Eleven months ago - just after SpaceX astonished the world by launching and landing its titanic Falcon Heavy rocket while beaming back images of a red Tesla leaving Earth orbit - company founder Elon Musk had already begun to look beyond the moment.
The Falcon Heavy was a big, capable rocket. But it wasn't large enough to fulfil his aspirations of reaching Mars. Neither did the company have a spacecraft capable of landing there. "They really need to be way bigger than that," Musk said of the Falcon Heavy rocket at the time. Moreover, he noted that the launch in early February 2018 had confirmed the company's ability to model rocket launches on computers. "It gives me a lot of faith for our next architecture. It gives me confidence that BFR is really quite workable."
In this case, BFR stood for Big Falcon Rocket. This vehicle has since been renamed "Super Heavy," and it will launch the spacecraft SpaceX is building to land on Mars, take off from Mars, and land back on Earth. The rocket is certainly titanic in size, but the spacecraft it will carry - since branded Starship - is the greater innovation. No nation or company has ever built a single vehicle capable of flying dozens of people into space (especially deep space), landing on distant worlds, and then flying back to Earth.
Musk has shared several different versions of the Starship in presentations. However, we are now starting to see test hardware. During the last two months, observers near the company's site in southern Texas have been taking photos of a silvery test-version of Starship that the company will use for a series of take-off and landing tests this spring. And Musk has been sharing some of these photos (and a lot of details about them) on Twitter.
Since December 22, Musk has tweeted about the Starship vehicle more than two dozen times. Among the details that can be gleaned from those tweets:
- The vehicle's exterior will be made from a stainless-steel alloy that will not buckle and will remain stable on the launchpad even when unpressurised. The strength and weight of "full hard stainless" at cold temperatures is slightly better than carbon fibre, at room temperature it is worse, and at high temperature it is vastly better.
- The metallic skin of Starship will get too hot for paint, so it will have a stainless mirror finish. It will need much less shielding as a result, and areas that take the brunt of atmospheric entry heating will be activity cooled with residual liquid methane. As a result, "Starship will look like liquid silver."
- A "radically redesigned" Raptor engine will be ready for test firing early this year. This is the engine that will power both the first stage "Super Heavy" as well as the Starship. For the test hopper, there will be three Raptor engines (there will be seven on the full Starship). Engines currently on the vehicle are essentially mock-ups. The first engine for hopper test flights "is almost finished assembly in California."
- SpaceX developed a "superalloy" to withstand the incredible pressures inside the Raptor engine and its hot, oxygen-rich gas. "Our superalloy foundry is now almost fully operational. This allows rapid iteration on Raptor."
- Musk expects the first hopper tests to occur in March or April of this year, sooner than expected. "I will do a full technical presentation of Starship after the test vehicle we're building in Texas flies."
- Musk believes a single-stage-to-orbit launch from Earth is "pointless." A large booster is needed to escape Earth's gravity well if one wants a decent-sized payload. But the single-stage Starship alone is great for launching from Mars and the moons of the Solar System.
"Starship will look like liquid silver."
No doubt Elon will be in touch with DSM soon to order some of our Stainless Steel wash basins, perfect for the astronauts to keep squeaky clean during their long journey to Mars! (if they can find a way of keeping the water in the basins in zero gravity that is....)