How much does StarRoad cost?
Costs and Payback
Capital expenditure, financing structure, delivery cost and sources of return.
~$300 billionmedian estimate for the complete system
$100–150 billionGATES and energy storage
$150–200 billiontransport component
8–12 yearsestimated overall payback period
Economic model
Capital expenditure, the energy component, storage, industrial centres, delivery cost and payback dynamics.
Methodology and key assumptions
The economic model is based on the following principles:
- Series production and in-house manufacturing — equipment costs for tunnel-boring machines, generators and storage systems fall by 30–50% through scale.
- Localization — using local resources, labour and construction materials in Africa, as supported by Spon's African Construction Cost Handbook.
- Current market prices — 2025–2026 figures for battery energy-storage systems (BESS) and geothermal power stations.
- Exchange rates — 1 USD ≈ 100 RUB / 0.90 EUR, for context. All calculations use constant 2025 US dollars and exclude inflation. An uncertainty of ±30% is consistent with pre-feasibility-study standards.
Tunnel-construction costs under African conditions
- Spon's African Construction Cost Handbook provides detailed labour and material costs for 13 African countries. It contains no direct unit price for very large-diameter tunnels because conditions vary greatly, but it provides a basis for calibrating the estimates.
| Type of work | Quantity | Average cost per km | Total cost (USD billion) | Basis |
|---|---|---|---|---|
| Main tunnel (17.5 × 12.5 m) | 2,050 km | $12–18 million | $24.6–36.9 | Extrapolation from global data for large cross-sections, adjusted for African conditions. |
| Collector tunnels (6 × 2,050 km, ø2 m) | 12,300 km | $3–5 million | $36.9–61.5 | Based on actual African mine-development costs of $3,500/m for small cross-sections. |
| Service tunnel (ø3 m) | 2,050 km | $4–6 million | $8.2–12.3 | As for the collector tunnels, adjusted for the larger cross-section. |
| Inclined tunnels (40 × 16 km, 17.5 × 12.5 m) | 640 km | $12–22 million | $7.7–14.1 | As for the main tunnel, with a premium for the 30° incline. |
| Total tunnelling | 17,040 km | $77.4–124.8 |
Tunnel-boring-machine fleet with in-house production
- A series order comprising 40 main TBMs, 240 collector TBMs and 40 service TBMs, together with an in-house assembly line in Gabon and the Democratic Republic of the Congo, reduces costs by 30–50%.
| Shield type | Diameter | Quantity | Unit price (series, in-house production) | Total (USD billion) |
|---|---|---|---|---|
| Main TBM (SR-Main) | ~18 m | 40 units | $35–60 million | $1.4–2.4 |
| Collector TBMs (SR-Collector) | 2 m | 240 units | $0.8–1.5 million | $0.19–0.36 |
| Service TBM (SR-Service) | 3 m | 40 units | $1.2–2 million | $0.05–0.08 |
| Assembly plants (2) | — | — | $1–2 billion | $1–2 |
| Total TBM fleet | $2.64–4.84 |
Geothermal Autonomous Thermal Energy System (GATES)
- A real 35 MW geothermal plant at Menengai in Kenya cost about $35–40 million, or $1,000–1,250/kW including drilling and the steam well. With 40 stations built in series and manufacturing localized, unit cost can be estimated at $800–1,200/kW.
- Cost of one 2.5 GW station: US$2.0–3.0 billion.
- Cost of 40 stations: US$80–120 billion.
- The range uses the lower bound of Russian geothermal-plant costs—approximately US$650/kW based on Iturup—and an upper bound of US$1,500/kW for complex projects.
- The calculation uses an upper estimate of 100 GW for total GATES capacity. Actual available power can be established only after geological exploration and may be far lower, potentially only several gigawatts. Funds released in that case would build alternative generation.
Energy-storage system
The storage system has three levels:
Primary level — long-duration storage at the terminals
- Located at 40 terminals, this level stores enough energy for one launch, 360 GWh, with a reserve. Preferred technologies at current prices are:
| Storage technology | Unit cost | Source |
|---|---|---|
| Gravity energy storage | $50–100/kWh | Energy Vault operating experience: 25 MW / 100 MWh costs $7.7 million, or $77/kWh. Round-trip efficiency is 75–85%, with a service life of 30–40 years. |
| Pumped-storage and small hydropower using the Hydrothermal Trunk Canal | $80–150/kWh | Uses the natural elevation difference along the route. |
| Lithium-ion BESS | $125/kWh for the complete installation | According to Ember (2025): $75/kWh for equipment from China plus $50/kWh for installation. At a scale of 215 GWh, the cost may fall to $100/kWh. |
- Total primary-level capacity is 360 GWh, covering the complete acceleration cycle. For a combined system of 70% gravity/pumped storage and 30% BESS, the cost is:
| Component | Capacity | Unit cost | Cost |
|---|---|---|---|
| Gravity storage + pumped storage | 250 GWh | $60/kWh | $15 billion |
| BESS | 110 GWh | $125/kWh | $13.75 billion |
| Total primary level | 360 GWh | $28.75 billion |
- Uncertainty range: $22–35 billion.
Secondary level — buffer storage beside the windings and in the tunnel
- Flywheels are installed directly beside the windings to smooth transient loads. Unit cost is $0.5–1 million/MWh; 1–5 GWh of buffer capacity costs $0.5–5 billion.
Pulse level — microsecond stabilization
- Supercapacitors compensate only for microsecond pulsations and stabilize voltage during sharp load changes. Total capacity is less than 1% of launch energy, or 1–3 GWh. At $300–500/kWh for pulse systems, the cost is $0.3–1.5 billion.
Total energy-storage cost
| Level | Technology | Capacity | Cost (USD billion) |
|---|---|---|---|
| Primary | Gravity storage + pumped storage + BESS | 360 GWh | $22–35 |
| Buffer | Flywheels | 1–5 GWh | $0.5–5 |
| Pulse | Supercapacitors | 1–3 GWh | $0.3–1.5 |
| Total storage | $22.8–41.5 |
Industrial centres and logistics
| Cost item | Cost (USD billion) | Basis |
|---|---|---|
| Industrial centre in Gabon — shuttle and launch-module production | $3–6 | Shipbuilding docks, plants and cranes |
| Industrial centre in the Democratic Republic of the Congo — high-altitude atmospheric gateway and high-speed modules | $2–4 | Mountain industrial cluster and electrolysis system |
| Port development in Gabon and on Lake Tanganyika | $1–3 | Berths, cranes and warehouses |
| Power lines and roads along the 2,050 km route | $4–8 | 220 kV power lines, roads and bridges |
| Hydrothermal Trunk Canal (HTC) | $2–5 | Excavation, lining and locks |
| Total | $12–26 |
Research, development and prototyping — Phase 0
| Cost item | Range (USD billion) | Basis |
|---|---|---|
| Mathematical and computational-fluid-dynamics modelling | $0.01–0.03 | Comparable case: development of digital twins for a hyperloop system, CHF 4.5 million. |
| Geological survey of the 2,050 km route | $0.015–0.025 | $7,000–12,000/km for detailed investigation in hard-to-reach areas. |
| Engineering design and BIM documentation | $0.02–0.05 | Technical requirements, concept designs and detailed construction designs. |
| Test site for the gateway and superconducting systems | $0.01–0.03 | A test stand for a prototype gateway chamber and levitation modules. |
| Consortium formation and legal agreements | $0.005–0.015 | International negotiations, registration and insurance. |
| Total Phase 0 | $0.06–0.15 |
- The R&D budget of $0.06–0.15 billion is not fixed. More detailed engineering, a full-scale gateway prototype or large-scale test rigs could raise it to $0.5–3.0 billion. The consolidated CAPEX table therefore uses a range of $0.1–3 billion and a median of $1.5 billion.
Final consolidated project CAPEX
| Cost item | Range (USD billion) | Median (USD billion) | Share of CAPEX (%) |
|---|---|---|---|
| Tunnel construction | $77.4–124.8 | $101.1 | 41% |
| TBM fleet and production | $2.64–4.84 | $3.74 | 1.5% |
| GATES — 40 stations of 2.5 GW each | $80–120 | $100 | 40% |
| Three-level energy-storage systems | $22.8–41.5 | $32.2 | 13% |
| Industrial centres and logistics | $12–26 | $19 | 8% |
| R&D, licences and administration | $0,1–3 | $1.5 | 0.6% |
| Contingency reserve (15%) | $31–49 | $40 | 16% |
| TOTAL CAPEX | $225–365 | $295 | 100% |
- Key conclusion: the median estimated cost of the StarRoad project is about $300 billion.
Distribution by phase (USD billion)
| Cost item | Phase 0 | Phase 1 | Phase 2 | Phase 3 | Phase 4 | Phase 5 |
|---|---|---|---|---|---|---|
| Tunnel construction | — | — | $5 | $20 | $70 | $6 |
| TBMs | — | $2 | $0.7 | $0.8 | $0.2 | $0.1 |
| GATES | — | $60 | $20 | $20 | — | — |
| Energy storage | — | $10 | $10 | $8 | $3 | $1 |
| Industrial centres and logistics | — | $5 | $3 | $3 | $5 | $3 |
| R&D and licences | $1.5 | $0.2 | $0.1 | $0.1 | $0.05 | $0.05 |
| Contingency (15%) | $0.23 | $11.6 | $5.8 | $7.8 | $11.7 | $1.5 |
| TOTAL by phase | $1.73 | $88.8 | $44.6 | $59.7 | $90 | $11.7 |
| Cumulative total | $1.73 | $90.5 | $135.1 | $194.8 | $284.8 | $296.5 |
Payback and delivery-cost dynamics
- All figures in this subsection are strictly theoretical.
Evolution of launch frequency and per-kilogram cost
- StarRoad does not reach full capacity immediately. Launch frequency and payload-delivery cost evolve as new lines enter service, the shuttle fleet grows and orbital infrastructure is deployed.
- Modelled delivery cost to GSO and beyond, USD/kg:
| Period | Lines | Launches per year | Frequency | Delivery cost ($/kg) | Comment |
|---|---|---|---|---|---|
| Years 1–2 — pilot period | 1 | 12–24 | 1–2 per month | $80–120 | First commercial launches. Operations are refined; overheads are high and the production run is small. |
| Years 3–5 | 1 | 50–100 | 1–2 per week | $30–50 | Series operation begins. The fleet grows to 3–5 shuttles, and economies of scale reduce costs. |
| Years 6–10 | 1 | 200–300 | About 1 per day | $10–20 | The first line reaches design capacity, with fully automated maintenance. |
| Years 11–15 | 2 | 500–700 | About 2 per day | $3–8 | The second line enters service, sharing fixed costs between two accelerators. |
| Years 16–25 | 3–4 | 1000+ | 3–5 per day | $0.8–3 | The system scales to 3–4 parallel lines. Space-based solar power stations exceeding 1 GW are deployed to provide orbital energy for manoeuvres and cargo processing. |
| Years 26 and beyond | 5+ | 1500+ | 5–10 per day | $0.3–1 | Mature infrastructure. Space power stations supply the accelerator and orbital plants; the marginal energy cost is close to zero. |
Cost calculation for one launch ($/kg)
- The formula for each period is: Ckg = (Cenergy + Cmaintenance + Cdepreciation + Coperations) / Mpayload, where:
- Cenergy is the cost of electricity, including cooling and auxiliary systems.
- Cmaintenance is maintenance of the shuttles and infrastructure.
- Cdepreciation is depreciation of $300 billion in CAPEX over 50 years.
- Coperations covers other operating expenses: personnel, logistics and insurance.
- Mpayload is payload mass per launch: 10,000 t.
- Final parameters by period:
| Period | Launches per year | Energy ($/kg) | Maintenance ($/kg) | Depreciation ($/kg) | Operations ($/kg) | Total cost ($/kg) |
|---|---|---|---|---|---|---|
| Years 1–2 | 12 | 1.8 | 6.63 | 50 | 3.57 | 62 |
| Years 3–5 | 50 | 1 | 1.25 | 12 | 0.67 | 14.92 |
| Years 6–10 | 250 | 0.36 | 0.23 | 2.4 | 0.13 | 3.12 |
| Years 11–15 — 2 lines | 600 | 0.12 | 0.113 | 1 | 0.061 | 1.29 |
| Years 16–25 — 3–4 lines | 1200 | 0.045 | 0.049 | 0.5 | 0.026 | 0.62 |
| Years 26+ — 5+ lines and space-based solar power | 2000 | 0.015 | 0.015 | 0.3 | 0.008 | 0.34 |
Launch-cost structure in absolute figures
- For a representative year in each period, using a 10,000 t payload:
| Period | Number of launches | Energy per launch (USD million) | Maintenance (USD million) | Depreciation (USD million) | Operating expenses (USD million) | Total per launch (USD million) |
|---|---|---|---|---|---|---|
| Years 1–2 | 12 | 18 | 66.3 | 500 | 35.7 | 620 |
| Years 3–5 | 50 | 10 | 12.5 | 120 | 6.7 | 149.2 |
| Years 6–10 | 250 | 3.6 | 2.34 | 24 | 1.26 | 31.2 |
| Years 11–15 | 600 | 1.2 | 1.13 | 10 | 0.61 | 12.93 |
| Years 16–25 | 1200 | 0.45 | 0.49 | 5 | 0.26 | 6.2 |
| Years 26+ | >2000 | 0.15 | 0.146 | 3 | 0.079 | 3.38 |
Key calculation assumptions
- Energy: the baseline price is $0.05/kWh in the first years, falling to $0.005/kWh by year 26+ through space-based solar power and the project's own geothermal capacity.
- Maintenance: high during the pilot period because of repairs, commissioning and excess staffing; by year 10 it becomes an automated production-line operation.
- Depreciation: $300 billion of CAPEX over 50 years equals $6 billion per year. At 250 launches a year, this is $24 million per launch. This is a conservative estimate with no offset from other revenue. Alternatively, the same annually recovered CAPEX of $6 billion a year may be treated as a continually growing investment stream used to build new StarRoad branches.
- Space-based solar power: from year 16 it supplies orbital plants and part of the accelerator, reducing energy costs and increasing energy-sale revenue by orders of magnitude.
Integrated dynamics: revenue versus cost
| Period | Launches per year | Average market price ($/kg) | Launch revenue (USD billion/year) | Cost (USD billion/year) | Gross profit (USD billion/year) |
|---|---|---|---|---|---|
| Years 1–2 | 12 | $100 | 12 | 7.44 | 4.56 |
| Years 3–5 | 50 | $39 | 19.5 | 7.45 | 12.04 |
| Years 6–10 | 250 | $9.6 | 24 | 7.8 | 16.2 |
| Years 11–15 | 600 | $3.9 | 23.4 | 7.76 | 15.64 |
| Years 16–25 | 1200 | $1.6 | 19.2 | 7.44 | 11.76 |
| Years 26+ | 2000 | $0.5 | 10 | 6.75 | 3.25 |
- Note: revenue from GATES electricity sales, $35–44 billion/year, is not included in this table. It is a separate stream covering depreciation and infrastructure operating costs.
Conclusion on cost dynamics
- StarRoad begins with a delivery price of $80–120/kg to GSO and beyond—already 10–15 times less than Falcon Heavy at $1,400/kg to LEO and comparable to Starship's target of $200/kg to LEO. By year 10 the price falls to $10/kg, by year 25 to $1/kg, and by year 30, with 5+ lines and space-based-solar support, to below $0.5/kg. Solar energy and asteroid metals then become economically accessible to terrestrial industry.
- Key conclusion: StarRoad is competitive even in the pilot period. Scaling and energy synergy with space-based solar power reduce the price smoothly by two orders of magnitude over 30 years.
Comparison with alternatives
| Project | Type | Investment (CAPEX / R&D) | Payback period | Cost / LCOE | Note |
|---|---|---|---|---|---|
| StarRoad — energy component: GATES + storage | Energy | $100–150 billion | 5–7 years, from energy sales | $0.05/kWh | Geothermal generation and storage only. Pays back as an independent power project. |
| StarRoad — transport component: tunnel, gateway and shuttles | Transport | $150–200 billion | 8–12 years, including cargo revenue | $1–10/kg | Accelerator, gateway and shuttles. Pays back through cargo delivery while using energy from the first component. |
| StarRoad — complete system | Energy + transport | ~$300 billion | 8–12 years, combined revenue | $0.05/kWh and $1–10/kg | Integrated project, with revenue from energy and cargo. |
| Falcon Heavy — development | Transport | ~$5 billion in R&D | ~10–15 years at commercial launch frequency | ~$1,400/kg | An operational rocket. CAPEX here is development expenditure, not infrastructure. |
| Starship — development | Transport | ~$10 billion in R&D | ~10–15 years at the target market size | Target: $200/kg; potential: $50–100/kg | Under development. Investment is in R&D, not permanent infrastructure. |
| Grand Inga hydropower project, Democratic Republic of the Congo | Energy | $80–100 billion | 15–25 years | $0.03–0.05/kWh | A major hydroelectric project supplying energy only. |
| Large nuclear power station — 2 units, about 2.4 GW | Energy | $15–20 billion | 20–30 years | $0.05–0.08/kWh | A typical nuclear power station supplying energy only. |
Economic conclusion
- The economic model indicates that StarRoad is feasible, with median CAPEX of about $300 billion. The key factors are:
- GATES, at $80–120 billion, is the most expensive component but pays back as an independent energy project in 5–7 years.
- Tunnel construction, at $77–125 billion, is technically manageable through series-produced TBMs and in-house manufacturing.
- Energy storage, at $23–42 billion, is based on falling BESS prices of $125/kWh and gravity systems using leading global practice.
- R&D, at $0.1–3 billion, reflects the real cost of prototyping rather than full-scale construction.
- Economic case: at a baseline price of $0.05/kWh, StarRoad generates $35–44 billion a year from energy sales alone. This covers operating expenses and supports capital payback through energy exports even before full-scale space launches begin.