SpaceX Starship opened a new chapter in space travel and transportation as part of the Artemis programme. It is the most powerful and largest rocket ever built and made its maiden flight in April. Although the test launch was successful, the spacecraft failed to reach Earth's orbit. Regardless, it was still a huge success and a moment to remember. We've gathered what you need to know about Starship and the test launch!
The Starship story
The next-generation rocket system created by SpaceX was designed to take mankind to the Moon and Mars in an efficient and reusable way. It has the potential to revolutionise space transportation and spaceflight.
The Starship design, then called the Mars Colonial Transporter, began in 2012. It was 4 years before the development was officially introduced to the public: Elon Musk, CEO of SpaceX, gave a presentation on the development of a 12-metre diameter carbon-composite rocket. Then, in 2018, a decisive step was taken: the carbon composite was replaced by stainless steel, the reason being that the latter has much better properties at cryogenic temperatures. The change was also advantageous because carbon composite is much more expensive and heavier to produce than stainless steel, so development was accelerated significantly. It is important to note that the development, estimated at $2-3 billion, is being privately financed, with the largest investor being Maezava Yusaku, a Japanese businessman.
Prototype testing started in 2019, and SpaceX became an official contributor to the Artemis programme in 2020. This was for the development of Starship HLS, a manned lunar module consisting of a small cabin and a larger rocket compartment, with no movable control planes, no heat shield and powered by solar panels. The rocket will use liquefied methane and oxygen during take-off and landing and will be able to take off and land several times by refuelling. It is planned that the HLS will be launched by a Super Heavy launcher into low Earth orbit, refuelled several times to reach orbit around the Moon. SpaceX would thus make it possible to transfer fuel in space between two Starship spacecraft and to land an unmanned Starship HLS on the Moon.
Structure of the spacecraft
Starship is a curiosity not only because of its size but also because it incorporates unprecedented innovations. One of the biggest them is that both parts of the dual-structured spacecraft can be reused, making the system highly cost-efficient.
The first stage is the Super Heavy launcher and the second is the Starship spacecraft. The two parts are 120 metres high and 9 metres in diameter when stacked. The rocket is powered by liquid methane Raptor engines, each capable of generating 2 MN of thrust.
The Super Heavy
The Super Heavy is 70 metres high and weighs over 3,400 tonnes when fuelled. This weight is lifted by 37 Raptor engines, which generate 72 MN of thrust and consume 650 kg of fuel and oxygen per second. The basic idea behind the Starship concept is to have the cheapest and simplest structure to lift a spacecraft into space. With this in mind, Super Heavy has only a fuel tank and the aforementioned engines. The fuel tank is made up of 3.6 mm thick steel rings. This is an extremely thin wall thickness, comparatively speaking four times thinner than the wall of a beer can. To support the weight of the fuel, the tanks must be kept under constant pressure. The bottom two-thirds of the accelerator contains liquid oxygen and the top third liquid methane, separated by a dome.
The Super Heavy is used for acceleration, and after about 3 minutes it is detached from the spacecraft, which then positions itself with the help of thrusters and aero grids to help find the right direction. As the system re-approaches the ground, huge arms mounted on the launch station catch the Super Heavy in the air, ensuring it returns safely to its starting point and preparing it for the next journey.
The Starship is the second part of the full system, which is 50 metres high and weighs 1200 tonnes. The lower half houses the fuel tanks and engines, while the upper half houses the cargo hold. After detachment, the Raptor engine with 6 vacuum-optimised nozzles continues the acceleration. Starship has a huge cargo hold of 1100 cubic metres, which must be kept under pressure.
The fuel tanks contain liquid oxygen at the bottom and liquid methane on top. But it cannot hold enough fuel to get to Mars or the Moon, so it has to link up with another unmanned cargo spacecraft and buy fuel.
The steel that makes up the spacecraft is protected by a heat shield to protect it from the temperatures it will have to withstand on re-entry. An important difference compared to the Super Heavy is that the Starship approaches the ground in a horizontal position, thus facilitating deceleration. Two wings ensure that the weight is kept constant. As with Super Heavy, the Starship too will be gripped by the launch levers.
It will have different versions, such as a passenger spacecraft, a refuelling spacecraft, a cargo spacecraft, a lunar spacecraft, and a Mars spacecraft for returning and staying on Mars.
The first launch
The first test launch was scheduled for the 17th of April but had to be postponed due to a pressure valve failure. The launch finally took place on 20 April and was a success overall. The fast separation arms tested well, 6 of the Raptor's engines failed, but the rocket still reached 39 km, the atmospheric layer with the highest impact. However, the asymmetric thrust caused it to spin out of balance, which the software navigation could not correct. The next step would have been the separation of the Super Heavy and Starship, but this could not happen due to the prior malfunctions. SpaceX activated the emergency breaker and destroyed the vehicle.
The test was nevertheless a success, as the Starship left the launch pad intact and provided multiple valuable insights for the Starbase command on future corrections.
It is planned that a follow-up test will take place in a few months.