PROPULSION / Decision model
Let the evidence change the plan.
Ten routes. Three scenarios. A clear separation between published evidence and your research preferences.
External demonstrations and proposed Metric Flight work are separate. No Metric Flight propulsion measurement is reported. This tool does not estimate success probabilities or allow a typed likelihood ratio to upgrade scientific evidence.
Test how much your preferences change the plan.
Choose the relative importance of mission value versus ease of testing. Edit three scenarios for each route. Labels 0–5 are ordered editorial judgments, not measured ratios or dollars. Index = 20 × [weight × value + (1 − weight) × (5 − burden)]. Burden runs from 0 (least) to 5 (most). The index is a preference aid, not an engineering forecast.
Conservative = lower value / higher burden; optimistic = higher value / lower burden. The model requires this ordering. A changed rank across cases is marked sensitive; unchanged rank is not proof of robustness outside these three cases. Equal scores share a rank.
Magnetic nozzle
Published ground device
Field shaping and full electrical efficiency
Electrospray
Flight demonstrated externally
Precision control and lifetime
Hall / ion
Flight demonstrated externally
Benchmark for electric transport
Laser thermal
Concept and subsystem research
Receiver and beam feasibility
Laser ablation
Published laboratory devices
Repeatable impulse and contamination
Electrodynamic tether
Flight experiments externally
Environment-specific current closure
Particle beam
Concept study
Beam delivery and capture losses
Photon emitter
Established radiation recoil
Very small force per unit power
Fusion exhaust
Propulsion concept research
Fusion-powered directed exhaust
Anomalous vacuum thrust
No established anomalous mechanism
Null tests and ordinary coupling
Three scenarios, one visible sensitivity check.
| Route | Conservative rank / index | Reference rank / index | Optimistic rank / index | Sensitivity |
|---|
Version 2 replaces the former probability model. Old probability files are not converted into evidence or accepted by this tool. Values remain in this browser; exports record the model, date, assumptions and evidence boundary. No inputs are submitted.
Four longer-horizon routes
Particle beam
An external beam of matter supplies momentum. The accelerator, beam spreading, intercept efficiency and destination infrastructure belong in the system budget. Start with beam transport and capture calculations, not a heavy-payload speed claim.
NASA NIAC concept study ↗Photon emitter
An onboard directional emitter recoils at F = P/c for emitted optical power: 1 kW produces about 3.34 µN. Electrical losses and radiator mass make the spacecraft budget harder. This route needs no sail, but quantum coherence does not remove momentum conservation.
NIST radiation-pressure measurement ↗Fusion exhaust
A propulsion system must turn fusion energy into a directed exhaust and pay for confinement, fuel handling, shielding and heat rejection. A fusion reaction or a concept study alone does not establish a functioning fusion engine.
NASA NIAC fusion concept ↗Anomalous vacuum thrust
No established mechanism supplies sustained isolated thrust without momentum exchange. Treat apparent forces as a metrology question: bound thermal drift, cables, electromagnetic coupling, outgassing and photon recoil. Published high-accuracy EMDrive null results are relevant counterevidence. A slider cannot overturn them.
High-accuracy EMDrive null testing ↗THE NEXT MOVE / BUILD THE EVIDENCE
A better engine begins
with a better experiment.
Bring a measurement, a materials capability or a mission requirement. Help turn a promising mechanism into a testable design.