This is a massive update with fixes and improvements learned from my own playthroughs, and corrects bugs reported by players. The list is long, so be sure to check the full patch notes in the bottom.

The main intent of the update is to improve trajectory control in Mercury, Gemini and Apollo. This includes new tools for retrograde burn planning in Mercury and Gemini, and small improvements to the Apollo Maneuver Planner, Trans-Lunar Injection and Trans-Earth Injection tools.

The update also aims to improve the general flow of the game like improved fuel balancing, removal of various dev-flags, game mechanic fixes, and visual/rendering improvements.

Note: If you experience new issues related to this update, please report them. You can revert back the a previous build using the Steam betas tab for the game. Most recent rollback option: Reentry Version 0.99.81

Lunar Landing Report and Crash logic

This update rolls out a feature that will measure the impact force on the legs during landing, and is mainly the removal of the "indestructible LM" dev-flag. Previously you would get the landing achievement and mission completion even if face-planted the landing, or landing upside down.

From now, when landing, the game will spend a few seconds evaluating your landing attempt. You will receive a short status report containing some key parameters of the landing/impact and a minor landing evaluation.

If you land too hard the craft will crash and become inaccessible. You can continue the mission in the CSM. When landing, try to stay withing the limits of 8 ft/s vertical and 4 ft/s horizontal, and land on a flat area.

Retrofire Planners for Mercury and Gemini

One of the larger missing pieces for 1.0 and feedback areas was to let players plan their entry trajectory more visually across all programs. I have finally created a new tool for both Mercury and Gemini entry planning (and improved the Apollo TEI tool, see below). You can input the desired GET/MET of when you wish to perform the retrograde burn, and the Tool will visualize the predicated landing area (taking earths rotation into account).

The tool can be set to the current craft configuration (takes the current Time of Retrofire programmed in the Mercury Programmer/Sequencer, or the Gemini OBC into the Tool) so you can visualize where the landing location of the current programmed ignition time will be, or you can use the tool to test out where various retro fire ignition times would splash down on Earth, and once satisfied, you can insert the parameters directly into the Programmer/Computer automatically (simple), or manually(realistic).

You can now easily plan your entry-to-splashdown in a desired area.

Trans-Earth Injection Burn Planner improvements

I have improved the Trans-Earth Injection burn planner (aka. the TEI tool) to better predict the time of EI, visualize the estimated/planned trans-earth trajectory (just like the TLI tool), and also visualize the predicted landing zone (like the Retrofire planners). You can now, while using the Tool, switch to Orbit View, focus on the Earth to see where the tool thinks you will land. You can use this to plan a burn that will make the Command Module re-enter and splash down in a desired area.

In addition, the tool supports burn window offsets that can be used to nudge the burn to the next burn window for better entry control.

Earth Night Light visibility updates

I have updated the logic and shaders used to render the Earths night lights. These lights will now become dimmer or completely invisible as you venture further away from Earth.

Apollo Guidance Computer fixes

I have fixed some stability issues in the core AGC logic, and program flows related to P11 and P15 to allow them to exit as stated in the in-game checklists. They will now behave like the other programs and exit to P00 when complete. Realistically you would see V37 flashing and have to input the program to transition to, this is something I might implement as the game progress towards 2.0.

TLI Tool fixes

I have iterated on the burn that will take you on a trajectory towards the Moon and corrected some issues that I have experienced with the planner in my own playthroughs. I have also fixed the time it displays for ignition, what parameters it inputs to the LVDC, and LOI-1 burn estimations. This will make it slightly easier to use as you better see when ignition happens, and when the LOI burn happens. Keep in mind that these are estimates and will slightly deviate from your actual burn. You can correct this with a mid-course correction burn once you have reached Lunar SOI.

Star Depth Testing

I have fixed an issue with the star rendering system/shaders to make it easier to control their lighting, brightness and depth testing. The main issue corrected here is that you would be able to see stars rendering above the geometry of the Earth and the Moon in some cases.

Screen Resolution reverting to 1x1 for some players

After the Engine Update patch rolled out earlier in the summer, some players has experienced a full screen solid colored square being rendered as the game window when starting the game. This is because an issue in the games initialization logic would, for some players only, set the screen resolution to 1x1. This could be fixed by changing the screen resolution settings in both the INI file and in the games regedit area before launching the game. I have not been able to reproduce this issue myself but have found the most probable cause for this to happen. Let me know if this patch fixes it for you, or not.

Lunar Module Battery fixes and monitoring

An issue with the Lunar Module battery would show an inaccurate voltage when the battery is disconnected and during light loads. This has now been fixed and the battery readings should now be in the correct range.

Configurable UDP Package Rate

For those building panels, hardware, peripherals etc, or those using these: you can now configure the UDP package rate from the games setting. This will make the game send out more frequent update packages to external devices. An additional suggestion was to make this part of the API, so I can eventually look into that.

LM pressurization fixes

I have improved some of the logic related to the pressurization of the Lunar Module, and improve the instrumentation of this. This will at the same time correct an issue where the pressure gauge would stabilize at a pressure difference on 1.0 instead of 0.0.

Fixes to the Mercury Excess H2O warning cycle and lights

A balancing issue with the logic related to the excess H2O causing icing would trigger the Excess H2O warning lights during entry preparations. This was especially visible during cold soaking before entry as you would set the cooling to maximum settings, while some loads are reduced (like turning off the lights). The cooling combined with reduced loads would cause the icing that triggers these lights. This system has now been refined and balanced to avoid these cases during normal procedures.

Removed Sun Reflection blob on Earth ocean

I removed the excessive sun reflection blob visible on the oceans of the Earth while in orbit or from far away. This was a very large specular reflection artifact of the lighting model used in the Earth Rendering shader. I have completely removed this feature and will continue to iterate on the general brightness of Earth (being too bright in many cases).

Apollo Maneuver Planner Ap/Pe Nodes

I updated the Apollo Maneuver Planner trajectory renderer to also include the Ap and Pe nodes, and lines to easier see exactly where they are during maneuver planning. This is especially useful when you try to plan the DOI (Descent Orbit Injection) - the burn that defines where you land.

Lunar Module DPS fixes

I have made some fixes to the Lunar Modules Descent Propulsion System to better balance its thrust and better match the landing point predictor before PDI ignition. When you request the PDI, the landing point predictor will follow a brute force algorithm and show you where it predicts the craft to land. Keep in mind that the landing predictor only have a minor influence of the descent guidance. The descent is mostly set by the orbits Pe point, where it is, and what altitude it is. The DOI burn controls this (the new Ap/Pe nodes on the Burn Planner can help you design better DOI burns).

Note: Remember to always Reset the tool between each use to avoid inaccurate calculations and predictions.

Transition to Lunar Landing fixes

I have improved some bugs related to the lunar landing transition, and started to slowly improve the logic related to this. Some dev-flags are used to reset various parameters during this transition while I have been writing the core transition logic. This patch will remove one of these dev-flags to transform the vertical velocity you have before the transition. This will not affect your descent much but you will see that upon transition, the Lunar Module will have some vertical velocity. At this point the craft is, in Reentry, switched to Attitude Hold mode and the LGC will stabilize the rate of descent so you can control it with the ROD-switch.

I will keep iterating on this both towards 1.0 and towards 2.0, where the attitude upon transition, orbital velocity, sun position etc. is transformed as well.

Lunar Ascent fixes

I have received reports of the Lunar Ascent being unstable, especially during transition from Lunar Surface Rendering mode to Orbital Mode. I have not been able to reproduce these issues but I have improved some of the transition logic and guidance logic related to the transition to potentially fix this. Let me know if this works for you, or not.

Fuel Balancing

I have decided that the game is getting ready and more stable to support more realistic fuel consumption. As a first iteration of this I have improved the fuel usage/consumption balancing in the Gemini OAMS, Gemini RCS, CM/SM RCS, CM RCS, LM RCS, CSM SPS and LM DPS. I have also completely removed all dev-flags that would result in infinite fuel (if the fuel was depleted, the logic would still let you fire the thrusters - mostly used during Gemini and Apollo rendezvous work) in any system.

TEI planner inserts garbage into the CMC desired attitude noun

After using the Trans-Earth Injection tools to calculate the burn that will take the Apollo CSM back to Earth, you would typically see that as you would maneuver towards the burn attitude using for example V49E, the tool would have added garbage attitude into the computer memory. Most players have not cared about this as V25E would be used to set these to all zeros. However, if you would just accept the random values existing in the routine, you would ignite the engines in the wrong attitude, potentially making you crash into the Lunar Surface. I have fixes the issue that caused this. The burn would typically be done using all zeros on the attitude if you use P52 opt 1, or if not, use the attitude suggested in the burn PAD.

DPS and SPS sound mixing fixes

I have changed the sound logic related to the SPS and DPS engines to implement a better transition experience when going from ignition to full thrust, and from cutoff to no thrust. You will now hear the sound fade and follow thrust commands.

Thanks to GeometryPrime for some great screenshots.

Update: This patch had two additional rollouts due to metadata and function call changes, the list of features are identical. If you suddenly experienced a new patch, this is the reason for that.

Patch notes:

• Added impact force, velocity and landing evaluations to the Lunar Surface landing

• TLI Tool Ignition time display text fix

• Apollo Flight Documents pad: Added reference to Apollo 8, Apollo 11 and Apollo 16 documents (flight plan, etc)

• Fixed a font glyph issue (visible in all Career tree node texts) after the Unity 6 engine migration

• Fixes to the Career tree Gemini Elite Commander note to also require completing the burns lesson

• Increased Apollo FDAI drive speed while Time Scaling

• Fixed CMC P11 and P15s logic that prevented transition to P00.

• Improved the Earth night light rendering to reduce light visibility at distances

• Apollo: Fixes to the star rendering depth testing logic to avoid drawing stars over other geometry

• Save State: Fixed an issue with restoring the Moon position when loading into an Earth Orbit state in Apollo

• QualitySettings/ini SetResolution fixes

• Added better coverage of the flashlight in the academy and the loading tips

• Made fixes to the LM Activation Academy lesson

• Made fixes to the LM EPS Academy Lesson

• LM battery fixes for more accurate EPS monitoring and behaviors.

• Made the UDP package rate frequency configurable

• Mercury reticle camera position fix

• Fix to the LM pressure stopping at 1.0 psi diff.

• Excess H2O warning logic fixes in Mercury

• Fixes to the sun reflection in the 16k and the 64k Earth renderer

• Added the Ap/Pe nodes to the CSM/LM Maneuver Planner trajectory

• Retrofire Planner tool for Mercury and Gemini (no VR version yet)

• Started to improve the Lunar Descent transition logic

• -> Starting with vertical velocity

• Lunar Descent DPS thrust tweaks

• Minor modelling changes to the CM panels

• DPS and SPS sound mixing fixes

• SPS fuel balancing

• DPS fuel balancing

• SM RCS fuel balancing

• CM RCS fuel balancing

• OAMS fuel balancing

• Fixed a bug where the TEI tools inserts wrong attitudes for the V49 maneuver

• TEI tool landing prediction