Starship: Humanity's Way to Mars?
- LMadgit
- Jul 14, 2024
- 7 min read
[Opinion piece]
I believe Starship to be humanity’s way to colonise Mars. Not in 100 years, not in 200 years - but in the next few decades. In this article, I will lay out why Starship is such a transformative vehicle, and the way that it will be used to build colonies on the red planet, as well as its current developmental status.
Firstly and perhaps most importantly, what is Starship? [It may sound like a sci-fi name, but it is in fact real!] Starship is a rocket that is being developed by SpaceX at Starbase, in Boca Chica, South Texas. It has flown 4 fully integrated test flights so far and has continually made progress on each one, this is part of SpaceX’s iterative design approach, using the motto, “fail fast, learn faster”. The rocket is powered by 33 Raptor engines on the first stage (known as Superheavy), and 6 on the second stage (also known as Starship!) The second stage is planned to come in many variants, with Starlink deploying ones (Starlink being SpaceX’s LEO internet constellation, with over 6000 satellites), cargo ones, refuelling ones, orbital fuel depots, and HLS (the human landing system being developed for NASA’s Artemis 3, humanity’s return to the moon). In the long run it is also planned to take cargo and people to Mars.
The “secret sauce” behind Starship is the phenomenal Raptor rocket engine. It is liquid - fuelled, meaning it combusts cryogenically stored Liquid Methane and Liquid Oxygen. It is a complicated piece of engineering - however SpaceX is producing these at a rate of more than 1 per week! It uses a form of combustion cycle known as the Full Flow Staged Combustion Cycle. In this, both the Oxygen and Methane go through what are known as ‘pre burners’, getting them into gaseous form and extremely hot by slight combustion with the other propellant before entering the main combustion chamber, this allows SpaceX to push main chamber pressures up extremely high, with that being what gives the engine thrust as the gases are exhausted. As well as this, it means they combust more fully - releasing far more energy than a standard liquid rocket engine. This increased thrust allows Raptor to power a much larger rocket, meaning it is capable of lifting the whole Starship stack, weighing in at just over 5000 metric tonnes fully fuelled. This increased performance translates into increased payload mass - something which is essential if humanity wants to take cargo to Mars!
As previously mentioned, Starship has completed 4 test flights so far, with each one meeting more objectives than the last. On the 20th April 2023, Booster 7 and Ship 24 (known as the B7/S24 stack) lifted off from Starbase, successfully clearing the pad and ascending to an altitude of around 40 km. However, an explosion on engine 19 led to cascading failures of engines in the engine bay, as there was no adequate fire suppression system installed at this time. As a result of this, the vehicle massively underperformed on the ascent, never reaching the correct altitude or speeds required for stage separation to occur. The fires in the engine bay severed control of the engines from the flight computers, leading to an uncontrolled spinning a few minutes into flight. The automated flight termination system fired, however this failed to immediately destroy the vehicle, leaving the stack spinning end over end at 2000 km/h, simply refusing to die! The lessons from this flight were taken onboard by SpaceX, and they made 10s of 1000s of improvements before the next flight of Starship on November 18th 2023. On this, Booster 9 and Ship 25 were mated to try and progress further than the last flight - and Booster 9 delivered! All 33 Raptor engines successfully lit and fired for the entire duration of their planned burn, meaning the vehicle reached the altitude necessary to perform stage separation. One of the changes for this flight was ‘hot staging’, a manoeuvre in which the Starship second stage fires its engine whilst still attached to the booster, increasing payload mass to orbit.
This worked flawlessly, and the second stage continued on its planned trajectory, whilst the booster started its boostback burn to try and soft land in the ocean. Cloggages inside led to an explosion however, and the booster was lost. During Ship 25’s ascent, an oxygen dump led to fires in the engine bay, and the automated flight termination system fired just before it reached its planned orbit. This was a significant milestone for the program, despite the loss of the vehicle, as it showed Starship was capable of executing a long burn. The next flight would come just 4 months later, on the 14th March 2024. This time, Ship 28 was flying atop Booster 10, and they soared off the pad under the power of all 33 engines again! Booster 10 achieved a flawless ascent, hot staging went smoothly, and the booster began its boostback burn. This was cut short due to blockages in the liquid oxygen filters again, and the booster plummeted like a stone towards the ocean. For the landing burn, it ignited just 2 of the planned 13 engines, and the booster experienced a RUD (rapid unscheduled disassembly) at 500 m above sea level. The ship successfully reached its (almost) orbit this time, the first time for this program, however a block in one of the roll control thrusters led to it tumbling throughout its coast phase in space, and reentering at the incorrect angle. Ship 28 burnt up at 65 km above sea level, but not without giving us some phenomenal views of the reentry plasma live via Starlink. Due to the relative success of IFT-3, it only took 2 and a half months to get to IFT-4, which launched on the 6th June 2024, with Booster 11 and Ship 29. Again, the booster performed a successful ascent burn, and this time a flawless boostback burn - putting it on the correct trajectory for landing. For landing it ignited 12 of its 13 centre engines, and performed a pinpoint soft splash down in the Gulf of Mexico - essential for proving that in the near future SpaceX can catch them with the launch tower, using two large arms (known as “chopsticks”) - in order to reuse them to save money. Ship 29 continued to orbit flawlessly, and this time maintained the correct angle throughout. It reentered and rode out the plasma all the way through the atmosphere - with the front flaps just hanging on as the steel began to melt in our live view! To the amazement of everyone watching (including me!), the ship ignited the planned 3 of its engines, and performed a perfect landing in the Indian Ocean - decelerating from over 27000 km/h to 0 in about 20 mins, almost entirely from aerodynamically braking! This proves that SpaceX can reuse both the ship and booster in the future - something which is absolutely essential to complete the vast number of flights that building a city on Mars would entail!
SpaceX launched the vast majority of mass to orbit last year with their Falcon family of launch vehicles - now this talk is not about them, but it is demonstrative of the cadence scaling - from the first launch in 2010 - to 96 last year! They are targeting 148 this year, and are currently on track to meet that target (just!), although the launch failure on Starlink Group 9-3 might put a stop to this. Starship will have to scale to far surpass this target - a city on Mars will require ~1 million tonnes of cargo, that’s thousands of launches in a window of 2 years (due to the planets’ orbits around the sun). This might sound utterly preposterous, but so did landing an orbital class rocket booster 10 years ago - and now SpaceX have done it well over 300 times with the Falcon 9! On the topic of reuse - that is absolutely critical to any Mars ambitions - imagine how wasteful it would be to throw away the entire booster, with 33 expensive engines, every single launch! SpaceX is planning to “catch” the booster with large arms on a tower. CEO and chief technical officer of SpaceX, Elon Musk has said that “rapidly reusable, reliable rockets are essential to making life multiplanetary”. Musk has said he wants a city of a million people by 2040, personally I find that a bit unlikely - but I would be shocked if people don’t land on Mars in the 2030s. The first trips would be one way, as it is harder to get back from Mars than it is to get there. This would mean that people would have to be willing to pick up and move their entire lives off planet, in a way this is quite similar to the first European settlers moving via ship to North America - an adventure into the unknown! Of course, SpaceX cannot build a city by itself - it is projected to cost many 10s of billions over a period of decades - so this project requires other companies and governments to get involved. Thankfully, NASA is working on this exact problem - the Artemis Accords are a set of agreements signed by nearly 40 countries, committing them to safe, responsible exploration and settlement of space.
Moving forwards into the future - I think that the coming colonisation of Mars will be, and is, one of the most exciting endeavours in human history - potentially rivalled by the development of human level artificial intelligence (a topic for another talk). And I would like to remind all of you - this is not like what has been talked about since the 1960s and the era of the Apollo programme, endless talks, studies and ideas. This is happening - the vehicle that will take humanity back to the moon, out to Mars, and beyond (Musk has said he wants to reach Uranus with Starship, albeit this should probably not be taken in all sincerity). This is happening, and it is something that we should all be enthused about. In a world plagued with endless problems and miserable issues - we need something to wake up to in the morning and be excited about - and I think that this is just that!
Thanks for reading this article, written and edited by Luke Madgett and Eve Carruthers.
