Reentry - A Space Flight Simulator News

0.94 is another stability update where a lot of bugs has been fixed. The main features are updates to the Mercury physics model (ascent, guidance) and retrofire engines, some Mercury interior fixes and updates, in addition to some huge updates to the Lunar Module inertial platform and the Lunar Guidance Computer.

Mercury Physics Update
The physics model of ascent, deorbit and entry in Project Mercury has received an overhaul, and it is finally possible to fly similar missions to what was flown in real life. Launching into orbit, with retrofire scheduled after about 4 hours and 30 minutes, just like in Mercury-Atlas 6 (Glenn), will make you splash down in a similar location to real life.


Mercury Cockpit Window
One of the features is the addition of panels or doors that can shut the Window in Mercury. It consists of three doors that can be adjusted by clicking on them, just like any other selector/knob.


Mercury Cockpit Interior
The model of the Mercury fuses has been updated to better reflect how they looked in real life, and the UV mapping issue has been fixed. Additional cockpit props has been added and the attitude gauge needles has been colored. This makes it easier to see what's pitch, yaw and roll on the attitude rate needles as they match the coloring of the axis.


Lunar Module Inertial Platform updates
The inertial platform in the Lunar Module is updated to behave more realistically. It is used to improve the methods that uses the REFSMMAT to execute other tasks such as alignment and burns.


Lunar Guidance Computer: P30 & P40
Requesting burns using the Burn Planner will insert a planned burn into the LGC (if you use it when the Lunar Module is the active space craft). The data and logic has been overhauled to be more predictable, with better default values for attitude. A new button is added to the burn planner that lets you request the REFSMMAT before the burn is requested. This allows you to align the IMU using P52. If you then request the burn, the default attitude values should make more sense (this is only needed if you want to torque your gyros ahead of a burn).

The old procedures still works, but it required you to be in control of the attitude to set in V49 (usually all zeros).



Lunar Guidance Computer: P52 opt. 1 and opt. 2
The updates to the REFSMMAT lets P52 opt.1 behave more predictable, and can be used to orient the spacecraft with the burn direction. Requesting burns using the DPS will for example give you the option to align the S/C so that the DPS engine faces prograde/retrograde (90 degrees / 270 degrees pitch). It should now be simpler to execute a DOI burn using the Lunar Module instead of the Command Module, like they did in Apollo 11.

P52 opt. 2 will let you align the platform with the local vertical at a specific mission time.


Inverted Mission Transcript
I have also reverted the Mission Transcript to make it easier to see the last message received.


Links to Space Flight Academy videos
Going forward I will be focusing on creating videos that will teach you and show you the key procedures for each space craft. I link to these has been added to the Academy.

A brief overview of 0.94 can be seen here:
https://www.youtube.com/watch?v=cVLlvt4JkB0


Please see the list below for a full list:

• Mercury Physics update for more realistic atmosphere (ascent, entry)
  
• Slight Mercury Cockpit updates: New fuses and cabin props, adjustable window shields
  
• LM REFSMMAT updates to better support DPS burns
  
• LGC P30 and P40 updates. When requesting a burn, note the burn attitude offset of about 90 degrees on attitude
  
• Added support for LGC P52 opt. 2
  
• Reverted the Mission Transcript so last message is on top
  
• Some additional tuning on the CM ECS and Gemini ECS
  
• Fixed: OBC Catch-up rounding issue, so numbers match with comms
  
• Fixed: Added the missing highlighter support for 3 circuit breakers in the Command Module
  
• Fixed: Inverted LM x-pointer scale control
  
• Fixed: SPS exhaust visible when fuel is depleted
  
• Fixed: SPS fuel depletion logic
  
• Fixed: PAD toggle should now care about UI work, preventing to open them when typing in a text field etc.
  
• Fixed: dV THRUST A/B labels
  
• Fixed: G-trace line disappears when setting EMS to off
  
• Fixed: G-trace graph renderer rendered it outside the EMD display area. It's a graph but the TSS scaling changed the size of it
  
• Fixed: CM/SM jets temperature sensor offscale
  
• Fixed: Gemini navigation lesson asks to set the FDI selector to the wrong position
  
• Fixed multiple typos and issues in checklists
  
• Fixed multiple typos in language files
  
• Fixed multiple typos in missions
  
• Fixed: Inverted the Gemini lift vector. Heads up -> Lift down, as with the Command Module is correct
  
• Fixed: Gemini Event Timer sign issue
  
• Fixed: Gemini CO2 gauge limit to prevent negative readout
  
• Fixed: Agena RCS visibility
  
• Fixed: Agena engine SFX
  
• Fixed: Blank PAD visibility in Apollo
  
• Fixed: Mercury Stable Orbit should work again now (had a slight roll before)
  
• Fixed: Gemini Abort Handle (part of it was baked into a static mesh, preventing animation)
  
• Fixed: Flickering Gemini Attitude Indicator during startup routines
  
• Fixed: Gemini Rendezvous orbit prediction showed a circular orbit, it should be an elliptical orbit. Wrong lookup data was used
  

A special shoutout to all the alpha-floor testers, those who report issues and provide feedback, and to the Test Pilots. Thank you all for helping me creating a better game for all of us.

// Petri W.

Version 0.93 is another update where the game mechanics and existing features are improved. In this update, the main feature is an improved gravity model affecting how orbiting bodies naturally rotate as they orbit Earth or the Moon. This affects all space crafts. In addition, a lot of updates has been made to Gemini, both for the OBC, burn procedures and options, and the Gemini re-entry logic.

Note: If this update causes issues for you, please report and revert to a previous version of Reentry. This can be done on the Steam Betas Tab for the game.

Improved Gravity Model
The gravity model is updated to improve the way orbital bodies rotate relative to their center of gravity. This applies to all the supported space crafts and docking targets. You will mostly notice that the RCS jets won't need to work that much to maintain a stable attitude in orbit, and that the docking targets will maintain their attitude relative to you in a much better and predictable way (as you no longer will need to constantly fight an invisible angular rate between you and the target vehicle).
IMAGE: MCDONNELL/NASA

This affects most parts of the game and will require more testing over time, so please let me know if you experience strange behavior such as orientations snapping/teleporting to another orientation upon staging and so on.


Gemini: On-Board Computer Improvements
The OBC (On-Board Computer) used in Project Gemini has received a long awaited update, and will change the way you are used to operating it. To perform burns with the OBC you will now only need to insert a time of ignition (GETI) and the dV at Local Vertical in the CATCH-UP program.


So how do you execute a burn?
When the burn parameters has been inserted (TIG is core 1 and 2, dV is core 25,26 & 27), hit START and the burn will be computed. The IVI's will then show the burn vector relative to your local body axis (if you change attitude, the IVI's will update to reflect the burn vector relative to this new attitude). Core 83 shows minutes and seconds (MMM:SS) to ignition, and when it's zero, simply zero out the IVI's from any attitude.


Gemini: Burn PAD for "Catch up" maneuvers
I have implemented a similar system to introduce players to PADs (Preliminary Advisory Data), as they are used a lot in Project Apollo. The PAD is used to set up and prepare for burns using RCS/OBC.


Gemini: Simplified burn planning
I have created a new tool that will simplify burn planning in Gemini. Gemini will be the first craft (if you follow the game sequence) where you can perform orbital maneuvering. Most of the burns require you to either circularize the orbit or perform a rendezvous burn followed by a circularization burn.

The new burn tool will let you request either Ap or Pe circularization burns, or rendezvous burns from GROUND, and they will provide you with the burn data on a CATCH UP maneuver PAD. The data will also be uplinked to the OBC using DCS.

The circularization and rendezvous checklists has been updated to reflect the changed procedures.


Gemini: Plane Change burn support
I have added the first Plane Change (PC) burn method to Reentry, and can be tested in Gemini. The burn tool will let you set a target inclination, and requesting a burn will give you a CATCH UP maneuver PAD to execute the burn. The burn will take place at either the ascending or descending node (the one with the least delta velocity required to change the plane), and will be in the Up/Down (ΔY LV) direction (thanks to pclaurent for the suggestion).


Gemini Academy: Lesson 10 - burns and maneuvers
A new lesson is added to the Gemini Academy to cover how to perform burns.


Gemini: Improved Entry
I have improved the entry mechanics and physics used when performing atmospheric entry in the Gemini capsule. You will now spend a bit longer time in the atmosphere, and must control G-load using roll. It's a bit simpler to do than in Apollo, but still requires you to maneuver a bit to not hit the limits of the craft. The entry lesson has been updated to reflect the changed procedures.


When the RE-ENT OBC program is started right before retrograde fire, it will display the total dV accumulated by the retrograde engines, and its direction. After EI (400K' ft alt) and 0.05G detection, the IVIs will show the range to the predicated splashdown area.


New achievement: Apollo Command Module atmospheric entry
I have added a new achievement that will be awarded to those who are able to guide the Apollo Command Module through the atmosphere without exceeding 12 G's.



I will be uploading a lot of lessons, videos and tutorials to showcase these features:
https://www.youtube.com/channel/UCaTAqRYeGxQRZ1CNZLJ439g

Did a live stream to showcase and go deeper into the new features, it can be seen here:
https://www.youtube.com/watch?v=wDMeZx7h71U

Other
- Added a blank piece of sheet (paper) to let you write and draw in-game (Gemini and Apollo)
- Added bindable hotkeys for toggling PADs
- New achievement: Apollo Atmospheric Entry without exceeding limitations
- Fixed: Invisible switches in the Command Module (XINJECT etc.)
- Fixed: Random exploding SPS engines causing Game Overs (when they burn)
- Fixed: Request PADs for CM Earth Entry
- Fixed: Mission Time will start at 000:00.00 every 24 hours
- Fixed: MOCR material artifacts (white bright panels)
- Fixed: Updates to some checklists and typos

Hello!
I will go live later today to showcase some of the new features planned for the 0.93 update.
https://www.youtube.com/watch?v=wDMeZx7h71U

As usual I will host an AMA-session (Ask Me Anything), so please ask questions in the chat and I will try my best to answer. :)

Hope to see you there!


// Petri Wilhelmsen

Reentry version 0.92 is primarily about improving existing features in preparation for the 1.0 milestone (keep in mind that 1.0 is just the beginning towards version 2.0). The major features in this update is a big overhaul of P30 in the AGC, a central piece of software used in all AGC controlled SPS/RCS burns, the introduction of a Preliminary Advisory Data (PADs) system and a big overhaul to atmospheric entry in Apollo and the related Entry Monitoring System (EMS).

In addition, hundreds of bugs and issues has been resolved in Mercury, Gemini and Apollo.

Note: If this build causes issues for you, you can use the Steam Beta Tabs to roll back to version 0.91.

Let's dive into the details:
https://www.youtube.com/watch?v=CxAFpUnJfzo

AGC P30
P30 has now been rewritten to provide you with a better experience when using the AGC to prepare burns. You can now use P30 to plan burns without the need of the Maneuver Planner, and all the data shown during P30 and P40 should now make sense. Previously you would see a lot of dV data and orbit prediction data that did not make sense, especially when in Lunar Orbit. What you now should see is a clear time of ignition, a correct local body dV vector and a correctly predicted orbit if the burn would be executed perfectly.

The Maneuver Planner will not make much magic behind the scenes anymore, and instead just insert the burn data into the AGC for you. You will still need to use P30 to prepare for it, but the data you saw in the Maneuver Planner should now be similar to what you see when navigating through P30.

Note: TLI (S-IVB burn planner), TEI (TEI planner) and LOI (SPS Maneuver Planner) still requires the use of these tools as special computation and logic is required for the trajectory.

When P30 is running, a new green prediction line will be visible in Orbit View that shows you the prediction as you progress through P30. When P30 shows you the predicted orbit, this line will show how it looks in Orbit View as well.

In the image below, I'm planning a dV burn of 30 ft/s at TIG 2h 4m 10,00 sec.



First Preliminary Advisory Data aka. PADs!
During the Apollo missions, the crew had forms they could use to write down data about upcoming procedures. A P30 PAD would for example contain all the data required to perform the burn, in addition to data required during a backup procedure if for example the primary systems would fail.


The CREW MEMBERs menu has now received a PADs section where you can request various PADs. The Maneuver Planner will also now give you a P30 PAD when you request a burn.
The PADs you now can request are:
- Circulate at Ap burn PAD (P30 PAD)
- Circulate at Pe burn PAD (P30 PAD)
- Maneuver Planner PADs (P30 PAD)
- Lunar/Earth Entry PAD
- Trans-Lunar Injection PAD
- P52 alignment form (similar to a PAD)


In addition, the game has the P30, Entry and P52 forms available in-game with a drawing tool that will let you fill out the form as you receive the data from GROUND or a live MOCR session.

This feature combined with the P30 improvement will greatly increase the realism and immersion of planning, preparing and executing burns.

Keep in mind that this is the first version of the PADs, a system that will improve as we progress towards 1.0 and 2.0.


Apollo Atmospheric Entry Overhaul
Requesting an Entry PAD will now give you all the information you need about your entry experience. This information can be used to correctly set the entry REFRSMMAT (during entry, the inertial platform is aligned so that the FDAIs behave more like an aero plane), and better prepare the EMS (Entry Monitoring System).

The aerodynamics of the Command Module has also been improved to give you a better experience of flying through the atmosphere. The RSI needle will show you the Up-vector direction (if GDC is aligned correctly with the IMU), and the EMS has been improved to show the current entry trajectory (G-forces vs. velocity), and almost every aspect of entry has been improved.

A splashdown predictor is visible in the Orbit View after planning a deorbit burn or when requesting an entry PAD while on an entry trajectory.

A Lunar Entry scenario has been added and can be found in the Apollo Scenarios mission selector.

I recommend watching the Apollo - Atmospheric Entry Phase (1968) video for details regarding atmospheric entry in Apollo:
https://www.youtube.com/watch?v=MTKHqfloB7Q


Runnable Entry Checklists
The Earth and Lunar Entry checklists has now been made runnable. You can now use the Checklist Guide to help you with Entry, and to configure everything correctly.


High G-Forces will kill you
With the new entry overhaul in Apollo, the G-forces can get the crew killed. This feature can be toggled in Realism Settings, and is also disabled in the Academy Entry lesson (override). During the entry lesson, if you exceed the structural limits, you will get a message instead, letting you know that they have been exceeded.


Game Over screen
A Game Over screen has been added, and will give you the reason for Game Over, and a way to return to the Main Menu, similar to Mission Accomplished.


Entry Monitoring System overhaul
The EMS has been fixed so it can better be used as a tool during your missions. Tests can now be run on the pad (GTV) or in-orbit, and the various functions should work better during SPS burns, monitoring and Entry.


On the EMS scroll, you will find the various tests referenced on the checklists (pre-launch, pre-entry etc) as well as preparing for entry:

For example, the image above tells you to set the EMS mode to standby, and the function on Test 5 (it is required to set the EMS to Test 5 before entry for correct behavior, all other tests can be skipped if you wish). Move the scroll to the 37.000 line (start of entry pattern), then set the EMS function to RNG SET and set the RTOGO from PAD or P61 N63 R2, then set EMS function to Vo SET and move the pattern so the orange line matches the EI velocity (Entry PAD or P61 N63, typically around 25.500 for Earth Entry and 63.200 for Lunar entry).

Once the 0.05G is detected, set the EMS mode to Normal. This will start the EMS and your entry trajectory will be drawn on the mylar-scroll.

It is important to also remember to read other indicators during entry than only looking at the EMS. For example, the altitude indicator and preparing the ELS so chutes will be deployed as planned.


Command Module RCS fixes
The RCS system of the Command Module has been improved to fix some major bugs related to it's pressure, way of pressurizing it and RCS jet-temperatures. The CM heaters also have an overhaul to make it work better during entry preparations.


Command Module System Test
An initial version of the Command Module System Test feature has been added. This is a system located on panel 101 and consists of two selectors (OFF, 1 -> 7 and A, B, C, D) and a VOLTs indicator. This can be used to check various internal systems (not all is yet added) such as RCS CM jets temperatures, battery relay bus, etc.


The System Test gauge is designed to be able to monitor systems not commonly monitored, thus not prioritized on getting it's dedicated space on the MDC. The system uses a volts gauge to display a voltage signal on a selected system. The chart below show show the volts indicator can be read:





Some other fixes not covered in the above section
Lots of typos fixed
Lots of mission updates and academy updates
Chute Lines improvements
Panel texture fixes in all crafts
Gemini Commander left hand inside panel fixed
Gemini lock-on light fixes
Gemini uncommand thrust in orbit fixes
Gemini volts/amps indicator updates
Gemini rigid docking fixes
Gemini 220 (undock) command fixes
Mercury switch highlighter visible outside cockpit fix
Some improvements to reported Mercury graphics glitches
Fixes related to resetting the challenge mode correctly

Going live with this video tomorrow to talk about the new features you will find in Reentry update 0.92!
[previewyoutube][/previewyoutube]

Hope to see you there, and feel free to ask me any questions (AMA) on the chat, I will be available during the entire show to answer your questions about Reentry - An Orbital Simulator.