Since humankind could first look up at the sky, they dreamed of flying with the birds. Our longing for adventure drove us to figure out how to soar into the skies and, eventually, into outer space. It makes sense then that aerospace engineering has always been a very natural part of the human experience. It's in our nature to dream and then to accomplish. For hundreds of years, engineers have collaborated and built upon the work of each other in order to advance our knowledge of flight. Eventually, it became about more than just flying. It's about exploring new worlds, and figuring out the answers to some of life's biggest questions: who are we, and why are we here? If you're reading this article, you are probably wondering if aerospace engineering is right for you. I hope that by going through the history, the coursework, and some emerging fields within aerospace engineering, I can help you answer the questions: is aerospace engineering right for you and is it a good major?
01 | The History of Aerospace Engineering
Our journey to fully controlled flight started off very humbly. They say a baby learns to walk before it can run. In the same way, we first learned to rise before learning to glide. We learned to glide, before we learned how to fly.
On October 19, 1783 the Montgolfier Brothers launched the first manned hot-air balloon flight. It was the first device to carry humans into the sky! However, there was no steering mechanism so the brothers couldn't control where they were going. They had used the principles of buoyancy to rise above the air and into the clouds. (Hot air is less dense than cool air. Therefore, it floats on top of the cooler air like a ping-pong ball in water.) This was a magnificent accomplishment.
Sir George Cayley
In 1846, Sir George Cayley - also known as the “father of the airplane” - performed some groundbreaking research on aerodynamics. He discovered the four forces of flight: lift, drag, weight, and thrust.
Thrust: the force that pushes an aircraft forward. This force can be generated by jet engines and propellers.
Drag: a frictional force - often referred to as air resistance - that wants to slow down and stop the aircraft.
Weight: the downward force on an aircraft due to gravity.
Lift: the upward force on an aircraft that counteracts the force of gravity. It lifts the aircraft.
Cayley discovered that an aircraft's lift could be increased by curving its wings. Curved wings generate lift by creating a pressure gradient across the wing. Pressure is higher on the bottom side of the wing and lower on the top side of the wing. Because pressure travels from high to low, a lifting force is created.
Sir George Cayley also created the first glider to carry a human being. A small, local boy was carried on a free, and untethered flight. Free flight just means that there were no mechanisms in place to control variables of the flight such as direction, or speed.
The Wright Brothers
December 17, 1903 is a very infamous day. It marks the day that The Wright Brothers successfully performed the first sustained, controlled, powered, and heavier-than-air flight. The brothers made significant contributions to the field of aeronautical engineering. You see, when a flight becomes powered it becomes significantly harder to control than unpowered flight. The Wright Flyer I had state-of-the-art control mechanisms in place, compared to aircrafts of the past. It had control over its flight along all three axis' (x, y, z).
Yaw: is the side to side movement of the aircraft. A craft that can rotate about its z-axis is able to control its yaw.
Roll: is the banking motion of an aircraft. A craft that can rotate about its x-axis is able to control its roll.
Pitch: is the upwards and downwards motion of an aircraft. A craft that can rotate about its y-axis is able to control its pitch.
The Wright Brothers invented a technique known as wing warping which allowed them to literally warp - or move - the craft's wings mid-flight and control its roll. The Wright brothers also used a rear rudder to help control the yaw of the craft.
World War 1
Demand for aircrafts increased with the onset of World War 1. As a result, methods of production had to get more efficient and war began to fuel innovation. Nations realized that having control over the skies was critical to winning any war. Engineers from all over the world began to outdo each other with how fast, manoeuvrable, and dangerous they could make their planes.
World War 1 also marked the beginning towards a more mainstream use of airplanes. Previously, aircraft were only flown by inventors or pioneers of flight.
In 1915, a German engineer - by the name of Hugo Junkers - invented the first practical, all metal aircraft.
Post World War 1
After World War 1, the structural make-up of planes transitioned from wood and fabric to metal. On top of that, aviation became a much more respected field. Pilots with extreme aerial skill were held in high regards. These skilled pilots, also known as barnstormers, would put on great aerial spectacles for the people to watch. Soon, pilots began to compete in order to prove that they were the best. This rise in competition sparked more innovation, leading to aircraft that could fly faster and further.
Shortly before World War 2, a young engineer by the name of Hans von Ohain collaborated with a large aircraft manufacturer at the time - Ernst Heinkel - in order to construct the world’s first jet plane: the Heinkel He. 178. The power produced by the jet engine allowed planes to produce a greater thrust. As a result, planes could fly much faster and higher than in the past.
After World War 2
Soon after World War 2, an amazing feat had been accomplished. A man, by the name of Chuck Yeager, broke the sound barrier. Previously, it was thought that we could not travel faster than the speed of sound; hence the name: sound barrier. I can only imagine what a paradigm shift this was. It would have been similar to being told that we can't travel faster than the speed of light but then go on to accomplish it. The plane he flew - the Bell X-1 - used a “four-chamber XLR-11 rocket engine” to travel faster than any jet engine at the time. Here's a cool compilation video of jets breaking the sound barrier. You'll notice that you hear a "sonic boom" after the jet has passed. This is because the jet is flying faster than the speed of sound.
After World War 2, we witnessed a real movement towards commercial aviation. Old planes that were used in the war were now used to move people or cargo. On July 27, 1949 the 1st commercial jetliner took to the skies, “de Havilland Comet”. This plane is also considered one of the pioneers of pressurized cabins in aircraft. It wasn’t the first plane to have a pressurized cabin but, naturally, it was the first commercial plane to have one. Pressurized cabins allow us to fly more safely and comfortably. They allow us to breathe better. Unfortunately, due to the shape of the windows on de Havilland Comet, the plane's body suffered a lot of stress and fatigue. Eventually, it began to crack. The pressure inside the plane was higher than the atmospheric pressure outside. As you may remember from before, pressure likes to move from high to low. The pressure gradient between the outside atmosphere and the plane cabin is what caused it to fail. Real Engineering has a fascinating and detailed video on the topic that you can check out below.
The Space Age
In 1957, Russia launched the first satellite into space: Sputnik 1. The reason for this was two-fold:
- They wanted to gather intelligence on Earth’s atmosphere.
- They wanted to be the first country into space.
After World War 2, a lot of tension still remained between countries.The remaining superpowers - Russia and America - had begun a space race as an indirect way to show their supremacy over the other.
In 1961, the Russians accomplished another extraordinary feat. They had launched the first man into space, Yuri Gagarin. Gagarin orbited Earth in the Vostok 1, and this feat marked the beginning of the Space Age for humankind.
However, America was still determined to win. In 1969, the space race was effectively ended when the Americans (Neil Armstrong and Edwin "Buzz" Aldrin) landed on the moon. The Apollo 11 mission was an amazing showcase of human potential. For the first time, we had travelled to a celestial body outside of Earth.
The Hubble Space Telescope
In 1990, the engineers at NASA had constructed the Hubble Space Telescope. Granted, the Hubble Space Telescope is not the first space telescope but it is probably the most well known. It allows us to get clear photos of space because it orbits the Earth. There is no interference from the atmosphere. By creating and studying the Hubble Space Telescope, engineers were also able to learn a lot about what it takes to get a satellite to survive in lower Earth orbit. I love the way NASA describes the function of the Hubble Space telescope:
The International Space Station
The International Space Station (ISS) began construction in 1998. From then on, it has continued to expand and grow. The ISS was designed to house life for a long period of time in low Earth orbit. So, we can only imagine the engineering challenges that had to be overcome to construct it such as:
- creating a livable environment
- expanding and building it in space (its weight on Earth would be close to 1 million pounds!)
- getting supplies to the crew members
The ISS is one of the greatest collaborative achievements in human history. According to Wikipedia,
"[the] ISS consists of Canada, Japan, the Russian Federation, the United States, and eleven Member States of the European Space Agency.”
The ISS is meant to be a place of research but also a hub for future missions to the Moon and Mars. If you want to learn more about the ISS, check out this insanely cool documentary on it that contains actual footage from inside:
02 | What do Aerospace Engineers Study in School?
Now, I’d like to go over some of the courses that aerospace engineers study in school. Aerospace engineering has a lot of overlap with the field of mechanical engineering. You can even argue that it is a branch of mechanical engineering. Therefore, aerospace engineers study several of the same courses as mechanical engineers such as:
- Math (calculus, algebra, and differentials)
- Mechanics (statics, dynamics, fluid mechanics, mechanics of materials, and aerodynamics)
- and heat transfer
If you want to learn more about what these subjects entail, I’d recommend watching my video on mechanical engineering.
Courses that are more unique to aerospace engineering would be:
Propulsion & Flight Dynamics
Propulsion is the study of how to create lift and thrust using various flight mechanisms such as an internal combustion engine, a jet engine, a turbomachine, or rocket propulsion.
Essentially, dynamics is the study of how the motion of an object is affected by forces. Therefore, flight dynamics is the study of how an air or space craft in motion is affected by forces.
As an aircraft flies, it experiences many forces on its body. This can cause various problems such as structural failure, or instability. Aerospace engineers learn how to prevent these problems through the study of aeroelasticity.
Vibrations & Control Engineering
In control engineering, students learn how to CONTROL how a system will behave. Flight is a very dynamic experience. Pressures, temperatures, and wind speeds can change very quickly in the air. Therefore, it's important that the proper control mechanisms are put in place, to help the aircraft adjust to its dynamic environment. An example would be a control mechanism that adjusts to wind speed and direction in order to keep an aircraft stable.
Flight test studies are all about learning how to study the data obtained by an aircraft flight test and use it to assess the performance of a craft. This allows aerospace engineers to ensure all air and space crafts are safe and reliable.
Aircrafts and spacecrafts are frequently subjected to extreme environments. Structural mechanics is the study of designing crafts that will be able to survive flight in the skies or in space.
03 | What is the Future of Aerospace Engineering?
As of today (March 8, 2017), I believe that we are entering into a very exciting period for aerospace engineering. We are starting to see space exploration step outside of governmental organizations like NASA and be headed by privately funded companies like Space X, Orbital Sciences, and Blue Origin. Of course, Elon Musk heads Space X and Blue Origin is owned by Jeff Bezos, the owner of Amazon. I believe that many students will shift from wanting to work for NASA and instead work for companies like SpaceX or Blue Origin. Without further ado, I'd like to talk about what I believe are some of the big challenges that aerospace engineers will have to solve in the coming years.
Eventually, Earth will run out of fossil fuels. Therefore, it’s up to aerospace engineers to help design spacecrafts that can run on alternative fuels in order to travel further into space. Some scientists believe that we can make fuel through the electrolysis of water. By running a current through water, we can separate it into its components: hydrogen and oxygen. Potentially, these component can then be used as a fuel source.
As it stands, spacecrafts are much too slow for us to reasonably navigate through space. It takes extremely long to travel relatively short distances. It took the New Horizons space probe over 9 years to reach Pluto! Aerospace engineers will have to learn how to increase the speed at which we can travel through space by alternative methods such as photonic propulsion. Here's a cool video by SciShow on photonic propulsion.
Increasing the speed of commercial aircrafts is another interesting idea. Imagine being able to reduce travel times by at least 50%! This is exactly what the Concorde, a supersonic passenger jet, did. Normally, it takes a commercial plane 7 hours to fly from New York to Paris. The Concorde flew that distance in only 3.5 hours. Currently, it doesn’t make sense for commercial planes to travel at mach speeds. The constant sonic booms from breaking the sound barrier would be annoying to regular civilians (note: the Concorde flew over the Atlantic Ocean so that noise wouldn't be an issue), and fuel would burn up too fast. However, if aerospace engineers could help make this technology more quiet and fuel efficient, it would be a revolutionary change for commercial travel.
Spacecraft Design for Mars and Beyond
This one of the main challenges that aerospace engineers will always have to deal with. How can we design crafts that can operate and survive in all sorts of extreme conditions? When you’re designing for space exploration, you have to deal with extreme pressures and temperatures that we haven’t dealt with on Earth. If we ever hope to become cosmic travellers, aerospace engineers will have to work in collaboration with other engineers to determine how to design various spacecrafts, and satellites that can operate in these extreme climates.