These two weeks were very productive. I’ve spent them stabilizing the game after the release of v0.22.0 update. I got a lot of good feedback and bug reports and fixed most of them. Now I'm satisfied with the quality of the update and can move to the development of v0.23 version. I have big plans for it and prepared a huge list of changes I want to make. As always I will uncover some of them in a future dev update.

Now let’s move to highlights for this patch. First of all, I’ve added an ablative variant for each heat shield. You can now configure the thickness of the ablation layer and it will resist the radiative heating which appears when you enter the atmosphere at speeds higher than 9 km/sec. This allows you to make a return mission from the Moon or break against the planet’s atmosphere in the interplanetary flights. Be careful tho, this heat shield will not save you if the re-entry angle will be too steep.

A small but pleasant change: the heated shields are now emitting light.

I also fixed a lot of bugs that were in the game for years. For example, I finally found a way to deal with those circle artifacts visible on high Earth orbit. You can still notice the small ones, but they are much less prominent.

Earth no longer loses its atmosphere when you enter the Moon’s sphere of influence.

And a quick load made during the flight will finally load you directly into the flight!

You can find a full list of changes since v0.22.1 below. Thank you and see you in the v0.23 update!


🔸 added ablative configuration variant for all heat shields;
🔸 you can change pass resources state on decoupler during the flight;
🔸 quick load during the flight will load directly into the flight;
🔸 state indicator on probe cores now change color depending on the state of probe core;
🔸 you can directly switch to select mode when right click on the part and the assembly is in rotate mode;
🔸 heat shields now glow when heated;
🔸 added "Lock thrust limiter" toggle to engines, so when it is enabled engines will ignore any global thrust limiter changes and keep its configured value;
🔸 added several additional tutorial steps to the base tutorial that explain side attachments and part configuration;
🔸 added protective "shadow cone" for heat shields, so side attached parts will not receive heating if they are covered by reentry shadow from the heat shield.

🔸 improved bluntness calculations for reentry: partially occluded surfaces should not receive increased reentry heating like it was before;
🔸 significantly optimized spacecrafts list in the control center if it contains a lot of spacecrafts;
🔸 optimized thermodynamics system performance on time warps greater than 1h/sec
🔸 improved heat shield part tooltip in the assembly shop;
🔸 adjusted heat shields center of mass to make them more stable;
🔸 parts no longer heat at when they are oriented at 85-90 degrees relative to airflow;
🔸 increased max internal temperature for all decouplers;
🔸 scroll speed is the same in both directions, when adjusting maneuver using scroll wheel;
🔸 improved logging when rocket part is destroyed because of overheating;
🔸 activating the next stage will no longer override thrust limiter if it was previously set to any value other than 100%;
🔸 twr and burn time now recalculated for stage when changing the thrust limiter for engine in the assembly;
🔸 thrust limiter in part config in the assembly now have proper rangnes;
🔸 moved center of mass for all probe cores down a bit, to make them more aerodynamically stable;
🔸 tweaked parameters of parachute, so it is more resistant to reentry heating.

🔸 unstable thermodynamic simulation on high time warp;
🔸 exception after that part stats stop properly update in the part window;
🔸 "Clap" longitudinal decoupler not passing resources after docking;
🔸 sometimes game crashes when quick loading;
🔸 a lot of small bugs related to resource transfer via docking port module;
🔸 sudden rotation around y axis of spacecrafts when docking;
🔸 empty dropdowns in the navball mod;
🔸 fonts have different sizes in the surface mod;
🔸 part attachment systems sometimes breaks when reattaching small parts;
🔸 rare crash on reentry;
🔸 negative total mass when adding some parts, changing variants and then removing it;
🔸 planet atmosphere disappears in main menu if you replace spacecraft with custom one;
🔸 rotated heat shields generate wrong heat shadow;
🔸 fixed Earth losing its atmosphere on SOI change;
🔸 greatly reduced dot artifacts on planet surface on high altitudes;
🔸 Rumble decoupler overheat very quickly;
🔸 rocket state in flight (amount of fuel, etc) reset after save loading;
🔸 fins used as a rudder work incorrectly on some attachments;
🔸 fins control surfaces not correctly shown when symmetry is enabled;
🔸 infinite exception loop when trying to change side booster parameters;
🔸 combustion chamber rotates around up axis for no reason;
🔸 thrust limiter is showing as 0 in flight / assembly windows, when it set exactly to 50%;
🔸 memory leak when duplicating rocket;
🔸 tutorial stuck if you attached more parts to the rocket than was requested by the tutorial;
🔸 exception when opening the map using button in the control center (and back to spaceport);
🔸 engines attached to cockpit or rover become start rotating 90 degrees down if they have TVC;
🔸 not saved window close button doesn't work (Assembly);
🔸 can't attach anything small into side slots of Adapter 1.2-0.55;
🔸 when changing fuel tank attachments and it is a root part, attachment positions become broken;
🔸 removed launch button from the UI in the rocket assembly mod;
🔸 "in", "out" buttons and fuel amount slider doesn't update and change state in docking port window.

🔸 game crashes when opening any mod preview and then trying to continue the game (Unity issue, can't do much about it for now)

Rocket Science v0.22.1 “Foundation” update has finally arrived! I’ve decided to change my update highlights format a bit and made a video that clearly demonstrates the most important changes. As always, you can find full release notes below.

I want to touch on some things that were not included in the video. Firstly, there are not many implications of thermodynamics at the moment other than engines, re-entry and solar radiation overheating. So you will be able to try it out and tell me if it is working as expected in all cases and all possible part combinations (it is not possible to test everything by myself). I hope to have all the thermodynamics related bugs fixed and any missing thermal control parts added for the next update. Since I am going to introduce operating temperature ranges for some parts, you will have to pay even more attention to spacecraft thermal control in the future.

Secondly, I will spend the next couple of weeks not only fixing new and already reported bugs by players, but working on a thermodynamics tutorial, where I will try to explain all processes that are happening in this system. Also I am planning to add several parts that I didn't have time to work on this time.

That’s all, thank you for your support and have a nice flight!


Some spacecrafts may be broken because of these changes.

🔸 thermodynamics was introduced to the game;
🔸 added re-entry effect;
🔸 extended Earth and Mars atmospheres density, pressure and temperature calculations up to its maximum altitudes supported by models;
🔸 [Flight] total rework of all part windows;
🔸 [Assembly] rocket stages now support undo / redo;
🔸 [Assembly] added an ability to change root part;
🔸 [Assembly] you can change side attachments on already placed part;
🔸 [Assembly] you can configure any module on placed part;
🔸 [Map] you can now pin any tooltip on right mouse click;
🔸 fins are aerodynamic surfaces now that can be used to control the rocket;
🔸 you can disable and hibernate probe cores now to reduce electricity consumption;
🔸 you can disable reaction wheels;
🔸 added new fuel pair: kerosene - lox and engines that support it;
🔸 engine plume was completely reworked;
🔸 all tutorial windows can be dragged now;
🔸 added new thermal part category.

🔸 "Razryad-518", “Zaryad-021”, “Duga-8” liquid fuel engines;
🔸 General-Purpose Heat Source (RTG) and Multihundred-watt RTG;
🔸 Payload Fairing Strait Base GO-5;
🔸 Small Fin;
🔸 Passive Heat Shields for 0.55 m, 1.2 m and 2.5 m
🔸 Passive Radiator Panel and Passive Radiator R-2.

🔸 Basic Fin now have control surfaces
🔸 “Vega-072” engine was made bigger and now requires star socket to attach to;
🔸 tweaked ISP and thrust for “Iskra-758”, “Energia-C8.95” and "Yuzhniy-348" engines to be inline with real analogs;
🔸 Structural Adapter 1.2-Cube and Structural Adapter 1.2-Module were moved from structures category to adapters.

🔸 flight part window now opens on right mouse click for consistency with assembly;
🔸 engine system performance was increased by a factor of 5 in some cases;
🔸 engine heat emission is no longer fake;
🔸 reworked "warp to" algorithm, it is now much more precise;
🔸 improved precision at which drag data is baked;
🔸 reaction wheels consume energy evenly (previously small wheels consumed first);
🔸 camera will continue to follow spacecraft if its command module was destroyed;
🔸 [Assembly] you can now open part config by right clicking on part;
🔸 [Assembly] removed angle restrictions from all socket types for attached part rotation;
🔸 [Assembly] you can't reattach already attached part to another one;
🔸 [Assembly] significantly improved "Reset all stages" algorithm, that composes stages better now;
🔸 all selection and hover outlines now brighter;
🔸 increased electricity capacity up to 2x for all batteries, probe cores and command modules;
🔸 collapsed solar panel partially produce electricity, reduced by amount of area hidden from the Sun;
🔸 solar panels energy production now depends on distance to the Sun.
🔸 added "burnTime" into engines tooltip. This is the amount of time an engine can burn in vacuum continuously without overheating.
🔸 added area and volume parameters to all tooltips;
🔸 all single side attachments were rotated 90 degrees to be consistent with the direction of line attachments;
🔸 some positions of side attachments were swapped to better support changing them on already placed part;
🔸 cleanup a lot of code and assets related to old timeline system;
🔸 build size was reduced by 2 GB.

🔸 when clicking on item on parts panel, click event happens twice;
🔸 reaction wheels consume 2x time more energy than in spec under heavy load;
🔸 Rocket does not reset if you make changes to it and then exit to space center via main menu;
🔸 if you create new rocket, not make any changes to it and then try to exit from editing mode, not saved window is not shown;
🔸 orbit raycast sometimes not working on highly eccentric orbits (again).
🔸 game freezes when entering atmosphere on high time warp;
🔸 sometimes rocket parts suddenly rotate after coupling;
🔸 [Assembly] center markers get wrong positions if you move spacecraft and then attach any part to it;
🔸 [Assembly] part resets its rotation when reattaching from one socket to other;
🔸 navball autocorrection buttons not change state, when autocorrection was changed from command module window;
🔸 Seeker Decoupler can not be clicked during the flight
🔸 exception when changing part config when part is not attached to the rocket;
🔸 sometimes fuel indicator near navball stuck after decoupling;
🔸 rocket with extended landing struts / solar panels has incorrect bounds when loading from save;
🔸 wrong tooltip for reaction wheel status indicator;
🔸 countless bugs tied to old flight window system;
🔸 stage loses selection outline, when stage button was pressed and there are no more stages left;
🔸 all aerodynamic surfaces have wrong position of lift force application point;
🔸 if aero surface had no control surface, it doesn't change when selecting any other one in part config;
🔸 you can not hover or select engine during the flight if it was placed inside tail block 0 and was smaller that it;
🔸 when spacecraft is in physics simulation, time in spaceport is at 10x speed, not 1x
🔸 infinite exception loop, when you have part selected with symmetry, and then closing spacecraft with changes reset;
🔸exception related to orbit panel when you first time load flight.

When I started working on thermodynamics for “Rocket Science” I couldn’t even imagine how deep a rabbit hole. I am close to a finish line and now I understand why some recent space simulators choosed a very simplified model of thermal processes. Because everything appeared to be much more complicated compared to what I told in the previous dev update. To describe all of this I wrote an article that is so big, that doesn't even fit into a standard Steam news post. It also contains a bunch of formulas written using LaTeX, which also is not supported by Steam. So I'm suggesting to read the full version of article[blog.unbegames.com] in my blog.

For starters, here is some screenshots from that artickle:

Interesting, what is happening here?

And there?

You can also find some pretty interesting gifs in that article. As for the release date of v0.22.0, I can't provide any yet, but I am pretty sure it will be ready no later than at the end of summer.

Thank you and have a nice flight!

Greetings, fellow rocket scientists!

One of the big features which I get asked about all the time is the re-entry effect. I've been putting this feature off for the future for a long time because I didn't know how to even get started with it. You need not only to add the whole thermodynamics simulation into the game while trying to maintain the game's performance, but also somehow solve a re-entry effect for the crafts of any shape and form. Not many other games have done this before and there is very little info out there on how to properly do it.

But now I think I have gathered enough expertise to accept this challenge. Because the whole new system not only should improve the depth of the game and bring a lot of new rocket parts, but it will solve one of the big problems it has. See, the game is capable of maintaining several physics simulations in the background. So if you launch a plane and then return to the space center, it will continue the flight (if it is stable enough). In the meantime you can launch another rocket or assemble a spacecraft and then return to your plane in an hour and continue the flight.

The drawback of this feature is that it will simulate any other craft in the background even if it is just a used decoupled stage that entered the atmosphere. But any background physics simulation locks timewarp to a maximum of 10x which can be annoying. But if we add the aerodynamic heating of atmosphere entry vehicles into the mix, almost all debris should quickly burn and there will be no problem with that.

So there were basically two parts of research I had to make: thermodynamics itself and the re-entry and part heat visuals. Let’s talk about thermodynamics first.

After reading different articles on the subject for several days straight and nearly going crazy from the amount of math that dropped into my head, I decided to stop and approach this task incrementally as I did with aerodynamics. It is much better to start with a simpler, predictable and understandable system and refine it, adding complexity over time, than just be buried under the formulas creep and don't produce anything meaningful.

So, what are the sources of heat gains and losses that most spacecrafts will experience? There are a lot of them, but I decided to start with these ones:

• incoming solar radiance;
  
• outgoing thermal radiation;
  
• modules that produce thermal energy during the work (engines, command modules, instruments, charging batteries etc)
  
• parts that dissipate heat over time, like radiators;
  
• aerodynamic heating;
  
• atmospheric cooling or heating due to convection.

Most of the formulas for heat flux above are not very complicated (except for aerodynamic heating). But they are non-linear either, so you can’t just write it as a function of time, you need to integrate it. It would not be a problem for physics simulation, since we have plenty of integration in it already. But spacecraft will constantly receive solar radiation and radiate heat even during the math simulation. So it needs to support time warps up to one month per second and give consistent results.

While you can find an analytical solution for thermal radiation integration, it is not so easy for incoming solar radiance. Because it is a function of time and distance from the Sun and distance can not be described as a simple function of time, because it will depend on the spacecraft's orbit. But I think I will find or invent some approximation for that.

As for aerodynamic heating it is much more complicated than everything I encountered before. There are dozens of papers published by NASA with complicated math I can barely wrap my head around. And even if I could understand all of this, it would be very computationally expensive to add into the game.

My brain immediately turns off when I see something like this

But I found an approximation that I could use to begin with.

Nice and simple formula, but...

The problem is that k is the precalculated constant for a specific atmosphere and I found values for it only for Earth and Mars. Also R is the bluntness of the rocket part. I understand what this means and why it is there but I didn’t find out yet how this value is calculated or at least in what ranges it lies. If you know any of this or at least could point me in the right direction please let me know in the comments below.

Enough of math for today. Let’s talk about the visual component of reentry heating. It is a combination of plasma and flames which should encompass the spacecraft when it enters the atmosphere at a high speed.

It would be easy to do if you know the shape of the rocket ahead of time. But in this game spacecraft could be of any shape. And not many games have rocket construction combined with the re-entry heating, so this problem has no commonly known solution.

There is a talk on Youtube “Unite 2013 - Building a new universe in Kerbal Space Program” where the original developers of the game talk about their solution of this problem. They basically take the rocket part mesh and render it multiple times with some offset and increasing opacity and scale.

It is interesting, that this shader is also used for fur rendering

The drawback of this solution is that you can notice bands of color along this effect. You can decrease these visual artifacts by increasing the number of render steps or by applying some dithering algorithm on top of that. But this solution is expensive and pretty limited in visual expression. I didn't find anything else on the topic, so I decided to try to implement re-entry effect by myself.

I took a simple quad sphere, copied it, scaled it a bit and started experimenting. After several days of tinkering with shader magic I ended up with something usable.

All screenshots will be from Unity Editor, since I didn’t incorporate this effect into the game yet

But how can we apply this effect on any rocket part? See, the great property of the quad sphere is that it has uniformly distributed vertices.

A simple quad sphere wireframe. In fact this is the basis also for planet generation

So we can apply vertex offsets to it from any direction. And we need this mesh property, because spacecraft can be in any orientation when entering the atmosphere. This means we can’t take rocket part mesh, scale it and just apply this shader. Because most of the parts have meshes with sparsely distributed vertices.

Here is an example of a Fuel Tank mesh, there are not a lot of vertices, especially at the bottom

Another example: this is a command module mesh, it is better suited for this effect, but vertices still non-unifromly distributed and effect will look bad in some cases

So we need a mesh that will follow the shape of the part but would have a uniform vertex distribution. Manually creating such a mesh just for re-entry effect for each existing rocket part in the game and for all future ones is not an option. I heard you can easily do it using Houdini, but I have no time to learn a new tool and also I can’t afford it. I am pretty sure you can do it in Blender, but the workflow would not be ideal. So is there any way to do it faster, preferably using only Unity Editor?

After some hard thinking I remembered my signed distance field terrain generation experiments from three years ago.

Every experiment is a great for gaining an experience and expertise even if it had no use in the beginning

Here is a terrain generated using a signed distance field or shortly SDF. SDF is a scalar field for each given point of which we can obtain a distance from some surface. If the distance is negative then this point lies inside this surface, if positive then outside. Then we can build a model from any SDF using a mesh extraction algorithm such as Marching Cubes. Mesh, generated in this way, has a property that we seek – a pretty uniform vertex distribution per unit of volume. On the screenshot above the SDF was generated by the noise function. But the great news is that we can turn any model into SDF first and then reconstruct it using the mentioned algorithm!

Unity has a built-in mesh to SDF generator. But has no tools for the other way around. So I’ve implemented the Marching Cubes algorithm specifically for my case. And tried to reconstruct the command module from above using it.

The result was closer to what I need, but as you can see, there are a lot of unnecessary vertices in some places which not only affect the quality of the effect, but would also be a bit taxing.

After some additional time spent on research I found and implemented another algorithm called Surface Nets. It generates less accurate representation of the surface, but produces less vertices and they are more uniform.

This was exactly what I needed. I plugged the resulting mesh into my earlier shader and got the following results.

There are a lot that can be improved here but I think it is a good starting point

Thanks to uniform mesh, the effect works from any side

So I’ve written a special tool for Unity, that can convert meshes with a single button press.

While the process is greatly automated now, it still requires a bunch of manual tweaking for each rocket part. I think this is as far as I can push automation forward. And I beleive I have a good foundation now on which thermodynamics effects will be built upon. But there are still a lot of work with the shader. I need to account parts occlusion, rocket bounds, add flutter and pulse, also make it more dynamic and varied.

Here is a quick proof of concept, that it will work for assembled rocket

This dev update is already huge and I told only 20% of all things I needed to research and experiment with while working on thermodynamics for the game. I will probably continue this story another time (or better record a video about it at some point). But I need to get back to v0.22.0 development which has a big scope and not a lot of time to work with.

Thank you for reading this post and have a nice flight!

I got a lot of bug reports thanks to our amazing Discord[discord.gg] community and some of the videos that were published on youtube last week. I fixed all the critical bugs with reproducible scenarios. And a bunch of less important ones that didn’t require big changes to the game.

This patch includes some features and a lot of changes too. I’ve added a third rocket assembly tutorial to the game that shows how to use some tools that weren't touched in the previous ones. And I changed the orbit parameters panel. In the collapsed state it shows the most important parameters for any flight: orbit apoapsis and periapsis and time to these nodes. If your spacecraft’s trajectory ends up on the planet’s surface it shows time to impact instead of time to periapsis.

Using this panel you can now put a spacecraft on orbit without opening the map even once

If you click the expand button, then you will get all the other orbit parameters.

This panel is gigantic in the expanded state, but what can you do

There is still one major bug that I am trying to hunt down where the rocket sometimes becomes corrupted during rocket assembly and can’t be loaded. But you still can find the rocket file in the save folders. If it happens to you, please contact me via email or Discord[discord.gg] and send me this rocket file with the description of what happened. I will be able to fix your rocket and also it could help find the issue.

This is the last big patch to v0.21 version. I can push some smaller hotfixes here and there but I will mainly focus on the next game update now. All other non-critical bug reports I received will be included in that one.

Stay tuned and have a nice flight!


🔸 added time to apoapsis/periapsis/impact to the orbit stats panel;
🔸 added third rocket assembly tutorial;
🔸 navball mod now supports black colors for numbers and have a separate intensities for each channel.

🔸 added expand/collapse button to orbit panel which will toggle visibility of additional orbit parameters;
🔸 reduced assembly colliders of "Raduga-52" and "Vega-072" engines so they can be attached to big fuel tanks in more different ways;
🔸 engines are now grouped by fuel pair first and then by thrust on the parts panel.
🔸 added fuel name and image to rcs tooltip;
🔸 increased camera exposure compensation range that could be set during the flight and on the map;
🔸 improved memory allocations on assembly shop scene;
🔸 improved "Citrine" external RCS plume effect;
🔸 reduced mass for "Clap" Longitudinal Decoupler;
🔸 added hydrazine fuel variant to "The little one" Fuel Tank FT-0;
🔸 removed fog from assembly blueprint scene;
🔸 automatic time warp is no longer interrupted by physics simulation, it is just capped at 10x speed;
🔸 part name properly updates when changing its config using select tool;
🔸 increased resolution of navball texture and tweaked colors a bit.

🔸 big memory leak on spacecraft mode scene;
🔸 switching pass resources mode in the attached parts using “Select” tool, doesn’t work (mode switches, but part continue to work in the previous mode);
🔸 not being able to open context menu and raycast highly eccentric orbits;
🔸 equatorial inclination doesn't account for orbit's longitude of ascending node and can produce incorrect results;
🔸 part rotation is lost when detaching part and then using undo;
🔸 sometimes assembly stuck when constantly switching from grab to select mode and back and clicking on different parts;
🔸 1.2m radius parts could not be attached to the bottom of rover_fairing_0;
🔸 command module porthole shows Earth's water through the part;
🔸 some props are missing in the control center;
🔸 engine thrust effects and sounds start playing when turning on engines end time is paused;
🔸 center of lift and center of drag forces overlays are swapped between each other;
🔸 ALT+click on rocket part doesn't focus camera, when "Select" or "Rotate" mode was selected;
🔸 game loads in initial 10x time warp and then switches back to 1x;
🔸 sometimes game stuck when quitting to desktop or main menu;
🔸 sometimes game stuck after using Select tool and selecting one of the parts;
🔸 buttons are vertically stretched on instruments panel on surface and navball mods;
🔸 stages are cut off by the bottom of the screen in the ultra-wide resolution;
🔸 game stuck when several parts was selected using symmetry and then they were removed by pressing undo;
🔸 part params window is clipping through celestial bodies filter when solar system map is open.

I usually make only fixes and do not add any new features in patches in between updates, however since many new players are joining and trying out the game I decided to process feedback faster and implement features that do not require big changes to the game as soon as possible.

One of those features was the request to decouple some side boosters without needing additional decouplers to match the behavior “Proton” or “Souz” rockets have. And now you can easily do that.

Just select new decouple mode in the part configuration

And enjoy the new behaviour. No additional decouplers required!

Other than that, I updated some outdated information in tutorials. And made several fixes that will make the game more stable.


🔸 added additional configuration to side boosters Side Fuel Block and Conic Fuel Block so they can be decoupled from rocket without using a dedicated decoupler;
🔸 added one more time warp step in between 1 day and 1 month, equal to 1 week;
🔸 added toggle to orbit stats panel that switches orbit inclination display mode from the ecliptic to equatorial plane and vice versa;


🔸 re-enable thrust limiter slider for all engines in the engine parameters window during the flight.
🔸 all "Reach orbit" contracts now have correct inclination set relative equatorial plane (previously was incorrectly set to ecliptic plane);
🔸 Molniya and Tundra contracts now have correct periapsis and orbital periods;

🔸 Molniya and Tundra contracts can't be completed;
🔸 game stuck after completing any "Reach orbit" contract and trying to exit to main menu or quit the game;
🔸 crash when changing from select mode to grab mode removing previously selected part and switching back to select mode;
🔸 sometimes there is no missing fuel warning displayed when attaching some engines to the fuel tank that have no required fuel for them;
🔸 mods list window have no background;
🔸 navball is black in the navball mod scene;
🔸 some translation strings are missing;
🔸 some tutorial steps have outdated information;
🔸 fixed missing caption in one of the advanced tutorials

🔸 switching pass resources mode in the attached parts using “Select” tool, doesn’t work (mode switches, but part continue to work in the previous mode);
🔸 geostationary orbit contract references ecliptic plane instead of equatorial one;

Hi, there! Three months have passed in a blink of an eye and it is time to publish the next update. This is a medium-sized update but it has a lot of changes under the hood. Because most of the changes were localized and there were no engine version updates, I decided to release this update without the beta cycle. We will see how it goes, but without further ado let’s dive into it.


As I mentioned in the previous update, all the engines in the game are based on real world counterparts. And the last two engines I’ve added have a much higher ISP, but should consume a hydrogen / oxygen fuel pair instead of UDMH / dinitrogen tetroxide all the other engines use. But while the game was designed around different fuel pairs, some game systems were still not fully reworked to support that. For this update I’ve added a hydrogen / oxygen fuel pair and support for every single one of them. For example, stage dV calculation, fuel level indicators, maneuver dV calculations and even fuel transfer in docking ports are working not only for the H2 / O2 pair but for any other one I will add in the future.

All engines and fuel tanks tooltips have color coded fuel indicators now

This change would greatly affect the rocket design. See, liquid hydrogen has a very small density and mass. At the same time engines that use it have much higher ISP which means they are more efficient. So the upper stages of a typical rocket will be much lighter, but carry less fuel for the same volume. Because of that you will probably build smaller lower stages or could make the upper ones bigger depending on your need. I'm looking forward to seeing screenshots of your new designs.

Stages now grouped by fuel consumption, have fuel indicators too and change color to red, when the stage doesn't have fuel that engine use

It is also interesting that the USSR designed and built only three different engine models that used hydrogen as a fuel. So I’ve added the missing one. But it looks like another popular fuel pair is just around the corner.

Meet 1-socket "DVK-1" Liquid Fuel Engine


You can finally change configuration for already attached parts. All you need to do is to switch to “Select mode” on the instruments panel and then click on the part you want to change. Symmetry is working too. Note, that at this moment, only existing configurations are supported. For example, you can change fuel type, decoupler resources pass mode or control surface parameters for the attached part. I will add full configuration support for all the parts in the next update, because it will be easier to change by combining it with the redesign of the rocket part flight windows.

Just switch to the Select mode and click on part you want to change

I’ve also added support for 8-way radial symmetry. It is a bit awkward because it can produce buggy looking results when trying to attach 8 fuel tanks that have the same size as a central one. But this is not the only use case for that and it opens more design space, so why not.

Below some new parts structure parts, made with 8-way symmetry in mind.

Octagonal Prism O-100

Octagonal Prism O-200

Structural Adapter Octahedron-Hexagon

I’ve also made a full rebalance pass on all fuel tanks in the game. I have developed several formulas and carefully recalculated all part parameters, including mass, surface area and volume, making it much more consistent. Thanks to this change, most of the tanks, especially medium sized ones, can hold more fuel now. I also found a bug in the calculations that made all cubic-shaped tanks hold two times less fuel than they should do. And now it is fixed too.


Another one most requested feature is to warp to a point on the orbit. And now you can finally do it!

I can't even imagine how I lived without this feature before

I’ve also added a button to the maneuver panel, so you can warp 10 seconds before the start of engine burn. Not only that, but there are a set of indicators with sounds that will help to make your maneuvers much more precise.

Making maneuvers become very enjoyable process

I’ve also added two more indicators to the time panel. One will light up every time the game is in physics simulation. Another one – when automatic time warp was initiated. I hope this will answer a common question, why time warp sometimes is not working as expected.

The third indicator is reserved, I haven't figured out what it can be used for yet


Assembly shop and main menu UI was visually redesigned to approach the quality standard set by the flight UI. There are plenty of old interfaces left in the game, but I will deal with them sooner or later.

Parts, rockets, spacecrafts and assembly lists were greatly improved

As well as some smaller UI elements


Solar map textures of all gas giants were improved. I’ve also added solar map materials to 4 biggest Jupiter satellites.

If a planet still has no surface materials, it will load solar map texture now. I think it is better that just a white sphere, despite it has very limited resolution

As always, there is much more that this update brings. You can find full patch notes below. Thanks for playing and stay safe!

⚠️Important!
Your old save file is compatible, but it is highly recommended to rebuild all your rockets, because old ones will not recive updated paramters or simply could not work properly.


🔸 added H2 and O2 fuel pair;
🔸 added Select mode for Assembly and ability to change rocket part configigration for already attached parts;
🔸 full rebalance pass on all fuel tanks parameters;
🔸 added 8-way symmetry and part variants, that support it;
🔸 added warp to maneuver button and start burn indicators to maneuver panel;
🔸 all planets, that still have no surface, now use textures from the scaled space model, instead of just a white sphere;
🔸 added Callisto, Ganymede, Io and Europa solar map textures;
🔸 improved all gas giants solar map textures;
🔸 [Space context menu] added warp to point option;
🔸 added two indicators to the time panel, that will show if the game is running physics simulation or if auto time warp is used;
🔸 added more sfx to the game;
🔸 redesign of some old interfaces;
🔸 added irregular moon celestial body type and corresponding map filter;

🔸 "DVK-1" Liquid Fuel Engine
🔸 Octagonal Prism O-100
🔸 Octagonal Prism O-200
🔸 Structural Adapter Octahedron-Hexagon
🔸 "Mini-Prizm" Fuel Adapter
🔸 "Mini-Cone" Fuel Adapter

🔸 engine 6 and engine 7 now uses H2+O2 fuel pair;
🔸 corrected engine_skycrane hydrazine consumption;
🔸 adjusted visuals and slot positions for decoupler_radial_1

🔸 significantly improved fuel tanks attachment stability, when trying to connect it to the radial decoupler;
🔸 advanced assembly tutorial received additional tutorial steps, clarifying some assembly mechanics;
🔸 advanced assembly tutorial was split into two parts, to reduce its size;
🔸 stage groups with engines now have fuel type indicators;
🔸 collapsed stage groups are now grouped by fuel type;
🔸 stage fuel navball indicator now works with any fuel that engines consume;
🔸 stage fuel navball indicator now calculate amount and % for entire fuel pair instead of only fuel alone;
🔸 added indication that engines have no required fuel in the stage to stage group;
🔸 base time warp in the spaceport is 1 now (previously was x10);
🔸 time warp acceleration / deceleration is frame rate independent now;
🔸 game will unpause if you click pause button a second time;
🔸 changing time warp using hotkeys will also unpause the game if it was paused;
🔸 orbit raycast no longer processed if orbit point is behind the celestial body;
🔸 small improvements to scaled space atmosphere computation, that will improve its quality;
🔸 added window for parts, that contain kerosene;
🔸 improved UI for widescreen displays;

🔸 symmetry not working when trying to detach / reattach fuel tank from decoupler;
🔸 sometimes you can notice a strait line on a planet surface;
🔸 sometimes there is a wrong ambient light color when flying over the planet;
🔸 dV is not calculated for hydrazine engine on stages;
🔸 dV is incorrectly calculated when stage contains more fuel or oxidizer than required by engine's consumption ratio ;
🔸 sometimes maneuver placed using orbit context menu, appeared in the wrong place or not appear at all;
🔸 orbit raycast distance is resolution-dependent;
🔸 orbit with section sometimes looks broken;
🔸 orbit raycast doesn't work on high eccentric orbits with no sections;
🔸 orbit with encounter doesn’t reset it's shape after switching to spacecraft with this orbit and to another one;
🔸 wrong door connection between coal generator and elevator;
🔸 sun flares are visible through solid geometry, when the sun is near the edge of the screen;
🔸 fuel transfer in docking port window doesn't work;
🔸 placeable actions subpanel remains visible, when exiting to rocket list and assembly was in Select or Rotate mode;

Here is a small patch with a bunch of fixed bugs that was mostly found by the community. Also this patch brings a pretty big change in rotation steps of big hexagon-like sockets that can be found mostly on fuel tanks. Initially those sockets supported only 60 degrees turns to follow the hexagon sockets restrictions. After receiving some feedback and thinking about it for a while I decided to remove this restriction and allow rotation on those sockets with a 10 degrees step. Despite being not very “socket accurate” It should not break anything and will greatly increase customizability of all rockets. I hope you will enjoy this change.


🔸 rotation step for hexagon, heptahedron, star and heptahedron range sockets increased from 6 to 36 steps;

🔸 updated to latest Unity patch version, increasing the game stability;
🔸 removed CRC check on asset bundles, that can randomly prevent the game from starting up;
🔸 removed some shader duplication wich should improve performance;
🔸 update game input module to a version that fully supports current Unity Engine.

🔸 spacecraft item lose status line when spacecraft name is too long;
🔸 newely created rocket could failed to save, if rocket with the same id did not load properly;
🔸 game crashes on quit from flight or spaceport;
🔸 black squares appears on windows in the assembly shop;
🔸 orbit stats panel breaks when changing SOI from Earth to Moon;
🔸 flipped socket for nano reaction wheel;
🔸 visible tiling on skycrane material;
🔸 crash on skycrane detach when spacecraft is on the ground;
🔸 crash when adjusting manever using mouse wheel, when editing values in input fields at the same time.

This was a very hard beta cycle. Unity 2022.3 kept raining bugs, different problems and unexpected changes that constantly broke the game in different places. I couldn’t hope that those issues would be solved on the engine side in time, because even getting a reply from Unity staff is almost impossible nowadays, so I needed to find workarounds to them. Should I mention that most of the issues that I reported in August are still not fixed?

Anyway, I think this update is ready to come out. I’ve described most of its features in the previous post, so let’s talk about the new parts that were not part of the beta and will be available in this release.

I’ve added two new engines this time. The process of adding them is pretty hard, because every single engine in the game is based on the parameters of the real ones and I spend a lot of the time on research of existing technology. These ones have a much higher ISP and are best suited for second and third stages of rockets. They have their own drawbacks and should not become the only and obvious choice during rocket assembly (at least I hope so).

"Electron-0210" Liquid Fuel Engine

"Aragna-6410" Liquid Fuel Engine

The only catch, that they should use a hydrogen-oxygen fuel pair. While the game was designed around different fuel pairs, some game systems are still not fully reworked to support that. For example, stage dV calculation, fuel level indicators, maneuver dv calculations is expecting a single UDMH/N2O4 pair. Also there are no warnings during rocket construction that will indicate that current engines are missing fuel. So, to simplify things, I decided to not add a new fuel pair for now, but I will definitely do it in the next update with the necessary improvements and reworks.

FT "Piston"

FT "Bublik"

5 m diameter is getting more love now. New Apollo-style decoupler for that radius will make your rockets look much cooler and more convenient for use. Note that it actually consists of two separate parts, like payload fairings.

"Rumble" Decoupler Adapter

"Rumble" Decoupler

I’ve also added another 5 m payload fairing set that should be easier to use for placing rovers inside.

Payload Enclosed Base GO-5

Payload Enclosed Section GO-5 1.4m

Payload Enclosed Cap GO-5

And the first 2.4 to 5 m adapter will provide you more choice while designing your rocket of dreams.

Adapter 1.2-5

There are two new solar panels that are not only compatible with each other, but can be perfectly tiled on a hexagonal connection.

"Gektoplast-A" Solar Panel

"Gektoplast-M" Solar Panel

They are also very light and could be used on a spacecraft, where each kilogram counts

Combinatorial examples

I released rovers in the previous update, but the game lacked some important parts to build fully functional skycrane. Using the next two parts combined with the rover payload fairing, you should be able to finally do it now.

V-1 Sky Crane Base

Nano Reaction Wheel

Putting those parts into good use

There are a lot of changes made to the game during this five month cycle, so I expect that not all bugs were hunted down. So if you encounter something strange, please report it to our discord or on the steam forums and I will try to fix it as soon as possible.

You can find full release notes down below. Another year has come to an end and I wish you good fortune in the year to come. Thanks for playing and see you in the next one.

Flying over Ceres

Flying over Vesta

🔸 added Ceres;
🔸 added Vesta;
🔸 Mars textures rework
🔸 added scaled space filters;
🔸 added celestial bodies list into Control center;
🔸 added search functionality to tracked objects list in the Control center;
🔸 added panel for manual adjustments of the selected maneuver dV during the flight;
🔸 resources panel can display all resources, that spacecraft has;
🔸 added orbit info panel during the flight;
🔸 predicted orbits are displayed relative to target frame of reference now, when you focus camera on it;
🔸 added correct ambient light when flying over surface of the planet;
🔸 added manual brakes for wheels and the corresponding indicator to navball (use ALT+B to toggle).

🔸 V-1 Sky Crane Base;
🔸 "Rumble" Decoupler and "Rumble" Decoupler Adapter;
🔸 "Aragna-6410" Liquid Fuel Engine;
🔸 "Electron-0210" Liquid Fuel Engine;
🔸 FT "Bublik";
🔸 FT "Piston";
🔸 "Gektoplast-A" Solar Panel;
🔸 "Gektoplast-M" Solar Panel;
🔸 Payload Enclosed Base GO-5;
🔸 Payload Enclosed Cap GO-5;
🔸 Payload Enclosed Section GO-5 1.4m;
🔸 Nano Reaction Wheel;
🔸 Adapter 1.2-5.

🔸 Zarya engine geometry rework;
🔸 "Mgnovenie\" Probe Core decreased in size;
🔸 batteries slightly reduced height and mass;
🔸 simplified all engine colliders;
🔸 adjusted size of combustion chamber on some engines.

🔸 added safeguard, that should check if any spacecraft received a NaN position during orbit calculations and destroy that;
🔸 parachute auto cut now triggers when spacecraft touches the ground, instead of near zero speed check;
🔸 rocket command module selection will prioritize ordinal command modules if there are cockpit or rover present alongside;
🔸 riteg will calculate decay time from launch not from the time it is created in the assembly shop;
🔸 you can toggle on/off delete hotkey for tracked objects list now;
🔸 improved control center tracked objects list UI;
🔸 improved loading times, when entering spaceport or assembly shop;
🔸 game consumes on average 400 Mb less memory;
🔸 "time" debug command now supports input date in string format;
🔸 added support for DirectX12 and Vulkan API (that can be faster on some PCs), that can be enabled via command line parameters:
-force-d3d12
-force-vulkan

🔸 planet surface disappears if you quit to main menu from the assembly shop in blueprint mode;
🔸 exception when trying to attach something on top of engine 4;
🔸 spacecraft with wheels no longer transitions into sleep state when it is no longer moving and after steering was used once;
🔸 rocket can still receive wheel commands even when command module is destroyed;
🔸 maneuver sometimes not placed via context menu;
🔸 orbit planner sometimes predict wrong intersect nodes;
🔸 crash when setting the Sun as a target;
🔸 you can't unset target when surface object was set as a target;
🔸 riteg uses part attachment date as a decay start instead of launch day;
🔸 Circular Extended Unit has wrong orientation for radial dual attachments;
🔸 time warp not working, if spacecraft's lights are on and there is little electricity left
🔸 different typos and missing translations in assembly;

🔸 navball text changes brightness depending on exposure (unity bug);
🔸 SSAO is mostly turned off during the flight because of artifacts (unity bug);