Pure air breathing
CH₄ fuel with atmospheric oxygen. Ram compression feeds the chamber; inlet momentum is deducted from gross thrust. Requires an external Mach 2.2 start. No static thrust and no vacuum operation.
METHANE / AIR / LIQUID OXYGEN · INITIAL DESIGN STUDY
A small shuttle.
A difficult orbit.
Explore two wobbling-disk engine concepts and a one-person spaceplane. Follow the computed ascent, inspect the CAD, and see where the physics stops supporting the ambition.
Loading feasibility result…
Preliminary numerical study. Sustained engine detonation, flightworthiness, and SSTO feasibility remain unestablished.
01 / FORM & PACKAGING
Inside the concept
Loading real CAD tessellation…
14 m × 9 m · packaging envelopes
Drag to orbit · scroll to zoom · hover to identify
Air + rocket
CH₄/LOX supplies runway acceleration and high-altitude thrust. A proposed isolation system closes the air path for rocket operation. This is a combined-cycle concept; both propellants are liquids in storage.
A slower mechanical cycle
The previous 844.7 Hz candidate failed its structural screen. This candidate uses 20 Hz wobble, separate from approximately 0.9–1.3 kHz ideal gas-wave circulation. Pressure supports and seals remain unresolved.
02 / ASCENT & ORBIT CLOSURE
Fly the numbers
Ascent ground track
Altitude / km · downrange / kmSpeed / km s⁻¹
Thrust, drag & lift / kN
Propellant remaining / tonnes
Dynamic pressure / kPa
Proper acceleration / g
Nose heating estimate / kW m⁻²
LOSS ACCOUNTING
Lower gravity loss is only one term.
Lift can keep the path shallow, reducing the gravity component along the flight direction. It also costs induced drag; longer atmospheric flight accumulates drag and fuel consumption. Orbit still requires enough horizontal speed and a perigee above the atmosphere.
Signed integrals run from liftoff to the displayed endpoint, including coast. Runway impulse and fuel use are separate. Comparisons use different endpoints and do not establish a universal Δv saving.
LIVE MODEL / FIXED GUIDANCE
Change the assumptions
Runs Python on machine 146. Sensitivity experiments, not validated engine settings. Guidance is not reoptimized.
Flight equations, constraints, optimizer and uncertainty
The model integrates a spherical, rotating Earth, variable gravity, separate propellant inventories and RK4 time stepping. The equatorial eastward launch is favorable; no launch-site restrictions are modeled. Layer atmosphere through 84.852 km geopotential altitude, followed by a simple low-density extension.
ḣ = V sin γ V̇ = (T cos α − D)/m − (μ/r² − Ω²r) sin γ γ̇ = (T sin α + L)/(mV) + [V/r − (μ/r² − Ω²r)/V] cos γ + 2Ω L = q S CL D = q S (CD₀ + 0.16 CL²) Tair = ṁair [(1 + f) Ve − V] Trocket = ṁprop Isp,vac g₀ − pamb Ae Inertial velocity: Vt = V cos γ + Ωr, Vr = V sin γ.
Assumed methane LHV 50 MJ/kg; air equivalence ratio ≤0.9; inlet total-pressure recovery from 0.82 at Mach 2.2 to 0.20 at Mach 5; combustor pressure multiplier 0.92, with no detonation pressure-gain credit. Averaged hot-gas cp and γ and ideally expanded variable nozzles make this a preliminary cycle map. High-temperature inlet chemistry and installed nozzle losses remain unresolved.
Search limits: 55 kPa dynamic pressure, 4 g proper load, 800 kW/m² nose heat-flux estimate. A 150 km altitude goal accompanies maximum osculating perigee. Penalty optimization is a search aid; violated limits are displayed as failures. No global-optimum claim. Sutton–Graves heating is an estimate, not a TPS or safe-landing analysis.
03 / GAS CHEMISTRY
Detonatable mixture ≠ qualified engine
Ideal CJ speeds and finite-rate planar ZND profiles. ZND uses 1% overdrive to avoid the sonic endpoint singularity. No cell-width, ignition-success or sustained rotating-engine claim is inferred.
| Mixture / state | Upstream | CJ speed | Induction length | Reaction scale | Status |
|---|
Planar temperature profile
Distance behind shock / mm. View focuses on reaction region; raw full profiles remain downloadable.
What remains to make it work
Real refill, mixing and wave survival must be solved in the moving chamber. Methane and oxygen are cryogenic liquids in storage; these chemistry calculations start with gases and do not establish vaporization or injection performance.
Cold methane–air has a much larger computed induction scale than preheated air. The short oxygen-case reaction scale and high shock pressure make the earlier 11.7 mm CFD cells inappropriate for claiming resolved methalox detonation.
A manufacturable load path, cooling, pressure losses, mechanism sensitivity and mesh-resolved sustained operation remain open.
Full chemistry output ↓04 / PROVENANCE & DELIVERABLES
Evidence you can inspect
The earlier engine
Original files remain at /root/wobble-engine on 146 and D:\work\projects\wrde on TH155. The old candidate produced 100 μs of reactive startup CFD, not established sustained detonation.
The structural screen predicted 28.45 mm displacement and 11.62 GPa elastic extrapolated stress at 844.7 Hz. That invalidated the rigid elastic design; those are not post-yield operating predictions.
Recovered evidence summary ↓Reproducible study
Parametric CAD, traceable cycle assumptions, deterministic trajectory search, CSV histories, planar chemistry and a live sensitivity model.
Source + data bundle ↓CAD and packaging audit ↓
Trajectories and search results ↓
SHA-256 manifest ↓
Concept, with explicit limits
No physical engine test, new coupled engine CFD, inlet CFD, six-degree-of-freedom stability, detailed flexible-body analysis, thermal protection design, crew qualification or return-and-landing simulation has been completed for this candidate.
Reaching 100 km is suborbital. This study does not certify a feasible SSTO or detonating hardware.
Detailed findings and next decisions ↓Primary references
- NASA — Rotating Detonation Rocket Engine Development · experimental methalox context.
- Methane-air continuous rotating detonation in the hollow chamber · experimental mixture feasibility.
- Caltech EDL — Shock & Detonation Toolbox · CJ and ZND methods.
- Cantera 3.2 documentation · thermochemistry.
- NASA Glenn — Ramjet / Scramjet Thrust · inlet momentum.
- NOAA / NASA / USAF — Standard Atmosphere 1976 · atmosphere layers.
- NASA Langley — Airbreathing/Rocket SSTO Design Matrix · integrated vehicle trades, not evidence for this craft.
- Sutton & Graves — Stagnation-Point Convective Heating · heating estimate.