There are 2 ApolloX programs addressed in my REPOS:
-
[1] ApolloX (Earth → Moon → Earth)**
-
[2] ApolloXM (Earth → Mars → Earth) (this REPO)
Intended audience
- Aerospace enthusiasts
- KSP / RO users
- Systems & architecture engineers
- Readers interested in launch vehicle design tradeoffs
Can the Saturn V architecture/design be reborn for a new Mars mission, using current and available technology?
Yes — it can. If we scale the Aris-I solid booster concept to Mars-class payloads, and replace the S-II and S-IVB with modern, high-thrust methalox engines, we can create a credible Apollo-derived architecture for Mars missions.
ApolloXM for Mars, just Like apolloX demonstrates that the Saturn V launch architecture remains viable when implemented with modern propulsion, materials, and avionics.
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By replacing:
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By Keeping:
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Main realistic mods:
- pmborg
- RealFuels
- RO Tanks
- SolverEngines
- Real Scale Boosters
- RSS
- TweakScale
- CryoTanks
- SystemHeat
- ProceduralParts
Installed Mod List (Click to expand)
AmpYear (AmpYearPowerManager 1:V1.5.9.0)
Animated Decouplers (AnimatedDecouplers v1.5.0)
Antenna Helper (AntennaHelper 2:1.0.7.8)
AT Utils (AT-Utils v1.10.1)
B9 Part Switch (B9PartSwitch v2.21.0.4)
Background Resources (BackgroundResources 1:v0.18.0.0)
BahamutoD Animation Modules (BDAnimationModules 1:v0.6.7.1)
BetterCrewAssignment (BetterCrewAssignment 1.4.1)
Bluedog Design Bureau (BluedogDB v1.14.0)
BreakingGround-DLC (BreakingGround-DLC 1.7.1 (unmanaged))
ClickThrough Blocker (ClickThroughBlocker 1:2.1.10.22)
Community Category Kit (CommunityCategoryKit v112.0.1)
Community Resource Pack (CommunityResourcePack v112.0.1)
Community Tech Tree (CommunityTechTree 1:3.4.5)
Contract Configurator (ContractConfigurator v2.12.0.0)
Craft Manager (CraftManager 1.2.0)
Cryo Tanks (CryoTanks 1.6.7)
Cryo Tanks Core (CryoTanks-Core 1.6.7)
Deployable Engines Plugin (DeployableEngines 1.3.1)
DMModuleScienceAnimateGeneric (DMagicScienceAnimate v0.23)
Docking Port Alignment Indicator (DockingPortAlignmentIndicator 6.12.0.0)
Draggable Navball (DraggableNavball v1.0.1.5)
Dynamic Battery Storage (DynamicBatteryStorage 2:2.3.7.0)
Easy Vessel Switch (EVS) (EasyVesselSwitch 2.3)
Environmental Visual Enhancements Redux (EnvironmentalVisualEnhancements 3:1.11.7.2)
FASA (FASA 1:v7.2.7)
Filter Extensions - Plugin (FilterExtensions 3.2.9.1)
Flight Manager for Reusable Stages (FMRS) Continued (FMRSContinued 1.2.9.6)
FreeIva (FreeIva 0.2.20.2)
Fuel Tanks Plus (FuelTanksPlus 2.0.2)
Hangar (Hangar 3.6.2.2)
Hangar Extender (HangerExtenderExtended 3.6.1)
Harmony 2 (Harmony2 2.2.1.0)
Heat Control (HeatControl 0.6.2)
HullcamVDS Continued (HullcamVDSContinued 0.2.2.4)
Kerbal Alarm Clock (KerbalAlarmClock v3.14.0.0)
Kerbal Attachment System (KAS 1.12)
Kerbal Changelog (KerbalChangelog v1.4.2)
Kerbal Engineer Redux (KerbalEngineerRedux 1.1.9.5)
Kerbal Inventory System (KIS 1.29)
Kerbal Joint Reinforcement Continued (KerbalJointReinforcementContinued v3.8.6.0)
Kerbal Reusability Expansion (SpaceXLegs 2.9.3)
KerbalX Part Mapper (PartMapper 0.4.2)
Kopernicus Planetary System Modifier (Kopernicus 2:release-1.12.1-235)
kOS KerbalEngineer (kOS-KerbalEngineer v0.1.1)
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kOS: Scriptable Autopilot System (kOS 1:1.2.1.0)
KSC Switcher (KSCSwitcher v2.2.0.0)
KSP Community Fixes (KSPCommunityFixes 1.39.1)
KSP Recall (KSP-Recall v0.5.0.2)
KSP Texture Loader (KSPTextureLoader 0.0.22)
KSPBurst Compiler (KSPBurst v1.5.5.2)
KSPBurst Plugins (KSPBurst-Lite v1.5.5.2)
KXAPI (KXAPI 1.2.0)
Lunar Transfer Planner (LunarTransferPlanner v1.0.0)
MakingHistory-DLC (MakingHistory-DLC 1.12.1 (unmanaged))
MechJeb 2 (MechJeb2 2.15.1.0)
Moar Filter Extension Configs (MoarFEConfigs 1.0.5.2)
ModularFlightIntegrator (ModularFlightIntegrator 1.2.10.0)
Module Manager (ModuleManager 4.2.3)
Near Future IVA Props (NearFutureProps 1:0.7.2)
Near Future Solar (NearFutureSolar 1.3.3)
Near Future Solar Core (NearFutureSolar-Core 1.3.3)
Neptune Camera (NeptuneCamera v4.3)
Parachutes? Let's Use Maths! (PLUM 1:1.1.4)
PartInfo (PartInfo 0.0.8)
Patch Manager (PatchManager 0.0.17.7)
Procedural Parts (ProceduralParts v2.8.0.0)
Real Fuels (RealFuels 1:v15.12.0.0)
Real Scale Boosters (RealScaleBoosters 0.16)
Real Solar System (RealSolarSystem v20.1.3.0)
Real Solar System Textures - 4096 x 2048 (RSSTextures4096 v18.6.1)
RealChute Parachute Systems (RealChute v1.4.9.5)
RealFuels-Stock (RealFuels-Stock v5.1.0)
RecoveryController (RecoveryController 0.0.4.3)
REPOSoftTech-Agencies (REPOSoftTech-Agencies V1.5.9.0)
Resurfaced (Resurfaced v1.3)
Retractable Lifting Surface Module (RetractableLiftingSurface 0.2.1.2)
RO Library (ROLib v2.0.0.0)
RO Solar (ROSolar v2.1.2.0)
RO Tanks (ROTanks v2.10.0.0)
ROUtils (ROUtils v1.1.1.0)
RSS DateTime Formatter (RSSDateTimeFormatter v1.12.1.0)
Scatterer (Scatterer 3:v0.0878)
Scatterer Default Config (Scatterer-config 3:v0.0878)
Scatterer Sunflare (Scatterer-sunflare 3:v0.0878)
Shabby (Shabby 0.4.2)
Ship Effects Continued (ShipEffectsContinued 1.0.13)
Simple Adjustable Fairings - Plugin (SimpleAdjustableFairings v1.12.0)
Solver Engines plugin (SolverEngines v3.14.0)
SpaceCore kOS Script Pack (kOS-SpaceCore 1.1.1)
SpaceTux Library (SpaceTuxLibrary 0.0.9)
SpaceX Launch Vehicles - Real Size (SpaceXLaunchVehicles 6.5)
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System Heat (SystemHeat 0.8.2)
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Trajectories (Trajectories v2.4.5.4)
Transfer Window Planner (TransferWindowPlanner v1.8.0.0)
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Tundra Techonologies (TundraTechnologies 7.1.2)
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TweakScale Redistributable (TweakScale-Redist v2.4.8.6)
USI Tools (USITools v112.0.1)
Waterfall Core (Waterfall 0.10.5)
Zero MiniAVC (ZeroMiniAVC 1:1.1.3.3)ApolloXM is the Mars extension of the ApolloX project.
While ApolloX focuses on lunar missions, ApolloXM explores a realistic, staged Mars architecture based on the same core principles:
- payload before crew,
- return capability before departure,
- mass efficiency over spectacle,
- mission logic over brute force.
This repository defines the spacecraft, staging, and mission flow. Automation (KOS) will be added later, once the architecture is stable.
ApolloXM is not a single launch mission.
Each vehicle exists for a specific role:
- Apollo-XM-1F — Fuel delivery (fuel is the payload)
- Apollo-XM-1L — Life support and consumables
- Apollo-XM-1C — Crew mission
- Apollo-XM-2R — Return vehicle, injected to Mars orbit in advance
No crew is launched without a confirmed return path.
ApolloXM is not a single launch mission.
It is a staged, pre-positioned Mars surface architecture designed for safety, redundancy, and controlled mass scaling.
The missions are executed in the following order:
Payload: Surface propellant infrastructure
Role: Establish surface ascent capability before any crew is committed.
- Fuel is the payload.
- Uncrewed, autonomous landing.
- Provides ascent propellant for later crew departure.
- Acts as the core surface logistics anchor.
No crew lands until fuel is already waiting on Mars.
Payload: Life support systems and consumables
Role: Surface habitation readiness
- Lands near XM-1F fuel depot.
- Higher Δv margin for landing precision.
- Provides environmental systems, reserves, and redundancy.
Surface survival capability is established before crew arrival.
Payload: Crew + Ascent Mission Module (AMM)
Role: Human Mars landing
- Lands near previously deployed 1F and 1L assets.
- Includes 3 crew seats.
- Equipped with AMM (4 engines) for Mars ascent.
- Uses pre-positioned surface fuel.
Crew never depends on assets that are not already verified on the surface.
Configuration: Two-stage RS-25 propulsion stack
Role: Mars orbit return platform
- Injected to Mars orbit in advance.
- Includes fuel and life support for return trip.
- Remains in stable Mars orbit awaiting crew rendezvous.
Stage Overview:
- Stage 1: High-thrust departure stage
- Stage 2: Trans-Earth injection and return systems
The return vehicle is waiting in Mars orbit before the crew ever departs Earth.
After Mars ascent and rendezvous with XM-2R:
- Crew returns toward Earth–Moon system.
- ApolloX mission performs lunar-orbit interception.
- Final recovery occurs in Moon orbit.
Earth reentry mass is minimized.
Lunar orbit becomes the controlled recovery node.
- Pre-position critical infrastructure before crew launch.
- Surface fuel exists before ascent is required.
- Return vehicle exists before departure from Earth.
- Each step reduces risk through sequencing, not complexity.
ApolloXM is not expansion-based colonization.
It is controlled, geometric scaling of the Apollo principle to interplanetary distances.
ApolloXM Mars Descent & Landing Module
| Parameter | ApolloXM DMM |
|---|---|
| Primary Role | Mars orbital braking, powered descent, landing |
| Crew | No (autonomous / remotely supervised) |
| Mission Domain | Mars atmosphere and surface |
| Architecture | Dedicated descent & landing module |
| Main Engines | Multi-engine, distributed configuration |
| Propellant | Aerozine-50 / NTO (hypergolic) |
| Engine Type | Deep-throttle, restartable |
| Thrust (Mars ATM) | ~637 kN total |
| Thrust (Vac) | ~640 kN total |
| Isp (Vac) | ~323 s |
| Engine Mass | ~0.25 t (total propulsion system) |
| Tank Pressurization | Helium |
| Ignition Capability | Multiple (hypergolic) |
| Throttle Capability | Yes (precision Mars landing) |
| Redundancy | Multi-engine + distributed tankage |
| Reusability | Single mission (Mars surface) |
| Design Philosophy | Reliability-first, controllability over minimum mass |
| Total Mass DMM | ~122.3 t |
ApolloXM Mars Ascent Module
| Parameter | ApolloXM AMM |
|---|---|
| Primary Role | Mars surface ascent to low Mars orbit |
| Crew | No (autonomous / remotely supervised) |
| Mission Domain | Mars surface → Mars orbit |
| Architecture | Dedicated ascent module mounted above DMM |
| Main Engines | 4 × Mk-55 “Thud” liquid fuel engines |
| Propellant | Aerozine-50 / NTO (hypergolic) |
| Engine Type | Deep-throttle, restartable |
| Thrust (Mars ATM) | ~476.6 kN total |
| Thrust (Vac) | ~480 kN total |
| TWR (Mars, ATM) | ~4.47 |
| Isp (Vac) | ~325 s |
| Engine Mass | ~0.76 t (4 × 0.19 t) |
| Tank Pressurization | Helium |
| Ignition Capability | Multiple (hypergolic) |
| Throttle Capability | Yes (precise ascent & attitude control) |
| Redundancy | Multi-engine + reaction wheels |
| Reusability | Single mission (Mars ascent) |
| Design Philosophy | Control authority first, ascent reliability over minimum mass |
| Total Mass AMM | ~27.4 t |
ApolloXM Mars Descent & Landing Module (DMM)
This procedure is based on repeated, successful Mars landings using the ApolloXM DMM and is considered stable, reliable, and pilot-memorizable. Altitude references are Radar Altitude (RA) unless stated otherwise.
- Initial orbit altitude: ~212 km
- Initial orbital velocity: ~3.45 km/s
- Reference altitude: Radar Altitude (RA) — altitude above terrain, not sea level
- Initial conditions:
- Altitude: ~212 km
- Velocity: ~3455 m/s
- Orientation: Retrograde
- Throttle: 66%
- At 60 km RA
- Reference speed: ~1100 m/s
- Throttle: 100%
- At 20 km RA
- Reference speed: ~350 m/s
- Throttle: 33%
- Below 1200 m RA
- Hold vertical speed ≈ 30 m/s
- Between 200 m RA → 100 m RA
- Gradually reduce speed from 30 m/s → 10 m/s
- Transition to fine throttle control
-
Below 100 m RA, apply the rule:
Target vertical speed = Altitude / 10 (integer)
Examples:
- 90 m → 9 m/s
- 50 m → 5 m/s
- 20 m → 2 m/s
-
Final meters:
- Target touchdown speed: 0.5–1.0 m/s
- Vertical only, no lateral correction unless required
- This profile is robust and repeatable.
- Once learned, it becomes instinctive (“ride-a-bike rule”).
- Closely matches real-world Mars powered descent logic.
- Radar Altitude (RA) is critical; do not rely on sea-level altitude
- Throttle changes should be smooth and anticipatory
- The procedure prioritizes control authority and predictability over fuel minimization
- Typical residual Δv after landing: ~100–300 m/s
- The profile is robust and repeatable once learned
“Once you learn it, you never forget it — like riding a bike.”
This landing method reflects Apollo-style powered descent logic, adapted to Mars:
- Continuous braking
- No suicide burn
- No last-second throttle spikes
- Pilot-friendly timing and margins
- C — Crew
- L — Logistics
- R — Return / Upgrade
Monolithic Architecture
- All-in-one
- Single launch
- Short duration
- C + L + R together
This program mirrors classic Apollo lunar missions: one stack, one launch, one landing, one return.
Distributed Architecture
- Modular
- Multiple launches
- Long duration
- C, L, R separated
Apollo-XM is a campaign-style program where mission roles are split across dedicated vehicles.
- Ships/VAB/Apollo-X/
- Apollo-X-v3_3.craft
- Apollo-X-v3_2.craft
- Ships/VAB/Apollo-XM/
- ├─ Apollo-XM-1F-Lander.craft
- ├─ Apollo-XM-1L-Lander.craft
- ├─ Apollo-XM-1C-Lander.craft
- ├─ Apollo-XM-2R-Vehicle.craft
- ├─ Apollo-XM-1F-Stack-v1_6.craft
- ├─ Apollo-XM-1L-Stack-v1_6.craft
- ├─ Apollo-XM-1C-Stack-v1_6.craft
- ├─ Apollo-XM-2R-Stack-v1_6.craft
- └─ Apollo-XM-v1_6.craft
- Apollo-XM-1F — Fuel Lander
- Apollo-XM-1L — Life Support Lander
- Apollo-XM-1C — Crewed Mars Lander
- Apollo-XM-2R — Return / Upgrade Vehicle
- Craft files define hardware geometry only
- Mission duration, crew count, and consumables are handled by configuration
- Launchers are interchangeable infrastructure
- Names reflect function, not iteration history
Missions keep their names.
Launchers evolve underneath them.
This program relies on a set of custom ModuleManager patches
installed under Kerbal Space Program/GameData/.
These patches modify engines, tanks, life support, staging, and realism parameters used by both Apollo-X and Apollo-XM.
They are global runtime configurations, not craft-specific assets.
Craft files do not embed these settings.
Apollo-X and Apollo-XM rely on a shared set of custom ModuleManager patches installed under:
Kerbal Space Program/GameData/
These patches define the physical simulation environment used by all craft in this repository.
- Engine thrust and ISP corrections
- Ullage and ignition behavior
- Upper-stage restart reliability
- Saturn, Falcon, Agena realism tuning
- Real propellant densities
- LM and Saturn tank mass fixes
- Procedural tank enforcement
- Cryogenic vs storable propellant behavior
- Interstage separation behavior
- Decoupler corrections
- Fairing and adapter fixes
- Landing leg stability
- TAC Life Support configuration
- Crew capacity normalization
- Cross-compatibility with capsules and habitats
fix-*→ Corrects broken or unrealistic behaviorprocedural-*→ Enforces procedural part constraintsRSB*→ Realism subsystem patcheszzz_*→ Late-load order enforcement
These patches are global runtime configuration. They apply equally to Apollo-X and Apollo-XM.
Craft files define hardware geometry only and do not embed engine, tank, or life-support parameters.
The GameData/ directory contains custom ModuleManager patches and plugins
used to enforce realistic behavior across all craft.
These patches apply globally and are shared by:
- Apollo-X (Moon)
- Apollo-XM (Mars)
They are not craft-specific and must remain in GameData/
for proper operation.
Contains custom realism patches developed for Apollo-style vehicles:
- Saturn stage mass and tank corrections
- LM tank and ascent-stage behavior
- Procedural tank enforcement
- Decoupler and interstage fixes
- Ullage and ignition behavior
Contains engine, tank, and structural realism patches originally developed for Falcon and Starship systems, reused here for shared physics consistency:
- Engine ISP and thrust corrections
- Fuel density fixes
- Landing leg stability
- Solar panel and RCS fixes
- TAC Life Support integration
Contains early-load compatibility patches.
The 000- prefix ensures correct load order
before other ModuleManager patches are applied.
- Do NOT move or rename files inside
GameData/ - Do NOT place
.craftfiles insideGameData/ - Craft files define vehicle geometry only
- Physical behavior is controlled by ModuleManager patches
To fairly contextualize Apollo-XM Stage 1, it is compared not with the flown Saturn-V,
but with a credible Saturn-V evolution that never flew:
a first stage using eight F-1B engines.
This represents the upper practical limit of kerolox-heavy booster scaling.
| Parameter | Saturn-V (8 × F-1B, hypothetical) | Apollo-XM Stage 1 |
|---|---|---|
| Engine Type | F-1B | Mk4 RAP-39000-B “Kingfisher” |
| Engine Count | 8 | 7 clusters |
| Propellant | RP-1 / LOX | LCH₄ / LOX |
| Thrust per Engine (ASL) | 8,000 kN | 65,709.9 kN |
| Thrust per Engine (Vac) | 9,000 kN | 71,306.1 kN |
| Total Thrust (ASL) | ~64 MN | ~460 MN |
| Total Thrust (Vac) | ~72 MN | ~499 MN |
| ISP (ASL) | ~280 s | 364 s |
| ISP (Vac) | ~315 s | 395 s |
| Engine Mass (each) | 7.5 t | 20.3 t |
| Combustion Cycle | Gas-generator | Full-flow staged combustion |
| Power Generation | Minimal | 300 EC/s per cluster |
| Throttle Capability | Limited | Full |
| Restart Capability | Limited | Yes |
- 8 × F-1B Saturn-V represents the maximum plausible evolution of Apollo-era technology
- It achieves high thrust, but:
- Lower ISP
- Higher propellant mass
- Limited throttling and restart capability
- Apollo-XM Stage 1 exceeds this limit by changing the propulsion paradigm:
- Methalox instead of kerolox
- Full-flow staged combustion
- Extreme parallel clustering
- Higher efficiency at all ascent regimes
Apollo-XM Stage 1 is not an over-scaled Saturn-V.
It is what Saturn-V might have become if:
- combustion physics had advanced,
- methalox propulsion were available,
- and Mars-class payloads had driven the requirements.
Apollo-XM preserves Apollo’s thrust-first philosophy —
but removes the chemical and structural limits of the 1960s.
Historical note — Saturn S-IC-8
The comparison baseline uses a hypothetical but historically grounded Saturn V variant.
NASA studies in the late Apollo era defined S-IC-8, a first-stage upgrade designed to fly with eight F-1–class engines instead of five.
The S-IC-8 tank was:
- lengthened and structurally reinforced
- designed for higher thrust loading
- intended to support advanced Apollo, Mars, and nuclear upper-stage missions
This configuration represents the maximum credible evolution of Saturn V within kerolox chemical propulsion.
Stage 1 is a single integrated launch stage combining solid radial boosters and a central super-heavy clustered engine core.
Both systems ignite at liftoff and operate in parallel to maximize thrust-to-weight during the atmospheric ascent phase.
| Parameter | Value |
|---|---|
| Role | Atmospheric lift & initial gravity well escape |
| Vehicle | Apollo-XM Launch Vehicle — Stage 1 |
| Architecture | Integrated core + radial boosters |
| Staging Philosophy | Parallel burn, booster separation |
| Structural Role | Primary atmospheric booster stage |
| Reusability | Engine hardware reusable (design intent) |
| Parameter | Value |
|---|---|
| Booster Count | 8 radial boosters |
| Booster Type | Ares-I Solid Rocket Booster (scaled) |
| Scale Factor | 240 % |
| Propellant | Solid Fuel |
| Thrust per Booster (ASL) | 1,444.8 kN |
| Thrust per Booster (Vac) | 1,600.0 kN |
| Total Booster Thrust (ASL) | ~11.6 MN |
| Total Booster Thrust (Vac) | ~12.8 MN |
| ISP (ASL / Vac) | 242 s / 268 s |
| Gimbal Range | 8.0° |
| Throttle Control | None (solid) |
| Mass Component | Value (per booster) |
|---|---|
| Dry Mass (structure) | ~1,327 t |
| Propellant Mass (Solid Fuel) | ~8,361 t |
| Total Mass (per booster) | ~9,688 t |
| Total Booster Mass (×8) | ~77,500 t |
Note:
In RealFuels / RealScaleBoosters, fuel mass is stored separately from part dry mass.
The extreme total mass reflects 240% scaling, where volume (and propellant mass) grows cubically.
| Parameter | Value |
|---|---|
| Engine Class | Super Heavy Booster Cluster Engine |
| Engine Implementation | Mk4 RAP-39000-B “Kingfisher” |
| Engine Count | 7 clusters |
| Propellant | LCH₄ / LOX |
| Thrust per Cluster (ASL) | 65,709.9 kN |
| Thrust per Cluster (Vac) | 71,306.1 kN |
| Total Core Thrust (ASL) | ~460 MN class |
| Total Core Thrust (Vac) | ~499 MN class |
| ISP (ASL / Vac) | 364 s / 395 s |
| Engine Mass (per cluster) | 20.3 t |
| Total Engine Mass | ~142 t |
| Throttle Control | Full |
| Gimbal | Enabled |
- Solid boosters provide immediate thrust dominance at liftoff
- Kingfisher clusters sustain high-efficiency thrust through max-Q and upper atmosphere
- The combined system replaces Saturn-V-style sequential staging with extreme parallel thrust
- Very high thrust margin compensates for:
- Exceptionally heavy upper stages
- Long-duration Mars mission payloads
- Conservative, pilot-friendly ascent profiles
This is architectural continuity, not replication:
Apollo-XM preserves Apollo’s thrust-first philosophy while scaling it to Mars-class mission requirements.
Stage 1 operates as a single continuous burn, but Kerbal Engineer Redux reports two distinct performance regimes due to changing vehicle mass and effective ISP.
| Parameter | v1.6 (8×240% + 7 Raptor Clusters) | v1.7 (16 × (2 × 150%) + 1 Raptor Cluster) |
|---|---|---|
| Active Propulsion | Solid boosters + Kingfisher clusters | Solid boosters (dual geometry) + Kingfisher clusters |
| Effective ISP | 312.3 s | ~Improved mass-weighted ISP |
| Total Thrust | 1,641,332 kN | Increased (geometry-optimized) |
| TWR (Max) | 1.24 (3.50) | ~1.03 → 2.09 dynamic ramp |
| Δv Contribution | 3,172 m/s | ~3,3xx m/s (flight-verified) |
| Burn Time | 2m 34s | Slightly extended due to scaling |
This phase provides maximum thrust dominance during liftoff and early atmospheric ascent, at the cost of lower effective ISP due to solid propellant contribution.
| Parameter | v1.6 (7 Raptor Clusters) | v1.7 (7 Raptor Clusters) |
|---|---|---|
| Active Propulsion | 7 Kingfisher clusters | 7 Kingfisher clusters |
| Effective ISP | 395.0 s | 395.0 s |
| Total Thrust | 499,143 kN | Same |
| TWR (Max) | 1.38 (3.86) | Slightly improved due to lower initial mass |
| Δv Contribution | 3,996 m/s | ~5,067 m/s (core fuel now dominant) |
| Burn Time | 3m 04s | Extended — full core utilization |
Note: Engines do not restart.
This phase is a continuation of the same ignition after booster separation.
The solid booster configuration used in v1.7 is conceptually based on the Ares I First Stage Booster, a five-segment solid rocket motor derived from the Space Shuttle Solid Rocket Boosters (SRBs).
It was designed to provide the initial thrust required to launch the Orion spacecraft as part of NASA’s Constellation Program.
In the Apollo-XM-1L project, this booster serves as a conceptual architectural reference rather than a direct reproduction of the real Ares I performance specifications.
| Configuration | Booster Layout | Stage 1 Δv | Total Δv |
|---|---|---|---|
| v1.6 | 8 × 240% | 6,546 m/s | 22,162 m/s |
| v1.7 | 16 Booster Units (2 × 150% each) | 6,783 m/s | 22,381 m/s |
Note: Each booster unit consists of two 150% scaled solid motors mounted as a single structural pair. Separation events occur at the unit level (16 total), not per individual motor.
- Stage 1 uses one ignition and one continuous burn
- KER separates reporting due to mass and ISP transitions
- Total engine runtime is the sum of both phases
- No coast, no shutdown, no restart
Stage 2 represents the first true upper stage of the Apollo-XM launch vehicle.
Although Kerbal Space Program assigns multiple numeric stages due to decouplers and
booster separation, Stage 2 is architecturally defined by propulsion role, not
by KSP stage numbering.
Stage 2 begins at KER stage S4.
Stage 2 ignition occurs immediately after completion of Stage 1 atmospheric lift and booster separation, under the following flight conditions:
| Parameter | Value |
|---|---|
| Entry Altitude | 268.5 km |
| Entry Velocity | 4,965 m/s |
| Atmospheric Regime | Upper atmosphere / near-vacuum |
| Guidance Mode | High-altitude ascent & orbital acceleration |
At ignition, the vehicle has already cleared the dense atmospheric regime.
Stage 2 therefore operates as a super-heavy high-altitude accelerator, bridging the gap between
atmospheric ascent and true orbital insertion.
This stage assumes the role traditionally split between upper first-stage burnout and classical second-stage acceleration in Saturn-era launch vehicles.
| Parameter | Value |
|---|---|
| Role | High-altitude acceleration & orbital insertion |
| Vehicle | Apollo-XM Launch Vehicle — Stage 2 |
| KSP Stage Index | S4 |
| Architecture | Vacuum-optimized, thrust-first |
| Structural Role | Upper ascent / orbital injection stage |
| Restart Capability | Multiple (design-enabled) |
| Reusability | Not reused |
| Parameter | Value |
|---|---|
| Engine Class | Vacuum-optimized methalox engine |
| Engine Implementation | Mk4 RAP-39000-B “Kingfisher” (vacuum regime) |
| Engine Count | 1 cluster |
| Propellant | LCH₄ / LOX |
| Thrust (Vacuum) | 71,306.1 kN |
| ISP (Vacuum) | 395 s |
| Throttle Control | Full |
| Gimbal | Enabled |
| Parameter | Value |
|---|---|
| Effective ISP | 395.0 s |
| Total Thrust | 71,306.1 kN |
| TWR (Max) | 0.91 (1.73) |
| Δv Contribution | 2,481 m/s (of 9,650 m/s remaining) |
| Burn Time | 3m 24s |
Stage 2 performs:
- Sustained acceleration above the dense atmosphere
- Completion of Earth orbital insertion
- Velocity shaping for Earth escape
- Preparation for continuous burn injection strategy
- Minimization of gravity and cosine losses
Stage 2 is not payload-optimized.
It is architecture-optimized, prioritizing thrust continuity and ascent stability
over absolute mass efficiency.
Stage 2 preserves the Saturn V S-II role, but replaces:
- hydrogen complexity
- low thrust-to-weight ratios
with:
- methalox simplicity
- higher thrust margins
- improved guidance authority
- seamless integration with continuous-burn interplanetary injection
This reflects architectural continuity, not replication: the staging logic remains Apollo-derived, while propulsion technology evolves.
In summary, Stage 2 functions as a super-heavy booster operating in vacuum.
The fundamental difference relative to Stage 1 is not architectural, but environmental: Stage 2 ignites at approximately 268.5 km altitude and ~4.97 km/s velocity, inherited directly from Stage 1.
From this point onward, Stage 2 continues aggressive thrust-first acceleration outside the atmosphere, prioritizing velocity accumulation and orbital energy rather than lift.
Stage 3 represents the final high-thrust acceleration stage of the Apollo-XM launch vehicle. Although numbered as S3 in KSP by coincidence, its operational role is consistent with a classical orbital acceleration stage, operating entirely above the sensible atmosphere.
Stage 3 ignites after completion of the super-heavy booster phases and continues velocity build-up toward orbital insertion and mission-specific departure profiles.
Stage 3 ignition occurs after completion of the super-heavy booster phases, under the following flight conditions:
| Parameter | Value |
|---|---|
| Entry Altitude | 432.5 km |
| Entry Velocity | 7,093 m/s |
| Atmospheric Regime | Near-vacuum |
| Guidance Mode | Vacuum-optimized ascent |
At ignition, the vehicle is already well above the dense atmosphere, allowing Stage 3 to operate entirely as a high-efficiency orbital acceleration system, unconstrained by aerodynamic or thermal limits.
| Parameter | Value |
|---|---|
| Role | High-altitude & orbital acceleration |
| Vehicle | Apollo-XM Launch Vehicle — Stage 3 |
| KSP Stage ID | S3 |
| Architecture | Multi-engine liquid propulsion stage |
| Operating Regime | Near-vacuum / vacuum |
| Structural Role | Final ascent propulsion stage |
| Restart Capability | Enabled |
| Parameter | Value |
|---|---|
| Engine Type | RS-25 (Space Shuttle Main Engine) |
| Engine Count | 5 × RS-25 |
| Propellant | RP-1 / LOX |
| Thrust (ASL) | ~9,225 kN |
| Thrust (Vac) | ~11,395 kN |
| ISP (ASL / Vac) | ~452 s / ~452 s |
| Gimbal Range | 10.5° |
| Throttle Control | Full |
| Engine Mass (total) | ~19.5 t |
| Metric | Value |
|---|---|
| TWR (max) | 0.31 (0.77) |
| Δv (Stage / Total) | 4,007 / 13,657 m/s |
| Burn Time | 14m 23s |
Stage 3 performs:
- Final atmospheric exit (upper fringe)
- Primary orbital velocity accumulation
- Orbit shaping and circularization
- Injection setup for downstream mission phases
Unlike a payload-optimized upper stage, Stage 3 preserves thrust-first logic, ensuring stable guidance, controllability, and generous margins for heavy Mars-class payloads.
Stage 3 completes the Apollo-XM ascent stack by:
- Using multiple high-ISP engines for redundancy and control authority
- Operating exclusively in low-drag conditions
- Maintaining Apollo-style continuous acceleration
- Avoiding coast-heavy or fragile staging strategies
This ensures operational robustness over minimum-mass optimization, consistent with the Apollo-XM philosophy of reliability-first design.
Important staging note:
In Kerbal Space Program, decouplers and separations are counted as stages.
Apollo-XM Stage 4 corresponds to KSP stage S2.
Stage 4 is the final propulsion stage of the Apollo-XM launch architecture.
It receives a vehicle that is already escaping Earth’s gravity well and performs
the final orbital energy shaping and injection burn.
| Parameter | Value |
|---|---|
| Entry Altitude | ~1,473 km |
| Entry Velocity | ~9,968 m/s |
| Orbital State | Earth-relative, committed escape trajectory |
| Delivered By | Apollo-XM Stage 3 |
| Parameter | Value |
|---|---|
| Role | Final orbital acceleration & injection |
| Vehicle | Apollo-XM Launch Vehicle — Stage 4 |
| Architecture | Single-engine liquid stage |
| Structural Role | Orbital injector |
| Restart Capability | Enabled |
| Throttle Control | Full |
| Parameter | Value |
|---|---|
| Engine Type | RS-25 (Space Shuttle Main Engine) |
| Engine Count | 1 × RS-25 |
| Propellant | RP-1 / LOX |
| Thrust (ASL) | ~1,844 kN |
| Thrust (Vac) | ~2,279 kN |
| ISP (ASL / Vac) | ~366 s / ~452 s |
| Gimbal Range | ~10.5° |
| Engine Restart | Enabled |
| Parameter | Value |
|---|---|
| TWR (max) | ~0.91 (1.73) |
| Δv Contribution | ~2,481 m/s |
| Burn Time | ~3 min 24 s |
| KSP Stage ID | S2 |
Stage 4 operates entirely outside the atmosphere and performs:
- Precise acceleration while already escaping Earth
- Energy trimming of a hyperbolic trajectory
- Final injection cleanup for interplanetary transfer readiness
This stage does not provide lift —
it operates purely as a precision orbital injector.
Stage 4 is the Apollo-XM analogue of the Saturn V S-IVB, but pushed to much higher entry energy:
- Single, high-efficiency engine
- Long-duration, controlled burn
- Restart capability for trajectory shaping
Apollo-XM preserves Apollo’s staging logic while scaling velocity, altitude, and mission scope to Mars-class escape conditions.
Stage 5 is the final propulsion stage of the Apollo-XM launch stack.
It completes Mars Injection, performs all interplanetary correction maneuvers,
and executes a two-pass Mars orbital capture strategy using continuous braking logic.
This stage operates entirely in vacuum and remains attached until stable Mars orbit conditions are achieved.
| Parameter | Value |
|---|---|
| Orbital Frame | Sun-centric (heliocentric) |
| Entry Location | Post-Earth SOI exit |
| Entry Velocity (heliocentric) | ≥ 33,000 m/s |
| Orbital State | Interplanetary transfer to Mars |
| Delivered By | Apollo-XM Stage 4 |
| Parameter | Value |
|---|---|
| Role | Mars injection, transfer correction, orbital capture |
| Vehicle | Apollo-XM Launch Vehicle — Stage 5 |
| Architecture | Single-engine liquid stage |
| Structural Role | Interplanetary propulsion stage |
| Restart Capability | Enabled (multiple restarts) |
| Throttle Control | Full |
| Parameter | Value |
|---|---|
| Engine Type | RS-25 (Space Shuttle Main Engine) |
| Engine Count | 1 × RS-25 |
| Propellant | RP-1 / LOX |
| Thrust (ASL) | ~1,844 kN |
| Thrust (Vac) | ~2,279 kN |
| ISP (ASL / Vac) | ~366 s / ~452 s |
| Gimbal Range | ~10.5° |
| Engine Restart | Enabled |
| Parameter | Value |
|---|---|
| Primary Function | Mars Injection + Orbital Capture |
| Δv Allocation | Mars transfer + corrections |
| Burn Profile | Multiple long-duration burns |
| Operational Mode | Continuous braking (no suicide burn) |
Stage 5 executes a two-pass Mars orbit insertion, optimized for control and margins:
-
Initial Mars Encounter
- Elliptical capture orbit
- Initial periapsis (PE): ~56 km
- Continuous retro-burn at periapsis
-
Second Periapsis Pass
- Orbit refinement
- Final periapsis (PE): ~50 km
- Transition to stable Mars orbit
This approach minimizes:
- peak thermal loads
- extreme thrust spikes
- last-second braking risks
- Stage 5 replaces a classical single-burn MOI with Apollo-style continuous braking
- The RS-25 provides:
- exceptional vacuum efficiency
- fine throttle control
- restart reliability for long missions
- This stage remains attached until:
- Mars orbit is stabilized
- rendezvous or descent preparation begins
Stage 5 completes the Earth → Mars propulsion chain, delivering the Apollo-XM payload into a controlled, pilot-friendly Mars orbit.
Apollo-XM follows a strict, physics-driven reusability rule.
| Stage | Reusability | Reason |
|---|---|---|
| Stage 1 | Recoverable (design intent) | Atmospheric booster stage; sub-orbital energy allows controlled recovery |
| Stage 2 | Not recoverable | Excess orbital inertia after separation prevents return |
| Stage 3 | Not recoverable | High-energy orbital acceleration stage |
| Stage 4 | Not recoverable | Expended into heliocentric (Sun) orbit |
| Stage 5 | Not recoverable | Expended during Mars injection and lost during Mars atmospheric entry |
All Apollo-XM landers are designed to enter Mars operations from a stable circular parking orbit, ensuring repeatable, low-risk deployment.
Apollo-XM landers are equipped with auxiliary electric wheel assemblies intended for low-speed surface repositioning after touchdown.
These wheels are not rovers and are not designed for sustained traversal.
| Parameter | Value |
|---|---|
| Mobility Type | Electric wheels (auxiliary) |
| Drive Purpose | Fine positioning & short relocation |
| Recommended Max Speed | ≤ 5 m/s |
| Absolute Limit | Not defined (structural risk increases rapidly) |
| Steering | Differential / limited steering |
| Power Source | Onboard electric system |
| Terrain Assumption | Flat to mildly uneven terrain |
Surface speed limits are driven by inertial and structural considerations, not weight.
- Speeds above 5 m/s are not recommended
- Risks increase sharply beyond this limit:
- wheel motor overheating
- landing leg side-load amplification
- structural fatigue at wheel attachment points
- loss of traction on regolith
- Wheels are intended for:
- pad clearance
- docking alignment
- hazard avoidance
- Wheels are not suitable for:
- long-distance travel
- slopes
- rough terrain traversal
Primary surface mobility for Mars missions is expected to be provided by dedicated rovers, not landers.
This design preserves Apollo-style landing stability, with minimal but practical post-landing mobility.
| Parameter | Value |
|---|---|
| Target Orbit | Circular Mars Orbit |
| Entry Altitude | 212 km |
| Entry Velocity | ~3,455 m/s |
| Environment | Mars (thin atmosphere) |
| Parameter | Value |
|---|---|
| Lander Mass (Mars) | ≈ 149.9 t |
| Mars Surface Gravity | 0.38 g (Earth) |
| Effective Weight on Mars | ≈ 57 t (Earth-equivalent) |
While the mass is unchanged, the operational load on engines, legs, and wheels is significantly reduced.
- Descent is fully propulsive (Apollo-style continuous braking)
- No parachutes or aero capture reliance
- Thrust margin allows:
- Controlled descent
- Hover / divert
- Abort ascent if required
- Engine clustering provides redundancy against single-engine failure
This configuration defines the baseline standard for all Apollo-XM landers.
| Parameter | Value |
|---|---|
| Role | Fuel delivery and surface propellant infrastructure |
| Vehicle | Apollo-XM-1F Fuel Lander |
| Configuration | Uncrewed, autonomous |
| Wet Mass | ~149.9 t |
| Power Systems | Passive |
| Structural Role | Surface propellant depot |
Although the lander mass is ~149 t, Mars gravity reduces effective surface weight to approximately 38% of Earth, significantly lowering static wheel and landing leg loads.
Environment-corrected values (Mars atmosphere ≈ near-vacuum)
Apollo-XM-1F and Apollo-XM-1L share the same descent propulsion architecture and structural platform.
The difference lies in payload mass and mission role.
| Parameter | Value |
|---|---|
| Engine Type | Gemini LR-91 Mini Rocket Engine |
| Engine Count | 6 |
| Propellant | Aerozine-50 / NTO |
| Throttle Capability | Yes |
| Restart Capability | Yes (multiple ignitions) |
| Ullage Requirement | Yes |
| Auto-Mobility | Yes |
| Parameter | Value |
|---|---|
| Total Thrust (Mars ATM) | ≈ 956 kN |
| Total Thrust (Vacuum) | ≈ 960 kN |
| ISP (Mars ATM) | ≈ 321.5 s |
| ISP (Vacuum) | ≈ 323.0 s |
| Burn Time (full tanks) | ≈ 6 min |
| TWR on Mars (max) | ≈ 1.70 |
| Parameter | XM-1F (Fuel Lander) | XM-1L (Life Support Lander) |
|---|---|---|
| Role | Surface propellant depot | Life support & consumables |
| Configuration | Uncrewed | Uncrewed |
| Wet Mass | ≈ 149.9 t | ≈ 131.7 t |
| Total Δv (Mars) | ≈ 4,186 – 4,205 m/s | ≈ 5,715 - 5,741 m/s |
| Structural Role | Fuel storage | Habitable systems supply |
Although both landers have similar wet mass, the XM-1L allocates internal volume and mass to life-support consumables instead of surface propellant reserves, slightly reducing available Δv.
Mars gravity (~38% of Earth) significantly reduces effective landing loads for both configurations.
- Apollo-XM-1F is the first surface asset deployed in the Mars campaign.
- Delivers ascent and surface propellant for later crew operations.
- Uses Apollo-style continuous braking (no suicide burn).
- No crew systems, no return capability.
- After landing, the vehicle becomes permanent surface infrastructure.
This lander forms the logistics foundation of the Apollo-XM Mars architecture.
| Parameter | Value |
|---|---|
| Role | Crewed Mars landing and ascent vehicle |
| Vehicle | Apollo-XM-1C Crew Lander |
| Configuration | Crewed (3 seats), autonomous descent |
| Wet Mass | ~149.9 t (descent configuration) |
| Power Systems | Passive / fuel-cell supported |
| Structural Role | Crewed surface lander with integrated ascent module |
Unlike XM-1F (Fuel Lander), XM-1C carries crew accommodations and a fully integrated Ascent Mission Module (AMM).
Environment-corrected values (Mars atmosphere ≈ near-vacuum)
| Parameter | Value |
|---|---|
| Engine Type | Gemini LR-91 Mini Rocket Engine |
| Engine Count | 6 |
| Propellant | Aerozine-50 / NTO |
| Throttle Capability | Yes |
| Restart Capability | Yes (multiple ignitions) |
| Ullage Requirement | Yes |
| Parameter | Value |
|---|---|
| Total Thrust (Mars ATM) | ≈ 956 kN |
| ISP (Mars ATM) | ≈ 321.5 s |
| Burn Time (full tanks) | ≈ 6 min |
| Total Δv (Mars) | ≈ 4,186 – 4,205 m/s |
| TWR on Mars (max) | ≈ 1.70 |
Descent propulsion is identical in capability to XM-1F.
| Parameter | Value |
|---|---|
| Engine Count | 4 |
| Configuration | Dedicated ascent cluster |
| Propellant | Aerozine-50 / NTO |
| Throttle | Limited / mission-optimized |
| Parameter | Value |
|---|---|
| Total Δv (Mars Ascent) | ≈ 5,361 m/s |
| Mission Role | Surface-to-Mars-Orbit crew return |
The AMM provides independent ascent capability to rendezvous with the pre-positioned return vehicle (XM-2R).
- XM-1F establishes propellant infrastructure.
- XM-1L delivers life support and consumables.
- XM-1C performs crewed descent and ascent.
- XM-2R waits in Mars orbit for crew return.
Apollo-XM architecture separates descent mass from ascent survivability, maximizing robustness while preserving mission redundancy.
Apollo-XM-2R is injected to Mars orbit in advance of the crew mission.
It serves as the Earth Return Vehicle (ERV), carrying:
- Return propellant
- Life support reserves for transit
- Earth re-entry stack
This architecture removes ascent-to-transit mass from the surface mission, dramatically improving crew safety margins.
| Parameter | Value |
|---|---|
| Role | Mars orbit return vehicle |
| Configuration | Uncrewed pre-deployment |
| Engine Type | RS-25 (Vacuum optimized) |
| Engine Count | 1 per stage |
| Stage Count | 2 |
| Propellant | LH2 / LOX |
| Power Systems | Passive / minimal orbital support |
| Structural Role | Earth return propulsion stack |
| Parameter | Value |
|---|---|
| Vacuum ISP | ≈ 452 s |
| Total Thrust | ≈ 2,279 kN |
| Wet Mass | ≈ 146.8 t |
| Dry Mass | ≈ 78.6 t |
| Δv (Mars orbit) | ≈ 2,946 m/s |
| Burn Time | ≈ 2 min 19 s |
| TWR (Mars orbit) | ≈ 4.13 |
This stage performs:
- Trans-Earth Injection (TEI)
- Major orbital corrections
| Parameter | Value |
|---|---|
| Vacuum ISP | ≈ 452 s |
| Total Thrust | ≈ 2,279 kN |
| Wet Mass | ≈ 64.6 t |
| Δv (vacuum) | ≈ 9,501 m/s |
| Burn Time | ≈ 1 min 51 s |
| TWR (Mars orbit) | ≈ 9.39 |
This stage provides:
- Final injection shaping
- High-energy maneuver capability
- Abort and contingency margin
Combined Δv (usable mission stack):
≈ 2,946 m/s (primary stage)
≈ 9,501 m/s (upper stage capability envelope)
This provides:
- Mars orbit departure margin
- Trajectory correction margin
- Safe Earth return window flexibility
Apollo-XM-2R is deployed before crew arrival, ensuring:
- Return vehicle is confirmed operational in Mars orbit
- No dependence on surface fuel production
- Surface crew only needs to reach orbit
This mirrors Apollo lunar logic:
“Return capability is guaranteed before descent.”
- High Isp hydrogen architecture
- Extremely high TWR margin in Mars orbit
- Minimal structural mass overhead
- Dedicated life-support mass allowance for return transit
Apollo-XM-2R completes the closed-loop Mars mission architecture.