SpaceX's Starship rockets designed to send humans to Mars will take off from ocean-based spaceports, CEO Elon Musk stated Monday.
During a Twitter conversation about the future of space travel, the SpaceX CEO confirmed that the Starship vehicle and the Super Heavy booster used to lift it away from Earth will "will mostly launch from ocean spaceports long-term." Musk later clarified that "occasional flights from land are ok, but frequent (daily) flights probably need ~30km / 18 miles clear area for noise."
The comments illuminate SpaceX's thinking around the Starship, which is designed to transport up to 150 tons, or 100 people, into space at a time. The reusable ship measures some 400 feet when paired with its booster. It is expected to take on missions currently completed by the existing Falcon 9 satellite launches, and to enable more ambitious missions, like crewed trips to the Moon and Mars. Its use of liquid oxygen and methane fuel means a crew could feasibly visit Mars, harvest resources from the planet to refuel, and either return home or perhaps venture even further.
Musk explains why SpaceX will use an ocean-based spaceport for launches. The firm's CEO has previously suggested that one Starship can complete 1,000 launches per year – a huge number considering the company has completed only 100 missions over its 14 years of flights. The majority of SpaceX's flights — 57 of them — have taken off from the land-based Space Launch Complex 40 at Cape Canaveral Air Force Station in Florida. Starship's increased flight frequency could require a greater distance from land.
Perhaps the biggest benefit for an ocean-based seaport would be frequent Earth-to-Earth flights. Musk claimed in June that SpaceX would start test flights within two to three years. The ships could also transport 1,000 people at a time across Earth, jetting from London to Hong Kong in just 34 minutes.
Musk has floated the idea of ocean-based spaceports before. In November 2019, he claimed they would be located 20 miles offshore. In June 2020, he shared a job listing for an offshore operations engineer in Brownsville, Texas, where SpaceX is developing Starship.
Musk made his most recent comments in response to the news Monday that Russia plans to restore its floating Sea Launch cosmodrome. The project was started in 1995, and supported launches until 2014. Russian deputy prime minister Yuri Borisov placed the cost of restoration at some 35 billion rubles (around $470 million).
The platform supported 36 Pacific Ocean launches with the Zenit rocket. This rocket, designed by engineers in the Soviet Union, took its debut flight in 1985. The ship's RD-171 engine produced 1.6 million pounds of thrust at sea level. SpaceNews reported ahead of the rocket's final mission in 2015 that it used the most powerful operational liquid-fueled rocket engine.
The most powerful rocket currently in operation today is SpaceX's Falcon Heavy, with liftoff thrust over five million pounds. The Starship's booster is designed to improve on that even further, offering 16 million pounds of thrust.
The Inverse analysis – The Starship is likely to offer an impressive display when it launches, both in terms of sight and sound. A spaceport placed far away from cities makes a lot of sense, but it could reduce the time-saving benefits offered by inter-Earth flights.
Musk may have a solution there, as outlined in 2018. The hyperloop, his proposed 700 mph vacuum-sealed pod transit system, could — in theory — whisk people from the city to the spaceport. It's a cool idea, but it'll depend on teams like Virgin Hyperloop perfecting their work on the system and linking it up to the futuristic spaceports. The future of infrastructure may finally be coming together.
Update 08/27 12:50 p.m. Eastern time: An earlier version of this article claimed the Zenit rocket launched "off the coast of the United States." It has since been updated.