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 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.

Aerospace engineering comprises two primary branches: 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 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.

Learning Objectives

  • Understand some of the primary disciplines and activities pursued by engineers working in aeronautics and astronautics.
  • Know more about the myriad of interdisciplinary technical problems that aerospace engineers face.
  • Better appreciate some of the roles and responsibilities of an aerospace engineer.

You Want to be an Aerospace Engineer?

Newcomers 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 broad range of technical tasks, including designing aircraft and spacecraft, selecting materials and propulsion systems, and testing and operating these vehicles. Goals in aerospace engineering also include making flight vehicles 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 businesses and organizations, including private industry and government labs. In addition, 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, and Air Force.

Many practicing aerospace engineers transition into education and training roles, sharing their expertise with students and training 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 career 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 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 aerospace engineering is multifaceted, multidisciplinary, and interdisciplinary, and successful engineers must deeply understand many subjects. In this context, the term multidisciplinary means that engineers work in many disciplines involved in aerospace problem-solving. The word interdisciplinary means synergistically combining or applying several fields or specializations to solve these problems.

For example, aeroelasticity is an interdisciplinary subject 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. Understanding these essential disciplines and using them effectively requires that aerospace engineers have a deep knowledge of physics, chemistry, mathematics, numerical methods, and computer programming. It also needs 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 computer programming and 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 comprising libraries of subroutines and many built-in tools with an interpretive user interface. MATLAB is also proprietary software, which significantly restricts the portability and sharing of the code. FORTRAN is a high-level compiled language, and the compiler is 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 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 and their associated components and systems.
  • Determine through engineering analysis that proposed projects will result in safe aircraft, spacecraft, and all 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 to identify sources of in-service problems and possible airworthiness solutions.
  • Assess project proposals to determine if they are technically and financially feasible.
  • Lead and direct research to better understand and advance the field.

An aerospace engineer’s role is much broader than just 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 advancements in aeronautical technology.

The aerospace industry has evolved rapidly over the last century, with technological advances leading to the development of increasingly complex aerospace systems. Today’s aerospace systems must meet a broad 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 ensuring safety and reliability. The evolution of technology and customer needs drives 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 will likely 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 vital role in developing new technologies for aircraft and spacecraft. Still, 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 allow them to gain in-depth expertise in specific areas of aerospace engineering and contribute to developing new technologies and solutions that advance the field.

Developing new flight vehicle designs requires a significant investment in testing and verification to ensure they meet or exceed certification requirements. Over-designing can be a considerable 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.

Wind tunnel testing is integral to improving the aerodynamics of existing flight vehicle designs and developing new ones for the future. This is a model of the Space Launch System (SLS) installed in a wind tunnel at NASA.

Engineering Problem Solving

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

Developing problem-solving skills is an integral part of an aerospace engineering education. Students can improve these skills by practicing and solving homework problems and working on projects and assignments that require applying their knowledge and skills to real-world situations. Students can hone their problem-solving abilities by continuously challenging themselves so they can become skilled and confident aerospace engineers.

Sometimes, the problems engineers encounter are so new and different that they require fundamental or foundational research, so they may only have a longer-term solution. Aerospace engineers must take a holistic and interdisciplinary approach to problem-solving. They must be able to consider not just the technical aspect of a problem but also the broader implications and trade-offs of their solutions. Practical oral and written communication skills 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 requires the traditionally separate engineering disciplines to be more fully integrated during the design process to obtain a more optimized outcome, a process known as multidisciplinary 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 ensure 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 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 word “aerodynamics” is derived from the Greek words “aero,” meaning air, and “dynamis,” meaning the study of matter in motion. Aerodynamics plays a critical role in the design and optimization 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. In contrast, 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 must also address aerodynamic issues during the spacecraft’s launch and re-entry phases. A thorough understanding of aerodynamics is essential for designing efficient, stable, safe aerospace vehicles.

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

  • The prediction and measurement of aerodynamic forces on airfoils, wings, fuselages, engine nacelles, and entire airplanes. These types of problems are classified as external aerodynamics.
  • The prediction and measurement of the aerodynamic loads and kinetic heating on high-speed flight vehicles, ranging from supersonic and hypersonic aircraft to rockets, spacecraft, satellites, re-entry vehicles, as well as probes entering the atmospheres of other planets.
  • Determining the characteristics of flows moving through ducts, pipes, and channels, e.g., through hydraulic or pneumatic systems or the flow conditions produced in wind tunnels. The preceding are examples of problems in internal aerodynamics.
  • Understanding and predicting flow properties into and inside rockets and air-breathing jet engines, such as calculating thrust values, pressures, temperatures, etc.
Aerodynamics is the underpinning of atmospheric flight. This image shows a Computational Fluid Dynamics or “CFD” simulation of the flow over a 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, power, and efficiency, 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. Turbojet engine developments during WW2 revolutionized aviation, 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 engines, liquid rocket engines, hybrid rockets, and possibly advanced nuclear propulsion systems.
Pratt & Whitney Advanced Ducted Propulsor Engine Test
The Pratt &​ Whitney Advanced Ducted Propulsor (ADP) engine is 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 engineering structures because they need 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 tailoring 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 a much better fatigue life compared to metallic structures. A multifunctional material is a hybrid material with parts that can perform several functions, e.g., a load-carrying structure and energy storage ability or load-carrying plus electrical or thermal conductivity. Multifunctional materials in aerospace applications 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. 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 calculating 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, spacecraft, and engine designs.
  • Understanding the material and structural stability under diverse loading conditions, particularly under combinations of high bending, torsion, and compression combined with aero-thermal loads, may require careful design optimization of the structure.
  • Developing 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 may use embedded actuators within the structure to progressively change its shape to meet the varying and diverse flight requirements. Deploying 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 that it gives 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 in the atmosphere or space. Aerospace engineers specializing in atmospheric flight dynamics and control must have a solid multidisciplinary systems background and an in-depth understanding of aerodynamics. They use their expertise to design, analyze, and improve flight vehicles’ performance, stability, and safety. This field is crucial for ensuring flight vehicles can operate effectively and efficiently.

Such engineers are often involved in developing advanced digital “fly-by-wire” flight control systems, as shown in the figure below, and they 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 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.

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:

  • Understanding and predicting configuration effects on aerodynamics, performance, and stability, as well as predicting 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.
  • Measure and evaluate aircraft handling qualities from flight testing and suggest improvements to the aircraft design and 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 synergistically to achieve the system’s overall functionality. This approach requires extensive testing and failure analysis to guarantee the integrity of all components, including structural, mechanical, electrical, electronic, hydraulic, and others that comprise the complete system. Testing and system integration plays 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 last three decades, aircraft and aerospace systems have become much more complicated with sophisticated co-dependent components. Consequently, the engineering design process now requires a complete “systems engineering” approach to testing, evaluation, qualification, and certification. 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 among the most challenging and demanding industry disciplines. System engineers typically have broad aerospace, mechanical, or electrical engineering backgrounds with many years of experience; they may or may not be subsystem 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., and assessing the risks associated with various types of component failures.

An illustration of NASA's Artemis Basecamp near the Moon's South Pole.
A proposed mission to another planet, such as the Moon or Mars, requires many individual engineering systems to be carefully integrated to make it work in totality. NASA’s Artemis program has been optimized to lay 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, and 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 the final system is fully validated and contains verified hardware/software components.
  • Ensuring 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 careers in this field. 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.

The leading aerospace companies continue to invest in research facilities to develop new technologies that will lead to advancements in performance, reduced manufacturing costs, and improved 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.

Aerodynamics

Aircraft organizations will continue to refine aircraft shapes to improve aerodynamic efficiency. They also 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 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 help minimize the aircraft’s drag 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.

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

Composite Materials

Large composite structural parts are now used for primary aircraft components such as tails, fuselages, wings, helicopter rotor blades, propellers, and the fan blades on jet engines, the latter being shown in the figure below. 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 somewhat lighter than conventional metals. Still, the structures from which they are built can be tailored to be more structurally efficient for carrying the same loads.

The blades on the GE90 turbofan engine are made from carbon-fiber composites instead of conventional materials such as titanium alloys. This results in a lighter and more efficient engine, allowing airlines to save fuel.

Supersonic Aircraft

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 so intense that regulatory aviation authorities currently prohibit the flight of supersonic aircraft over land. 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 engineers and passengers alike.

Air-breathing Propulsion

Jet engine design will also see changes in the future. Engine manufacturers already use 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 kinds of small particulate matter, nitrous oxides, and other pollutants that can all have significant long-term effects on the atmosphere. Research and development efforts are underway to explore and implement sustainable aviation fuels (SAFs). These fuels are derived from renewable sources such as biofuels, hydrogen, and synthetic fuels. SAFs have the potential to significantly reduce carbon emissions compared to traditional jet fuels.

Rocket Engines

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.

Unoccupied Aerial Vehicles

An Unoccupied Aerial Vehicle (UAV), commonly known as a drone, is an aircraft without any human pilot, crew, or passengers. Unlike 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 uses are rapidly expanding into many civil applications. This field will likely see significant growth in the coming decades.

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

Noise

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.

CFD prediction of the noise propagation from a small jet.

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 quieter. Advancements in aircraft design, including quieter engines and improved aerodynamics, help mitigate the noise impact on communities near airports. 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 built in the last 40 years.

Sustainability

Sustainability is a much-used word in today’s aerospace industry, but what does it mean? Sustainability means following practices that can meet the needs of the present generation without compromising the needs of future generations. This responsible approach means following sustainable practices and considering the long-term impact on the environment, society, and the economy. Because aerospace is one of the most technologically advanced and resource-intensive industries, aerospace sustainability must continue to focus on minimizing the environmental impact of aircraft manufacturing, operations, and end-of-life disposal while continuing to address social and economic considerations.

Aerospace organizations continue to develop environmental management systems to monitor and continuously improve their sustainability performance. These systems help identify areas of improvement, set targets, and ensure compliance with environmental regulations. Evaluating the environmental impact of aircraft throughout their life cycle is essential, and factors such as raw material manufacturing processes, operational efficiency, and end-of-life disposal must be considered. Aerospace companies increasingly focus on recycling materials, reducing waste generation during manufacturing processes, and implementing proper disposal methods for end-of-life aircraft components.

Sustainability for Students

Engineering students can significantly impact sustainability by adopting environmentally responsible practices and principles into their education and lifestyle. They should try to gain a deeper understanding of the environmental challenges facing the aerospace industry and society. Studying topics like carbon emissions, noise pollution, and resource depletion, including aviation-related issues, is critical. They should also learn about and advocate for integrating renewable energy sources into aviation, such as electric propulsion or alternative fuels like hydrogen and biofuels. Staying informed about environmental policies and regulations is essential for those engineers joining the aerospace industry because they will become increasingly important issues in the decades to come. In the short term, students can learn about applying sustainability principles in their daily lives by reducing their carbon footprint through energy conservation and recycling plastics and other products. In particular, never drop batteries into the trash – put tape over the terminals and place the batteries in a recycling container at your institution or nearest recycling station.

Being a Successful Engineer

William J. M. Rankine, known as Macquorn Rankine, was the first Regius Professor of Civil Engineering and Mechanics at the University of Glasgow from 1855 until 1872. He campaigned to have engineering recognized as a degree subject in its own right, the first Bachelor of Science (B.Sc.) degree in engineering in the world being awarded in 1876.  Professor Rankine, during a lecture in 1856 entitled “On the Science of the Engineer, annunciated:

Let the young engineer then be convinced that the profession which he studies is not a mere profitable business, but a liberal and noble art, tending towards great and good ends, and that to strive to the utmost to perfect himself in that art, and in the sciences on which it depends, is not merely a matter of inclination or policy, but a sacred duty.

Becoming a successful engineer takes hard work and practice. There is no one path to follow, but there are established steps to success that countless generations of engineers have followed. The Pyramid of Success, advocated by Professor James D. Jones at Purdue University, suggests good practices for students to follow in their engineering studies.

The “pyramid of success” suggests good practices for engineering students to follow to be successful in their studies.

ERAU’s Dr. James Ladesic’s “Tenets of Success” for engineers are also good to follow; they apply equally to students taking courses and practicing engineers in the workplace. These tenets follow the general theme of the pyramid of success.

Dr. 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, take responsibility for yourself, your work, and your spoken and written statements in a professional engineering manner.

Goal Setting

Goal setting is also an essential part of professional development. An aerospace/aeronautical/astronautical engineer’s career goals might be the following.

Shorter-term goals:

  1. Gain hands-on experience in the aerospace industry by working as an engineer at a large aerospace company or a startup.
  2. Develop expertise in a specific area of aerospace engineering, such as aerodynamics, structures, propulsion systems, or spacecraft design.
  3. Attend industry conferences and events to network with other engineers and stay up-to-date on the latest developments in the field.
  4. Participate in continuing education courses to expand knowledge and stay current with new technologies and best practices.

Longer-term goals

  1. Obtain an advanced degree in aerospace engineering, such as a Master’s or Ph.D., to increase expertise and improve career opportunities.
  2. Work on high-profile aerospace projects, such as human spaceflight missions or developing new aircraft technologies.
  3. Take a leadership role in an aerospace company, such as a team leader, project manager, or department head.
  4. Contribute to developing new technologies and advancements by conducting research and publishing papers.

Internships

Internships offer aerospace engineering students many advantages, providing hands-on experience to apply theoretical knowledge in real-world contexts. Exposure to industry practices enhances understanding of classroom material, while skill development in CAD and CFD software prepares students for professional challenges. The networking opportunities foster connections with industry professionals, contributing to future job prospects and mentorship possibilities. Internships also help develop proactive attitudes and the ability to apply classroom knowledge. Additionally, they allow for career exploration, helping students discover specific interests within the broad field of aerospace engineering and provide insights into industry trends, ensuring that they are well-prepared to enter the workplace when they graduate.

Advanced Degrees

Obtaining an advanced degree in aerospace engineering can offer significant advantages to an engineer’s career, including increased expertise, improved job opportunities, and the ability to take on more challenging and high-profile projects. Additionally, advanced degrees can open up opportunities for leadership and research positions, allowing engineers to contribute to the advancement of the field and shape the future of aerospace engineering. The decision to undertake the education and training for an advanced degree is difficult, but it is never too early to plan ahead.

Summary & Closure

Aerospace engineering is a complex and interdisciplinary field that requires a comprehensive understanding of many core subjects. Aerospace engineers must continuously expand their knowledge and expertise to keep up with this evolving field. Engineers apply scientific and mathematical principles to tackle complex challenges and create innovative new designs and design improvements. The key aeronautical advancements include aerodynamic efficiency, airframe weight reduction, fuel efficiency, and reduced pollution. Recent developments have led to new aeronautical technologies like electric and hybrid propulsion systems.

Aerospace engineering offers many opportunities for growth and innovation, making it an exciting career choice for those interested in this field. With increasing focus on space exploration, missions to revisit the Moon and perhaps even Mars are expected to accelerate. Moreover, commercializing space flight activities has shown that cost-effective technology solutions can enable much broader access to space. The field of astronautics is expected to be marked by numerous exciting new developments, increasing the understanding of the universe.

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?
  • Human colonization of space remains a hugely ambitious goal. NASA’s return to the Moon has begun with its Artemis program. Make a list of some of the technical and other challenges in sending humans back to the moon, Mars, and perhaps even 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 five, ten, or even twenty 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 you believe are needed for that specialization.
  • Many aerospace employers prefer to recruit a fraction of new engineers with a Master’s degree or suggest that their engineers pursue online graduate courses. Consider 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 (Astronautics).
  • Why, yes, actually, it is rocket science – watch these fun TED videos
  • The U.S. Bureau of Labor Statistics runs a good website about the field of aerospace engineering.

License

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Introduction to Aerospace Flight Vehicles Copyright © 2022 – 2024 by J. Gordon Leishman is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, except where otherwise noted.

Digital Object Identifier (DOI)

https://doi.org/https://doi.org/10.15394/eaglepub.2022.1066.n1