Road Trip On The Interplanetary Superhighway

eegad writes: "CNN has an article about a new idea from NASA springing from chaos theory called the interplanetary superhighway. It will purportedly allow easier space travel by steering through regions where the net gravitational force exerted by nearby bodies is smallest. The actual NASA news release is here. Sounds like an interesting concept but it is unclear how the scientists will account for every source of gravity, including the elusive dark matter."

Warp Theory

This actually sounds a lot like the theories exhibited in the star trek series about warp travel and how different vessels in warp flight have to adjust their courses to travel between the stars to minimize gravitational distortions affecting their flight path. Personally I think it's a great theory and very logical. Especially since gravity creates friction and drag and those are both bad for travel in space or not.

come on....

Dark Matter?! Absolutely negligible on interplanetary scales.

dark matter?

Who cares? The key here is *interplanetary*.

Dark matter's not a problem

Dark matter is only important on galactic scales. We know where all the (important) mass in the solar system is.

Confirmation at last

let's look at the facts: Big government bureaucracy. Foul smelling, funny looking employees. Interplanetary highway construction. It's all there in black and white.

NASA is run by the Vorgons.

Re:Confirmation at last

PROBABILITY .......... Infinity Minus One that NASA's metric ->english conversion will allow an accurate Interplanetary Highway to be built

Infinite Improbability Drive
Bush's Rise to Power

3-body problem?

the sun is pulling, the Earth and moon and other objects are constantly pulling," said Martin Lo of NASA's Jet Propulsion Laboratory in Pasadena, California.

"Our theory has refined to the point where we can actually compute these trajectories

Really? I thought the 3-body problem [uoregon.edu] was not solvable.

Computing versus solving

You're right in that we (so far) cannot solve (in the sense of a mathematical proof) a 3 body problem using nice neat equations like we can for 2 body problems. However it is possible to calculate a trajectory and has been for some time. Takes a reasonably large amount of computing horsepower and a good idea of the initial conditions but a useful approximation can be calculated. Not an elegant or exact method but does work.

Hyperspace bypass

Great! This finally explains why the Vogons had to destroy earth for a hyperspace bypass.

There is no dark matter

According to MOND [umd.edu] there is no dark matter. So you wouldn't have to worry about its gravitational effect. You also wouldn't have to worry about bumping into it.

WOOT!

As much as I love to hear theorys like this out of NASA, and as much as I love NASA, I think they have a few other bugs to iron out first.

While this is a great idea.. and something that has been proposed since the earliest days of Sci-Fi, (using heavy masses as centerpoints for gravitational slingshots, among other things), we
need to get a lot of other things settled first.
People back on the moon looking for raw materials, some actual exploration of Mars, the ISS up and running properly and actually doing something that John Q Public cares about, would be a good start.

This is really coool, and Hubble will probably help a lot, as well as that Muckin Huge Telescope they are building, and SETI may even factor in, as it picks up signals from objects that we cant see, but we can hear.

Its good to see that even in times of "national trouble" NASA is forging ahead and is out on the edge with theorys and predictions, but unfortunately, thats all they are, or are likey to be, unless the Gubmint gets serious about funding space travel. Or NASA becomes self sufficient.. which they could be, if only they collected royalties on the mundane uses of some of the hundreds of things that have been invented/developed by them for the space program.

*sigh*

in a perfect world...

Maeryk

it's local, folks

The research is about finding low-cost paths through the solar system, not interstellar space. The dynamics of the solar system are very well understood, and all of the important gravitating bodies are known (there isn't any significant dark matter inside the solar system, by the way). You just have to do some heavy-duty computations to take advantage of all that.

Slingshot

Interesting concept but doesnt the slingshot effect [raytheon.com] use the gravity of planets (hence zero fuel ?) for travel ? Hence a path with nett gravity pulling the body to its destination would be of more use I think. Already the cassini mission [nasa.gov] used this principle to propel the craft to saturn (since the spacecraft lacked the fuel and the engines to propel itself to saturn).

-Dracken

should be pretty easy

Sounds like an interesting concept but it is unclear how the scientists will account for every source of gravity, including the elusive dark matter.

i am sure this can be empirically figured out. send hundreds of thousands of little probes all over the solar system and track their movement. each probe only need to be a beacon w/ a solar panel so they should be make very, very light. (prefabbly something degradable so no more space trash! -- or crash all of them into jupiter later, so something).

this way you can figure out to a good degree what the gravimetric forces are within a good error margin.

p.s. there is no accepted theory on what, or where dark matters exist. frankly so far their interactions we can see is on a galaxy-level. hence their existance, or effect within something as small (ha!) as the solar system is not well understood; and since we pretty much sent all the other probes etc (say, voyager) on their routes fairly predictably, i would say contemplating about dark matter interactions within the solar system is unnecessary.

but, if you really wanted to, you could ;-)

Chaos theory itself also rules this out...

"CNN has an article about a new idea from NASA springing from chaos theory called the interplanetary superhighway."

Uh, just back up a minute there. Chaos theory also punches a massive hole in the idea which none of the articles seem to address. To be able to utilise this idea, you need to know in advance exactly where the planets will move to. Chaos theory states that this isn't possible, since you would need a tremendous amount of precision (down to inches) to be able to predict how and when all of these planets will be just right such that you are in a zero-gravity path. If you're wrong, you have to burn fuel to get onto the path, assuming you aren't too far off in the first place. After all, predicting where planets move requires a "complex iterative model", and if your starting data is even slightly out, then it will drift far away from the correct answer over time.

Each planet and moon has five locations in space called Lagrange points, where one body's gravity balances another's.

Right. So what you're saying is if I have the Earth and the Moon, there will be five points where the gravitational forces from the both of them cancel out. Uh, wouldn't there be *TWO* such points? Think about it.

Chaos theory mandates this

The point is that the earlier you know that you are off the correct path, the earlier you can correct it, the less fuel you need to spend.

Contrary to what you say, the position of the planets is known to astonishing accuracy- it's only over millions of years that they move significantly chaotically, over a few months their position is entirely known.

A small body bouncing around between them is rather different however- that can be very chaotic.

Plotting a course through the solar system is quite routinely achieved. Remember Voyager?

Uh, wouldn't there be *TWO* such points? Think about it.

Do a web search on Lagrange points, you'll find it. There's 5. One between the earth and moon, one the other side of the moon, one opposite from the moon, one 60 degrees ahead of the moon and one 60 degrees behind.

Mad buzzword attack from outer space

would be the correct title of the article.
The idea of using gravitational forces of other bodies in the solar system is neither new nor wasn't used yet.
Modern computational power allows to drag in the forces of several bodies, making better result possible, but that's hardly surprising.
And the "chaos theory" probably means that they just considered the stability of their trajectories. This is hardly very exciting. The problems of unstable trajectories should be known to any maths undergrad.

So it just boils down to the mad buzzword attack on the holy quest for more govermental funding.

Sounds like "Fuzzy Boundary" techniques.

A similar idea was proposed many years ago (and used for one of the satellites studying the moon). Do a google search for "Earth-Moon fuzzy boundary" for references to that particular application.

The idea is that you can more or less coast through regions where the competing gravitational effects of many bodies cancel out, making part of your path from point a to point b less expensive than the standard transfer orbit.

The article describes an extension of this idea.

Technical Data Here

The Genesis Mission is the technical application of this data.

Go to the website here:

http://www.genesismission.org/ [genesismission.org]

includes pictures, decent diagrams, etc.

The Layman's Translation

Scientist1: Well, it appears that there's some parts of space where there's no gravitational pull. So, if we chuck the craft along one of these paths, it will umm...
Scientist2: It will probably need less energy.
Scientist1: Right. Since it doesn't have to do any work counteracting any gravity.
Reporter: Makes sense fellas. Now, you called a press conference. What's that all about?
Scientist1: Well, that was it.
Reporter: (short pause) I see. (another longer pause - an uncomfortable silence, actually) Now, seeing as you just worked this out, how did you fly craft before then?
Scientist2: Well, gas was so cheap and all...
(Scientist2 slaps Scientist1 and NASA lose what funding they have left)

IN RELATED NEWS: Liberal Arts graduate? Want to work for the JPL? We're hiring! Call NOW!

Another overhyped article

My understanding is that the JPL come with a way to calculate gravitational effects with more precision, thus saving fuel required to correct the orbit. Hardly anything exciting, but it became the "planet freeway" in the journalist's imagination. Another uninformed, overhyped article on CNN, not to mention the "Artist's concept of interplanetary superhighway", apparently not reviewed by any knowlegeable person.

The reference to "dark matter" makes no sence to anybody ever studied general relativity. External gravitational field doesn't vary significantly in the Solar system, therefore it's irrelevant. Even if we all accelerate in the gravitational field of some dark matter, we do it uniformly.

A highway, but continually shifting off ramps

It certainly seems like as the position of the planets change, the highway itself would alter radically, closing routes entirely in certain circumstances. So, 6 month trip to Mars until February, then no (special) route until two years later.

I wonder what relationship, if any, this highway bears to the routes that Voyager and Pioneer missions took. Maybe a slingshot route is a continual HOV lane ;).

to clarify a few points...

CHAOS THEORY...

It does apply to everything, but the little bit that is applies to really big things like planets and their effect on a space craft is negligile.

SLING SHOT...

A lot of people are talking about using gravity to propel a space craft, but don't seem to understand exactly how it works. When a space craft sling shots around a planet, what happens is this. The SC is captured by the gravity of the planet. The SC begins to fall towards the planet. However, it is falling at such an angle that it will never hit the planet or a significant portion of its atmosphere and is therefore release back into space. Now, conservation of energy applies and says that the kenetic energy gained by falling towards the planet is lost when it escapes on the other side. BUT (this is the heart of how the sling shot works) the planet is orbiting the sun. When the SC begins falling towards the planet, it also gains some of the energy from the planet itself. The SC picks up a significant portion of the velocity of the planet in it's orbit around the sun. When you apply the law of gravity for 2 bodies, you will figure out that the planet actually slows down because some of its energy is given to the SC. The end result is a SC that is going much faster and it didn't have to burn any fuel.

SPACE CRAFT'S FUEL...

several people are saying that the SC doesn't need to use fuel. If we could calculate exactly where everything is in the universe, then we could do it with almost no fuel. But we can't. Also, as all the calculations are only a pretty good estimate, the SC carries enough fuel to make in flight corrections.

LAGRANGE POINTS...

There are 5 points where gravity cancels exactly.

1. directly between the earth and the moon.

2. leading both the earth and the moon. It is in orbit around both the earth and moon, but does not move realtive to them because it can't fall around both.

3. same as 2, but trailing instead of leading

4. on the opposite side of the earth from the moon

5. on the opposite of the moon from the earth.

HOWEVER, only 2 points are STABLE. Points 1,4 and 5 are unstable, points 2 and 3 are stable. If you solve the problem, you realize that points 1,4, and 5 are sources and points 2 and 3 are sinks.

Now to qualify myself. I've only had 2 astro engineering courses (taken for fun) a few years ago back in college, so if i've made any mistakes, please forgive me and correct me.

time-of-flight differences?

Does anyone have a rough estimate about the difference in time-of-flight for an object taking the "interplanetary highway" versus the old-fasioned fuel assisted "off-road" travel? I would imagine that in some cases the fuel and gravity assisted flights, while more expensive, would be able to reach its destination faster than some of the roundabout pathways of the highway.(?) Or is the travel time difference not very substantial for an interplanetary mission because the old-fasioned travel methods involved their own roundabout gravity assists from various intermediary planets along the way to its real destination?

Ceci n'est pas une Vorgon joke

In my day, we didn't have no inter-planetary sup-er high-way. We got to Triton O-45 the old fashioned way, and it was up a gravity well both ways!

Some scientists theorize that a killer asteroid traveled along the highway when it smacked into Earth and wiped out the dinosaurs 65 million years ago.

Oh my gosh! Interplanetary superhighways facilitate terrorism! Tear it down! Think of the children!

Ben Franklin's Gulf Stream Experiments?

Probably I just know too little about this to make any sense (kinda like how I couldn't understand Enron's bandwidth trading operation) but isn't this sort of like what Benjamin Franklin did with studying the Gulf Stream and other oceanic currents? Only this time, the ship makes its own current and just steers itself away from things which would slow it down. Hm. Maybe it isn't quite like that.

Maybe it is more like get launched, then just coast and steer. I kinda don't see why this is such a big deal... Wouldn't some kind of gravitational radiation antenna be able to just figure out where the gravitation is lowest?

Somehow, I don't think I'm qualified yet for the space pilot position. (Also, for some reason, probably the coast and steer part, I was thinking about Japanese pagodas, with the central stability beam and all the layers resting on each other, but not using the beam for structural support, only stability. Maybe just randomness...)

Environmental damage

Being that humans tend to overdue things, I imagine that eventually we will start stealing momentum from some of the planets to such a degree that their orbits will be noticably different, possibly throwing off orbit frequency balances [1] that have been acheived over billions of years, and asteriods in otherwise stable circular orbits will start to go wacko.

I am sure they laughed at the idea that cars and factories could ruin (alter) the Earth's atmosphere. But, we did it. Maybe it will take longer to bust Jupiter, but I woudn't put it past us. If we can harness the energy of the sun from places beyond earth, then we have the potential for *huge* population growth. The energy falling on Earth is a speck compared to all the energy potentially capturable via solar panels made from asteroid materials, etc. The raw materials are all out there and so is the energy. It is only a matter of time until we learn to combine the two.

[1] I forgot what they call that. Synchronicity? Orbit Ratio patterns? Orbital Vibration? stumpage.

Informative paper

While the CNN article is truely hyped and mostly fluff there is an informative paper here [caltech.edu].

In summary: If you find yourself in orbit around a Lagrange point you only need to change your velocity a little to change your orbit radically (thats the chaos part). The orbits you can enter in the Sun-Earth system is forming two horseshoes with the Earth placed in the gap (or perhaps more precisely: Like the figure 8 with the smallest of the loops folded within the larger one and the Earth placed in the cross between the loops). One of the orbits lies within earths orbit. The other lies outside of Earths orbit.

What makes this particular interesting is that the horseshoes of the Sun-Earth system overlaps the horseshoes of the Earth-Moon system. So, if you're travelling along one of the horseshoes in the Sun-Earth system, you can pull the trick again when you cross the horseshoe of the Earth-Moon system and enter an orbit around earth with virtually no fuel consumption. It works the other way around too: If you place a spaceship in one of the Lagrange points of the Earth-Moon system you can reach far into the solar system for almost free by entering the horseshoe of the Sun-Earth system at the right time. The only catch is that you're travelling pretty slow.

Now the CNN article talks a lot about interplanetian travel, but the reality is that the mechanics have only been worked out for the earth-moon-sun system and the Jovian system. Interplanetarian travel requires heavy computatios and is still in the works.

And to dispell some of the confusion in this thread about the nature of the Langrange points this [nasa.gov] page gives a good explanation.

Space travel for Wussies.

Oh sure, you could calculate a series of mathematically elegant trajectories that would allow spacecraft to use minimum energy to traverse the solar system by surfing along various gravipotential boundaries. Or you could build big, throbbing manly Orion rockets.

http://www.amazon.com/exec/obidos/ASIN/0805059857 [amazon.com]

http://www.islandone.org/Propulsion/ProjectOrion.h tml [islandone.org]

I personally favor building big manly throbbing Orion rockets, but that's because chaos theory makes my brain hurt and because things that explode are cool.

Fantastic announcements and boring math

This is just silly PR; but of course his colleagues say nice things, it probably helps NASA.

Another guy from JPL had a Berkeley dissertation circa 1965 on this topic; the minimum energy orbits are called Hohman transfer trajectories. They neglect the rest of the planets, but those are minor perturbations -- that's what the "tubes" are about.

There are five orbits around the Earth-moon neighborhood where the derivative vanishes, the Euler points and the Lagrange points; the forces [including momentum!] all balance out, but they aren't necessarily stable [the 60 degrees ahead/behind in the moon's orbit are, if some mass ratio condition is satisfied, cf "trojan asteroids" in Jupiter's orbit].

The guy may know something, but NASA is a big organization, and the press release writers in any such were typically English majors. The chaos theory angle is largely bullshit [but heaven forbid I should utterly squelch young spirits, as one of my professors used to say:]

If this leads someone to learn the math, great, but it's really a crock (tm).

Dark Matter? feh.

I never much liked the theory of dark matter. "Our calculations indicate a bunch of stuff we don't observe...must be invisible stuff." Uh, yeah. It's the ether, guys, and planets spontaneously generate from it.

Seriously, though, when a calculation doesn't match up with oberservable fact, you're supposed to adjust the calculations (chaos theory, heisenberg, quantum mechanics), not invent something. And there's a theory right now, explained in the latest scientific american (you ARE a subscriber, right? If not, drop the $35 per year, it makes you a better person), that does just that -- adjusts gravitational constants unchanged since Newton's days when matter moves very quickly. I kind of like it...it makes more sense to me than this "hey, 95% of the galaxy is invisible and undetectable and that's why things spin in wierd directions!" crap.

Dark Matter. Feh. In another 70 years it'll rank with phrenology, dowsing and psychoanalysis.

Maps and methods

Sounds like an interesting concept but it is unclear how the scientists will account for every source of gravity, including the elusive dark matter."

They won't. They'll do the astrogational equivalent of firing a shotgun out in front of the ship, waiting a week and seeing which particles have had their trajectories distored most severely.

Those that don't get pulled off course met the least accelleration due to gravity and friction.
(Transverse redshift, blah blah blah.)

Problem solved.

(Jeez, people. Computers aren't always the best solution. Get out from behind your desks, once in a...

Right. Slashdot. Got it.)

Wait a minute

I thought Al Gore invented the interplanetary superhighway?

More thoughts on the topic

Absolutely fascinating work by Martin Lo. If highway coordinates are publicized this might be the best place for spaceguard and amateur asteroid searchers to look. Currently amateurs are discovering asteroids very frequently.

I also wonder if this implies a similar superhighway among the stars which could determine where a stream of matter might be coming over the millenia from outside the solar system. (i.e. where are the off-ramps to our solar system?)

The interview [genesismission.org] with Lo is much more interesting; he believes we are on a cusp of where advanced theoretical mathematics is going to inform a new generation of engineering.

I would like to understand the math better, specifically to see if it might have applications to software. I'd also like to plot the superhighway, or understand how they are doing it. But only have a year of college math. Where is a good and free place to learn about it online? Been to Mathematica.

Old Hat

This has already been done before -- see the section on "CHAOS, ORBITAL DYNAMICS, AND FUZZY BOUNDARIES" on this page [bway.net]. I know it was detailed in Scientific American back in the mid/late 90's.

Options: Optimize Fuel, Time, Locations

This kind of thing should have been identified long ago. Not knowing that, I'm sure that it was, for some reasons.

1, NASA uses all kinds of math to plot orbits and trajectories. If you look at the math long enough, it can only naturally occur to you to find "paths" through space for various criteria: fuel, time, locations. Unfortunately, the question most implied by default is "What is the minimum time path?", since Mission Control is not a generational job.

2, NASA already knows about certain types of paths that are unconventional. One particular one that I recall has a spacecraft whipped at the moon; the craft has a close encounter with the Moon (pun: the Moon is grey); it ends up making a relatively huge ellipse away from the Earth-Moon system; and finally the craft comes back to Luna and makes a puny insertion burn to orbit. Total fuel cost is lower than just doing the Apollo route; but you traded time and Lunar inertia for it.

The "interplanetary superhighways" thing is the usual type of innovation that in retrospect was a no-brainer. If I had spent time plotting orbits and trajectories for various spacecraft, I would have seen that set of solutions soon enough. But will the politics and optimizations of spacecraft launches and travel allow these solutions to be used, much less become more public? For example, just think on how cheap in fuel terms it will be to send out probes on solar sails; with fuel being free and stored off-craft, more cheapness arises in the double-increase of spacecraft mass, getting more done for the money. (I say double-increase due to no main propulsion, which opens mass for instruments, and "infinite" fuel, which means you can make the craft about as heavy as you want (limited by sail size, 'course).) Sail-driven craft will take a bit of time to get where they are going in the Outer System; instead, we chose what are essentially launched and boosted billard balls for those jobs.

Re:I want my fund

Just confused, whats a History of Xanth got to do with the IP super H/way???