Starshot System Model
The Breakthrough Starshot system model draws an ontology of simpler models to compute cost-optimal interstellar mission point designs.
This is a non-public model: Requests for access may be directed to Breakthrough Initiatives.
Reference Cases
(please run only one or two of these at once to minimize the load on the datacenter)
0.2 c Centauri System Convergence Missions: https://models.parkinresearch.com/inference?161?0.2%20c%20%CE%B1Cen?Sailcraft[t%E2%82%84=0].%CE%B2=0.2?
100 au/yr Solar System Science Chipsats: https://models.parkinresearch.com/inference?161?100%20au/yr%20Solar%20System%20Chipsat?Beamer.n=1000?Beamer[t%E2%82%83=0].Motion.RTA.A=1e-05?Beamer.Lasers.CapEx.$/W=1?Sailcraft.Payload.Mass.kg=0.1?Sailcraft[t%E2%82%84=0].%CE%B2.au/y=100?
10 au/yr Solar System Polar Cubesat: https://models.parkinresearch.com/inference?161?Polar%20Cubesat?Beamer.Lasers.CapEx.$/W=1?Sailcraft.Payload.Mass.kg=1?Beamer[t%E2%82%83=0].Motion.RTA.A=0.0001?Beamer[t%E2%82%83=0].Motion.RTA.R=0.2?
30 au/yr Ecliptic Picosat: https://models.parkinresearch.com/inference?161?Ecliptic%20Picosat?Beamer.n=1000?Beamer%5bt%E2%82%83=.M.R.A=1.0e-05?Beamer.L.C.$/=0.1?Sailcraft.P.M.kg=0.1?Sailcraft%5bt%E2%82%84.%CE%B2.a=30?
Adjustable inputs (not exhaustive)
| Description | Variable name |
|---|---|
| Cost of energy generation and transmission to beam director site per pulse [$/kWh] | Beamer.Rate_per_pulse |
| Number of missions that the beamer is cost-optimized for (capital cost of beamer plus energy cost of this many missions is the quantity that is minimized) | Beamer.n |
| Fraction of transmitted laser power that successfully exits the atmosphere (is not lost to scattering or absorption) | Beamer.Beam.η₃ₐ |
| Initial distance between laser source and lightsail | Beamer[t₃=0].Beam.r.km |
| Fraction of wallplug to transmitted laser power | Beamer.Lasers.η |
| Laser capex per unit power | Beamer.Lasers.CapEx.$/W |
| Optics capex per unit area | Beamer.Optics.CapEx.$/m² |
| Energy storage capex per kWh of capacity | Beamer.Storage.CapEx.$/kWh |
| Grid to storage energy transfer efficiency | Beamer.Storage.η₁₂ |
| Storage to radiated energy transfer efficiency | Beamer.Storage.η₂₃ |
| Maximum power provided by the grid (e.g. via transmission lines) that is not provided from locally stored energy | Beamer.Storage.P₁_max.GW |
| Areal density of sail material (excludes payload) | Sailcraft.Substrate.ρₐ.g/m² |
| Lightsail absorptance | Sailcraft.Substrate.Optical.A |
| Lightsail reflectance | Sailcraft.Substrate.Optical.R |
| Lightsail total hemispherical emissivity | Sailcraft.Substrate.Thermal.ε |
| Maximum allowable lightsail temperature | Sailcraft[T⁺].Substrate.Thermal.T.K |
| Lightsail cruise velocity | Sailcraft[t₄=0].β.c |
Notable outputs (not exhaustive)
| Description | Variable name |
|---|---|
| Capital cost of the beam facility needed to carry out the specified mission(s) | Mission.CapEx |
| Lightsail payload fraction | Mission.M₂/M₀ |
| Mission capex per unit payload | Mission.CapEx/M₂ |
| Payload specific energy cost | Mission.M$/M₂_PP |
| Time dilation factor in cruise | Sailcraft[t₄=0].Rel.γ |
| System energy efficiency. Fraction of stored energy that becomes sailcraft kinetic energy as measured at the start of the cruise phase. | Mission.η |
| Peak power transmitted by beam director as measured just after leaving beamer primary optic | Beamer.Beam.P₃ |
| Pulse duration as measured in the beamer frame | Beamer[t₃].Closed.t |
| Acceleration duration as measured in the beamer frame | Beamer[t₃].Closed.tᵦ |
| Acceleration duration as measured in sailcraft rest frame (proper time) | Beamer[t₃].Closed.t₄′ |
| Acceleration distance since t₃=0 | Beamer[t₃].Δr.au |
| Acceleration at t₃=0 (beam start) | Beamer[t₃].Initial.Sailcraft.Rel.rest.a.g |
| Acceleration at t₄=0 (beam cutoff) | Beamer[t₃].Final.sailcraft.Rel.rest.a.g |
| Mean photon pressure felt by sail | Sailcraft[T⁺].Substrate.<σ₁₁> |
| Mean force felt by sail | Sailcraft[T⁺].Substrate.F |
| Mean radiant exitance of the beamer when operating at maximum power | Beamer.Beam.<I₃>.kW/m² |
| Mean radiant exitance of the beamer when operating at t₃=0 (beam start) | Beamer[t₃=0].Beam.<I₃>.kW/m² |
| Mean radiant exitance of the beamer when operating at t₄=0 (beam cutoff) | Beamer[t₄=0].Beam.<I₃>.kW/m² |
| Mean irradiance over sail at maximum allowable sail temperature | Sailcraft[T⁺].Substrate.<Iᵦ>.GW/m² |
| Mean irradiance over sail in its rest frame when operating at t₃=0 (beam start) | Beamer[t₃=0].Beam.<I₄′>.GW/m² |
| Mean irradiance over sail in its rest frame when operating at t₄=0 (beam cutoff) | Beamer[t₄=0].Beam.<I₄′>.GW/m² |
Associated Models
Lightsail Carrier Satellite [U.S. persons only]: https://models.parkinresearch.com/inference?248?Starshot%20carrier%20satellite