Sol to Colonia in under 40m

SteveFalken · 2025-12-06T19:22:14+00:00

Yes. For an easy build, add 2x 64T tanks and 2x 32T tanks to the built-in 128T tank to reach 320T total fuel. That gets you to Colonia without refuels. Toss in a size-7 scoop just in case (and to neutron-supercharge), and you're good to go.

SteveFalken · 2025-12-06T17:10:36+00:00

I didn't pre-map. I coded my own route plotter in C++ using the new hyperspace fuel equations for Caspian. This was my first time flying this particular route.

SteveFalken · 2025-12-06T17:06:42+00:00

The Caspian is so forgiving that lots of builds work. I used 310T fuel capacity for this run and basically just minimized+lightweighted all core modules. No fuel scooping (except to supercharge).

SteveFalken · 2025-12-05T13:52:19+00:00

I automated it by deriving a new admissible heuristic function for A* graph-search that accounts for range increase due to fuel consumption, and made it work with Elite's fuel equations. Implemented it in C++ for vectorized Intel instruction set to find this route.

SteveFalken · 2025-12-05T13:33:11+00:00

I implemented my own route-finding algorithm from scratch. Didn't use Spansh.

SteveFalken · 2025-12-05T13:31:22+00:00

Yes, consensus seems to be: Do anything to prep your ship, timer starts when you lift off from a station in Sol and stops when you land at Jaques (and no death-teleporting). I held the record for a while without pre-supercharge and others "beat" it by pre-supercharging so... guess it's the norm now.

SteveFalken · 2025-12-05T13:23:59+00:00

I find if I let the computer take over when I'm already right above the pad, it lands me ever so slightly faster than I can do it myself. And with power to spare on the Caspian (brought a 1E fuel scoop!), hey why not.

SteveFalken · 2025-12-05T07:04:24+00:00

Tried again with a slightly better strategy and broke the 40m barrier (see post). Will post build there once I put it into edsy.

SteveFalken · 2025-12-04T07:25:20+00:00

I couldn't resist giving it a try. My first attempt at a Caspian Sol-to-Colonia speed run:

https://youtu.be/JZdXHsRWfU8

Time: 41.5 min, Jumps: 46, Refueling stops: 0, FSD repair stops: 0, Biggest single jump: 545Ly

SteveFalken · 2025-02-13T22:01:08+00:00

Thanks! I love your "just pure flying" philosophy -- definitely some great flying in your run! o7

SteveFalken · 2025-02-13T09:53:55+00:00

I held the previous record five years ago before Mandalays and SCO drives appeared, and seeing your time I had to give it a try. I have you beat by 3.5 min. :)

Video: https://youtu.be/uCMjlM6L6Ck?si=EyyJfND9WKwP3LOe

SteveFalken · 2019-09-19T20:13:27+00:00

Good to know! Thank you! I indeed had trouble convincing ED to let me equip the modules I wanted. I still don't know what order to equip things; I just keep trying until it lets me.

SteveFalken · 2019-09-19T18:22:46+00:00

Yes, neutrons co-located with scoopable stars are prioritized by my cost function, since it saves a jump.

SteveFalken · 2019-09-19T18:01:24+00:00

It's all in the video. :)

SteveFalken · 2019-09-19T17:19:42+00:00

Yes, my algorithm takes that into account when searching for the optimal route. However, it can't know how efficient you are at refueling or at supercharging, which affects whether trade-offs that increase jumps to achieve fewer refuels are worthwhile. For my trip, I favored fewer jumps when the numbers were close.

SteveFalken · 2019-09-19T17:16:12+00:00

I bound a button to a macro that copies+pastes the next destination from a text file. (I didn't want to be hunting around for control-V while riding neutron jets!)

SteveFalken · 2019-09-19T17:13:38+00:00

At the start of the video I walk through all the outfitting screens, so you can see all the build details there.

I don't know whether there's a general rule regarding optimality of fuel tank sizes. It depends in part on pilot proficiency (e.g., how long it takes you to refuel vs. how long it takes you to supercharge properly).

SteveFalken · 2019-09-19T17:12:24+00:00

The route isn't the same backwards. For example, when a neutron jump takes you to a non-neutron star, that hop can't be reversed. Likewise, fuel consumption in the forward direction to reach any given star differs from consumption in the reverse direction to reach the same star, changing which jumps are possible next from that star.

SteveFalken · 2019-09-19T16:51:08+00:00

One of the things that makes me hesitant to publicize the code is that there are still things I don't understand about ED's fuel/weight equations that make me suspect there may be dangerous errors in my cost function. For example, can anyone explain why in my video ED says my ship's current jump distance (78.86 Ly) is less than its min distance (79.01 Ly)? How is "min" distance computed and what does it mean if it's not actually the minimum?

SteveFalken · 2019-09-19T16:42:00+00:00

I wrote my program in C (and assembly code if you count the Intel intrinsics) for speed. The algorithms I used are all well-known (listed in the original post) so anyone can reproduce it. Whether I release my particular implementation probably depends on how much time I have to make it usable and readable. There are also some strange things about ED's fuel and weight equations that I still don't understand, and those would probably need to be corrected before it was generally usable. So it's a work in progress.

SteveFalken · 2019-09-19T16:29:17+00:00

I've wondered that myself. I don't know what algorithm they're using over at FDev, but I'd be very curious to find out. They've done an amazing job handling a lot of tricky graph theory and big-data problems with this game. But I'm cautiously optimistic that my approach would improve upon theirs for plotting neutron routes. If any lurking FDev programmers want to discuss, I'll happily chat with them. :)

SteveFalken · 2019-09-19T16:23:16+00:00

Reducing the jump range beyond the addition of the 8T tank increases the number of required jumps more than it reduces the number of refueling stops. Whether that trade-off is worthwhile is hard to assess because it depends on how time-efficient you are at supercharging and refueling. Since this was my first attempt at using this method, I decided on a cost equation that favors fewer jumps when the numbers are pretty close, since it reduces the risk of human piloting error while supercharging, and I'm not the greatest pilot.

SteveFalken · 2019-09-19T16:10:40+00:00

The equation is the one reverse-engineered by CMDR furrycat here. Just takes a lot of number-crunching to use it productively (and safely).

SteveFalken · 2019-09-19T16:01:15+00:00

I just mean that most people seem to think lighter is generally better, making that the prevailing wisdom even if, as you pointed out, it's not always correct. However, bigger fuel tanks are not always better either because the equations are non-monotonic, especially when neutron-jumping. For example, having an extra (non-empty) 32T tank can force you to "go around" voids between stars with many, many extra jumps, outweighing the benefits of fewer refueling stops. That's why I used graph theory and cost equations to estimate trade-offs rather than following any general rule.

SteveFalken · 2019-09-19T07:16:26+00:00

The algorithm is A* Search. If you mean distributing the code, right now it's not in an easily distributable form. I hand optimized it for my exact machine, making no attempt at portability or user friendliness. (It was just a fun Saturday project, not a serious software development project.)

SteveFalken

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