific impulse, a rare combination of traits in the rocket world.
Re:New Method? (Score:4, Interesting)
But that wasn't what killed the project. What killed the project was the Nuclear Test Ban treaties of the 1960's. The Orion team actually felt that they could reduce the fallout further, potentially to levels where no one would die from a launch. This was due to the fact that the Orion actually attempted to contain its explosions rather than the military goal of causing the maximum damage possible.
Truth be told, if Red Mercury really does what it's supposed to (the Russians ARE selling the stuff), we may have a way of making Orion launches 100% safe. Of course, our government claims that Red Mercury is a hoax all the while other countries are buying the stuff up. Hmm...
Speaking of which, does anyone know what the heck Mercuric Pyro-Antimonate is useful for besides "creating" Red Mercury? There appears to be a whole bunch of the stuff on the open market, but no documents actually stating what it's useful for.
Re:New Method? (Score:5, Informative)
Apollo 12
Apollo 13
Apollo 14
Apollo 15
Apollo 16
Apollo 17
Pioneer 10
Pioneer 11
Voyager 1
Voyager 2
Galileo
Ulysses
Viking 1
Viking 2
Nimbus
Transit
Les
All of the above carried highly radioactive Plutonium into space. The above list does not include Russian launches, nor does it mention missions (like the Mars Exploration Rovers) which used plutonium heaters to prevent mechanical damage from low temperatures.
Linky [wikipedia.org]
Here's another way (Score:3, Funny)
First mission report (Score:4, Funny)
increased speed equals drastically increased risk (Score:4, Insightful)
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.
Re:increased speed equals drastically increased ri (Score:4, Insightful)
Re:increased speed equals drastically increased ri (Score:4, Informative)
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.
Re:increased speed equals drastically increased ri (Score:5, Informative)
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?
Re:increased speed equals drastically increased ri (Score:3, Insightful)
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 (a
Re:increased speed equals drastically increased ri (Score:3, Informative)
A
Phooey (Score:5, Funny)
Why send people to Mars? (Score:4, Interesting)
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."
Re:Why send people to Mars? (Score:5, Funny)
I'm sorry sir, but you must now relinquish your Slashdot UID and turn in your geek card. Someone will escort you to the exit.
Re:Why send people to Mars? (Score:4, Insightful)
No. There is no direct scientific reason to send humans to Mars. However there is a hell of a lot of capacity for new discoveries to be made and new technology to be invented by trying. Just look at the sort of stuff that came from the space program of the 50's and 60's. Likewise look at some of the stuff that came from [D]ARPA projects which on the surface had no direct scientific applications, but in retrospect gave us things like the Internet.
Setting lofty goals and spending money on pure research and development without having to worry about practical application or reason is a great way to produce really good, useful science. Not mention it makes you look really good if you happen to be the nation doing it.
Re:Why send people to Mars? (Score:3, Informative)
Re:Why send people to Mars? (Score:5, Insightful)
We send people to Mars because it would be one glorious incredible acheivement of the human spirit and human will. We send people to Mars to hold our heads up high and say: Look what we can do, universe, now get out of our way.
And some day, the wild horses of humanity will go into space, and all the domesticated men and women they leave behind will huddle around their pathetic lives and fade away into the gray mist reserved for all mediocrity.
Article Text (Score:4, Informative)
Re:Article Text (Score:3, Funny)
The critical sentence:
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.
So this is a refinement of the laser/sail system proposed many years ago (and popularised by Niven & Pournelle's novel, The Mote in God's Eye).
An interesting idea
Re:Article Text (Score:3, Insightful)
There is, of course, a major problem here... (Score:5, Insightful)
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.
Re:There is, of course, a major problem here... (Score:5, Insightful)
It sounds terrible, but really: any sort of malfunction in a self-contained craft, and the crew is completely SOL. This isn't like driving a car, where if you're off by a little bit, you just correct and pull into the correct stall anyway.
All the equipment either works as planned and the ship stays on course, or it doesn't. If it doesn't, you're screwed. Period.
But this is nothing new. Exploring new frontiers has always been dangerous, and that hasn't stopped people from doing it. Sailing across the Atlantic wasn't exactly safe; if something went wrong (including something like the wind not blowing), you were done. Travelling from the US east coast to the west coast wasn't exactly a joyride, either, as anyone who's played Oregon Trail can tell you.
The point is, if we get ourselves hung up on making it perfectly safe, we'll never actually do it. Safety stagnates progress, because risk/reward is immutable. It's the unknown. That's both its value and its danger. What we need is a best-effort at safety, and willing volunteers.
Something tells me that there'd be no shortage of the latter. Say someone walked up to you and said "you can be one of the first people on Mars...but there's a 10% chance you won't make it. Want to go?"
It's possible you'd say no, I suppose. But there are plenty of people who'd leap at the chance, myself included.
Re:There is, of course, a major problem here... (Score:5, Insightful)
Apollo 13 begs to differ with you.
Doug
Re:There is, of course, a major problem here... (Score:3)
At least with a malfunctioning beam projector you can repair it on station, have a spare station on standby, or try and capture the craft using an Earth based projector on the far side of Earth's orbit.
If a conventional propulsion system fails on
Why dont we (Score:5, Funny)
Then we can quickly invade when they least expect it. When you play enough Rome Total War these things become soooo obvious.
For every action... (Score:4, Interesting)
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?
Re:For every action... (Score:5, Insightful)
Horse before cart (Score:4, Interesting)
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?)
Second Law (Score:5, Insightful)
You are not protected! (Score:5, Funny)
Re:Second Law (Score:3, Insightful)
You could first use the reaction force of the beam to make the pusher leave orbit (in a carefully calculated way). Later you point it at the spacecraft, and the reaction force will bring the pusher back into orbit. You just have to calculate the first firing of the beam such that the second firing will be in a direction that is useful for bringing the pusher back.
Since the mass of the pusher will likely be bigger than the mass of the
Shipping the fuel to Mars = $T (Score:5, Informative)
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.
Re:Shipping the fuel to Mars = $T (Score:5, Insightful)
The article appears slashdotted. But,
Using this system means that you can't use conventional rockets and air-breaking to slow you vessel? Why can't the craft get a massive push from Earth orbit, then slow down using another form of propulsion once it gets to its destination?
Granted it makes coming home a major pain. Now you have to come home the old fashioned way. But, getting there isn't so bad... and sending supplies out to outposts doesn't take too much either.
The first few trips is to Mars in 45 days, to earth in 6 months. You can send all you want out to Mars or to meet a craft in transit in 45 days or less. Going home is a bigger problem.
Think... boot strapping... start small... build up infrastructure. Eventually when enough infrastructure is built up at a remote location you can do Plasma Jets both ways.
This just in... (Score:4, Funny)
Old idea, new medium (Score:4, Insightful)
(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.
You'd need an equivalent beam at Mars (Score:3, Interesting)
Phileas Fogg, 90 days around the solar system (Score:5, Insightful)
In todays world, I cannot imagine how restrictive travel must have been, in tomorrows, they will pity us with our cars and segways!
Nasa page has same info and DOES respond (Score:5, Informative)
Scientists are not engineers. (Score:4, Interesting)
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.
Action/reaction - am I missing something? (Score:4, Informative)
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.
Re:At what speed? (Score:3, Funny)
Re:At what speed? (Score:3, Informative)
Re:At what speed? (Score:4, Insightful)
Re:At what speed? (Score:5, Informative)
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.
Re:High Speed? (Score:5, Informative)
W.W.K.D
What Would Kirk Do?
Re:High Speed? (Score:5, Insightful)
Re:High Speed? (Score:5, Funny)
Re:High Speed? (Score:3, Insightful)
I'll tell you what Kirk would do (Score:5, Funny)
Re:thoughts (Score:5, Informative)
Re:Coral cache link (Score:3, Informative)
Re:Yeh but... (Score:3, Informative)
Re:Yeh but... (Score:3, Informative)
Re:Yeh but... (Score:4, Informative)
In 1952, E. R. Ballinger, leader of the research program at Wright-Patterson, conducted one of the earliest series of centrifuge tests directed expressly toward the problem of g forces in space flight. Ballinger found that 3 g applied transversely would be the ideal takeoff pattern from the physiological standpoint, but he realized that the rocket burning time and velocity for such a pattern would be insufficient to propel a spacecraft out of the atmosphere. Consequently he and his associates subjected men to gradually increasing g loads, building to peaks of 10 g for something over two minutes. Chest pain, shortness of breath, and occasional loss of consciousness were the symptoms of those subjected to the higher g loads. The tests led Ballinger to the conclusion that 8 g represented the acceleration safety limit for a space passenger.
They will have to spread the acceleration and deceleration down over a few miles
Re:Energy (Score:4, Informative)