Starship prototype SN8 exploded, but Musk was full of confidence. Reusable engines are the key

If SpaceX wants to send humans to Mars, it must first have a powerful rocket engine that can provide sufficient power for interstellar flight.

Therefore, SpaceX has spent nearly ten years developing a new type of engine, and has succeeded. It is the Raptor engine, one of the most advanced rocket engines in the world.

The successful development of the Raptor engine has made Musk’s dream of Mars more realistic. Why?

According to Musk’s vision, the new Raptor rocket engine has two main features.

1. Reusable.

Reuse means saving time and money. The Raptor engine is designed to be reused 1,000 times. If this can be achieved, it will be easy to launch a spacecraft from the earth.

Generally speaking, rocket fuel only accounts for 0.3%~2% of the total cost of a rocket, which can be said to be insignificant.

For example, the total cost of the Falcon 9 rocket is US$50 million, and the cost of propulsion fuel is only about US$200,000.

Most of the other costs are spent on the manufacturing of the rocket body and engine. If the engine can be reused and the rocket body can be recycled, the cost of each launch will be greatly reduced.

Musk’s idea is that when migrating to Mars, a fleet of starships must be formed, and starships must be launched from the earth every day. If they cannot be reused, it will be too late to rebuild them.

2. Use easily available fuel

To achieve interstellar travel, fuel is essential. A major innovation of the Raptor engine is the use of methane as fuel, which is also what makes it special.

Compared with fuels such as kerosene, methane can prevent the accumulation of deposits in the engine, has high combustion performance, and is cost-effective.

There are differences in the cost of using different fuels. For example, the cost of toxic undimethylhydrazine is as low as US$10/kg, while the cost of specially refined kerosene is relatively higher. The next step is liquid hydrogen fuel. Different countries The cost of making liquid hydrogen varies depending on the production method.

But this is not the main thing, because in terms of cost, fuel is relatively cheap.

Accessibility of the fuel used is key, and methane fits the bill.

On the surface of Mars and in some places in space, methane can be extracted to fuel engines.

This is the so-called ISRU, in-situ resource utilization, as the saying goes, it is to use local materials.

In addition to the above two points, the Raptor engine’s full-flow staged combustion and high thrust are also special. In particular, full-flow staged combustion allows the engine to save fuel as much as possible and make full use of every drop of propellant. This is a very important feature in the vast space travel.

As a result, the Raptor is also known as the most efficient rocket engine ever built.

The successful development of the Raptor engine gives hope to SpaceX’s ambitious space program. Although some indicators still need to be upgraded, it can also be said that the Raptor has helped SpaceX clear a big obstacle on the road to Mars immigration. Perhaps in the near future, Musk's dream will come true.

However, there is a question here. Even if the spacecraft is available, do so many people really want to immigrate to Mars?