7 ms·
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 fas
by sxp 6y ago
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]
[1] http://www.projectrho.com/public_html/rocket/torchships.php http://www.projectrho.com/public_html/rocket/torchships.php
[2] https://www.youtube.com/watch?v=oDR4AHYRmlk https://www.youtube.com/watch?v=oDR4AHYRmlk
[3] See the Impulse vs Brachistochrone table at http://www.projectrho.com/public_html/rocket/appmissiontable.php http://www.projectrho.com/public_html/rocket/appmissiontable...
- xwdv 6y agoWe can reach Mars in a couple months. Beyond that, the only further places I could imagine humans wanting to go is Europa or Titan, maybe Ceres.
- warent 6y agoIn a couple months like, what, once every 10 years or something when it's closest to earth? Otherwise iirc it takes much longer
- paledot 6y agoOnly 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.
- FlyMoreRockets 6y agoThere are lots of gravitationally attractive resoures scattered throughout the asteroid belt.
- aquova 6y agoTo put that into perspective, it took Voyager 2 8.5 years to reach Uranus, and 12 years to reach Neptune.
- yborg 6y agoThat 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.
- ummonk 6y agoDude Hohmann transfer to Mars is less than a year.
- sitkack 6y agoWho is "Dude Hohmann" ?
- inetknght 6y agohttps://en.wikipedia.org/wiki/Hohmann_transfer_orbit https://en.wikipedia.org/wiki/Hohmann_transfer_orbit
- s_gourichon 6y agoDude, Hohmann...
- jagger27 6y agoI think “trade winds” is better analogy than “super highway”.
- chrisweekly 6y agoYes, by far! And to extend it, we're at the "canoes" (or maybe "swimming and surfing") stage regarding our technology for exploring those horizons.
- weego 6y agoFeels more like we threw someone in and watched to see if they could doggy paddle back.
- ben_w 6y agoFor 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]). [0] http://www.wolframalpha.com/input/?i=Distance%20to%20Uranus%2FDistance%20to%20moon http://www.wolframalpha.com/input/?i=Distance%20to%20Uranus%... [1] https://goo.gl/maps/rvV5cXeb8i8xbVwr9 https://goo.gl/maps/rvV5cXeb8i8xbVwr9
- dmos62 6y agoReally 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.
- hinkley 6y agoIs 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.
- dmitrygr 6y ago> 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.
- dragonwriter 6y ago> You cannot just slow down. If you engineer to survive it, aero- and even litho-braking are alternatives where you can “just” slow down, without using onboard reaction mass.
- Zanni 6y agoThank 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).
- JPLeRouzic 6y agoIsn't what a plane is doing while landing on the airstrip?
- JPLeRouzic 6y agoSo in the worst case the average speed is half of the maximum speed. Still something attractive.
- moonbug 6y ago[3] It's called the moon, not Luna.
- DavidSJ 6y agoIn-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. And good luck getting back.
- GoblinSlayer 6y agoAll this hype about automation, but we still want to launch meat into the space.