Long Passage (V1)
Colony transport, inner system to Saturn
Colony transport, inner system to Saturn. Arriving on her fourth crossing of about a year, with settlers and the habitat modules for the next Titan wing. Her radiators glow orange, her reactor rides far behind a shadow shield, and her two counter-rotating drums give her passengers 0.56 g.
Propulsion: D-3He fusion, magnetic nozzle, hydrogen mass addition. Envelope: 650 m long by 122 m maximum diameter design · reactor about 400 m from the habitat drums behind a shadow shield (Meridian heritage)
All input and derived values below are read from assets/data/vehicles.json, generated by scripts/analysis/vehicle_budget.py. Values marked “verify” are not established facts.
Open the 3D model See it in the tour How the propulsion works
Inputs
| Input | Value | Basis and notes |
|---|---|---|
| Exhaust velocity, km/s | 200 | challenge Verify before treating as established Razin et al. 2014, A direct fusion drive for rocket propulsion, Acta Astronautica 105, doi:10.1016/j.actaastro.2014.08.008 (DFD concept) DFD-class concepts span roughly 50-500 km/s depending on mass addition |
| Mission Δv, km/s | 100 | design |
| Departure mass, t | 10,000 | design |
| Acceleration, g | 0.001 | design |
| Jet efficiency | 0.6 | challenge Verify before treating as established |
| Hot waste fraction | 0.2 | challenge Verify before treating as established |
| Radiator temperature, K | 1,200 | challenge liquid-droplet radiator |
| Habitat drum radius, m | 56 | design |
| Habitat spin, rpm | 3 | design |
Derived performance
| Quantity | Value |
|---|---|
| Mass ratio | 1.649 |
| Dry mass, t | 6,065.3 |
| Reaction mass LH₂, t | 3,934.7 |
| LH₂ volume, m³ | 58,354 |
| Tanks | 6 x 18 m diameter, 44 m long |
| Thrust, kN | 63.7 |
| Jet power, GW | 6.37 |
| Fusion power, GW | 10.62 |
| Total burn, days | 142.9 |
| Fusion fuel burned, kg | 371 |
| Fuel energy density, J/kg | 3.531e+14 |
| Hot radiator area, m² | 10,630 |
| Tank count | 6 |
| Tank diameter, m | 18 |
| Tank length, m | 44.2 |
| Radiator wings | 4 |
| Radiator wing length, m | 150 |
| Radiator wing chord, m | 17.7 |
| Trip estimate, days | 366 |
| Spin gravity, g | 0.56 |