Electric Space Tug Design Analysis
This analysis designs an electric space tug using the Turion TIE-20 GEN2 thruster for transporting a 1000 kg payload from LEO to a lunar pass (TLI-like trajectory) in 1 year or less, with return to LEO empty. Three propellants are considered: Xenon, Krypton, and Argon. Estimated ISPs: Xenon 4500 s, Krypton 5625 s, Argon 8145 s. Delta-v per leg: 6770 m/s. Number of thrusters: 7 for all cases to meet time constraint.
Masses and Costs Table for Each Propellant
Xenon
| Component | Mass (kg) | Cost ($) |
|---|
| Thrusters (7 x 23 kg) | 161 | 1,050,000 |
| Solar Panels (7 x 20 kg) | 140 | 700,000 |
| Structure | 20 | 50,000 |
| Tank Dry | 93.9 | 46,950 |
| Reaction Mass (Propellant) | 312.9 | 2,503,200 |
| Payload | 1000 | N/A |
| Total Dry Mass (Tug + Tank) | 414.9 | 1,846,950 |
|---|
| Total Propellant | 312.9 | 2,503,200 |
|---|
| Total Mass Launched (m0) | 1727.8 | N/A |
|---|
| Total Other Costs (Disposable) | N/A | 4,350,150 |
|---|
Krypton
| Component | Mass (kg) | Cost ($) |
|---|
| Thrusters (7 x 23 kg) | 161 | 1,050,000 |
| Solar Panels (7 x 20 kg) | 140 | 700,000 |
| Structure | 20 | 50,000 |
| Tank Dry | 72.2 | 36,100 |
| Reaction Mass (Propellant) | 240.6 | 721,800 |
| Payload | 1000 | N/A |
| Total Dry Mass (Tug + Tank) | 393.2 | 1,836,100 |
|---|
| Total Propellant | 240.6 | 721,800 |
|---|
| Total Mass Launched (m0) | 1633.8 | N/A |
|---|
| Total Other Costs (Disposable) | N/A | 2,557,900 |
|---|
Argon
| Component | Mass (kg) | Cost ($) |
|---|
| Thrusters (7 x 23 kg) | 161 | 1,050,000 |
| Solar Panels (7 x 20 kg) | 140 | 700,000 |
| Structure | 20 | 50,000 |
| Tank Dry | 47.3 | 23,650 |
| Reaction Mass (Propellant) | 157.5 | 1,575 |
| Payload | 1000 | N/A |
| Total Dry Mass (Tug + Tank) | 368.3 | 1,823,650 |
|---|
| Total Propellant | 157.5 | 1,575 |
|---|
| Total Mass Launched (m0) | 1525.8 | N/A |
|---|
| Total Other Costs (Disposable) | N/A | 1,825,225 |
|---|
Total Costs and Cost per kg Payload for Each Case
| Propellant | Case | Total Mass Launched (kg) | Launch Cost ($) | Other Cost ($) | Total Cost ($) | Cost per kg Payload ($/kg) |
|---|
| Xenon | Disposable HighCost | 1727.8 | 1,727,800 | 4,350,150 | 6,077,950 | 6,078 |
| Disposable LowCost | 1727.8 | 345,560 | 4,350,150 | 4,695,710 | 4,696 |
| Reusable HighCost | 1406.8 (Payload + Tank + Prop) | 1,406,800 | 2,550,150 | 3,956,950 | 3,957 |
| Reusable LowCost | 1406.8 | 281,360 | 2,550,150 | 2,831,510 | 2,832 |
| Krypton | Disposable HighCost | 1633.8 | 1,633,800 | 2,557,900 | 4,191,700 | 4,192 |
| Disposable LowCost | 1633.8 | 326,760 | 2,557,900 | 2,884,660 | 2,885 |
| Reusable HighCost | 1312.8 | 1,312,800 | 757,900 | 2,070,700 | 2,071 |
| Reusable LowCost | 1312.8 | 262,560 | 757,900 | 1,020,460 | 1,020 |
| Argon | Disposable HighCost | 1525.8 | 1,525,800 | 1,825,225 | 3,351,025 | 3,351 |
| Disposable LowCost | 1525.8 | 305,160 | 1,825,225 | 2,130,385 | 2,130 |
| Reusable HighCost | 1204.8 | 1,204,800 | 25,225 | 1,230,025 | 1,230 |
| Reusable LowCost | 1204.8 | 240,960 | 25,225 | 266,185 | 266 |
Notes: Propellant costs per kg - Xenon: $8,000, Krypton: $3,000, Argon: $10. Tank cost: $500/kg of tank mass. Launch costs: High $1,000/kg, Low $200/kg. Total mass launched for reusable is payload + (tank dry + prop). All times meet <1 year for outbound trip.