Phase Four develops radio-frequency (RF) plasma thrusters that operate without electrodes, eliminating a primary failure mode of traditional Hall-effect and ion thrusters. The Maxwell thruster offers a lower-cost, more reliable in-space propulsion option for small and medium satellites.
| Round | Amount | Valuation | Lead Investors | Date |
|---|---|---|---|---|
| Series B | $15M | ~$100M | Lockheed Martin Ventures | Jul 1, 2024 |