Aegis Dynamics

KSP 1.12 mod adding regen-cooled heatshield engines inspired by Stoke Space's Andromeda upper stage. Combines a heatshield and ring of thrust chambers into a single integrated part, with thrust vector control via differential throttling.

Features

• Thureos engine + heatshield part (setup for 1.25m to 7.5m via TweakScale)
• Adjustable chamber count (6 to 36), each chamber adds thrust and mass
• Active heatshield cooling (burns propellant during reentry to absorb heat)

• Differential throttle TVC with slight thrust reduction during "gimbal" action

• Akron booster engine, basically a smaller, MethaLOx-balanced Vector engine (re-using stock or ReStock's models for now)

• CryoTanks compatibility, all three fuel modes are implemented, complete with dedicated Waterfall plumes

• ReStock compatibility (adjusted attach node positioning)

Dependencies

Required dependencies

• ModuleManager
• B9PartSwitch

Recommended dependencies

• Waterfall
• StockWaterfallEffects
• TweakScale
• MechJeb2
• CryoTanks
• ReStock

Installation

Drop the GameData/AegisDynamics folder into your KSP GameData directory. Should be supported by CKAN too.

Usage

The Aegis Thureos appears in the Engines tab of the VAB. Place it as the bottom of your stack. The chamber count slider in the part action window controls thrust and mass; TweakScale right-click options control size.

During reentry, active cooling activates automatically when heat flux exceeds the threshold. It draws from your craft's LiquidFuel and Oxidizer reserves at the engine's mixture ratio.

The Akron engine may be used as a first stage booster engine, just like any other (especially the stock Vector)

Changelog

v0.4.0 — Akron Booster Engine

Added

• Aegis Akron — new methalox-first first-stage engine, designed to cluster. Inspired by Stoke Space's Zenith. Single bell with gimbal TVC, scaling from 0.625m to 2.5m via TweakScale. Three fuel modes via B9PartSwitch (Methalox default with CryoTanks, Kerolox fallback, Hydrolox optional). Cloned from Vector with adjusted mass, thrust, and propellant tuning. Per-fuel Waterfall plumes when Waterfall is installed.

Changed

• Thureos
  • Hydrolox is now the default fuel mode when CryoTanks is installed (was Kerolox). Kerolox remains the fallback default without CryoTanks.
  • Thrust per chamber reduced ~1.5x across all fuel modes. Engine is now better balanced for use as a returning upper-stage engine rather than a primary booster (hopefully).

Fixed

• Active cooling now correctly drains the right propellant when fuel mode is changed via B9PartSwitch. Previously cooling would silently fail for non-default fuel modes, causing heatshield destruction during reentry.
• Engine thrust now correctly scales with chamber count in flight. Previously B9PartSwitch's subtype application would reset maxThrust to the cfg default after OnStart, leaving the engine stuck at 18-chamber thrust regardless of the slider's actual value.
• MechJeb and the VAB info now show consistent TWR values in flight after chamber count changes (we now fire onVesselWasModified so cached engine data in third-party mods refreshes correctly).

v0.3.5 - CryoTanks active cooling fix

CryoTanks active cooling fix

Fixed a bug that disabled active cooling with CryoTanks

v0.3.4 - CryoTanks fuel switch

CryoTanks fuel switch

Using CryoTanks will no longer force the engine to run on HydroLOx. KeroLOx and MethaLOx are added as options, with matching performances (probably not balanced perfectly) and Waterfall plumes (if installed)

v0.3.3 - TVC visual effects

TVC visual effects

Each chamber's plume now visibly varies during gimbal action, giving visual feedback for thrust vector control. Chambers on the active side of the ring brighten/grow while opposite chambers dim/shrink, creating a "differential throttle" appearance. Works with both stock effects and Waterfall.

Re-entry rebalance

The part's thermal resistance was slightly lowered again to make active cooling more of a requirement.

v0.3.2 — Stock plume integration

Stock plume integration

This update solely focuses on making Waterfall and Stock Waterfall Effects a required dependency instead of a required one. The mod now works without these mods installed, although they are still strongly recommended for your eye's comfort.

v0.3.1 — Single TweakScalable Engine, Stock Gimbal TVC

TVC redesign

The differential-throttle TVC system is replaced with stock ModuleGimbal. This makes the engine behave like any standard gimbaled engine for SAS, MechJeb, and other autopilots. Benefits:

• Smoother control, especially through TimeWarp
• Full MechJeb compatibility (no more KSP Community Fixes interaction issues)
• 5° equivalent gimbal range, configurable in cfg

To preserve some of the old "differential thrust" feel, gimbaling now applies a slight thrust reduction (up to 10% at full deflection).

Reentry balance

Cooling is now more fuel-efficient (10,000 kJ/unit vs 8,000), but the part is less invulnerable when cooling runs out: - skinMaxTemp reduced from 3300K to 1700K - thermalMassModifier reduced from 2.0 to 1.0 - Active cooling becomes essential rather than optional during steep reentries

Mass scaling

Mass scaling is tuned to L^2.0 (was L^2.5 in v0.2 conceptually). Default 3.75m: 7.4t with 18 chambers. Smooth across all TweakScale sizes.

v0.3.0

Major change

The five fixed-size variants (Aspis, Pelta, Hoplon, Thureos, Scutum) and the composite architecture parts (Shield 3.75m + Chamber) are replaced by a single Aegis Thureos engine. Use TweakScale to set size from 1.25m to 7.5m via the part's right-click menu. All previous features (chamber count slider, active cooling, CryoTanks compatibility, differential throttle TVC) carry over to the unified part.

Why this change

• Single part to maintain instead of five variants plus two composite parts
• Continuous size choice via TweakScale instead of discrete steps
• Cleaner parts panel
• All sizes share the same balance pass

Breaking changes

⚠ Existing craft using Aspis, Pelta, Hoplon, Scutum, the previous Thureos, Aegis Shield 3.75m, or Aegis Chamber will not load. Recreate the engine on affected craft using the new Aegis Thureos at the appropriate scale.

Other changes

• TweakScale is now necessary to adapt to all formfactors
• Composite architecture (Shield + Chamber) deferred — may return in a future release if there's user interest

v0.2.0

• Added composite architecture: Aegis Shield 3.75m + Chamber
• Added active heatshield cooling for integrated variants
• Added chamber count slider with live mass and thrust scaling via IPartMassModifier
• Added CryoTanks compatibility (hydrolox mode for engines and cooling)
• Engine rebalance: smaller variants up, larger down, smoother scaling
• License switch to MIT (after discussing with the community, the use of AI make licensing tricky at best. For now, MIT seems more permissive, may totally un-license later. Feedback appreciated)
• Removed deprecated CleanupStoke.cfg patch

v0.1.3

• Renamed mod from "Stoke Engine" to "Aegis Dynamics"
• Greek-themed variant names (Aspis, Pelta, Hoplon, Thureos, Scutum)

v0.1.2

• ReStock compatibility patch
• KSP-AVC version file

v0.1.1

• Initial public release

Development & Licensing

Aegis Dynamics is developed with substantial AI coding assistance (Anthropic's Claude). All architectural decisions, balance tuning, debugging, and integration testing are performed by the human author. AI assistance is disclosed for transparency, not as a legal disclaimer. (after discussing with the community, the use of AI make licensing tricky at best. For now, MIT seems more permissive, may totally un-license later. Feedback appreciated)

Licensed under the MIT License. You can use, modify, redistribute, or fork this mod freely (including commercially). Just keep the copyright notice with any redistribution.

Contributing

Bug reports and pull requests welcome. The mod is small enough that significant contributions can land quickly. Open an issue to discuss before writing patches for major architectural changes.

Credits

• Inspired by Stoke Space's Andromeda upper stage design
• Built on Anthropic's Claude as a development collaborator
• KSP modding ecosystem: ModuleManager, B9PartSwitch, Waterfall, ReStock, CryoTanks, MechJeb
• Stock KSP heatshield meshes used by reference

Source

https://github.com/CapC0m/aegis-dynamics