The Starship Super Heavy rocket that Elon Musk and his SpaceX team are building at Starbase Texas will be the largest and most powerful spacecraft ever built, and we’re not just talking about incremental gains here, Starship is about double the bang.
The previous most powerful rocket was the Saturn V moon rocket of the Apollo program, but what makes Starship so powerful is a very special rocket engine at the heart of a 69 meter tall super heavy booster called the Raptor, which is actually is one of 33. That total is well beyond the phenomenal density of the nozzle, but it’s not just a numbers game to achieve a Starship-like feat.
We needed both quantity and quality and the Raptor engine brings it perfectly, it is an extraordinary engine, it pushes the limits of what is physically possible with chemical combustion, and SpaceX implemented a design that whoever did it, nobody before them was brave enough or crazy enough to even try, so today we’re going to find out what makes the Raptor engine so special and we’re going to do just that Are. In a very simple and informal way that you don’t need to be a rocket scientist to understand.
It’s enough to help you get excited for the upcoming starship launch, when you see the boosters light up you’ll know what’s up and you can use this information to play a genius prank on your friends can do to look like a person, so let’s move on, it’s a space race.
How A Rocket Engine Works
Let’s briefly talk about how rocket engines work so we’re all on the same page, the basic concept here is actually surprisingly simple. There are two propellant tanks inside the rocket. One for oxygen and the other for fuel. The oxygen side is the same for every type of rocket because fire needs oxygen to burn, it’s like blowing air into your campfire to fuel the flames.
To make oxygen into rocket propellant you must first liquefy it, you simply convert oxygen from gas to liquid state by super cooling. The boiling point of oxygen at cryogenic temperatures is negative 183 °C or negative 297 Fahrenheit, so at any given temperature it will freeze as a liquid that is cold enough, then in terms of fuel it will vary by rocket, most Use a chemical called RP1 which is basically pure kerosene, it is cheap and accessible and liquid at ambient temperature.
RP1 is a good rocket fuel, but it is also a very dirty fuel, burning kerosene produces a lot of soot and solid carbon material as a byproduct, which tends to stick. This is called coking inside the engine because most rocket boosters are disposable it doesn’t really matter, but for reusable boosters like the Falcon 9 it’s a huge pain because they have to clean the Merlin engine after every flight have to do.
And since SpaceX plans to rapidly reuse Starship and boosters several times per day, they don’t have time to deal with coking to solve this, Starship uses methane as its fuel source. This is what we commonly refer to as natural gas and we know it is a very clean burning fuel because we use it on a daily basis in our furnaces and stove tops without worrying about its cleanliness. Did it The same applies to rocket engines that burn methane.
You can use it repeatedly without maintenance. Oxygen methane needs to be converted to liquid form for use as a rocket fuel, so it also needs to be super cooled to the same cryogenic temperature, adding additional complexity to the entire system containing the two cryogenic fluids . And it’s a big reason why other companies don’t do it, the Raptor is the first methane burning rocket engine to be launched and will likely become the first to reach orbit. Okay so we’ve got our fuel and oxygen.
Now where do we go back to the basic concept here it’s pretty simple so we’ll do an overview and then we’ll see how the Raptor takes it to the next level when the rocket engine starts pumping both the oxygen and the fuel combustion to very high pressure will be carried to the chamber where they ignite and combustion releases a huge amount of energy as the propellants burn and expand to create pressure, all of this energy will exit the combustion chamber through the throat, it will be inhaled into your lungs Will enter Running out of air is like blowing out a candle. You create a high pressure inside your mouth by blowing out the gas through a small hole in your lips.
Then all that high-pressure, high-temperature combustion enters the exhaust nozzle, where it expands from throat to throat. When the nozzle is opened this expansion accelerates the exhaust to an even greater speed than is actually exiting the throat. The higher the expansion ratio from the throat to the end of the nozzle, the higher the exhaust acceleration. This process causes a rapid increase in pressure. The more we can get that exhaust gas out the back of the nozzle, the faster the rocket will go, for every action there is an equal and opposite reaction.
The basic concept to keep in mind here is that pressure always flows from high to low, where there is high pressure. There is less pressure at the throat and tip of the nozzle, so the exhaust flows in that direction, which is why the whole rocket doesn’t explode like a bomb, unless the pressure in the pump is greater than the pressure in the combustion chamber compared to the fuel.
How A Raptor Engine Works
The beauty of the Raptor engine is that it takes this process to the absolute limit of what is physically possible, combining extremely high pressure with extremely efficient combustion. The Raptor’s design is called a full flow staged combustion cycle as we said at the top, this is something that has never been put into production by any other aerospace company and this is due to the extraordinarily complex system design, We’re going to keep this as simple as possible while still not making it so rocket science that the main points are understood.
What’s going on there. So to visualize what’s going on inside the Raptor we need to add one more component to the path that our propellants take in the Raptor cycle from the tank to the combustion chamber, the fluid pumped out of the tank. are built and then directly into a pair of gas turbines with both the fuel and oxygen effecting separate turbines, many rocket engines will use a single turbine either on the oxygen side or in rare cases on the fuel side, but the Raptor is the only The engine is It consists of twin gas turbines.
When cryogenic liquid reaches these, the first thing it will encounter in the turbines is the pre-burner, which in itself is like a miniature rocket engine that burns just enough to turn the liquid into a gas, but since None of these liquids can burn on their own, so a cross is needed. The connection between the two pre-burners that allows some oxygen to join the methane flow and allows some methane to join the oxygen flow.
It converts the combustion liquid into a gas and that gas is blasted into the turbine housing where it drives the blades, the turbine blades, the pump and which sends our gaseous propellant under extreme pressure into the combustion chamber, if the turbine spins the pump and the pump sends the liquid into the turbine how the process starts first of all spacex uses equipment on the launch mount to spin the turbines externally this is what they were testing when between There was a booster explosion on the starbase.
When they turned the turbines a lot of methane came out and it came down to the rocket and ignited. There is a generator nearby so now we have both oxygen and methane coming out of the turbines as very hot and very high pressure gases and when they hit the combustion chamber the gas reactions make the most efficient combustion possible and very More energy is generated. Compared to liquid on liquid that can be generated by gas on gas, Elon Musk says this reaction is 99% efficient, which is the maximum physics allows.
Elon states that only God can do a better job at combining molecules than the Raptor combustion chamber, Elon also reveals that with the latest Raptor version 2 there is no need to even have an igniter in the combustion chamber, the gases Self-combustion occurs, he won’t go into detail about how this happens, but he said that removing the igniter system makes an important task possible. Reduced complexity, which in turn made the engine cheaper to manufacture and lighter overall.
If this all sounds very complicated it is because Elon refers to igniting the Raptor engine as a delicate dance between the fuel system and the oxygen system, everything is interconnected and everything is everything. So if anything goes wrong the whole engine will explode or at least some parts will melt. Elon says that SpaceX has already blown at least 20 Raptor engines during its testing, if not 30.
Melted at least 50 combustion chambers, but that’s okay because SpaceX built their infrastructure for the Raptor to allow extremely high production rates for one engine per day, the higher the production rate the faster you Designs can be iterated or changed, fast production allows for multiple iterations on the Raptor design and it doesn’t really matter if you blow something up in the process because a new one is already on the way.
Performance
So we know what the Raptor does, let’s talk about what this means for the performance and power of this engine, the Raptor is a small engine that produces a massive amount of thrust, the current Raptor version 2 230 metric tons of thrust is generating. It’s not the most powerful rocket engine on the ocean floor, that title goes to the F1 engine that lifted the Saturn V rocket, it had twice the thrust of the Raptor but it was an absolutely massive engine you could park a jeep inside.
The Raptor, on the other hand, is super compact at three meters long and 1.5 meters wide at the nozzle, allowing SpaceX to pack 33 of them into the Raptor, a 9-meter-diameter booster, the same size as the RS-25 engine. operated the Space Shuttle. Very small in comparison and also optimized for the SLS Moon rocket, but the RS-25 produces about 190 metric tons of thrust, so the Raptor punches well above its weight in terms of brute force, the Raptor 2 weighs just 1600 Kg, while the RS-25 is around 3 Kg.
200 kg and it accomplishes this by running the combustion chamber at significantly higher pressure than any other rocket engine in the world, the Raptor 2 chamber pressure is currently 300 bar which is approximately 4 351 pounds per square inch, the RS-25 The chamber pressure drops to about 206 bar. Remember that rocket engines use throats and nozzles to convert pressure into thrust, so more pressure means more thrust.
Elon Musk says SpaceX still has some room for improvement with the Raptor 2 design and can reach a maximum of 200 150. Too much thrust at some point in the near future Elon says they are still losing some performance by overheating the engine, right now they are optimizing for the overall robustness of the engine as opposed to performance as they were previously in orbit without detonation I wanted to go and after that they could be a little daring.
Now we don’t even understand how rocket engines are cooled because obviously they need a very complex cooling system to keep the whole thing from melting down, but that’s too much info for just one day So now knowing that a system has come in place to maintain temperature, Elon says that moving forward on the Raptor design will primarily be to make the engine more simple and therefore cheaper and faster. One of Elon’s favorites.
The adage that the best part is not the part is at the core of his first principles philosophy, when Elon is designing something he is the first to question the constraints and requirements and make them less foolproof doesn’t follow what doesn’t make sense then remove any part of the design process that isn’t essential if you haven’t been obligated to put back at least 10 percent of what you removed Not enough items have been removed.
Step Three Optimize Step Four Accelerate Step 5 Automate And we can already see this with the transition from Raptor 1 to Raptor 2. With significantly fewer parts visible on the new engine, Elon says he wanted to remove all obscure bits from the engine which meant integrating more short pipes and tubing and bolted flanges with solid welds. Elon says that by integrating more components of the engine they can actually remove the shroud which is essentially the protective heat shield, obviously removing anything from the rocket ship’s design would make it lighter.
And cheaper which is absolutely critical for sustainable space flight, this process will continue to make the Raptor cheaper and more production friendly which is the ultimate main goal, you might wonder if the rocket is going to be fully reusable, so Why all the engines are needed, we’ve got to think long term here, that’s where Elon is heading towards their ultimate goal, with Starship is to make these rockets as common as jet airliners, today there’s a fleet of over 1,000 Whether there are fewer chips or more, these ships will remain in continuous operation in transit.
Using the ship as point-to-point transport between Earth and Mars, between Earth and the Moon or even on Earth itself, the Starship Endgame is one of the most important vehicles ever created in human history to be, yes that’s right the first sailing ships to cross the ocean and connect the worlds, starships can connect the solar system and it’s great to be able to watch the games in real time, so keep calm and watch everyone, Thanks to Elon Musk for sharing.