Let us imagine this scenario – or perhaps play this game: we throw a lit cigarette into the sky with all our strength, and then try to catch it with tweezers as it comes back down. A pack contains 20 cigarettes, and the chances of all of them ending up on the floor are considerably high. Let’s change the scale: instead of a cigarette, we launch a structure so large it wouldn’t fit between the goals of a football field; and the tweezers become a pair of mechanical arms longer than two buses. And to further complicate things, the “cylindrical” tube comes down after reaching the mesosphere.
This is what happened on October 13. In the southern tip of Texas, overlooking Mexico, SpaceX launched Starship for the fifth time – the largest space rocket ever built; but this time, it went even further. The New York Times used the term “technical wizardry” to describe how, for the first time, a thruster – known as a Super Heavy booster – falling at supersonic speed was instructed to glide and return to the precise launch location. After getting caught by the “sticks” of the giant structure, the booster had only a few “scratches” and was practically ready to be reused.
The question is: why are we talking about a thruster, and why did Ana Pires – the first Portuguese scientist-astronaut and INESC TEC researcher – describe last week’s event as “the redefinition and revolution of space exploration and consequent industrialisation”? Are we closer to witness sunrises in Mars thanks to reusable systems? And are we wasting days on our planet while trying to do so? Are we once again damaging the ozone layer – which, according to a 2023 UN report, was finally making a “remarkable recovery”? The answers to all these questions are included in INESC TEC Watch’s third edition. Ready to take off?
A month before 5.000-ton Starship’s fifth take-off, SpaceX founder Elon Musk estimated that it would only take four more years for Starship to reach Mars – the world’s richest man had already advanced a similar scenario in 2016. The long-term plan – and we are talking about a situation that’s practically impossible to materialise over the next decade – is quite ambitious: to create a kind of “air bridge” connecting two planets, with regular shuttle flights capable of transporting hundreds of people; after all, we are talking about a business that also seeks to capitalise on all the investment made.
If this happens, October 13, 2024 will become a major milestone in the path seeking to address the question “How did we get to Mars”. Rui Moura, a researcher at INESC TEC, tried to contextualise this potentially historic milestone, and how Musk’s company’s approach can bring Earth closer to the red planet: “this new development approach that SpaceX uses has proven that quick and dirty prototyping, with successive test launches and limited strategic objectives, seems to work; in fact, it’s faster than more traditional approaches, in which any small innovation almost requires a subproject and feasibility study, which takes time and requires significant investment.” The fact that we’re witnessing an increasing number of new test launches is hardly surprising, with countdowns and aficionados armed with binoculars and pointing towards the sky, to keep track of the rockets.
A giant tower that is a beacon for the future
The manoeuvre we witnessed in Texas is “crucial,” stated the geophysics researcher, particularly “when it comes to reducing the costs required for spaceflight, whether for low Earth orbit or deep space missions.” That day, everything went smoothly: the thruster, equipped with 33 Raptor engines (we’ll come back to this later), successfully launched the main module – the Starship rocket – into orbit. The rocket then executed a controlled landing in the Indian Ocean and returned to base. According to Ana Pires, the cigarette getting caught by the tweezers will be part “of the engineering history books”. Could things have gone wrong? Yes – quite wrong.
“We must not forget the size of the rocket. With so many new manoeuvres and so many aspects to consider, there were more than enough instances that could cause a catastrophic failure. A small error of just a few metres during the rocket’s landing could have destroyed the huge and complex launch and landing system,” emphasised Rui Moura.
According to Ricardo Conde, president of the Portuguese Space Agency, SpaceX managed to overcome “a set of technical difficulties” ranging from the “reliability of the engines and restart capacity” and the ability to have “structures capable of dealing with the mechanical stress of launch and return”, as well as the need for “control algorithms capable of decelerating and landing in a coordinated manner”.
These “giant arms” stationed near the SpaceX base are part of a structure known as “Mechazilla”; the main goal is to pick up spacecrafts when they return from orbit and quickly prepare them for a new trip: with the continuation of the tests, SpaceX will one day be able to quickly recover and resend the rockets and main modules for future missions to the Moon or Mars. At least, this is the dream of the tycoon Elon Musk: “we want to wake up in the morning and address the future with hope, we want to feel excited about what will happen,” said the South African billionaire, owner of Tesla and X (formerly Twitter).
The dream started when the “Mechazilla arms” weren’t even ready. Before Starship, the Falcon 9 – rockets half the size that still travel to Earth’s orbit – claimed all the interest and attention. SpaceX is already able to recover and reuse the boosters of these spacecrafts. Now we’re talking about a larger scale. “Landing rockets after flight is a feat SpaceX mastered with the Falcon 9. Now, it seems that SpaceX can achieve this with the Starship system – which features a massive launcher (over 120 metres tall, with a diameter of nine metres) that integrates the Super Heavy Booster and the Starship; the former launches the rocket to the edge of the atmosphere, while the latter is capable of transporting various payloads and crews, either for orbital or lunar missions, and (in the future) to Mars,” stated Rui Moura.
Starship rocket booster caught by tower pic.twitter.com/aOQmSkt6YE
— Elon Musk (@elonmusk) October 13, 2024
A milestone in history?
Another important aspect is the engines’ capacity and efficiency. The Raptor, “more powerful and efficient” than the Merlin used in the Falcon 9, distanced themselves from all others used for space exploration by the ability to produce energy from liquid and cryogenic methane. The Raptor may even be the “passport” to a new era of space exploration and Musk wants to use the latest technology at least 1000 times to make SpaceX’s business model viable and sustain the ongoing dream of creating a self-sustaining city on the neighbouring planet.
And this is a “huge challenge”. In a Wired article that delves into the science behind the alloys of steel that line the Raptor, the magazine recalled that “the most re-used engines in space exploration history were the main engines on each Space Shuttle system“, which NASA operated for three decades. The three RS-25 engines part of each of the five space shuttles (OV-Orbital) “flew up to only a few dozen times”.
But the image of “Mechazilla’s embrace”, whose height almost reaches the Vasco da Gama tower, fuelled the hope of an upcoming “new era of space exploration”. Ana Pires had no doubts: “after witnessing the ‘Mechazilla’ system, I’m certain it will feature in the engineering history books. This feat shows how incredible engineering is, and how humanity could be closer to reaching Mars.”
Is Portugal also looking up?
Paying close attention to developments on the other side of the Atlantic, the Portuguese Space Agency used the term “incredible”, anticipating the “buzz” the demonstration may cause: “the pictures seem pure science fiction. A reusable vehicle this size will strongly impact the sector worldwide, reinforcing SpaceX’s dominance in access to space and putting pressure on its competitors to innovate and remain competitive,” mentioned Ricardo Conde.
Is there room to “innovate” in Portugal? Yes. The Portuguese Space Agency is working towards several goals, leveraging the country’s role in Space-Earth-Climate-Ocean interactions, paving the way for Portugal to become a player at European and global level. “In Portugal, we also have the ambition to promote disruptive space launch and return activities, through private initiatives and the Space Rider,from the European Space Agency. These initiatives will certainly not be competitors of SpaceX, but they’ll address current market needs, like micro launchers or vehicles capable of performing experiments in microgravity,” said the president of the institution.
Ana Pires, leader of the Camões mission – which, for seven days, simulated the environment found on the Moon inside a cave on Terceira island -, argued that even though Europe is not “at the same level” as the USA, there’s a clear “ambition”: “we require further investment to be competitive and progress without bureaucracy, faster and without fear of taking risks. We must show the importance of space exploration and associated resources, as well as our potential, and maybe soon we will also make history like SpaceX did. It just depends on us and Europe.”
Since it’s a small detour, we step foot on the Moon to reach Mars
It’s still too early to say if SpaceX will even be able to take people to Mars. If the destination is the Moon, we can – seemingly – put a reminder on the calendar. In two years (2026), the third mission of the Artemis space programme will seek to replicate Neil Armstrong and Buzz Aldrin’s experience on the Moon’s surface. Artemis is the name of the mission that represents NASA’s renewed intentions to return to a previous endeavour; but now the goal is not travelling there and return: the main objective is to create lunar bases (in the orbit and on the surface).
And how can the Moon help us reach Mars? There are Artemis missions scheduled until 2029, and the plan is to exploit the results of all these missions and prepare for the ultimate goal: to reach Mars. To better understand Moon’s role, let’s come back to Earth, and forget about astronauts: we’ll now focus on cyclists. Yes, we can compare both domains: one could argue that the only way to win the Tour the France is by practicing for months in advance, namely in higher-altitude regions; usually athletes try to cycle mountains reaching more than 2000 metres to get their bodies ready and increase the ability to absorb oxygen. This training could later help them to “go that extra mile”. After these missions to the Moon, NASA will study the effects of limited gravity on the human body, leaving nothing to chance when it comes to travel to Mars. And there are many aspects to consider: the Earth-Moon-Earth trip usually takes six days (or nine with three days on the surface); the “red dot” we dream of reaching is close to 210 days away. The Moon will be a testing stage for the Artemis, towards preventing unpleasant surprises when it comes to travel to Mars.
Do multimillionaires dream of Martian sheep?
The US Government’s Agency will resort to a Starship to land on the lunar south pole. NASA has made agreements with commercial companies, and the take-off will feature SpaceX and Blue Origin; Rui Moura pointed out that the company of billionaire Jeff Bezos “is preparing to make the first launch of New Glenn this year, a launcher almost equivalent in size to the Starship” and equally capable of making propulsive landings.
But reaching Mars will only be a possibility if the cries of joy that were heard when the Space Launch System rocket made its way to the Moon – during 2022’s Artemis mission – extend to all missions until 2029 (and NASA, SpaceX, Blue Origin and other commercial companies manage to develop an orbital station on the Moon).
Two years ago, Musk had already realised SpaceX’s intentions and “specifications” for future Martian cities: transporting humans, animals and creating an “oxygen factory” on the red planet. Deep down, paving the way for a fresh start on planet B. The multimillionaires who lead this new space race cherish this idea: Mars will help “preserve” Earth, and Musk even claims he will “transform us into a multi-planetary species.” This could be a nice theme for an upcoming edition of INESC TEC Watch. Until then, we focus on the actual impact on Earth, in the wake of this new space race.
Here’s a warning: “an increase in spaceflight activity could damage the protective ozone layer on the only planet we live on.” This is a statement by the National Oceanic and Atmospheric Administration (NOAA). Moreover, a tenfold increase in launches powered by hydrocarbon fuels is expected “over the next two decades, based on the latest trends in space traffic increase”. The result? Damage to the ozone layer and changes in atmospheric circulation patterns.
The “excitement” of the 3, 2, 1…
We can divide the environmental impact into two categories: during construction, while obtaining the necessary fuels, and during launch. Upon take-off, Starship releases CO2 and water vapor. “Concerning launchers, it is still one of the most environmentally friendly fuel combinations available,” said Ricardo Conde. However, “there are still many unknown aspects”, and the true environmental impact is unknown “since it is necessary to consider several factors”.
“One thing is for sure: Starship will feature a lower carbon footprint for each ton launched, when compared to the Falcon 9 and Falcon Heavy, the solutions currently marketed by SpaceX. “A Falcon launch is estimated to burn more than 110 tons of refined kerosene, emitting, in a matter of minutes, the same tons of CO2 as a person living beyond the age of 70. According to Rui Moura, “once SpaceX and Blue Origin have replaced kerosene with methane, it will be possible to reduce said footprint.”
And then there’s the pollution that happens… in space. ” Starship will allow to place many objects, at a reduced cost, in orbit, thus aggravating the congestion of orbits and enhancing a greater number of collisions and space debris”, reinforced Ricardo Conde. The constellation of Starlink satellites, operated by SpaceX, is a good example. Altogether, it is estimated that there are more than 6500 satellites in orbit. This number grows every day and many, deactivated, are no longer useful.
With all this attention to Space and the immensity that we still do not know, will we be able to look at the voyage of the USCSS Nostromo, in the Alien (1979) movie – which left planet Earth for a month-long trip to Neptune – as something we can achieve? “[In the future, with Starship,] we can even travel to Venus. The spacecraft is a general solution for going anywhere in the Solar System. Success is not guaranteed, but excitement is”, Musk anticipated. Starship’s sixth launch is set for November, and there is almost a countdown to hearing the ultimate countdown. There is, in fact, “excitement”. In this sense, Musk is right; we’ll see if he’s correct when it comes to other things.
News, current topics, curiosities and so much more about INESC TEC and its community!
