Phobos and Deimos were two retired deep-water oil rigs acquired by SpaceX in 2020 for $3.5 million each, intended to be converted into floating launch and landing platforms for Starship.
| Operator | SpaceX |
| Type | Floating Spaceport (Retired Concept) |
| Status | ● Retired (sold 2023) |
| Home Port | Formerly Brownsville, TX / Pascagoula, MS |
| Coast | Gulf of Mexico |
| Length | ~85m (deck) |
| Beam | ~78m |
| Built / Acquired | 2020 (acquired) |
| Name Origin | Named after the two moons of Mars — Phobos (fear) and Deimos (dread) in Greek mythology, fitting for SpaceX's Mars ambitions |
| Associated Vehicles | Starship (planned) |
In January 2021, SpaceX acquired two former Valaris deep-water semi-submersible oil rigs — ENSCO/Valaris 8500 (renamed Deimos) and ENSCO/Valaris 8501 (renamed Phobos). The vision was ambitious: offshore Starship launch platforms that could operate 20–30 miles from shore, avoiding noise and safety constraints of land-based launch sites.
CEO Elon Musk described the concept: "Most Starship spaceports will probably need to be ~20 miles/30 kilometres offshore for acceptable noise levels, especially for frequent daily flights, as would occur for point-to-point flights on Earth."
The rigs underwent initial refurbishment at Pascagoula, Mississippi, and were seen being moved between ports in early 2022. However, by February 2023, SpaceX president Gwynne Shotwell confirmed both rigs had been sold, stating they "were not the right platform."
Despite abandoning the oil rig conversion, SpaceX continues to develop the offshore spaceport concept. In 2026, the company confirmed it is still interested in sea-based launch platforms, with new designs under consideration.