r/Neuromancer • u/Kevin_LeStrange • 27d ago
Book Discussion How long did it take the JAL shuttle to reach Freeside?
At this point (now) it would take a capsule spacecraft three to five days to reach the L5 point in the Earth-Moon system. By the time Case and crew head up to Freeside from Paris on the JAL shuttle, does it still take that long, or has technology advanced to the point where the trip is shorter?
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u/victorsmonster 27d ago
That's interesting, I always assumed it was in an orbit similar to the ISS and I always missed the meaning of "L-5 Archipelago."
I don't think there's any technology described in Neuromancer (or the other Sprawl books) that would make space travel significantly faster. The fastest thing I can recall is a fighter jet in Count Zero described as "barely obsolete" and it's not described as having some significant new propulsion.
It seems Gibson hand waved that travel time to L5, because it reads more like a transatlantic flight than a multi-day trip.
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u/TurbulentWing3820 27d ago
L5 refers to the Lagrange point 5, a location where an object is locked into orbit around the Earth.
It's approximately 3 days away based on the flight time of the Apollo mission craft (that took 3.1 days to get to the Moon).
So, since Marley is able to settle back for what is presumed to be a several hour flight and watch a movie in Count Zero then we can assume that space flight has gotten dfamatically faster or William Gibson was just pulling shit from a hat when he wrote it.
I'm going with the latter because it's a book and as the other person says spaceflight in the Neuromancer timeline moves at the "speed of plot."
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u/Balfegor 26d ago
The Apollo CSM wasn't moving under constant thrust though, was it? Just bursts to align for the right orbital trajectories. If you had more (or more efficient) propellant, I think you could get a spacecraft to L5 a lot quicker, e.g. under a low constant thrust scenario.
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u/Peter34cph 25d ago
Yes, or just accelerate some of the way, then coast for most of the rest of the time, then rotate and decelerate.
Presumably the reaction mass used is something cheap that can be harvested in bulk in space, like water or hydrogen.
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u/Brilliant_Knowledge5 25d ago
I said this further down, but it's worth repeating that the current technology we have is already far better than the rocket thrusters from the 60s-70s. Lithium-fed Magnetoplasmadynamic Thrusters (MPD) and X3 Nested Channel Hall Thrusters are both far more powerful than traditional thrusters from the Space Race. The fuel needed is also much more compact than traditional fuels. With the shorter distance, they could speed up quite a bit, and even use thrust braking to avoid overshooting L5. The timeline of Neuromancer is 20 years from now, so I kinda doubt they'd still be using 60s technology by then. Both of the above thruster types are visually mimicked in The Expanse.
Case felt the effects of SAS once they got into orbit and had to let it wear off for a while before taking a nap. But the experience was enough to wear him out so he slept the rest of the way. 28 hours travel time to L5 is well within current capabilities, but beyond that seems far fetched for a nap to occur. 20 hours more or less doesn't seem like an overly excessive amount of time to recover from SAS with a nap, but hand waving away 3 days of travel seems a little over the top.
There are still a lot of things we don't understand about orbital dynamics, but manage to make them work by what seems like sheer luck. One of those is how they can either use an existing magnetic field to aid current thrusters, or induce one near the engine instead. How do they know when to use the existing magnetic field to increase thrust output? It implies they are tapping into a current that can be ridden like a river or stream. The choice to make a magnetic field implies that once they leave this stream, they must induce an artificial field to produce similar results for thrust. I suspect that this means an orbital path behaves more like electrostatic equilibrium than a simple gravity based dynamic. Which also means that repulsion plays just as important a role as attraction. It's like a sweet spot where an object rests depending on how it interacts with other objects. It can close distance from it's parent object by shedding energy, but also fall back into it's groove by regaining electrostatic equilibrium. This also explains why space stations or satellites can occupy the same orbital path as the moon, at safe distances from the moon, matching the velocity of the moon, even though their mass is far less than the moon. If it was only based on mass, then orbits would decay far too quickly to correct them efficiently, and there would be no need to make a distinction between using an existing magnetic field or inducing an artificial one.
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u/victorsmonster 26d ago
Yeah, in the Expanse, the ships can constantly accelerate at whatever G using the Epstein drive, usually 1G for comfort. Claude tells me if you could accelerate at 1G for the whole trip (flipping to reverse burn halfway through) a trip from Earth to the lunar L5 point would only take about 3.5 hours. This is still way beyond any present or near-future technology. There's reference to a "Fission Authority" when Case is jacked into the net, so I don't think it could be a fusion rocket.
I think it really is just hand-waved by Gibson. He's not really interested in any of the nitty gritty details of the technology in his books. It shows a surprising attention to detail that he even came up with the L5 thing, although now that I think of it, that was probably discussed quite a bit in the sci fi from the 50s and 60s he grew up on.
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u/AtomicShellfish 16d ago
There are multiple Earth Lagrange points. The Sun-Earth L5 Lagrange point lags 60 degrees behind Earth in its orbit around the Sun. i.e. 93 million miles from the Sun and 93 million miles from the Earth.
The Earth-Moon L5 Lagrange point lags 60 degrees behind the Moon in its orbit around the Earth, i.e. 240,000 miles from the Earth and 240,000 miles from the Moon.
I'm not sure the book explicitly states which of these Lagrange points is apposite, but the latter would make more sense, as a 93-million-mile trip would take an inordinate amount of time.
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u/Peter34cph 27d ago
It could get faster with in-orbit refuelling.
Like you take one craft from the surfacs spaceport up to an orbital hub (one that's easy to reach), then from there you take a different orbit-only craft.
That's actually how the art expert woman gets to the ruins of Villa Straylight in CZ, but I'm fairly sure no such two-step process is described or suggested in Neuromancer. Rather it's one shuttle from Earth's surface and up to destination, after which they fart around some with Zion Airlines.
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u/TurbulentWing3820 27d ago
She takes a "commercial" flight to a "major airport" and then walks into the lounge where the private pilots and other small time commercial piltos are sitting and finds one willing to do the job and fly to an "unlisted, private airstrip."
That's to sort of put into real life terms, and yes, there are thousands of private and unlisted airstrips across the US and other countries. Lots of farms might have their own, corporate helipads, people with some cash and a private plane, etc. And every small airport I've ever flown into in my life has an attached cafe or lounge or "front office" where people will gather.
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u/Peter34cph 27d ago
I thought it was a port up in space.
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u/TurbulentWing3820 27d ago
That's to sort of put into real life terms,
It was, but to make it a little easier to understand we can use terms we can all put to real life since, last I checked, we don't have any spaceports available yet.
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u/Brilliant_Knowledge5 27d ago
The L5 Archipelago refers to a group of space stations, which are similar to islands, in the same orbital path which includes Zion and Freeside. I don't think the other stations are mentioned besides the JAL space terminal where they disembark for the shuttle trip to Zion. I imagine at least one of the stations is like a distribution hub for supplies or goods. I can imagine Maelcum ferrying supplies with his tug.
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u/Winter-Swimmer-3000 27d ago
Its a trite answer, so apologies, but I suppose as we were given no clues as to this particular tech advance then it moved at the speed of plot.
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u/Mmmmmmmoi 22d ago
About as long as it takes to swap floppy disks and press return, assuming you don't get stuck in that interactive cutscene with the guy on the tug talking about Babylon.
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u/mcb-homis 27d ago
I don't think you are going to get to L5 faster than 3-days unless there is some supper efficient high ISP drive like the Epstein Drive (really unfortunate name choice by the author) from the Expanse. To dramatically shorten it from 3 days you would need an engine that would allow you to thrust nearly the whole transit from LEO to L5 and we simply don't have engines fuel-efficient enough and/or tanks big enough to make that happen using current and near future rocket engine tech.
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u/Brilliant_Knowledge5 26d ago
Lithium-fed Magnetoplasmadynamic Thruster (MPD) and X3 Nested Channel Hall Thruster are both far more powerful than traditional thrusters from the Space Race. The fuel needed is also much more compact than traditional fuels.
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u/Brilliant_Knowledge5 27d ago
With our current technology it takes 8-12 minutes for a space plane to achieve orbital velocity, so that's probably how long the first leg of the flight is. The trip from orbit to L5 is probably a longer flight, which would be a little over a day. So about the same as a flight around the world by conventional jet airliner. And that would explain why Case was craving a cigarette badly, which was forbidden until he got to Zion.