SpaceX originally planned to convert two retired oil rigs, named Phobos and Deimos after the moons of Mars, into floating launch and landing platforms for the Starship rocket system. The platforms, stationed in the Gulf of Mexico near Boca Chica, Texas, would have enabled rapid launch cadence and flights from optimal locations.
However, in February 2023, SpaceX President Gwynne Shotwell announced the company had sold the two rigs after determining they were “not the right platform.” While offshore platforms are still of interest for achieving extremely high flight rates in the future, SpaceX is first focused on gaining flight experience with Starship before pursuing sea-based solutions.
Technical Details
The two rigs, former deepwater oil platforms Ensco 8500 and 8501, were purchased by SpaceX in 2020 for $7 million. Some preliminary work was done to clear Phobos’ deck, but the extensive modifications needed to convert them into launch platforms did not substantially progress.
Specific technical requirements for floating launch pads capable of supporting the giant Starship system have not been revealed. Stable platforms that can withstand engine blasts and divert exhaust flames are needed. Self-propulsion or towing capability would enable repositioning for optimal launch trajectories.
Environmental Impact
Environmental concerns were raised regarding the impact of launching large rockets from offshore platforms on wildlife, habitat, and water quality. SpaceX’s Boca Chica site has already faced lawsuits alleging harm to endangered species. Further environmental reviews would have been required before launching from sea pads.
More broadly, rocket launches generate significant noise, blast pressures, and particulate emissions that can adversely impact health and ecosystems. The explosive demise of SpaceX’s first orbital Starship test in May 2022 scattered debris over a wide area, raising questions about mitigating future launch impacts.
Economic Considerations
Transitioning launches away from land to floating sea platforms could reduce regulatory constraints on rapid launch cadence. Spaceports stationed outside of U.S. territorial waters may enable SpaceX to skirt some domestic oversight.
However, developing and operating sea launch capability requires substantial additional expenses – crew, security, logistics support vessels, among others. The economic viability depends greatly on the realization of high flight rates to drive down costs through rocket reusability.
Current Status
With the sale of the two rigs, SpaceX has paused development of offshore launch platforms. The company is focused on progressing with Starship test flights from Boca Chica to better understand how to practically achieve extremely high launch rates. Once operational data is gathered, SpaceX may revisit concepts for floating spaceports.
The path forward remains unclear. Constructing ships or platforms specifically designed for rocket launch, rather than retrofitting old oil rigs, may be necessary. SpaceX continues working with regulators regarding Starship plans, while aiming to mitigate environmental impacts as much as feasible.
