SpaceX has acquired two decommissioned offshore oil rigs at ports in Texas, which the company plans to convert into spaceports to service its Starship launch system, a project that is still under development.
The rigs were purchased from the offshore drilling contractor Valaris for $3.5 million apiece in August 2020, through a company called Lone Star Mineral Development LLC, according to CNBC. The company is registered to SpaceX CFO Bret Johnsen; shortly after it was incorporated in June 2020, SpaceX announced that it was seeking “a team of engineers and technicians to design and build an operational offshore rocket launch facility."
SpaceX CEO Elon Musk confirmed that the company was “building floating, superheavy-class spaceports for Mars, moon & hypersonic travel around Earth” on Twitter. In keeping with this lofty goal, the two rigs have been renamed Deimos and Phobos after the two moons of Mars, a catchier rebrand compared to their previous designations: ENSCO/Valaris 8500 and ENSCO/Valaris 8501. Phobos is at the Port of Galveston, while Deimos is at the Port of Brownsville, reports NASASpaceflight.
There’s something inherently appealing about a plan of converting oil rigs, symbols of an industry doomed to decline, into bustling spaceports, which evoke visions of a futuristic era of easy space travel to the Moon or Mars (whether that dream is realistic is another story).
But how feasible is SpaceX’s goal of offshore launchpads and how might it be done?
As it turns out, the idea of spinning offshore oil rigs into spaceports is not new. From the 1960s to the 1980s, the Luigi Broglio Space Center launched payloads into space from a converted oil platform off the coast of Kenya. The multinational company Sea Launch converted the mobile drilling rig Odyssey into a launch platform in 1997; dozens of rockets have blasted payloads to space from Odyssey, along with a few failed launches.
Florida’s department of commerce considered creating floating spaceports on offshore rigs in 1989, but ultimately decided the “approach is too costly in the short run to service the anticipated market.” In 1996, a study published in IEEE Spectrum recommended that Russia marry its “agile Soviet rocket design with the best oil platform technology may provide an altogether new means of getting big satellites into orbit.”
Alla Pozdnakova, a professor of law at the Scandinavian Institute of Maritime Law, has extensively researched sea-based launch facilities, as well as their legal and technological implications.
“What is really new in SpaceX projects,” she said in an email, “is that all other projects launched small satellites into orbit and some suborbital objects.” Meanwhile, SpaceX is planning to eventually launch missions to the Moon, Mars, and into hypersonic orbits around Earth, some of which would carry humans, which “is quite different from earlier projects,” Pozdnakova noted.
SpaceX currently uses on-land launchpads at Cape Canaveral, Florida, Lompoc, California, and Boca Chica, Texas, though it has performed many landings of its reusable boosters at sea on drone ships.
The company is now in the process of developing a new super heavy-lift spacecraft called Starship; early prototypes of the vehicle have completed test flights at SpaceX’s facilities in Boca Chica, not far from Brownsville. SpaceX envisions loading up future iterations of Starship with cargo and passengers that could travel to Earth orbit, the Moon, and Mars.
If this tantalizing dream were ever to become a reality, it would reshape the space sector in myriad ways—including causing disturbance and noise around busy Starship spaceports, with cacophonous liftoffs and sonic booms from returning spacecraft. For this reason, among others, SpaceX is experimenting with less disruptive offshore launches and landings.
“Obviously, launching on the water can provide strategic advantages to include minimizing public safety risks, air traffic interference, limiting noise and nuisance to surrounding communities etc,” said Sara Langston, assistant professor of spaceflight operations at Embry-Riddle Aeronautical University, in an email.
Pozdnakova pointed out that mobile oil rigs can also easily move to new locations tailored to the needs of space missions. While she cautioned that she was not an expert in how to convert offshore oil platforms into spaceports, she said that “oil rigs already possess characteristics necessary for launches from sea.”
“They may float or even are self-propelled and are built to be stable on water,” Pozdnakova said. “However, they must have a system which allows stabilizing the platform for the launch. They would also need to have some support vessels, I would presume, to ensure initiating and control of the launch—someone needs to push the button and it can’t be done in the immediate proximity to the launch rig.”
Because SpaceX’s vehicles are partially reusable, these spaceports might also accommodate landings, which may add another layer of complexity to the company’s plans to retrofit the rigs. While SpaceX has performed many robotic ocean landings of its boosters, the stakes would be far higher if a returning spacecraft was carrying passengers, as is intended with Starship.
Beyond these engineering challenges, the use of offshore launch pads raises thorny legal and regulatory questions that reverberate well beyond these preliminary moves from SpaceX.
Pozdnakova pointed out that a broader adoption of sea-based spaceports could interfere with other maritime industries, such as fisheries or shipping, and that an “absence of international rules on safety” on offshore platforms could lead to lax oversight or poor working conditions for employees.
Sea-based spaceports may also use the same loopholes of maritime law that are employed by other commercial ocean industries, such as “flags of convenience.”
“Forum shopping for 'flags of convenience' when it comes to registering quasi-territory (movable 'territory' e.g. ships, platforms, aircraft, spacecraft) raises concerns for law, policy, and practical safety measures and enforcement among other things,” said Langston.
Sea Launch, for instance, is headquartered in Switzerland, but registered its Odyssey launch platform to Liberia, a nation that is commonly used for flags of convenience, noted both Langston and Pozdnakova.
“It looks like a number of actors have seen possibilities of commercially feasible launches from sea,” Pozdnakova said, though a lot of these plans remain thin on details. “So I think that there is much potential in sea-based space launches, for both state-run projects and private ventures. I think that also other private companies will become more active in this in the future.”
Update: This article has been updated with comments from Sara Langston.