SpaceX - as we all know - wants to send the first humans to Mars as soon as possible.
And that’s why we have seen so many starships upper stage testing in Boca Chica, Texas.
And so far the test flights have been looking good.
The rocket uses Raptor Engines for all its testing and will most likely use it in the future for real-world launches, during its missions to Moon, Mars, and beyond.
The engine is powered by subcooled liquid methane and subcooled liquid oxygen using a more efficient Full-Flow Staged Combustion cycle.
And this is where SpaceX beats all the odds.
No methane-powered rocket has ever made it to orbit, but Raptor is different.
It is designed to make use of every drop of propellant available, making it one of the most efficient rocket engines ever built.
Now, on earth getting propellant is not that hard.
We just need supercooled oxygen and methane.
And also methane is supposed to be one of the cheapest forms of fuel available to make on earth.
In our atmosphere, we have plenty of Oxygen - we just have to extract it and cool it.
But what about methane?
In nature, methane is produced by the breakdown or decay of organic material and can be introduced into the atmosphere by either natural processes – such as the decay of plant material in wetlands, the seepage of gas from underground deposits or human activities like oil and gas production, rice farming or waste management.
But for the use of methane in rockets, mining companies generally get them from beneath the earth’s surface.
We now even have some ways to use Carbon dioxide to generate methane known as Sabatier Reaction.
Sabatier process produces methane and water from a reaction of hydrogen with carbon dioxide at elevated temperatures (optimally 300–400 °C) and pressures (around 30 bar) in the presence of a nickel catalyst.
So this is how we are extracting fuel for Starship on Earth to send it to Mars.
But what about returning from Mars to Earth?
Well, it turns out that SpaceX chooses Methane and oxygen as the fuel for its rockets for a reason, that is, it’s available in plenty of amounts on both Earth and Mars and really easy to produce.
Methane and Oxygen can be synthesized on the Red Planet from subsurface ice and carbon dioxide in the atmosphere.
Creating this fuel on Mars will reduce the total amount of fuel that the spaceship needs to bring from Earth, lowering the cost of the trip.
The ship won't need a booster to take off from Mars, either.
Because Mars has less gravity than Earth, the spacecraft can produce enough thrust to escape the planet’s gravity well on its own.
Launching anything from Mars is viewed as a technological hurdle.
The planet may have less gravity, but any vehicle departing Mars still needs rocket engines and lots of propellants to take off.
Just getting such complicated machinery to the surface of Mars intact is a challenge in the first place.
If SpaceX is able to land and then launch from the Red Planet, it would be a major feat of engineering.
Musk spoke optimistically about SpaceX's ability to create propellant plants.
The first ship to land on Mars would bring with it a "small propellant plan," which would be expanded as time went on.
And further down the road, SpaceX hopes to build plants on various moons to send other ships even deeper into the Solar System.
This leaves some questions like how SpaceX alone will produce the propellant production farm which will enable rockets to return from Mars.
The answer to that is - No they won’t do it themselves.
SpaceX will most likely partner with some companies and organisations that can get them the necessary machines to work on these plans.
And always remember that SpaceX is just a rocket production company.
Most likely, NASA is the one who will send their astronauts through SpaceX’s rockets.
So, propellant production shouldn’t only be a concern of SpaceX, but NASA's too.
Now let’s look at How SpaceX will land its Starship booster.
Well, that sounds like a topic to discuss in a different episode of DiscoverZen.