1 What is Aerospace Engineering?

Introduction

The word engineering is derived from the Latin words ingeniare (“to create, generate, contrive, devise”) and ingenium (“cleverness”). Aerospace engineering is a specific field concerned with designing, constructing, testing, and operating all types of flight vehicles, including how they are propelled. Engineers in this field focus mainly on problems related to designing strong but lightweight vehicles that can achieve successful and efficient atmospheric or space flight.

The aerospace engineering field is comprised of two primary branches, namely aeronautical engineering (aeronautics) and astronautical engineering (astronautics). Aerospace engineers will typically specialize in either aeronautics or astronautics.

  • Aeronautical engineering or aeronautics is the field associated explicitly with designing and building atmospheric flight vehicles, i.e., aircraft that fly within the normal confines of the Earth’s atmosphere and are propelled by air-breathing engines.
  • Astronautical engineering or astronautics is the field associated with designing and building various types of exo-atmospheric vehicles, i.e., rockets or other launch vehicles, missiles, satellites, and other spacecraft. These flight vehicles are designed primarily to fly beyond the limits of the Earth’s atmosphere or in outer space and are propelled by rocket engines, i.e., non-airbreathing engines.
Objectives of this Lesson
  • Understand about some of the main disciplines and activities pursued engineers working in aeronautics and astronautics.
  • Know more about the myriad of inter-disciplinary technical problems that are faced by aerospace engineers.
  • Better appreciate some of the roles and responsibilities of being an aerospace engineer.

So You Want to be an Aerospace Engineer?

New students of the field must appreciate that aerospace engineering is a highly applied field, focused on the practical aspects of designing, building, and operating flight vehicles. Aerospace engineers work on a range of tasks including the design of aircraft and spacecraft, the selection of materials and propulsion systems, and the testing and operation of these vehicles. The goal of aerospace engineering is to make flight safer, more efficient, and more cost-effective.

According to the U.S. Bureau of Labor Statistics, aerospace engineers with degrees or other professional qualifications are employed in many business and organizations, including private industry and government labs. Aerospace engineers are performing a diverse range of engineering activities related to:

  • The design and construction of airframes, engines, and various aircraft or spacecraft products.
  • Other types of sub-component parts manufacturing.
  • Engineering services and other support services.
  • Research and development.
  • Government and military labs, e.g., at NASA, Army, Air Force.

Many practicing aerospace engineers transition into education and training roles, where they share their expertise with students and train the next generation of engineers. These engineers may also continue to conduct research and development work to advance the field, and provide specialized training to graduate engineers to help them become future leaders in their respective fields. Through their work in academia and research, they help to ensure the continued growth and development of the aerospace industry.

To successfully design any aircraft or spacecraft requires a detailed understanding of many fundamental engineering disciplines, which will include (but are not limited to):

  • Fluid dynamics and/or aerodynamics.
  • Propulsion systems, both air-breathing, and rockets.
  • Structures, materials, structural dynamics, and aeroelasticity.
  • Electronics, electrical systems, and avionics.
  • Acoustics (noise), both external and internal.
  • Flight dynamics and flight control systems.
  • Orbital mechanics.
  • Software and software engineering.
  • Other things such as economics, human factors engineering, safety matters, regulations, airworthiness, certification, etc.

Therefore, it becomes immediately apparent that the field of aerospace engineering is a multi-faceted, multi-disciplinary and inter-disciplinary one, and successful engineers must have a deep understanding of many different subjects. In this context, the term multi-disciplinary means that engineers work in many different disciplines involved in aerospace problem-solving. The term inter-disciplinary means combining or involving several fields or specializations in a synergistic way to solve these problems.

For example, the subject of aeroelasticity is an inter-disciplinary one that is important for all flight vehicles because their structures elastically deform under aerodynamic and inertial loads, i.e., the consideration of aerodynamic/structure interactions. Specifically, the behavior known as flutter is an example of undesirable aeroelastic behavior of lightweight and flexible elastic structures that must be avoided during airframe design.

While it can be appreciated that aeronautical and astronautical engineers usually face different specific problems and design challenges (i.e., those associated with aircraft versus spacecraft), the two fields overlap considerably. This overlap arises because both specialties depend on a detailed understanding of the same fundamental engineering principles. The ability to understand these fundamental disciplines and use them effectively requires that aerospace engineers have a deep knowledge of physics, chemistry, mathematics, numerical methods, and computer programming. It also requires a good understanding of statics, mechanics, kinematics, fluid dynamics, acoustics, thermodynamics, materials, electronics, and other disciplines.

Today, understanding computer languages such as Matlab, C++, Fortran, and Python is essential for all aerospace engineers. In addition, routine engineering problem-solving often centers around the use of computer programming as well as the use of specialist software to display results and seek understanding, e.g., with the help of TecplotFieldView, etc.

What is the difference between Matlab and Fortran?

Matlab is a medium-level programming language made up of libraries of subroutines and many built-in tools with an interpretive user interface. Matlab is also proprietary software, which is a significant restriction on the portability and sharing of the code. Fortran is a high-level compiled language, the compiler being open-source. Developing a Fortran code may take longer, but the final executable may be orders of magnitude faster than what is possible with Matlab. Many production-level codes in engineering use Fortran.

Roles of Aerospace Engineers

Aerospace engineers have the training and skills needed to lead the development of new aircraft and spacecraft as well as to make improvements to their numerous sub-systems. The U.S. Bureau of Labor Statistics tells us that aerospace engineers “primarily design aircraft, spacecraft, satellites, and missiles.” Also, they test aircraft prototypes and their subsystems to ensure that they function according to their design specifications. Aerospace engineers are usually considered to have the following roles and responsibilities:

  • Direct and coordinate the design, manufacture, and testing of all types of aircraft and spacecraft as well as their associated components and systems.
  • Determine through engineering analysis that proposed projects will result in safe aircraft and/or spacecraft as well as all of the associated parts.
  • Evaluate designs to ensure the products comply with sound engineering principles, customer requirements, regulations, and environmental challenges.
  • Conduct ground, flight, and wind tunnel testing of new designs.
  • Develop acceptance criteria for design methods, quality standards, sustainment after delivery, and completion deadlines.
  • Ensure that projects meet quality control and certification authority standards.
  • Inspect malfunctioning or damaged products so as to identify sources of in-service problems and possible airworthiness solutions.
  • Assess proposals for projects to determine if they are technically and financially feasible.
  • Lead and direct research to better understand and advance the field.

The scope of an aerospace engineer’s role is not limited to just the traditional engineering tasks. They may also be involved in consulting, education and teaching, management, legal and regulatory issues, and advising on future aerospace goals or long-term research strategies. The field is constantly evolving, and aerospace engineers may find themselves taking on a diverse range of responsibilities and opportunities.

JetStar Boeing 787 in final assembly.
This Boeing 787, shown here on the production line, is the culmination of multiple scientific and engineering disciplines, and represents just one example of the advancements made in aeronautical technology.

The aerospace industry has evolved rapidly over the last century, with advances in technology leading to the development of increasingly complex aerospace systems. Today’s aerospace systems must meet a wide range of demands, including customer specifications, operational requirements, and regulations. These systems can range from large airliners to small personal and autonomous aircraft, and they must be designed and manufactured to meet these demands while also ensuring safety and reliability. The ongoing evolution of technology and customer needs is driving continued innovation and growth in the aerospace industry.

While autonomous or semi-autonomous drones, often called Uncrewed Aerial Vehicles or Unoccupied Aerial Vehicles (UAVs), still face many design and operational challenges, they are likely to see widespread adoption in the coming decades. In the future, aviation and space activities will still need to see many innovations and advances in engineering technologies to meet the growing requirements for more functional, efficient, and environmentally friendly flight vehicles.

Aerospace engineers play a key role in the development of new technologies for aircraft and spacecraft, but they often work in teams with other types of engineers, such as mechanical and electrical engineers. After graduation, aerospace engineers may specialize in one or more sub-disciplines of the field, including aerodynamics, computational fluid dynamics, structural design, materials and metallurgy, performance, stability and control, flight control systems, propulsion systems, aeroelasticity, acoustics, wind tunnel testing, flight testing, non-destructive testing, and system integration. These specializations allows them to gain in-depth expertise in specific areas of aerospace engineering and contribute to the development of new technologies and solutions that advance the field.

The development of new flight vehicle designs requires a significant investment in testing and verification to ensure that they meet or exceed certification requirements. Over-designing can be a major cost factor for companies, so aerospace engineers must balance the need for safety and reliability with cost considerations. Additionally, aerospace engineers can specialize in different types of aerospace products, such as commercial or military airplanes, helicopters or other rotorcraft, UAVs and drones, spacecraft such as launch vehicles and satellites, and engines or other propulsive power systems. This specialization allows them to gain in-depth knowledge and experience in a specific area of aerospace engineering, which can lead to more effective and efficient designs and innovations.

Lockheed YF-12 Blackbird aircraft model in supersonic wind tunnel.
Wind tunnel testing is an important part of improving the aerodynamics of existing aircraft designs and in developing new aircraft for the future.

Engineering Problem Solving

Problem-solving is an essential skill for aerospace engineers. Aerospace engineers must be able to identify, formulate, and solve complex problems in a systematic and effective manner. This requires a strong foundation in engineering fundamentals, mathematics, and experimentation, as well as a deep understanding of the relevant rules and principles that can be applied to find a solution.

The development of problem-solving skills is an important part of an aerospace engineering education. Students can improve these skills by practicing and solving homework problems, working on projects and assignments that require the application of their knowledge and skills to real-world situations. By continuously challenging themselves and seeking out new problems to solve, students can hone their problem-solving abilities and become skilled and confident aerospace engineers.

Sometimes the problem encountered by engineers is so new and different that it requires basic research or foundational research, so it may have a longer-term solution. Aerospace engineers must take a holistic and interdisciplinary approach to problem-solving and must be able to consider not just the technical aspect of a problem but also the broader implications and trade-offs of their solutions. Effective communication skills, both oral and written, are also critical in this field, as aerospace engineers often work in teams and must present their ideas and findings to technical and non-technical audiences alike. Furthermore, in today’s world, understanding the impact of any engineering solutions in a global, economic, environmental, and societal context is also needed. Not all engineering solutions may prove to be practical for these latter reasons.

The complexity of modern aircraft and spacecraft is such that the traditionally separate engineering disciplines must be more fully integrated during the design process to obtain a more optimized outcome, a process known as multi-disciplinary design. All new engineers must acquire a deeper and broader engineering background, and be effective as part of an engineering problem-solving team.

As aerospace technology continues to advance, the role of aerospace engineers will continue to evolve. In addition to developing new technologies, they will also be responsible for ensuring that the systems they design are safe, efficient, and environmentally friendly. With a continued emphasis on interdisciplinary collaboration and the integration of technology and design, the future of aerospace engineering is bright and holds tremendous potential for innovation and progress. The aerospace industry will continue to require highly skilled and motivated engineers who can meet the ever-increasing challenges of designing and manufacturing the most advanced aircraft and spacecraft possible.

Aerodynamics: The Underpinning of Flight

Aerodynamics is a crucial aspect of aerospace engineering and is the foundation of all atmospheric flight. It deals with the motion of air and how it affects the performance of aircraft and other aerospace systems. The term “aerodynamics” is derived from the Greek words “aero” meaning air, and “dynamis” meaning the study of matter in motion. Understanding aerodynamics is essential for designing and improving the efficiency, stability, and safety of aerospace vehicles.

Aerodynamics is a crucial field for both aeronautical and astronautical engineers. Aeronautical engineers focus on understanding the aerodynamic effects produced on objects moving through the air, such as wings and complete aircraft, while astronautical engineers concentrate on all aspects of propulsion, the dynamic loads produced on rockets, satellites, and spacecraft, and their guidance and control. However, astronautical engineers also have to address aerodynamic issues during the launch and reentry phases of spacecraft. In both cases, a thorough understanding of aerodynamics is essential for designing efficient, stable, and safe aerospace vehicles.

More specifically, the types of problems encountered in the field of aerodynamics may include:

  • The prediction and/or measurement of aerodynamic forces on airfoils, wings, fuselages, engine nacelles, and entire airplanes. These types of problems come under the classification of external aerodynamics.
  • The prediction and/or measurement of the aerodynamic loads and kinetic heating on high-speed flight vehicles, ranging from supersonic and hypersonic aircraft to rockets, spacecraft, satellites, reentry vehicles, as well as probes entering the atmospheres of other planets.
  • The determination of the characteristics of flows moving through ducts, pipes, and channels, e.g., flows through hydraulic or pneumatic systems or the flow conditions produced in wind tunnels. The foregoing are examples of problems in internal aerodynamics.
  • The understanding and prediction of flow properties into and inside rockets and air-breathing jet engines, such as calculating values of thrust, pressures, temperatures, etc.
Air flows over an airplane's wing while undergoing fluid dynamics.
Aerodynamics is the underpinning of atmospheric flight. This image shows a Computational Fluid Dynamics or “CFD” simulation of the flow over an commercial airliner, focusing on the flow over the airplane’s wing.

Propulsion Systems: The Power for Flight

Propulsion involves studying the design and operation of propulsive systems, including air-breathing engines and rocket engines. All flight vehicles require a source of power to achieve flight. Aerospace engineers continuously strive to develop engines with greater thrust and/or power and efficiency, also making them more durable and reliable. Engineers also want to build as small and lightweight engines as possible, a goal that continues to provide many engineering challenges from both the design and manufacturing perspectives. So naturally, propulsion engineers must be well-versed in thermodynamics, fluid mechanics, combustion, heat transfer, dynamics and vibration, and materials science.

Until the beginning of the 20th century, sustained, powered, heavier-than-air flight, remained impossible because of the lack of suitable engines. The development of the internal combustion engine in the piston (or reciprocating) engine soon led to rapid advances in engines, including increases in their power-to-weight ratio, allowing them to be developed for aeronautical use. Developments in high-strength and high-temperature metals suitable for use in engines, as well as supercharging, soon led to improvements in reliability and power output, and better-performing aircraft followed quickly. The development of the turbojet engine during WW2 revolutionized aviation progress, allowing new aircraft to fly increasingly faster and higher.

Propulsion systems for today’s aircraft have seen many developments, even during the last two decades. Advanced turbofan engines produce massive amounts of thrust with excellent fuel efficiency. They can operate continuously for tens of thousands of flight hours at transonic Mach numbers seven or more miles high without mechanical problems.

More specifically, the types of engineering problems encountered in the field of propulsion systems may include:

  • The design, development, and improvement of all types of air-breathing engines, such as new generations of piston engines, turbojets, turbofans, and turboprops.
  • Predicting the fluid dynamics of high-speed internal flows, including the effects of thermodynamics and the combustion processes associated with engine operations.
  • The design, testing, and manufacturing of engine components such as inlets, compressors, combustion chambers, turbine blades, and various types of nozzles.
  • Research into the use of new types of fuels, such as biofuels, hydrogen fuel cells, or hybrid fuel systems, and ways of improving an engine’s fuel efficiency.
  • The design of fans, nozzles, and other engine components to ensure efficiency and low external noise levels.
  • The design of electric propulsion systems, including lightweight, high-torque electric motors and advanced propellers with high propulsive efficiency and low noise.
  • Improvements in rocket propulsion systems, including solid rocket motors, liquid rocket motors, hybrid rockets, and possibly advanced nuclear propulsion systems.
Pratt & Whitney Advanced Ducted Propulsor Engine Test
The Pratt &​ Whitney Advanced Ducted Propulsor (ADP) engine being tested in the large NASA Ames 40-by-80 ft low-speed wind tunnel. The engineers are aligning a laser light sheet for a flow visualization test.

Structures and Materials: Carrying the Loads

In the field of structures and structural mechanics, aerospace engineers study the mechanical behavior of aircraft and spacecraft structures. Aerospace structures differ from other types of structures found in engineering because of the need for both high strength and extreme lightness. To this end, aerospace engineers deal with thin-walled metallic structures made of aluminum and other lightweight metallic alloys, advanced composite materials, and perhaps various types of multifunctional or “smart” materials.

Composite materials have the main advantage of being able to tailor their fibers in the direction of the load paths, allowing a structure to be built with a higher strength-to-weight ratio. Composite materials also have much better fatigue life compared to metallic structures. A multifunctional material is a hybrid material consisting of parts that can perform several functions, e.g., a load-carrying structure and energy storage ability, or load-carrying plus electrical or thermal conductivity. The use of multifunctional materials in aerospace applications potentially offer better structural weight and volume efficiency.

A thorough understanding of material properties and their limitations is essential for achieving the desired performance levels in aerospace flight structures. Both aeronautical and astronautical engineers need to be knowledgeable in the theory of structures and the characteristics of materials. They use advanced numerical methods such as the finite element method (FEM) to perform various computations and experiments on structures. Additionally, they may also encounter practical implementation challenges with structural parts on aircraft and spacecraft. In this area of specialization, a thorough knowledge of material properties, structural analysis, and practical implementation is required to design and maintain safe and effective aerospace flight structures.

 

Diagram of critical attachment points of an airplane wing spar.
Structural analysis involves the calculation of stresses on component parts and complete aircraft, in this case a finite-element method (FEM) analysis of the critical attachment points for an airplane’s wing spar.

The types of problems encountered in the field of aerospace structures and structural mechanics may include the following:

  • The selection and characterization of advanced materials and material/structural design for new aircraft and spacecraft designs, as well as for engines.
  • The understanding of the material and structural stability under diverse loading conditions, particularly under combinations of high bending, torsion, and compression, combined with aero-thermal loads, which may require careful design optimization of the structure.
  • The development of methods to predict and understand structural dynamics and aeroelasticity, which deals with time-varying structural deformations and their interactions with aerodynamics, is especially important for very light and potentially flexible aircraft.
  • The development of various shape-changing or morphing structures, which may use embedded actuators within the structure to progressively change its shape to meet the varying and diverse flight requirements. The deployment of wing flaps for takeoff and landing is an excellent example of where the wing shape needs to be changed or morphed.
  • The development of structural health monitoring and management systems, where sensors and data processing algorithms are used to verify the integrity of critical flight structures, indicate actual locations of internal structural damage such as fatigue cracks. The main advantage of health monitoring is to give ample warning of any impending mechanical or structural malfunction or failure.

Flight Dynamics & Control: Flying on Course

The field of flight dynamics and control concerns the motion of all flight vehicles, whether they operate in the atmosphere or in space. Aerospace engineers who specialize in atmospheric flight dynamics and control must have a strong multidisciplinary systems background and an in-depth understanding of aerodynamics. They use their expertise in these areas to design, analyze, and improve the performance, stability, and safety of flight vehicles. This field is crucial for ensuring that flight vehicles can operate effectively and efficiently.

Such engineers are often involved in developing advanced digital “fly-by-wire” flight control systems such as shown in the figure below, which also require significant experience in computer programming and software engineering. Limiters can be included for “care-free” handling so that the pilot cannot inadvertently fly the aircraft outside of its aerodynamic or structural flight envelopes. Measurements of aircraft motions during flight are essential to advancing and understanding this field. To this end, dynamics and control engineers are deeply involved in all aspects of flight testing as well as certification/flight verification programs.

Schematic of a fly-by-wire system for a fighter aircraft, where the pilot’s control inputs connect to a flight control computer that provides electrical signals to actuate the flight controls.

The types of problems and challenges encountered by engineers in the field of aerospace dynamics and control may include the following:

  • The understanding and prediction of configuration effects on aerodynamics, performance, and stability, and the prediction of aircraft motions in response to different types of control inputs.
  • The estimation of an aircraft’s flight dynamics characteristics and handling qualities from its estimated geometric and inertial properties. Such work is critically important in developing flight simulators, especially before a new aircraft makes its first flight.
  • The analysis of the linear and nonlinear dynamic representations of all flight vehicles and the development of suitable flight control systems, stability augmentation systems, autopilots, etc.
  • The measurement and evaluation of aircraft handling qualities from flight testing and to suggest improvements to the aircraft design and/or the flight control systems.
  • The design and development of suitable control systems for spacecraft for guidance and navigation.

Systems Integration: Putting it all Together

Testing is a crucial aspect of aerospace engineering, and both individual components and complete systems are tested to ensure their functionality and performance. System integration is the process of bringing together all sub-systems to work together to achieve the overall functionality of the system. This requires extensive testing and failure analysis to guarantee the integrity of all components, including structural, mechanical, electrical, electronic, hydraulic, and others that make up the complete system. Testing and system integration play a vital role in ensuring the reliability and safety of aerospace systems, and aerospace engineers are responsible for designing and conducting these tests.

Over the decades, aircraft and aerospace systems have grown much more complicated and include sophisticated electronics, control systems, and various other co-dependent components. Consequently, this requires a complete “systems engineering” approach to testing, evaluation, qualification, and certification, and the approach has grown much more sophisticated and complex. In general, the systems engineering discipline addresses the complex process of ensuring engineering functionality, satisfying safety requirements, meeting costs and schedules, as well as solving reliability challenges.

Aerospace systems integration is undoubtedly one of the most challenging and demanding of the industry disciplines. System engineers typically have aerospace, mechanical, or electrical engineering backgrounds; systems engineers may or may not be sub-system specialists or experts. However, a common goal for these engineers is to evaluate aerospace components as part of a unified system, which may require a myriad of tests and other types of analysis, including fault tolerance, redundancy, etc., as well as assessing the risks associated with various types of component failures.

An illustration of NASA's Artemis Basecamp near the Moon's South Pole.
For a proposed mission to another planet, such as the Moon or Mars, many individual engineering systems must be carefully integrated together to make it work in totality. In this case, the NASA Artemis program has been optimized to lay down the foundation for a sustained long-term presence on the Moon.

The specific problems and challenges encountered by aerospace systems engineers may include the following:

  • Defining methodologies, processes, and other tools to enable the successful definition, development, certification, implementation, and operation of co-dependent aerospace technology components and systems.
  • Managing and reducing risks associated with complex technology systems, identifying possible failure modes, as well as searching for the “unknown unknowns” to find a cost-effective technology systems solution that can meet all design requirements.
  • Managing the “Risk-Cost-Safety” balance to ensure that the final system is fully validated and contains verified hardware/software components.
  • Ensuring that all systems are adequately certified and meet airworthiness standards.
  • Monitoring, operating and maintaining fielded systems, providing spares, monitoring for obsolescence management, and promoting long-term system safety.

Thinking Toward the Future

The future of aerospace engineering offers many challenges and exciting opportunities for those pursuing a career. As students begin to study their chosen field by taking courses in the fundamentals, they will also develop from their instructors a knowledge of contemporary issues and the methods being used to solve them.

Key technical aeronautical thrusts for the future will be to continue to develop new technologies that further improve aerodynamic efficiencies, reduce airframe weight, lead to better fuel efficiency, and limit all types of pollution. Key astronautical thrusts will help to solve space exploration problems, such as revisiting the Moon, developing deep space capabilities, and improving human life support systems. Commercializing space activities by the private sector continues to show that innovative technology solutions can significantly reduce flight costs.

Aircraft manufacturers will continue to research low-drag smooth “laminar” flow wings and active flow control technology to improve aerodynamic efficiency. In addition, a deeper understanding of the thin boundary layer that forms on the aircraft’s surface may reduce skin friction drag and improve fuel efficiency. “Non-stick” wings are being investigated to prevent insects from accumulating on wings and helping to minimize the drag of the aircraft in regular service. More ambitious efforts, which are still at the basic research stage, include the morphing or “shapeshifting” of wings to optimize their aerodynamic performance over different parts of the flight envelope.

Large composite structural parts are now being used for primary aircraft components such as tails, fuselages, and even complete wings. However, durability, reparability, longevity, and other issues with composites continue to pose challenges for the engineer in the quest for ever stronger and lighter airframes. In addition, composite materials themselves are not necessarily more lightweight than conventional metals. Still, the structures from which they are built, can be tailored to be more structurally efficient for carrying the same loads.

Government research labs and the aerospace industry have continued to push for developing new generations of supersonic transport (SST) aircraft. NASA’s latest program calls for the design and flight testing of a new X-plane to support the development of future generations of SST. However, one main problem is the formation of “sonic booms” from aircraft flying supersonically, leading to a loud “boom-boom” sound. This startling type of noise is of sufficient intensity that the flight of supersonic aircraft over land is currently prohibited. That may change when engineers learn how to mitigate the sonic boom problem, for which significant inroads have already been achieved. Another problem is the kinetic heating of the airframe at supersonic speeds, which needs special considerations in the airframe design and the type of materials being used for its construction.

Lockheed Martin's future quiet supersonic aircraft design.
The appeal of vastly reduced traveling time for flight at supersonic speeds remains intriguing to both engineers and passengers alike.

Jet engine design will also see changes in the future. Engine manufacturers are already using additive manufacturing technologies (i.e., three-dimensional printing) to make more complex and intricate metal parts that go into an engine. Research and development will continue into hybrid-electric jet engines, making engines smaller, lighter, and more efficient. More fuel-efficient and “greener” (low pollution) propulsion systems continue to receive much interest from the aviation community. All types of internal combustion engines produce carbon dioxide, various types of small particulate matter, nitrous oxides, and other pollutants that can all have significant long-term effects on the atmosphere.

More powerful rocket engines with greater efficiency will continue to be developed, as well as with the use of alternative fuels. Traditional fuels such as Rocket Propellant No. 1 or RP-1 (a type of densified kerosine) and liquid hydrogen, are being replaced by liquid methane or propane, which are attractive because of their excellent availability and performance. Methane and propane are also better for the environment and are easier to store than cryogenic liquid hydrogen. Liquid oxygen is generally used as the oxidizer for rocket engines. The SpaceX Raptor rocket engine, for example, as shown below, uses methane and liquid oxygen and will be used in both stages of the two-stage-to-orbit, super heavy-lift launch vehicle called Starship.

SpaceX Raptor rocket engine test fire.
The SpaceX Raptor is a methane-fueled rocket engine that will be used for future generations of launch vehicles.

An Unoccupied Aerial Vehicle (UAV), commonly known as a drone, is an aircraft without any human pilot, crew, or passengers. Compared to crewed aircraft, UAVs are often preferred for “dull, dirty, and dangerous” or D3 missions. As shown below, many are rotorcraft or S/VTOL capable of giving the required mission flexibility. While the development of UAVs was initially for military applications, their use is rapidly expanding into many civil applications. This field will likely see significant growth in the coming decades.

MQ-8B Fire Scout unmanned aerial vehicle flying on first unmanned biofuel flight.
A military MQ-8B Fire Scout UAV, which uses a turboshaft engine running on a  combination of JP-5 aviation jet fuel and biofuel.

Millions of people worldwide are affected by aircraft noise, especially those who live and work near airports. Most aircraft noise comes from their engines. Military aircraft (especially those using afterburners) can produce extremely high noise levels. The effects of aircraft noise can even cause vibrations in buildings and structures or disrupt various human activities.

While the noise levels produced by civil aircraft have been significantly reduced in recent years to meet increasingly stringent noise regulations, there are still many technical issues to solve to make future aircraft even quieter. It should be noted that noise is the main issue stifling the expansion or new construction of major airports; in the U.S., Denver International has been the only major airport to be built in the last 40 years.

The leading aerospace companies continue to invest in research facilities to develop new technologies that will lead to advancements in performance and reduced manufacturing costs, and improve competitive pricing for their aircraft and spacecraft. The aerospace industry’s future also lies in the better training and technical competency of its engineering workforce, which colleges and universities strive hard to accomplish in the education of their students. It is expected that the new graduates of the aerospace field will bring their vision and innovative ideas to make the advances in engineering needed for the future.

Flying-V in flight, showing off a distinctive V-shaped aircraft design.
Future commercial aircraft may look quite different than those of today, and may include blended-wing concepts.

Being a Successful Engineer

To become a successful engineer takes lots of hard work and much practice. There is no one path to follow but there are established steps to success that countless generations of engineers have subscribed to. The Pyramid of Success suggests good practices for students to follow in the engineering fields. The following are Dr. James Ladesic’s “Tenets of Success” for engineers. They apply equally to students taking courses and to practicing engineers in the workplace.

Ladesic’s Tenets of Success

  1. Volunteering for assignments.
  2. Planning ahead.
  3. Sharing workloads equitably.
  4. Maintaining and projecting a positive attitude.
  5. Working diligently.
  6. Participating productively in group and class activities.
  7. Responding to project demands in a timely fashion.
  8. Behaving ethically.
  9. Generally taking responsibility for yourself, your work, and your spoken and written statements in a professional engineering manner.

Summary & Closure

Aerospace engineering is a complex and interdisciplinary field that requires a comprehensive understanding of multiple subjects. Aerospace engineers must continuously expand their knowledge and expertise to keep up with the constantly evolving field. The aerospace industry is constantly striving for advancements in technology, including improvements in aerodynamic efficiency, airframe weight reduction, fuel efficiency, and reduced pollution. These efforts have als led to the development of new aeronautical technologies such as electric and hybrid propulsion systems. The field of aerospace engineering offers many opportunities for growth and innovation, making it an exciting and dynamic career choice for those interested in this field.

The field of astronautics, in particular, is poised for significant growth and advancements in the coming years. With increasing focus on space exploration, missions to revisit the Moon and Mars are expected to accelerate. Moreover, the commercialization of space flight activities has shown that cost-effective technology solutions can enable more organizations to access space. This trend is likely to continue and even accelerate in the future. The field of astronautics is expected to be marked by numerous exciting new developments and breakthroughs, increasing our understanding of the universe and our place in it. With these advancements, the future of astronautics promises to be full of opportunities and discoveries.

5-Question Self-Assessment Quickquiz

For Further Thought or Discussion

  • Think more about how quickly aeronautical engineering has evolved in the last century. Where do you think the field of aeronautical engineering will be in another century? What types of new aircraft do you think will be flying then?
  • The human colonization of space remains a hugely ambitious goal. NASA’s return to the Moon has begun with its Artemis programme. Make a list of some of the technical and other challenges in sending humans back to the moon, Mars, and perhaps even into deep space. Remember that Mars is over 250 times further away than the Moon.
  • Goal setting is an essential part of professional development. Think about your goals as a future aerospace engineer and where you might want to position yourself in the workforce in 5, 10, or even 20 years from now.
  • Aerospace engineers inevitably specialize in one field, such as aerodynamics, controls and flight mechanics, structures and materials, propulsion, etc. Think about what area of specialization might interest you the most and list the specific courses of study that you believe are needed for that specialization.
  • Many aerospace employers prefer to recruit a fraction of new engineers with Masters degrees or suggest that their engineers pursue online graduate courses. Think about some potential advantages and disadvantages of being in the workforce with an advanced degree. Hint: An advanced degree may not necessarily be in the engineering field.

Other Useful Online Resources

For more information on aerospace engineering and what aerospace engineers do:

  • Video on “What is Aerospace Engineering?”
  • Video on “What is Aerospace Engineering (Aeronautics).
  • Video on “What is Aerospace Engineering (Aeronautics).
  • Why, yes, actually it is rocket science – watch these fun TED videos
  • A good website about the field of aerospace engineering run by the U.S. Bureau of Labor Statistics.