The Monthly Blog...
Here is where I will be updating the website monthly on trending matters of aviation and make them plane simple (there is nothing like puns). Apologies there is currently an issue with images, I am working to get this solved as soon as possible. Until then, enjoy :D
SpinLaunch – the revolutionary ‘yeet’ we need.
by James Andradi 24/09/2022
SpinLaunch: the innovative new space Technology, that has the potential to revolutionise the way we access and expand into the final frontier - space. Whether or not this is in some critic’s views a waste of money, or a game changer, the point remains, that this is one of the few attempts actually made in tackling the ‘Tyranny of the Rocket Equation’, and this is one of the few that is so ingenious and has so much potential. So let’s dive into it!
By now, some of you may be wondering, what is the ‘Tyranny of the Rocket Equation’ and what is the Rocket Equation in the first place? The Tsiolkovsky Rocket Equation (or just the Rocket equation for short) is applied by engineers in aerospace, to in simple terms determine how much fuel is needed for a rocket to carry a certain payload to its destination. For those curious, the basic is:
m = m0e-Δv/c
Some of you may start to see an issue with this already. The fuel needed to deliver that payload to its destination, is a payload itself. So now you need more fuel to be able, to carry the new payload. Which in turn is a payload, so more fuel is needed for that amount, and the exponential growth continues. It’s a cycle that means an increasing amount of the rocket, has to be fuel - to the point where 90% or more of the rocket is simply fuel, wasting space, money and producing harmful emissions. What a blast! (pun intended). One way this can be solved is by finding a way to provide a rocket with kinetic energy through other (external) means. This is where SpinLaunch comes in.
The concept behind SpinLaunch is exactly that - to provide energy to the rocket through other means. The founder behind it, Jonathan Yaney, all the way back in 2014, was trying to look for a solution to this recurring issue, when he came across project HARP. Project HARP (High Altitude Research project) by Gerald Bull was an attempt done by the United States and Canada in the late 1950s to launch rockets and satellites into space using a railway style cannon. This concept of ‘yeeting’ a rocket to space without the need of a literal rocket, led to the Yaney coming up with the idea for a rotational accelerator to catapult the rocket to the outer atmosphere, which is where the rocket uses the largest amount of fuel and needs the most propulsion. For comparison, currently satellites cost around 7 million dollars to put into space, however Yaney claims that with SpinLaunch this figure could be reduced to half a million dollars or even less.
So how does it work you may wonder. It uses a ‘hypersonic tether’ (which would have the highest tensile strength in the world) to rotate all the way up to launch speeds, from where the payload gets released (timed by a precision computer) and hurled out of the exit tunnel at speeds of 8000kmph. All this happens in a vacuum chamber, meaning the chamber is devoid of air. This is necessary as this not only means there is no air resistance and hence less work to do but it also means that the tether and rocket don’t get heated up to extreme temperatures.
While this all may seem fantastic some believe it is a long shot (figuratively and literally), so lets delve into the limitations. For starters we have not even discussed the g’s experienced by the rocket, which potentially near 10000g. While this can be overcome for a normal payload, any living payload would be dead before the rocket even got launched. To put this into comparison, the usual range of g’s needed to kill a human (according to NHTSA standards) is 50gs for a child, 65 for a female and 75 for a male. However, the most a human can generally withstand is 9. There are exceptions but they most definitely do not go that high. That is one issue. The other issue is Physics. There have been successful tests of SpinLaunch, that is true, so they must have found a way to cancel the rotational inertia of the payload as it is released from the moment arm. However, on larger scale projects this may become an issue and not allow for the rocket to actually launch and instead get yeeted at 8000kmph into the walls.
Personally, I opine that it is not a viable alternative to projects such as SpaceX that are capable of transporting living things and large payloads safely, but while I see all the limitations, I believe that this project has a lot of potential when it comes to small scale launches such as satellites, and of course, even if projects like this may seem ridiculous, I applaud the ingenuity and recognise that it is these projects that are the compost for the seeds of innovation. I think it is a great idea that will save a lot of money when it comes to satellite launches, money that can be used for different purposes.
All credit for the images used in this article goes to https://www.spinlaunch.com/ and https://www.wired.com/story/inside-spinlaunch-the-space-industrys-best-kept-secret/.
Some say supersonic – others say Boom.
by James Andradi 14/10/2022
Boom: that one piece of innovation that has the potential to revolutionise the way we travel – to bring supersonic back. Tokyo to Seattle in 4:30h, LA to Sydney in 8, Singapore to Dubai in 4 – this would truly be a breakthrough. Up until now this concept may have gone the furthest in fulfilling the Concorde’s legacy, but is it viable, is it possible and is there even a point? Let’s delve into the matter and find out!
When someone thinks of an iconic plane, they may find themselves imagining the 747, or maybe even the DC-3, but none is as different and as unique as the Concorde (excluding the controversial Soviet Tu-144). Hence it is a big shame, that a plane so beautifully sculpted and ahead of its time was retired so soon, with its final flight on the 26th of November 2003. Moreover, it was retired without a replacement. However, while this may a big shame, it was frankly not a big surprise. Despite being a marvel of engineering, the Concorde was riddled with a variety of financial problems and experienced a tragic series of events towards the end of its life that led to its retirement.
Let’s now go over these complications that led to the Concorde’s downfall to understand some of the issues Boom must overcome. The Concorde started off very strong (and very fast, figuratively and literally), with over 100 purchase agreements by the major airlines of the time, however, soaring production costs made it a much riskier purchase, forcing everyone except British Airways and Air France to cancel their orders. This followed up by the drastically rising fuel prices and limited seating made making a profit from the aircraft a difficult ordeal for British Airways and Air France – even with ticket prices urgently put as high as $11000. Raising the ticket price raised other problems, as why fly on the Concorde’s cramped yet luxurious conditions, when you could afford even more luxury and comfort for a fraction of the price on a flight that took solely 4 hours longer? Due to this the Concorde started to struggle filling seats, usually not maxing out it’s 100 seat capacity, something that got even worse after the unfortunate crash of Air France 4590. Furthermore, supersonic travel was banned over North America, Europe and other areas, because of the disturbing sonic boom it created. However, due to its range it wasn’t able to capitalise on the alternative transpacific routes and was instead stuck to transatlantic routes. Consequently, the scarce routes available further limited the aircraft’s potential, worsening economic problems. While British Airways and Air France found ways to bring in extra cash, such as through the ‘Concorde experience’ - much cheaper, short Concorde flights done my standby crews for anyone wanting to experience supersonic travel – for normal flights overall the economics behind them were very challenging. This lack of profit meant that the Concorde did not cover the costs of development, which would have been impossible without the significant government backing it received.
So now we’ve seen what Boom must over-come. Three main issues: first, increasing the amount of routes it has access to, second, propulsion and third, making a profit. Starting off with increasing available routes, Boom must tackle those meddlesome sonic booms and/or range. Any mass travelling over the speed of sound is going to cause a sonic boom – that is the nature of physics. We cannot remove the sonic boom unless we are travelling in a vacuum. Hence we can only work to minimise this. However, when we compare the Boom Overture with the X59 (the embodiment of all the research by NASA), it lacks the distinctive low boom features of the X59, it has a pointy nose instead of a blunt one, and does not have a narrow fuselage that conforms to the area rule. So it seems that Boom are not working on removing this ‘boom’ (living up to its namesake) as it is simply not viable for an airliner that needs seats and as less drag as possible. However, they are keeping it in mind as when we look at the routes they advertise they are mostly transpacific or transatlantic. So what Boom are doing, is working to increase the range of the Overture. But how you may ask? For starters, Boom will be able to take advantage of all the developments in range (and fuel efficiency) that the aerospace industry has made since the Concorde for example with materials such as carbon fibre composites (that provide a massive range of advantages) as well as all the advancements in technology to develop the ‘perfect’ airframe, using computer simulations with extremely precise quantitative measurements and fast turnover times (when compared to the Concorde whose developers used pen and paper). Additionally, Boom will be looking to minimise all forms of drag, through features such as having thinner wings (thanks to carbon composites) and extending the delta wing up the aircraft all the way to making the fuselage fit the area rule as much as possibly practical. This will all help to increase range and allow Boom to take control of the neglected yet lucrative transpacific routes.
Moving onto the next major issue - the engines. Let’s take a look at the engine Boom needs. It will need to have a thrust output of 67-89 kilonewtons. Compared to the engines used by other aircraft, such as the 285-331 kN of force provided by the 787’s Trent 1000, it may seem that there is no issue. However, Boom is a supersonic aircraft. The 787 is not. What does this mean? Engines made for supersonic use are very different from those that you see used on most airliners – they must be pure jets. Boom will not be able to use engines such as the Trent 1000 or really be able to exploit all the advancements made over the years in engine efficiency as they have not been centred around supersonic aviation. The prime example of this is the large bypass ratio common in most modern engines that massively increase efficiency, where most of the air going through the engine doesn’t go through the engine core, instead going around the core and out the back. However as supersonic engines have to be the aforementioned pure jets, a high bypass ratio would be more of a hindrance than help and hamper engine efficiency as it would slow down exhaust air and these engines have a big frontal surface area, generating drag. Hence Boom would really need to come up with an engine from scratch. Yet luckily and unluckily there is 1 engine that comes quite close to what Boom needs; the GE affinity an engine designed for a different supersonic concept that got cancelled due to lack of funding. The lucky bit is that these plans still exist. The unlucky bit is that the engine itself is conceptual, and GE had specifically said, that GE have stated that it was not interested in developing this engine for the overture. Other big engine companies have said similar statements, with Rolls Royce seeming to come into an agreement but pulling out in September. This means that Boom will really need to design and make an engine from scratch, which leads us onto our next problem.
Funding and making a profit. It is important to remember that all of this needs money, a lot of it. Concorde’s development required much innovation, which would not have been possible without the government funding it received. However, we are no longer living in the cold war era, and this government funding cannot be something Boom expects, so it will need to take the full brunt of the price by itself and then make enough profit to recoup the cost and be able to pay back investors. However, despite the lucrative new routes available, making a profit will be hard, not only due to the sheer amount of costs, but also because Boom cannot rely on the techniques used by British Airways and Air France such as trip experiences to make a revenue because of the environmental considerations they must keep in mind. About environmental considerations, Boom are promising that their aircraft can function on net 0 carbon fuel, a fuel that is not abundant, available in mass or cheap, and quite frankly, any airline operator will not use expensive biofuels instead of kerosene on an aircraft that will already be struggling to make money. Not to mention that Boom are working to look for a market rather than meeting a demand in one, which will once again mean that it may struggle to fill seats like the Concorde. This will mean that Boom will struggle to make a profit, a make or break factor, in aviation.
Personally, I believe that while we can succeed in making another supersonic airlines, even better than the Concorde, I do not think that this is a successful business model, and I opine from what we can see that it will have a hard time succeeding economically. However, it is an air of change that the aviation industry needs, and this may be the first domino piece in changing the way people view aviation and work towards resolving its issues.
Winging it - the magic behind lift,
Part 1.
by James Andradi 06/01/2025
Flight in all its glory - impressive, awe-inspiring, you name it, what else could come to mind when you think of flight? When you imagine a lumbering 500 tonne beast taking to the skies, or a sleek fighter punching past on full afterburner? Who hasn’t looked up in fascination when they’ve heard the mighty deep rumble of a 747 on approach? Who can’t help but just think – how? You aren’t alone that’s for sure. From the ancients till now, flight has remained a timeless aspiration, an enduring desire, a wonder inducing high. And the magic behind it - its pretty quite simple. So read on, to lift the veil of mystery sky-high.
In truth, flight is often misunderstood due to the tangled web of theories out there, many of which don’t hit the nail head on, not being wrong, but offering a piece of the puzzle instead. Some approaches overemphasize the aerofoil (wing cross-section), while others cling erroneously only on Bernoulli’s principle - so rather than trying to patch up different ideas, let’s start with a clean slate, and go through lift as simply as possible. For today’s Part 1, we won’t be looking at the actual ways and theories behind how flight works, solely establishing the basics.
All right, so what is lift? Lift is simply a force – one that acts ‘up’. What is a force? A force we can call something that causes an acceleration (F = ma: Newton’s second law). Lift is a force causing an acceleration upwards. Well then, it will of course obey Newton’s laws of motion. As such, if there is a force acting up, that force, like any force should have a Newton’s Third Law pair - that is, an equal magnitude force acting in the opposite direction, down. So simplifying slightly, if we can likewise create a force acting down, we will also get a force acting up. And that is exactly how a wing generates lift: by diverting air downward. This interaction between the wing and the air is the essence of lift. It may seem counterintuitive, but it is the same way a rocket, or a plane engine work, by pushing ‘stuff’ in the opposite direction, and they seem very intuitive don’t they?
Now that we are on this, it is quite appropriate to address something that causes a lot of confusion with Newton’s third law. One doesn’t have to know Newton’s first law to realise that an acceleration will only happen if there is a resultant force. If you are playing tug of war, and both sides are tugging equally, nobody is going to anywhere are they? You need one side to pull more than the other for the thing to budge. This applies to any physical scenario, no matter the number or complexity of the forces. So if every force has an equal and opposite force, how can there be any resultant forces? The key is that the opposite forces aren’t acting on the same objects. Imagine you are punching a punching bag. You feel the bag ‘pushing’ against your fist. But the bag isn’t moving towards you, the bag is moving away from you, because it is getting ‘pushed’ by your fist, the force towards you isn’t acting on the bag – it is acting only on you. The bag is experiencing an equal force, but only forwards. The forces are acting on different objects. Likewise, for lift, the air is experiencing a force downwards, and the wing a force upwards, so even if both of those forces are equal, neither object is in equilibrium off the pair alone. As such, the unifying physics of flight, the core principle, is that air is accelerated in one direction, to create a force in the opposite one.
At the same time however, it is important to move beyond the oversimplified notion, that lift comes from air hitting the underside of the wing and being deflected down. Most of the lift actually arises above the wing, but how the wings actually produce lift is a matter, for part 2…
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