Note that "fast" is a relative term in this case. E.g, "On average, these particles reached Uranus and Neptune 38 and 46 years later, respectively, with the fastest reaching Neptune in under a decade."
It's more accurate to say that these are "cheap" paths rather than fast ones since the primary saving will be fuel. These paths will be too slow for humans to use and any dramatic improvement in human travel through the solar system will require a technological breakthrough like a high-powered torch drive [1] or laser-powered solar sails [2]. Otherwise, we'll still be stuck with multi-year trips to anything beyond Luna [3]
For interplanetary, I think it’s more like we looked at some flotsam in the water spinning around and wondered if we could make a canoe based on that principle get to the next island, having only just tippy-toed into the water up to our ankles just to prove it wasn’t immediately lethal.
(Scale difference: Uranus is 7800 times further than the moon [0], so if wading to ankle depth is 1m from the shore, then the metaphorical island is 7.8 km away — pretty close of the distance between the closest parts of Portsmouth and the Isle of Wight [1]).
Really enjoyed these water and swimming analogies, but I think air and flying analogies would be better, since it's just so damn hard to fly. You see the birds and dream, but to actually take off takes something else, and even then we stay relatively close to the ground (within our atmosphere). From someone who's not seen an airplane, to then keep going into the stars is pretty crazy. There's a saying that to become enlightened you have to be willing to fall upwards. I think there's an ingredient of that in exploring new frontiers.
I came here to complain that the headline is a rickroll. Not all their fault, though ... as they say, the researchers called it "a true celestial autobahn" (bottom of abstract). The article's title? "The arches of chaos in the Solar System". le sigh
That was thanks to a full "Grand Tour" alignment of the outer planets that allowed gravity slingshots at each destination. This unfortunately only lines up once every 175 years.
In-situ resource utilization to mine propellant from the Moon and near-Earth asteroids could bring a dramatic improvement in ∆v budget (and hence travel time), using only conventional rocket propulsion.
If you think about it, your car wouldn't get very far either without being able to refuel. If you wanted to travel across the country, the fuel tank would have to be dramatically larger, and then you'd have something very much like the rocket equation's exponential mass to ∆v relationship (except here it would be mass to distance traveled) as you have to carry more fuel just because the other fuel is weighing you down. As a result, eventually your fuel tank would be close to the entire mass of your car, and you might actually even require a two-stage vehicle, with your car detaching from a large tanker halfway across the country to finish the trip.
Is that entirely true though? Many of our highest impulse engines have fewer problems with the tyranny of the rocket equation, but also have low thrust. The beginnings of trips are going to be slow even if the end is not.
Using these paths for the beginning and end of journeys may make a lot of sense, even if they make no sense at all in the middle.
> The beginnings of trips are going to be slow even if the end is not.
Endings too. You cannot just slow down. No brakes in space. And if your engine is low thrust, you'll need a while to slow down too, unless your goal is kinetic impact unto your target.
Thank you for introducing me to "lithobraking." What a wonderful euphemism for "crashing into the planet" (albeit a controlled crash, or, as you say, engineered for survival).
Only 26 months in the Earth/Mars system, in fact. And that's still the fastest way to go, which is the only thing that's relevant for crewed spaceflight. Doesn't matter how much you're saving on gas if you still need to bring enough snacks for the drive.
I was under the impression that this was common knowledge among the astrophysicist set, going back, well, according to Wikipedia, to the 1890s when Poincare figured out you could do zero-energy orbit transfers[0].
I suppose the novelty here is that someone identified a subset of 'fast' paths along the Interplanetary Transport Network.
Bingo. This is a classic case of pop science misunderstanding half of a paper and sensationalizing the other half.
> This network can transport objects from Jupiter to Neptune in a matter of decades, rather than the much longer timescales, on the order of hundreds of thousands to millions of years, normally found in the Solar System.
By "objects" they mean asteroids and particles. "A matter of decades" is still a ridiculously long time by human spaceflight standards.
> "A matter of decades" is still a ridiculously long time by human spaceflight standards.
That's true when you are just exploring. When you start more long term projects, such as colonization, things are different.
Say you want to colonize something that is 30 years away using the cheap but slow network. What you do is 30 years before you want to start the colony you start sending regular loads of supplies via the slow cheap network.
Once those are near starting to arrive at the destination, you send your colonists the expensive but fast way.
You can also do this to speed up exploration. Suppose we know we are going to want to send a manned exploration mission to someplace eventually, but we've got other more important targets to occupy us for the next few decades.
Send fuel and other supplies to that place by the cheap and slow method. Then when it finally comes time to send a round trip manned mission, you only need to include enough fuel and other supplies for a one way trip. They can use the fuel and supplies that were sent the slow way for their return trip.
This way your exploration rockets only need to carry half the mass of fuel and supplies that they would otherwise need. This will allow higher acceleration and thus shorter travel time.
That only works when only a couple of governments are involved. Once (big if!) it becomes a free for all there is risk that you will send supplies and someone else will use them. Or maybe they just charge a ransom before you can get at your supplies - just send a robot out to where those supplies are going, "hide them", and ???. There are too many risks to trust that someone doesn't think of this.
I hope the rocket scientists are not caught as off guard as us computer people have been by ransomware and the like (note that viruses have been doing evil things for over 30 year and we still don't have a handle on it)
I love the way you think, but I suspect mastering the tyranny of the rocket equation is a lower hurdle than mastering the tyranny of small-minded governments. By the time humans are willing to commit sufficiently to colonization to send substantial amounts of supplies decades in advance of a planned colony or crewed exploration missing, nuclear or ion or quantum vacuum or Alcubierre drives will have rendered chemical propulsion and its associated problems obsolete.
If a one way trip takes X amount of fuel and supplies (let's assume it is the same for an outgoing one way trip and an incoming one way trip, for simplicity), then a two way trip has to carry an extra X outgoing to use for the return trip.
Since X is going to be many times the mass of the ship and crew and non-consumables, having an extra X as cargo massively ups the fuel requirements for the outgoing trip.
Gravitational "sweet spots" (label mine) produce orbital tracks that cause movement of things in the solar system in decades instead of centuries or millennia.
I want to point out and give a shout-out to Belgrade Observatory and their team.
These people work without huge telescopes or excessive equipment and we should celebrate major contributions when they come from smaller teams like this.
"Supreme Chancellor, delegates of the Senate. A tragedy has occurred. It started right here with the taxation of the trade routes, and has engulfed our entire planet in the oppression of the Trade Federation."
It's more accurate to say that these are "cheap" paths rather than fast ones since the primary saving will be fuel. These paths will be too slow for humans to use and any dramatic improvement in human travel through the solar system will require a technological breakthrough like a high-powered torch drive [1] or laser-powered solar sails [2]. Otherwise, we'll still be stuck with multi-year trips to anything beyond Luna [3]
[1] http://www.projectrho.com/public_html/rocket/torchships.php
[2] https://www.youtube.com/watch?v=oDR4AHYRmlk
[3] See the Impulse vs Brachistochrone table at http://www.projectrho.com/public_html/rocket/appmissiontable...