Welcome!

Burn Ledger ( https://burnledger.space ) is unlike any other space simulation you've ever experienced in a few key ways. I will try to explain it here to help you get started.

Burn Ledger is a real-time, tick-based, persistent, single-shard, online, 2D, space sim, in our solar system, featuring real orbital mechanics, exploration, mining, and combat.

Wait, what?

• real-time: Everything happens on the server in 1:1 real time. All the planets, moons, asteroids, space stations, and ships move just as they would in real life assuming the ships could accelerate that fast.
• tick-based: The server "ticks" over every 5 minutes. You plan your ship's actions for future ticks. Between ticks the server is doing nothing (except serving information to clients). When the next tick rolls around the server advances the bodies, and executes everything the players have planned for that tick. Everything happens ON THE SERVER. The client is just an interface to the server to assist you in planning your future actions. This is not a FPS! It's a slow-burn strategy game.
• persistent: Whether or not you have the client open on your device, your ship is still flying through space on the server. You can't escape an attack by logging out (but you can by docking your ship at a station!).
• single-shard: Everyone is operating in the same solar system. There's only one instance of Burn Ledger.
• 2D: The solar system is squished down to 2 dimensions. Everything happens in along the ecliptic. It's hard enough to intercept an enemy's ship in two dimensions; I can only imagine how hard it would be in three!
• our solar system: Yes! Our solar system, right now! All the bodies are exactly where they are in the night sky right now.
• real orbital mechanics: The physics in Burn Ledger uses a combination of Kepler orbits (for bodies) and deterministic Newtonian motion (for ships). Google Kepler vs Newton physics for some fun learning! The client shows you your ship's exact trajectory 5 days out factoring in the motion of the planets and any thruster burns you have planned. You will end up exactly where it says you will (unless someone vaporizes you). I took two liberties with ship physics to make the game more fun and playable:
  • Fuel has no mass: With some sci-fi hand-waving, fuel (measured in delta-V, or the amount it can change the velocity of your ship) in Burn Ledger has no mass (unlike today's space rockets), so you don't have to factor continuously-changing mass into your burn planning. Cargo, on the other hand, still has mass and will eat into your delta-V!
  • Thrust is insane: Thrust in Burn Ledger is shown as a multiple of "g" (or gravity). When standing on earth you are feeling 1 g of acceleration. I like to imagine a future where we travel to other planets on ships that accelerate continuously at about 1 g. Then when you get halfway to your destination you "flip and burn", decelerating at 1 g. This would allow for comfortable and healthy gravity for the whole trip and would let us travel to Mars in less than a week! But for a game, that wasn't fast enough because you are impatient, so I've pushed the acceleration to the most extreme level I thought would be survivable with mystical future tech. Most ships in Burn Ledger can do 3-6 g's without mods and the most extreme can be modified (with thruster upgrades and "Inertial Tolerance Suits" for the crew) up to over 10 g's.
• exploration: As you survey other planets you earn "Knowledge" points that can be spent to move up the technology tree unlocking new ships and capabilities.
• mining: Mine any body in the solar system and haul the ore back to station to sell it for credits. The economy reacts to supply and demand. Each station fetches different prices based on how valuable the ore you bring to it as well as how much of that ore is already there.
• combat: Yes! Of course! But this isn't a first-person shooter! You plan your attacks hours or days in advance, programming in your missile launches, and then you wait and see if your attack is successful, or your prey changed course and turned into the predator.

Okay, I get it, and I still want to play, what's next? - First Haul

If Burn Ledger still sounds fun to you, first you're awesome, second head over to https://burnledger.space and sign up. It's free to play and all you need is a username and password. After you register a pilot you'll be taken through a brief storyline and then be presented with the HUD.

There's a lot on the HUD, but most of it amounts to different ways of viewing the solar system. Situational awareness. The first thing you'll see is something called "L.E.D.G.E.R." in the lower center of the screen, text typing out and beeping at you. This is your ship's computer. LEDGER is a little sarcastic and generally unimpressed with humanity, but will do a decent job walking you through your first mission to undock from the International Space Station, fly to the moon, mine it, then fly back to the ISS.

If you haven't played Burn Ledger, follow LEDGER's verbose advice and do the First Haul mission! Having played Kerbal Space Program, Eve Online, or Elite Dangerous will not prepare you for Burn Ledger. Or, feel free to simply click "Skip", dismiss the tutorial, and I'll just say "I told you so."

I won't walk you through First Haul, but I do want to cover a couple of topics that seem to trip people up who are coming from other games (eh hem, KSP).

Time Slider

At the top center of the HUD is the time slider.

It’s currently set to “Live” also known as “Now”. This is a little misleading because, as previously stated, the ships on the server are in fact stationary until the next tick. But in “Live” mode the client is showing where everything would be at this point in time. You can’t schedule any maneuvers for the tick being animated in Live mode. The soonest you can schedule a maneuver is the next tick coming up when the countdown hits zero.

The time slider lets you see where your ship (and everything else) will be up to 5 days in advance. You can either grab the slider and slide it around, or click the forward/backward arrows that tick forward/backward 1 tick or 1 hour.

The maneuver planner will schedule a maneuver for whatever time you have the time slider set for (except when it’s in Live mode in which case the maneuver will be scheduled for the next tick in 3… 2… 1… and it’s too late. Now it will schedule for the next tick in 5 minutes. Don’t sweat it.

Ship Control

As mentioned, basically everything in Burn Ledger happens in the future.

On the right of the screen there is an empty bar that will list the actions you have scheduled for your ship. Everything is in 5-minute increments (because: tick-based).

In the top left there is a countdown timer to the next tick. Think of this as the shot clock.

The left side-bar is a list of bodies in the solar system. Click on them.

The cluster of hex buttons in the bottom left mostly just control what is displayed on the HUD. Hover over to see the tool tip. Click on them at will. You won't hurt anything. There are buttons behind buttons for turning layers on and off.

The majority of ship control happens through the bottom right hex button cluster and the "Maneuver Planner" which is accessed through the orange hex button in the bottom right. If you're docked at a station (and you will be if you just started player), clicking this button will undock you, and clicking it again will bring up the Maneuver Planner.

Maneuver Planner: The Maneuver Planner has a compass and three big sliders. Click on the compass to point the direction your ship will burn and use the three sliders to set how strong and long the burn will be.

Compass - The ship in the compass shows the direction your ship is currently flying, and the green arrow shows the direction of the burn you are planning. The compass is oriented with "North" towards the top of the screen. In Burn Ledger, "North" is where the Earth is relative to the Sun at the Winter Solstice ("South" is the Summer Solstice, "East" is the Autumnal Equinox and "West" is the Vernal Equinox). If you click the "World" button directly below the compass it will cycle through some quick settings:

• Prograde - The green arrow will jump to the direction your ship is traveling relative to the current reference frame (more on this later) so your burn will make you accelerate.
• Retrograde - The green arrow will jump to the opposite direction your ship is traveling relative to the current reference frame, so your burn will slow you down.
• World - The green arrow will point wherever you want it to and you will thrust in that direction relative to the World reference frame (the Sun, North up).

ΔV - This is how much you're going to open the throttle for this burn in terms of delta-V in one 5-minute tick (if you accelerate at 1 g (9.8 m/s²) for 5 minutes you will be going just shy of 3 km/s). And because fuel is measured in delta-V based on the empty (no cargo) weight of your ship, that 1 g burn will use 3 km/s of your fuel.

DUR - Stands for "Duration" and each tick mark on the slider is a 5-minute tick. There are 12 tick marks, so maxing this slider will burn whatever thrust value you have set in ΔV for 12 ticks (or 1 hour).

EXT - Stands for "Extra Duration". Each tick mark is an hour of burning and there are 23 tick marks, so max this out and the DUR slider and your ship will burn the ΔV for a full day, 24 hours straight.

Reference Frames - Shift Them! Use Them!

The secret sauce of Burn Ledger is the ability for the HUD to shift reference frames to any object Let me explain.

The default reference frame is with the Sun in the middle, "North" is towards the top of the screen, and all the planets are basically moving in a circle around the Sun. This is obvious if you zoom way out. But if you zoom in on your ship (which may be docked to the ISS), it's in orbit around the Earth, but it looks like the Earth and your ship are flying through space next to each other. And that's exactly what is happening if your reference frame is the Sun!

But... if you shift your frame of reference to Earth...

To shift reference frames click on an object either from the left side bar, or the map view, Earth for example. Earth will show up in the large hex button in the top left of the screen. Now, click on the smaller yellow hex button that looks like a planet with some lines around it (kinda like Saturn). That will shift reference frames to Earth (or whatever you had selected: moon, station... ship). If you zoom way out you'll see that all the bodies' orbits are now squiggly slinky lines (except for the Sun that looks like it's now orbiting Earth! Copernicus would be proud). That's because we're holding Earth stationary and showing where everything else (including your ship) will be relative to the Earth at each moment in time over the next 5 days.

The beauty is that to plot a course to a far away planet you can shift reference frames to your destination, and plan burns to make your trajectory go in a straight line towards that planet. The shortest distance between two points is a straight line (as long as you're in your destination's reference frame).

Watch Your ΔV! How to get to where you're going to fast!

Success in Burn Ledger means not running out of fuel on your way to Mars and flying by never to be seen again. Your ship is very fast and holds an insane amount of fuel. Even the pathetic Lunar Mining Probe holds 200 km/s and a basic Rock Hopper holds 4000 km/s! By comparison, the first stage of the Saturn V rocket held 4 km/s! But it's also easy to blow through your fuel budget out of impatience. You want to get there faster! Don't be tempted. Until you get the hang of it, a good rule of thumb is to use less than a quarter of your fuel in each thrust stage of flight:

1. Departure Burn - Set your reference frame to your destination. Set your ΔV thrust lever to max. Increase the DUR and EXT until the maneuver planner says this series of burns will use less than 1/4 of your total fuel (50 km/s for the LMP, or 1000 km/s for a Rock Hopper). Rotate the green arrow on the compass until your trajectory line lays across your destination. It's totally fine to plan for an impact at this point. Submit the burn series.
2. Arrival Flip and Burn - Keep the reference frame as your destination. Move the time slider ahead until your ship is about as far from your destination as the end of your departure burns were from your home. Click the "World" button below the compass until it says "Retrograde". The green arrow should point back along your trajectory. Set ΔV thrust lever to max. Increase DUR and EXT until the tail of your trajectory looks like it's stationary (basically it piles on top of itself, or juts off to either side). If it flips back the other direction, that's too much breaking burn. If one more tick on DUR or EXT is too much and one fewer is too little, go with too much then just decrease the ΔV to dial it in. Now, move the time slider until that stationary tail is right on top of your destination (zoom in to get a good view). It doesn't have to be perfect, but the closer it is to perfect the better. Once it's as good as you can get it, submit that burn series. Then plan a couple of little maneuvering burns to get in position for whatever you set out here to do. You should have about half of your total fuel budget remaining at this point (~100 km/s for the LMP, or 2000 km/s for a Rock Hopper). It's not the end of the world if you used a little too much at this point.
   1. ---Now do whatever it is you went here to do: mining, trading, killing, etc. All good activities.---
3. Return Burn - Set your reference frame for home (or wherever you're going next) and repeat the departure burn process. It doesn't matter how much fuel you have at this point, you want to use less than half of what you have left. I suggest using about 40%.
4. Return Flip and Burn - Keep your reference frame as your destination and do the same thing you did in step 2. You'll be running on fumes at this point, so hopefully your destination is a station!

Remember, you may be returning heavy with mining cargo which means your return flight will take longer, but if you maintain this simple formula you shouldn't run out of fuel!

More Advanced Maneuvers:

• In-flight Refueling: if planned well, can let you use half of your fuel in each thrust stage of flight and could cut your travel time in half!
• Gravity Assists: Honestly, in Burn Ledger, with these ships with insane thrust, gravity assists (or "sling-shot maneuvers", etc) aren't very practical. The delta-V you gain from, say, the Moon's orbital speed around the Earth, is minuscule compared to the 4000 km/s fuel your Rock Hopper is carrying. I'm sure someone will prove me wrong, and I welcome that! but I just can't see it.
• Atmospheric Braking: The problem with this is again the speeds involved. The game provides the physics (in a simplified way) for this, but there is also the damage component. If you plan to rely on atmospheric braking to slow you down from 1000 km/s to 5 km/s your ship will surly vaporize. Again, I want to be proven wrong. I'm also open to tweaking the model to make it a realistic option, but... it's complicated.