01 – E-gle: Hybrid Electric Regional Transport Aircraft

Over the past century, the consumption and production of fossil fuels in means of transportation has increased exponentially This leads to the emission of large quantities of greenhouse gasses, such as carbon dioxide and nitric oxides. It is therefore of paramount importance that cleaner, renewable energy sources are applied in the aircraft industry. Environmental goals of NASA N+3 and Flightpath 2050 push engineers into the race to design these cleaner future aircraft. The E-gle project aims to design a hybrid electric regional transport aircraft, meeting environmental goals, while ensuring a feasible design, being market ready in 2030. With an objective to reach high levels of technological innovations, the E-gle requires a 50% decrease in overall aircraft emissions and a maximum 10% weight increase, with respect to the Bombardier Q300 on a comparable mission. Moreover, a 15 dB noise emission reduction with regard to JAR-36 regulations is to be accomplished. From a market analysis it was found that, although commonly designed for longer ranges, similar regional aircraft usually perform flights with ranges of 500 NM or less. Due to rising oil prices, the hybrid solution of the E-gle can satisfy market demands for efficient transportation, carrying 50 passengers up to 500 NM at a cruise speed of around 500 km/h. In order to meet these requirements, the technique of distributed electric propulsion (DEP) is exploited. The concept of DEP relies on small propellers placed along the leading edge of the wing. These provide extra lift during landing and take-off and can be folded during cruise, limiting an increase in drag. This allows the main wing to be sized for cruise conditions, resulting in smaller, more efficient wing. Thrust is delivered to the aircraft by hybrid turboprop engines mounted on the tips of wings, leading to a reduction in induced drag by 35%. Both the DEP propellers and the hybrid turboprops are (partially) powered by electricity stored on board in batteries, leading to a higher propulsive efficiency. The batteries are swapped between flights, in order to bypass the long charging times. Combining the reduction in wing size, decrease in induced drag and increase in propulsive efficiency leads to an overall lower energy consumption and improved flight performance. The aforementioned design strategy has resulted in an aircraft with a maximum take-off mass of 20,446 kg, an aspect ratio of 15 and a surface area of 39 m2, reducing that of the Q300 by 30%. This enables the aircraft to achieve an increase in energy efficiency of up to 56%. Consequently, the E-gle only burns 320 kg of fuel on a nominal flight, resulting in a 75% reduction in fuel consumption compared to the Q300. In order to achieve this, 5800 kg of Zinc-Air batteries are taken on board, which are swapped between flights. As the refuelling phase is typically the critical path during the turnaround phase of the aircraft, the turnaround time can be reduced, leading to more flights. Altogether, the E-gle shows as increase in efficiency energy-wise, propulsively and financially, making it a promising advancement, contributing to the future of aviation.

02 – Small Satellite Constellation for Earthquake Precursors

Earthquakes belong to the most deadly and devastating natural disasters. Nevertheless, no short term global earthquake prediction system exists up to date. Out of this necessity, a CubeSat constellation is proposed to monitor changes in the ionosphere, which provide precursor data of large earthquakes (M>7). To date, several spacecraft missions have attempted to detect earthquakes by monitoring the ionosphere. However due to the complexity of the phenomenon, the lithosphere-ionosphere coupling before the occurrence of an earthquake is still poorly understood within the scientific community. Previous missions attempted this with only 1 or 2 satellites at most. To expedite the understanding of the coupling, make a scientific breakthrough, and save millions of lives, an innovation is proposed in the form of a global network of satellites to undertake this challenge. Recent satellite missions such as DEMETER have given positive indication of feasibility of such an earthquake precursors system. The proposed small satellite constellation consists of twelve 6U CubeSats, providing a four hour revisit time above earthquake areas. The S-band communication link transmits the earthquake precursor data within twelve hours, such that earthquake precursor information is delayed by sixteen hours at most. The constellation consists of six orbital planes, placed in a Walker-Delta constellation at 520km. Additionally, two CubeSats fly in formation per orbital plane separated by 400km, accommodating partially different payload. The formation flight ensures high quality data with respect to previous missions and significantly improves the reliability of the constellation. Considered scientific payload that tracks changes of the electric and magnetic field are a Langmuir probe, magnetometer, electric field probe, ion-neutral mass spectrometer, retarding potential analyser and energy particle detector. Next, all surrounding subsystems have been sized and optimised. Commercially off the shelf products are chosen for ADCS, telemetry, power, propulsion, structures and onboard data handling. These components are sized and selected in close contact with the CubeSat industry of Delft and by using the experience of professionals at Delft University of Technology. Finally, the constellation reliability of the CubeSat constellation is assessed on a global level, using Monte Carlo simulations and component level using a Markov model. Using redundancy, the constellation has a 90% probability of full lifetime availability.

03 – The Ultimate Personal Airplane

The objective of this project is to design a multi-purpose personal aircraft that will fulfil multiple mission profiles which are desired by the customers who have multiple aims for their aircraft use. The main focus points are: relatively high cruise speed with a long range, excellent handling qualities, the capability of aerobatic manoeuvres and flight by Instrument Flight Rules (IFR). The project start obviously dealt with familiarising with the project objective and specifics and this was used to setup a project planning. The next step was to make sense of the requirements provided by the customer and evaluating these to come up with the eventual requirements the design will have to satisfy. With these requirements in hand the design space was identified and a short evaluation delivered four viable design options for the aircraft configuration: a conventional configuration, a canard configuration, a blended wing body design and a box-wing. These designs were evaluated in more detail using class I and II estimations and using the acquired knowledge the choice was made to continue with the conventional configuration. Reasons for this decision included the reduced design risk, the extensive knowledge available and the versatility of the design. All in all, this configuration was deemed to yield the most promising business case as well as the safest yet still desirable design. The possibilities of coming up with a substantially more environmentally friendly design were also investigated, in the form of a hybrid aircraft, but this was determined not to fit within the set requirements. With this configuration the last design track of the project was entered; the preliminary design phase. Mathematical models were established for the structural, performance and stability & control disciplines. To investigate the aerodynamic properties a self-built model was constructed that made use of the vortex lattice method (VLM) principle. Using these models the finalised design was established through several iterations and at the moment of writing this design is being evaluated from a technical, manufacturing & operational and business perspective. In the time that remains this evaluation will be finished, a CATIA model will be completed and the report content will be finalised. For now, the model as generated in XFLR-5 is shown in figure 1.

Figure 1: Conventional configuration modelled in XFLR5

04 – Fast Assistance Search And Rescue

The occurrence of a natural disaster poses many challenges to Search and Rescue (SAR) teams on the ground. Lives are at risk and the ability to locate potential survivors is vital. In addition to the aforementioned challenge, news feed by media jeopardises SAR teams to communicate between each other by satellite phones. The latter happened in Kathmandu in 2015, as the media congested bandwidths of relay satellites by broadcasting their news. Hence, the mission of this project is to develop an Unmanned Aerial System (UAS), to assist SAR teams during catastrophic events, that can map regions struck by natural disasters and allow continuous communication between SAR teams. The design process resulted into two self-stabilising, fixed-wing, twin-boom Unmanned Aerial Vehicles (UAV) that can perform high range and long endurance missions anywhere in the world at a maximum of 8 Beaufort (62 ms-1 to 74 ms-1). Equipped with highly accurate mapping, sensing and communication payload the UAV can map areas of 10 km2 and provide communication relay in a 50 km range. Weather conditions do not affect the UAV’s performances as an RGB-camera, a LIDAR and an IR-camera are equipped on the UAV that can cope with different weather conditions each. Furthermore, the design consists of a UAV in combination with a Ground Station (GS) operable by only 3 members of the SAR team. The GS is packed with a generator to be self-sustaining during the mission as well as a manual controller for emergency scenarios. To establish 72 hours of communication in various weather conditions, the GS is fitted with two delta kites and two helium kites. Of the shelf products have been used to preserve sustainability and longevity of materials has been taken into account when designing the skeleton and skin of the UAV. However, saving people is considered priority in comparison to complying with sustainability. A long trajectory has been traversed to end up with the aforementioned design. Having started with a morphological diagram and innumerous design options, a succinct path lead to three concepts that have been further delved into; a fixed-wing aeroplane-like concept, in singular or multiple setup, and a helicopter concept. Digging deeper into the two branches lead to a trade-off between a fixed-wing aeroplane and a conventional helicopter UAV. A performance analysis and budgets for cost, mass and size were the driving factors to select the high-mounted, fixed-wing, twin-boom aeroplane-like UAV. Departments in aerodynamics, structures, avionics, control and a department for the GS developed qualitative and quantitative measures to underpin requirements and guarantee the quality of the UAV. The skeleton of the UAV was designed by the structures department and in combination with the aerodynamics, avionics and control department an optimum design was found. The aerodynamics department had its focus in designing an ideal propeller to minimise induced losses and to stay surety for maximised flight performance in cruise condition. The effort of the avionics division was put in designing the payload arrangement, the supporting electronics, flight sensors and to guarantee heat management. The focus from now will be on dotting the i’s and crossing the t’s of the UAV design. Manufacturability and the ability to assemble the design still have to be evaluated. To ease future progress of the project, a project Gantt chart and project design and development logic have to be constructed. All in all, a design is brought up that assists SAR teams in locating survivors.

Figure 2 Detailed drawing of the UAV used for

the FASAR mission. Drawing created using

CATIA V5.

05 - Medical Express UAV Challenge

In an era where the need for humanitarian aid increases, the need for smart technology is dire. It is therefore that the UAV Challenge board created a competition where anyone can compete to create a cost effective and innovative solution to autonomously find people in remote areas and retrieve blood samples from them. Our DSE team is designing a UAV system which shall be capable of winning the Medical Express UAV Challenge (MEUC),

taking place in 2018 in Dalby, Australia. Aside from the challenge, additional requirements have been added during the design process of the system, primarily from the Royal Netherlands Navy.

In order to win the MEUC the team has designed an X-wing and canard hybrid UAV that is capable of vertical take-off and landing and transition to horizontal flight. During take-off, the swashplate controls the rotation of the hover propeller and during cruise the

same swashplate will allow the hover propeller to be used as a canard and steering surface. The most critical part of the UAV system is the power subsystem, which consists of a proton exchange membrane fuel cell and a hydrogen tank. The fuel cell provides the main power during flight, and is supported by six LiPo batteries when peak power is reached. All the processes within the UAV system are coordinated by a Nvidia Jetson TX2 processor, which is in charge of processing inputs from sensing instruments such as the pitot tube, Chameleon 3 camera, LIDAR lite v3; commanding power subsystem; propellers and actuators. The camera is vital for autonomous search of a target and is therefore connected to an autopilot board running PaparazziUAV, which uses sensing algorithms to identify a person and choose a suitable landing spot. This particular algorithm will be implemented after the DSE project is finished. The system is completed with a suitable mobile ground station design consisting of a computer equipped with communication system hardware and software for control and pre-programming of the UAVs mission profile. Due to the remote location of the challenge, the whole UAV is designed to be easily separable and capable of being transported in a conventional airline standard size case. Later it can be assembled on-site, which makes the system modular and portable as well. Currently, the majority of the design is finished and final iterations are being done in order to select the most optimal configuration, materials and production methods chosen in compliance with sustainability requirements. Furthermore, the business strategy and operations and logistics are being worked out to secure financial success of the project. The team is confident that a final design that will be presented at the symposium, and that it will also be capable of winning the MEUC.

06 - PROJECT IRIS

Moon exploration initially started as a race between the superpowers of the time to see who had the highest technical capabilities to send a human onto its surface. Until recently, the frequency of Moon missions has been in decline. However, there has been an increasing interest of going back to the Moon to perform scientific studies that will give humanity a better understanding of the solar system formation and/or perform scientific observations without the influence of a thick atmosphere. As a result there will be need for a direct communication line between the lunar surface and Earth, so that rovers can be controlled in real-time and immediately relay their data back to Earth. The focus of this DSE is hence to design such a communication system, which will take the form of a satellite constellation orbiting the Moon. The corresponding mission needs statement of Project IRIS is:

The growing need for lunar exploration will be facilitated through the implementation of an economically viable communication infrastructure between the Earth and Moon from 2030 onwards.

The project objective statement adopted by Project IRIS fulfills this need:

To conceptually develop an economically viable 24/7 communication system between at least 10 lunar vehicles anywhere on the Moon and Earth-based operators, within a budget of €1 billion, by 10 students in 10 weeks.

The design of the system in terms of the constellation consists of two parts. There are six relay satellites, which are in two mirrored halo orbits around the first Lagrangian point of the Earth-Moon system. These relay satellites are designed as micro-satellites with dimensions of 0.3x0.3x0.4 m and have a total mass of approximately 31 kg. They are taken to their halo orbits using a low-energy transfer that utilises the influence of the Sun to minimise the required ∆V. A ring-shaped carrier vehicle facilitates their deployment.

Besides the relay satellites, there are 36 network satellites in a 1629 km altitude Walker-Delta constellation around the Moon with an inclination of 50.2º. These network satellites have dimensions of 0.2x0.2x0.3 m and a total mass of approximately 15 kg. A conventional, direct transfer is employed to take these satellites to their constellation. Furthermore, they are only launched after the relay satellites are in their desired orbits to minimise the overall mission risk. Two deployment vehicles using spring-loaded mechanisms take care of the deployment.

In the final days of the DSE, the focus will be on iterating the design to optimise it as much as possible with respect to mass and power within the timeframe of the DSE. Also the risk, market and sustainability analyses of the final design will be expanded.

07 – Water Business Jet

Mission Need Statement

A high speed executive aircraft with amphibious capabilities is needed to reduce transportation times between major business-centric cities by exploiting major bodies of water for take-off and landing

Project Objective Statement

The objective of the design project is to develop a preliminary design of a high speed executive amphibious aircraft and research its technical, operational and economic feasibility.

Project Outcome

A preliminary design of a water business jet has been developed. Large subsystems such as fuselage including hull, wings, empennage and propulsion system have been sized on a top level. Also smaller subsystems such as high-lift devices, avionics and hydraulics have been generally designed. Two critical subsystems have been addressed in more detail, with special attention to interface management. Firstly, a water jet propulsion was addressed, as this system allows the jet to taxi with almost no noise close to densely populated coastal areas, and furthermore removing the risk of a bird strike. Secondly the side floats, which provide stability on the water, have been sized for structural integrity and aerodynamic drag, so that roll-over on water in the harshest weather conditions likely to be encountered is prevented, while not resulting in a large fuel penalty.

Furthermore, detailed feasibility studies have been performed for aspects which were identified as critical to the feasibility of the design at the beginning of the project: hydrodynamic performance, operations on water, economic profitability and sustainability. The hydrodynamic analyses lead to certain design choices for the aircraft configuration, hull geometry and side float mechanism. The operational analyses resulted in a plan for landing on water, both near major business centric cities and at remote locations. Via market and cost analyses it was found that a great opportunity is available for the concept at hand. At last, the sustainability showed that firstly that the flexibility of landing locations enables operations that reduce noise disturbance, and secondly that it is possible to operate without impacting sea life any more than regular ships already do.

At the current state, the preliminary design seems feasible, both technically, operationally and economically. Through an updated risk analysis new key items were identified which could be addressed in further studying the feasibility of and developing the water business jet concept. This includes research on aerodynamic drag performance of the hull and the formation of shock waves in particular, and structural integrity when landing on water in rough weather conditions.

08 - Velo-E-Raptor

The mission need statement of the Velo-E-Raptor project is as follows: “Design an electrically assisted, human powered and sustainable method of flight that is accessible and safe for entertainment and sports usage.” The focus of the Velo-E-Raptor project is to take the concept of free flight of a hang glider and turn it into a popular sport by adding a human-powered element. Market analysis shows hang gliding is unpopular for two main reasons: safety and accessibility. This project aims to overcome these problems, while maintaining hang glider performance and maximizing the user experience. An impression of the configuration of the current design of the Velo-E-Raptor can be seen in the image below. The main results of the project are explained below in three steps: safety, accessibility and user experience. Most importantly, the Velo-E-Raptor is designed to ensure the safety of its operator. The wing planform is designed to resist stall and spin. The aircraft is equipped with a fly-by-wire control system with flight envelope protection, which is programmed to always remain within safe operating limits and overwrite the pilot input once the aircraft is pushed beyond its limits. If a critical failure does occur, the pilot can always deploy a parachute. In addition, the Velo-E-Raptor operations will be overseen by clubs comparable to current glider clubs to ensure beginner pilots can receive safe training, and frequent inspection and maintenance is always taken care of. Secondly, the accessibility of the Velo-E-Raptor will beat current hang gliders. Within certain weight and operating limits, Dutch and European aviation regulations do not apply: the aircraft does not need to be certified and its pilot does not need a pilot license. This makes the aircraft available to anyone who wants to fly. Furthermore, an intuitive control system is designed to help the pilot as much as possible with controllability and safety, such that any beginner pilot is able to fly the Velo-E-Raptor. Finally, the user experience is fundamental to the Velo-E-Raptor design. The propeller throttle is controlled by the pilot’s cycling input, and the control system by the pilot’s arms. Therefore the pilot has a feeling of full control over the aircraft. In addition to this, the pilot is positioned inside the wing. The Velo-E-Raptor feels like an extension of the human body and users are able to actually feel like flying as free as a bird.

09 - Greenhouse Pollinator Drone

Pollination plays an essential role in the world’s food supply. Many crops depend on this process, yet some are not attractive enough for bees to approach them. Furthermore, restrictions on their use in some countries and ever-increasing mortality rates contribute to challenges pollination faces. Recent technological advances in indoor navigation, miniaturization and vision-based control have created the opportunity for a Micro Air Vehicle (MAV) to assist in this process, when it is insufficient, endangered or ineffective. A group of nine aerospace engineering students have designed such a system. APIS – derived from the Latin word for bee, is an Autonomous Pollination and Imaging System that has been designed to improve the pollination process. The first phase of the project was used to explore three designs capable of pollinating tomato crops inside a greenhouse. This crop is chosen because it is widely used, well-researched and difficult to pollinate naturally. The first concept was a small, Delfly-like flapping wing vehicle, that is armed with a small tongue to touch and shake the plants. The two other concepts were quadrotor-like vehicles. One being a larger sized MAV, which uses an onboard wind blower to shake flowers and never physically touches them. The other being a smaller MAV that would come close to the flower, touch and vibrate it. After performing a trade-off which included parameters such as plant safety, mission effectiveness and estimated cost, the larger drone concept was selected as the most promising candidate. APIS has a weight of 249.5 grams and a size of 283 x 278 mm and a material cost of less than 400 euros. The dedicated onboard blower targets the flowers with an airflow of 2.5 m/s when located at a distance of 50 cm. A CFD analysis was performed to find this speed, as well as the accuracy of the airflow and the vibrations that are induced on the plant. An interesting feature of this blower is its modularity. When removed, 23 grams are available to accommodate a payload that can pollinate other flower types. The flowers are detected through a monocular side-facing fisheye camera. Navigation through the greenhouse will be done by a stereo pair camera and UWB. Two lasers placed on the top and bottom of the drone will help it to navigate over obstacles when they are encountered. All this data is processed by the Snapdragon 801 on the main board, a lighter redesign of the Snapdragon Flight board. A temperature-humidity sensor was added to gather extra data that is useful in a greenhouse environment. Finally, these payloads are put on a quadcopter with an H-configuration. Four 5-inch rotors propel the drone, which are powered by a state-of-the-art 1.5 Ah 65C 2S1P Li-Po graphene battery. The entire greenhouse should be pollinated every three days. To do so, multiple APIS drones will be used. In groups of 8, they will be allocated a specific area in the greenhouse. That same group will also have a dedicated ground station, hanging from the roof of the greenhouse. Moreover, the ground station will communicate to the drone where it should go for its next mission as it keeps track of the areas that have already been covered. To conclude, the APIS is the concept that the team proposes to provide pollination services in greenhouses. This will be done in an organized way such that all flowers are targeted within three days. The modularity of the payload can be further explored to comply with the needs of crops that require more attention in the pollination process.

10 – Fire Monitoring UAV Swarm

With the first appearance of terrestrial vegetation 420 million years ago, the phenomenon of wildfire soon followed and has since formed an integral part of the Earth’s ecosystems and biodiversity. As humans learnt to ignite and manipulate fire, they gradually became the prime cause of wildfires, disrupting the natural rhythms of paleontological wildfires; today, more than 95% of all wildfires in Europe are attributed to human activity. The rapid expansion of human settlement, especially across Europe, has necessitated the implementation of comprehensive fire management principles in order to reduce the risks to human life, wildlife, and the environment. In the face of these mounting challenges, Group 10 has designed an autonomous swarm of Unmanned Aerial Vehicles (UAVs), using off-the-shelf technologies, that provides an effective, low-cost solution to the problem of monitoring European forests and grasslands for wildfires. The swarm system will be sold to large operational centres of firefighting forces throughout the European Union, in particular those of the Mediterranean states. Currently, a total of 15 UAVs will be used. Three distinct roles exist within this fleet, namely ‘searching’ for fires, ‘tracking’ active fires, and ‘scouting’ the periphery of active fires. The searching role comprises 5 Penguin B UAVs equipped with bi-spectral technology, capable of monitoring a 50 km by 50 km area in under 2 hours and detecting a small campfire from an altitude of 3 km. They will also provide a vegetation index map which can be used to predict the spread of fires of when they occur. To perform both the scouting role and, more importantly, the tracking role, 10 Albatross UAVs are utilised. Equipped with bi-spectral technology as well as sensors for measuring local temperature, humidity, and wind, these UAVs are capable of providing real-time data to fire-fighters while flying at altitudes between 100m and 1000m. This data includes fire type, predicted fire spread, and actual fire spread. The scouting role exists in case a more detailed view of an area is required, and will be controlled by the operational centre. The proposed system is the first of its kind and although there is still room for improvement, it has the potential to significantly mitigate the economic and social costs of wildfires in Europe.

11 – APHRODITE - Revolutionising solar system dynamics For centuries, mankind has been trying to characterise the processes governing the so-lar system by combining Earth and space observations. The objective of the Aphrodite mission is to perform accurate ranging between Mars, Phobos, Deimos, and Earth for eight years. Doing so will give detailed insight into the characteristics of moons in the Martian system. With the accurate positions of all bodies within the Martian system, the fundamental forces acting in the solar system can be studied. Aphrodite consists of three main elements: two landers, one on Phobos and one on Deimos, and an orbiter around Mars. The distance to the bodies will be determined with an accuracy of 0.5 metres with the use of two-way laser ranging. The laser sys-tem is also used to communicate with Earth, however a redundant radio system is present in case of failure. The other subsystems are designed to support this communication and ranging system. Landing on Phobos has been attempted before, but never successfully. Nobody has ever attempted to land on Deimos. Combining this with Aphrodite’s relatively long mission lifetime, the mission is risky. An important aspect of the mission design is therefore based on risk mitigation. For example, since little is known about the landing surfaces of the moons, the harpoons anchoring the landers to the surface are designed to work for a big range of surface toughnesses. The lasers are equipped with their own actuators, this means they can point over a wide range without the orbiter having to make complicated turns. Next to that, redundancy of components is integrated in the complete design. The total project cost is set at one billion euros, which is low for such a complex sys-tem bringing three elements into the Martian system. This challenge was tackled by choosing off-the-shell products when possible for the subsystem components to minimise development and production costs. In addition to its main objective, the orbiter can be used as a communication relay during and after the mission, which will help future missions reduce their own communication requirements. Sustainability is also a main point of attention in the mission. This mission, by choosing for a revolutionary green propellant and using life cycle assessments, brings sustainability of spacecraft to new heights.

12 - Saturn Ring Observer

Saturn, one of the largest planets in our solar system, is famous for its unique rings, but little is

known about them. The occurrence of spokes, gravity waves, propellers and perturbed edges form an enigma that has intrigued scientists ever since the planet's discovery. More so, there is mystery behind the composition, particle sizes and its dynamics. The Saturn Ring Observer mission aims to design a spacecraft that will study Saturn’s rings in more detail than ever before. Designing such a mission brings forth several challenges. Light takes 1.5 hours to reach Saturn, implying a large design emphasis on autonomy and telecommunications. Additionally, hovering over the rings means that more fuel is needed in situ, snowballing into a high lift-off mass. The strive for reducing mass by exploiting solar electric propulsion also complicates the trajectory: a Venus flyby will heat up the spacecraft to high temperatures, while Saturn’s environment will cool the spacecraft to lower temperatures.

The mission concept is a follow-up to Cassini-Huygens, which will end its mission in September, 2017. It intends on answering questions and adding to its findings. Additionally, in the light of current interests in outer planets, it would complement the current ESA and NASA missions, JUICE and JUNO, and the proposed ice giant mission concepts to gain more knowledge of our solar system.

After assessing a number of concepts that were developed, in terms of scientific yield, sustainability and risk, to achieve user requirements, the Saturn AUtonomous Ring Observer Network (SAURON) was found to be the winner. SAURON is a concept with a pair of orbiters which will travel to Saturn through the use of two extra stages: a solar electric powered stage and an orbit insertion stage. The two main spacecraft are a larger Saturn orbiter and a smaller spacecraft, of which the latter will hover on top of the rings at a distance of 2 to 3 kilometres, for a month. The hovercraft will have four different hovering orbits on top of the ring plane to analyse different locations on the ring plane. Both will carry scientific instruments selected for their respective science missions. As of date, the Falcon Heavy launcher is expected to lift off the 11 tonne spacecraft in June 2025, however the weight is expected to decrease. The spacecraft is 7.9 m in height and 1.37 m in radius. Both spacecraft will be equipped with an autonomous particle detection and evasion system, using shielding and active evasion manoeuvring, to reduce the risk of stray ring particles damaging the spacecraft. This would be a bold mission with high risk, but when taking high risk, high return follows.

13 - National Safety System for the Netherlands

The ministry of Security and Justice wants to guarantee the safety of every civilian in the Netherlands by early detection of fire and smoke as well as tracking moving targets. Besides detecting smoke clouds, the composition also has to be determined, such that it is known whether a smoke cloud contains toxins. This should all be done using Earth Observation techniques of any kind. Currently, fire and smoke detection does not exist on national level, but some objects are being tracked already using beacons which send out radio waves or by simply following the car. Measuring the composition of clouds is also done manually. However, these methods require a lot of manpower, therefore a National Safety System (NSS) needs to be designed, which detects fires and smoke and its compositions as well as tracks targets more efficiently. At the end of the baseline report, four feasible concepts for the NSS were selected. The four different concepts make use of CubeSats, MiniSats, stratospheric airships, drones or a combination of these four. The concepts were traded off on the best performance on the following criteria: observational performance, communication ability, sustainability, cost, and technology readiness level. From this trade-off, the concept which uses stratospheric airships to perform all three tasks -- with drones for assistance as the airships cannot see anything during night time or cloudy conditions -- came out as the best solution. Detection of fire and smoke hardly poses a challenge: a lot of infrared cameras already exist for those tasks. Chemical analysis is done by imaging a cloud with a hyper-spectral camera. Identification and tracking of targets is done by first applying a coating to the target. The coating consists of a panchromatic metamer or quantum dots. The quantum dot method relies on the fact that the paint absorbs incoming visible light and re-emits it at a different wavelength, which causes a peak in the electromagnetic spectrum when observing the target. It has its limitations however, and that is why panchromatic paint is used as well. The latter relies on the fact that two objects can have the same colour, yet stemming from a different electromagnetic spectrum. A hyper-spectral imager can detect the difference in spectra, thereby concluding whether the target is marked and also which target it is. So the hyper-spectral camera does both chemical analysis as target tracking.

The NSS consists of 15 active airships, which cover nearly 100% of the Netherlands. Always at least one airship will be on the ground for maintenance and redundancy. In the figure the distribution of the airships and the ground stations are shown. The blue circles represent the field of view of the airships and the green circles represent the communicating range of the ground stations. Besides these elements, two types of drones will be used for target tracking and detecting fire and smoke at night-time or when the weather is cloudy.

14 - Hybrid UAV

The Unmanned Aerial Vehicle (UAV) market is growing, as the field of application becomes increasingly diverse. Various missions performed by UAVs such as transport, surveillance and monitoring missions can be less challenging and more efficient compared to missions carried out by manned aircraft. The new design principle of combining a helicopter and a conventional aircraft has been proven to be prominent, as it allows a UAV to be versatile and have capability of being retrofitted to different mission profiles; these Hybrid UAVs are able to operate at broader conditions, as they can take-off and land without a runway and have a horizontal flight performance of a conventional aircraft.

To start off the designing, a trade-off between five preliminary concepts was performed in order to determine what type of Hybrid UAV layout is optimal for the given requirements. The most important requirements are a top speed of 200 km/h, an endurance of at least an hour, a payload carrying capacity of 10 kg and the capability to take-off and land vertically. These requirements have been set by the client. However, it is determined that it is infeasible to meet all these requirements simultaneously while adhering to the EASA mass limitation of 25 kg. To solve this, modular payloads will be used, replacing payload weight with batteries if necessary. Out of the five preliminary concepts, the hybrid quadcopter design, as seen in the picture, outperforms the rest. This design scores highest on all criteria. Before the designing could start, preparation work had to be done. System Engineering tools, such as work flow diagrams and N2 Charts, are implemented to smooth the designing process and the aircraft was split into eight sub-systems which cover all the aspects of the aircraft. To prevent exceeding limits on mass, cost, and power, budgets have been implemented for each sub-system. To have an allowable margin of freedom, contingencies have been added to each budget. Subsystems were not allowed to exceed these budgets, if this was the case, changes had to be made to the design or budget. With the preparation done, five departments worked concurrently on the various subsystems to design the most optimal outcome. Using a master set document with all updated variables, each department worked with the most up-to-date values.

With the design phase completed, all subsystems are designed and optimised for the required missions. The aircraft is able to fly 40 km with a full payload, while being able to fly up to a maximum of 600 km by replacing payload weight with extra batteries. The requirement of having an endurance for an hour has been met, but not with the full payload capacity. The structure of the aircraft will be built with lightweight materials such as glass fibre and carbon fibre to ensure the mass of the aircraft will not exceed 25 kg. To conclude, the design meets the requirements using a modular payload, while staying within the budgets assigned to the subsystems.

15 – I-ACT Modular UAV

Although humanity is embarking into the most peaceful time period, wars and conflicts remain and human lives are still needlessly lost. It is good intelligence, threat data and detailed information that saves countless lives daily. But while our methods to gather data have improved drastically in the last 100 years, so have the abilities of our enemies to avoid and elude them. They tend to hide, conceal, and misdirect; consequently, getting reliable data today might be harder than ever. The aim of this project was to produce a flight system capable of providing reliable data without being detected. Our core design philosophy was as follows: to design a system that sees but is unseen; that hears but is unheard; and that gathers proof, yet leaves none behind.

After many hours of work the solution was found in the SPARTA concept seen in Figure 1. The Surveillance Platform for Aerial Reconnaissance and Target Acquisition (SPARTA) is a highly modular Unmanned Aerial System (UAS) that includes various payload modules and two main flying configurations. Depending on the mission requirements the drone can be configured on the spot to be either a fixed wing or a quadcopter. The UAS consists of a core module, quadcopter propulsion unit and fixed wing platform including a tail. Together with the ground station, the system was designed with portability in mind, fitting into two standard military backpacks.

The total drone weight of less than 5kg offers seamless hand-launch and landing capabilities. The assembly is done using click and lock systems, making assembly and re-configuration fast and reliable. The UAV has superior performance with endurance peaking up to two hours in fixed wing configuration when equipped with maximal payload. The drone is inaudible at 70 meters and its small size and large operation radius results in the drone easily to be missed or mistaken for a bird. Finally, the system was designed with safety as the primary concern. The system offers an availability of more than 90%, making this UAV one of the most reliable on the market.

The system is capable of providing eyes and ears where humans cannot go. Gathering information that could save numerous men and women, fathers and mothers, sons and daughters. This is SPARTA.

Figure 3 – Fixed wing and Quadcopter configuration

16 – Steps to Mars – Boots on Phobos

Human exploration of Mars is crucial for the future of mankind. It will both lead to further understanding of the origin of life and the possibility of colonising different environments. Since it is a difficult and dangerous task, achieving human presence on Mars requires division into a set of preparatory missions. These missions will act as proving ground to ensure safety and demonstrate sustainability of completing the task. One of the preparation missions to achieve this task has the objective of transporting a human habitat to the Martian moon Phobos by the year 2033. This DSE-project focuses on transporting the habitat from low Earth orbit to the surface of Phobos by means of a Solar Electric Propulsion transportation tug and a lander craft. The project unfolded with the organisational set-up and planning of the technical design. Five designs were traded off, of which the result was the PICARD. The design was regarded as most suitable for the mission phases, since it provides an enormous amount of power from solar arrays, which is required by the state-of-the-art propulsion system. The VASIMR-engines used have been specially developed for these kind of missions, to minimise the amount of propellant. Furthermore, propellant tanks from the propulsion subsystem and ADCS are combined, to prevent the use of extra tanks. These ideas all contributed to an overall significant driver in the design, the sustainability. Sustainability was addressed on both environmental and societal scale. During the design phase, incorporation of off-the-shelf technology was stimulated to limit the use of development resources as much as possible. This was also the case for the solar panels, which are very sustainable on their own. A very tempting option during such a mission is to discard the solar power requirement and go for nuclear power. However, the requirement was adhered to, preventing nuclear waste. To illustrate the challenges encountered, different critical points during the design arose. Those were mainly concerned with the power, habitat and landing. Large scale missions to Mars have never been conducted with a full electric propulsion. The solar arrays would become enormous, hence doubts on its feasibility emerged. Current mission designs actually indicate the use of these enormous arrays, debunking these doubts. Secondly, the overall mission had an increased mission difficulty due to the 50-tonne habitat. Finalising the mission, sticking the landing was considered as challenging, because of Phobos’ small sphere of influence. Structurally, an anchoring mechanism solved this issue. The design can be applied to the different mission segments, after a thorough analysis of the mission. Using the Space Launch System, the spacecraft is transported in separate segments to a pre-determined delivery and docking orbit. As a tug-lander-habitat configuration, the spacecraft travels to Mars using a spiral, low thrust trajectory as an electric propulsion subsystem is applied. For this reason, solar arrays are fitted to the tug with batteries for short term applications. Once in Martian orbit, the lander separates from the transportation tug to travel to Phobos with a Hohmann transfer. The landing system is equipped with chemical propulsion to hover and find a suitable landing spot. After landing on the surface of Phobos, the habitat is maintained and Phobos’ surface is monitored. To communicate to Earth, the transportation tug is placed in a Martian orbit to provide relay for the lander. There are some who say it cannot be done, let us prove them wrong.

17 - Next Generation Affordable Small-Payloads Launch System

The small satellite market has expanded in recent years. However, these small satellites depend on large launch systems, where many small satellites are bundled together onto a single launcher. This leads to inflexibility in terms of time and cost, as small satellite operators may have to wait for extended periods of time and pay exorbitant prices to have their payload launched. To solve this issue, ALTAR took on the challenge to design an affordable sustainable launch system to put payloads of up to 20 kg into low Earth orbit (LEO, < 700 km). To improve performance of the launcher and attract more customers, certain top-level system requirements have been changed from their initial state. After market analysis and discussion with the client the most important top-level system requirements for the “ALTAR” mission were determined to be:

• The launcher shall be able to accommodate payloads of up to 35 kg.

• The launcher shall put the payload into a circular orbit at up to 600 km altitude. • The launcher shall be ready for operational use by 2022.

• The launcher shall have a launch success rate greater than 0.9. • The launch costs shall not exceed 50 k$/kg. In developing a dedicated affordable launch system with a maximum capacity of 35 kg payload for a 600 km orbit, a stratospheric balloon concept has been selected. The stratospheric balloon will be launched from a ship in the Atlantic Ocean and it will lift a rocket up to 40 km altitude. Once the balloon has reached the desired altitude, the rocket will be launched and will bring the payload into LEO. This stratospheric balloon concept integrates sustainability and reusability to the system. During the ascent of the balloon no propellant is emitted into the atmosphere and thus it does not harm the environment through air pollution. During the descent, the balloon will land in a safe zone and will be reused for further missions.

The rocket consists of three stages, all using solid propellant. This propellant type has been chosen for reasons such as low cost, improved propellant handling characteristics and reduced complexity with respect to liquid and hybrid engines. In order to avoid catastrophic collisions of future payloads and launchers from space debris, there will be an orbital manoeuvring system (OMS) attached to the third stage which is powered by mono-propellant engines.

Current estimates place the cost per launch at 43.5 k€/kg, which meets the top-level system requirement of a cost below 50 k$/kg. ALTAR is currently undertaking a more detailed cost analysis, with the goal of being economically competitive against current piggyback-launch systems.

Figure 4 : The ALTAR launch system

18 - Velo-E-Raptor

The goal of this project is to develop a foot launched, electrically assisted human powered air sport. The idea is to make flying as easy, accessible and thrilling as kite surfing and similar sports. A canard configuration will be used as can be seen in the picture. As the goal is to make an easy and accessible sport the main focus was on the safety and fly like a bird feeling. The canard configuration is perfect for this application because a canard aircraft has a gentle stall. The pilot will be in prone position, which enhances the fly like a bird feeling. The Velo-E-Raptor will be able to takeoff and land by foot. The pilot will be running during takeoff and after liftoff he will change to the cycle position. The power the pilot generates will be amplified to a max of 10kW in order to reach speeds up to almost 100m/s. Because of the canard configuration, the stabilizer must generate a positive lift in order to be stable, which makes aircraft much more efficient. The canard wing will generate almost thirty percent of the lift, which enables the Velo-E-Raptor to have a big total wing surface area without the span becoming too large. Due to this big surface area the stall speed of the aircraft will be nearly 8m/s. This together with a selected airfoil with excellent stall characteristics will make the landing very easy and calm.

Also due to the reduced span the aircraft will be agile enough to

perform aerobatics like a Red Bull air-race. It will be possible to perform a looping in few seconds. The glide

ratio can go up to twenty, what makes the Velo-E-Raptor next to a Red Bull air-racer a good glider as well. This opens up a new sport aspect, for example gliding across the Wadden Islands. From cruise altitude it will be possible to glide up to almost 30km. The Velo-E-Raptor will be built out of carbon-fibre, which gives the aircraft a weight of 100kg with the heavy lithium-ion battery included. The V-Tail support for the main reduces the loads on the wing, which in turns makes the structure lighter. The structure is designed to withstand a load of up to 6g for aerobatic flight, this makes the aircraft almost unbreakable. The pilot will be supported during flight by a head up display (HUD) connected with a flight computer. This setup gives the pilot all the information he will need during flight which makes flying for new pilots almost too easy. The highest risk of crash occurs in the last turn before the landing due to stall. The flight-computer will make the flight envelope limitations visual on the HUD so the pilot will never be in danger. Also the controls will be attached to the pilots body in order to reduce the pilot induced vibrations and makes flying much easier.

19 - The Manned Drone

Objective

Urban populations have been growing rapidly throughout the past decades and with this pattern comes a new set of challenges, particularly when it comes to transportation. The current state of public transport and road networks is not sufficient to keep up with the rising demands for sustainable transportation. As a consequence, traffic congestion is becoming a greater problem within urban environments.

The goal of this project is to provide a fully sustainable solution for traffic congestion in the form of personal transport. The aim is to design a personal air-vehicle which is able to take off and land vertically. Furthermore the design should fly autonomous and have zero emissions.

Achievements

Throughout the whole design process sustainability was emphasized. That is, sustainability was the driving factor in the design of every component. The scope of sustainability was not only zero-emission, rather it was extended to noise-pollution and recyclability as well. This resulted in an innovative design of which the key characteristics are summed up below

• Hydrogen Fuel System: The innovative zero emission fuel system allows for longer flying time in comparison to batteries and produces no emissions. • Shrouds around rotors: Shrouds around the rotors are safer, lower the noise and increase the efficiency. • Cockpit which generates lift: The design of the cockpit allows the rotors to produce less lift during cruise and hence safe power. • Use of sustainable carbon fiber reinforced polymer (CFRP): The lightweight characteristics reduce the total mass of the vehicle. Furthermore they are fully recyclable which contributes to sustainability.

Future Work

From the moment of writing up till the point of the symposium, the design itself will not change anymore. The focus will lie on further designing the logistic system regarding the drone. This includes refueling, maintenance and manufacturing processes.

20 – Reconfigurable Unmanned Cargo Aircraft

The air cargo market is a rapidly growing sector with a promising outlook. This growth in the market size asks for more flexibility from air cargo operators. The use of a reconfigurable aircraft addresses this opportunity by introducing the possibility of using one aircraft system for drastically different missions. Unmanned operation of the aircraft allows for: transportation of dangerous goods without endangering human operators during flight, less personnel, and cheaper operations. The reconfigurability in combination with the unmanned operation delivers a unique and innovative product to the growing cargo market. The product, called the ModuLR, will consist of a fuselage able to carry a maximum of 40 m3 of cargo in standardized half pallets (96x64x61.5in). Depending on the operator’s runway and range need, a different wing-tail-engine combination can be installed on a fuselage of fixed length. The ModuLR-100 has a maximum range of 1000nmi and a take-off and landing distance of 3000ft. The ModuLR-200, on the other hand, has a maximum range of 2000nmi and a take-off and landing distance of 6200ft. Lastly, the ModuLR-300 has a maximum range of 4000nmi and a take-off and landing distance of 7400ft. The ModuLR system is therefore highly flexible, able to operate from small to large airports, and travel short to very long range missions. The ModuLR group does not only act as the design and production group, they also act as the service provider, by reconfiguring the aircraft at different hubs around the world, and providing maintenance and repair operations through a service model. Operators purchase the fuselage for a price of €20M and pay a subscription fee of €5M/year to lease and use the wing, tail, and propulsions systems. In this way, operators are able to enjoy a significantly lower upfront cost, whilst having access to a pool of mission specific reconfigurable parts. After 10 years, this model is still more than 20% cheaper than a 737 freighter. The next two weeks will be dedicated to finalizing the detailed design of the different design aspects, writing the final report, and preparing for both the final review presentation and the symposium.

Figure 5 – The three ModuLR versions with a constant fuselage

21 - The Smart Retrofit Wing

Aircraft account for a significant use of fossil fuels and emission of greenhouse gasses such as CO2. Considering the depletion of fossil fuels and the impact of greenhouse gasses on the environment, in the context of a growing demand, efforts are being made to make the aircraft industry more sustainable. New technologies can be applied to older aircraft, a process called retrofitting. In this project, the Airbus A330-200 will be retrofitted, in order to demonstrate a more short term option to reduce the impact of the aircraft industry on the environment.

Mission and Design The purpose of this project was to retrofit the wing of an Airbus A330-200 in order to reduce fuel consumption by 7.5%. Additionally, CO2 emissions were to be decreased by 7.5%, NOx emissions were to be reduced by 9.0% and the perceived noise level by 6.5%. The retrofit would need to be commercially attractive, which implies that the costs of the retrofit should not exceed the cost reduction due to a decrease in fuel use of the aircraft. Furthermore, the retrofit should not compromise the aircraft’s current performance. The solution to this problem was the implementation of several retrofit concepts, 4 to be exact. The first concept is a winglet: a more optimised, extended version of the current winglet with optional morphing. This will decrease drag by 3.7%. The second concept is a new configuration of a sharkskin coating: the herringbone riblet coating, which applies the texture of a birds feather to the aircraft and can reduce the total drag of the aircraft by 7.6% by reducing skin friction drag. The third retrofit will be a FishBAC (fishbone active camber) flap, which has an internal actuation system and will not extend, thus closing the gap at the trailing edge. This will cause a reduction in noise and in addition will allow for flap track fairings to be removed, resulting in a 1.1% drag decrease for the aircraft. Finally, the fourth retrofit is the addition of variable geometry chevrons to the engines, which will reduce engine noise by 2 dB. The combination of these concepts will reduce the fuel consumption of the Airbus A330-200 by 9.94% on a reference flight of 7.5 hours. Sustainability When designing any product, it is imperative to consider the impact that product will have on the world around it from day one of the design process, because not only the product, but also the design process itself has an impact on sustainability. There is no use in designing a retrofit that will save fuel if the environmental impact of the retrofit itself outweighs this benefit. This means that during the design careful attention was paid to the materials used and the retrofit process, with regular checks on sustainability throughout the process. The aim is to make the Smart Retrofit Wing a commercially attractive step to a more sustainable aircraft industry. Final steps In the final weeks of the DSE, the designs will be finalised. The Smart Retrofit Wing will prove that there is a more short-term solution to aircraft emissions, that can be applied to existing aircraft at a profit for the airline.

22 - Pseudo Satellite for Military Purpose

Mission

The Royal Netherlands Air Force (RNLAF) needs a high altitude, long endurance and autonomous platform which can carry multiple types of payloads to increase reconnaissance and surveillance capabilities by 2023. The objective is to design a fixed wing aircraft and corresponding ground station which fulfils these requirements. The driving requirements are flying at a station keeping altitude of at least 50,000 ft, staying aloft for 30 days and transporting three aircraft including all support material in a single C-17.

Work performed and design outcome

The design has been split into three main groups. The structural group, the power & propulsion group and the wing design (aerodynamics, stability & control). The key to flying for 30 days at the given altitude is a combination of a lightweight, aerodynamically efficient design, efficient powertrain and batteries with high energy density.

Summarized, the final aircraft design is a flying wing with a 45.6 m wingspan, which uses 6 electrical propeller engines powered by solar panels and batteries. A leading edge sweep of 20°, a taper ratio of 0.6 and a twist of 1.8° are applied. The aircraft is fitted with elevons and split drag rudders. During the day, the aircraft will charge the batteries and climb to an altitude of 75,000 ft. After sunset, the aircraft will glide back down to its station keeping altitude and use the batteries to stay in the air for the remainder of the night. The aircraft is capable of operating all year round up to 40 degrees latitude.

The main load carrying aircraft structure is a composite rod running along the wingspan with the skin being made of flexible foil. The structural weight is 135 kg. Together with the powertrain weight of 136 kg and other smaller aircraft systems, the total weight adds up to 308 kg.

The aircraft is fitted with an autopilot system, including a variety of sensors. Communication can go through line of sight or via satellite. The ground station can be as limited as a suitcase carrying the command station, however, using multiple screen allows for operating up to 10 aircraft by 2 operators from anywhere in the world.

The cost per aircraft is estimated at 4.6 million euros with production of 50 aircraft. This complies with the cost requirement of 10 million per aircraft.

Outlook into the final weeks

Currently, the conceptual aircraft design is finished. In the final weeks other aspects will be rounded off such as the production process, several block diagrams graphically representing different systems of the aircraft, a market analysis and some future project development aspects. The sustainable development approach will include investigating CO2 emissions during the production process, any non-sustainable events during operations and end of life solutions.

23 – Flying Doctor

In the never-ending search for cost reduction in airline operations, down-time reduction is currently referred to as “airline gold”. As aircraft only generate revenue while in the air, downtime reduction due to maintenance and repairs is key. Innovations play a more impor-tant role than ever in accomplishing the required downtime reduction. The use of Unmanned Aerial Vehicles (UAVs) provides a promising solution in order to perform faster maintenance on aircraft.

Mission Conventional solutions in aircraft maintenance involve the use of cherry pickers or scaffolding in order to repair hard to reach areas on aircraft. The setup time of these devices is significant and labour intensive. The mission of the Flying Doctor UAV team is to develop an autonomous flying drone which can carry the DMG MORI ULTRASONIC mobile milling unit, which is capable of repairing damaged surfaces on aircraft. Outcome Over the course of the DSE project, a UAV concept capable of lifting the 85kg milling machine was developed. The UAV was required to be able to be fit into a small space, and as such, it is modular and built for easy on-site assembly and disassembly. This ensures maximum mobility, as it is easily transportable. The UAV is capable of operation in the hangar as well as outside at the gate. The UAV will autonomously fly to identify and land on the target location, utilising computer vision to detect obstacles and determine its position relative to the aircraft. The UAV is able to access both the top and bottom of the aircraft due to a rotation mechanism, and an additional perching mechanism allows it to reach locations even on the side of the aircraft. Once it has landed on the aircraft, the technician can remotely repair the damaged location. As of now the conceptual design has been finalized. Both off-the-shelf components as well as custom designed parts are incorporated in the design. Furthermore, a detailed plan for the 3D printing of certain parts has been included. The next step for the team is to optimize the concept of operations to make sure that the UAV is allowed to perform inspections and repairs on the apron. The Flying Doctor UAV team is confident that the product will aid in reducing aircraft downtime and be a profitable asset for airlines.

Figure 6: Visualisation of the Flying Doctor UAV

24 - Automated Launching and Landing System for a Rigid Wing Airborne Wind Energy System

Airborne Wind Energy (AWE) is a relatively new and promising way of generating electricity using wind energy. In the past decade, many start-ups have been created that are each trying to produce a profitable AWE system in their own way. This makes for a very competitive and dynamic situation regarding the companies that are now involved. The general concept of AWE is that a kite attached to a tether flies figures of eight while reeling out the tether. The tether is attached to a drum at the ground station, where it generates energy by rotating the drum and driving a generator. After the reel-out phase is finished, the kite is quickly reeled in with minimum input energy. The difference between the energy that is generated during reel-out and the energy that is needed for reel-in, is the energy that the system produces per cycle.

Our project focuses on the launching and landing system of a rigid kite that is used for such an AWE system. This process needs to be fully autonomous and the rigid kite that was designed by the DSE 2014 fall group is taken as a basis. There are many concepts that can be used for the launching and landing procedure; even the largest companies investigating AWE, such as Ampyx Power and KitePower, do not agree on which concept works best. After an elaborate trade-off process up until the mid-term report, we chose to design the vertical take-off and landing (VTOL) concept in more detail. This concept uses rotors to lift the kite vertically and bring it to its desired altitude and attitude. During landing, the rotors are used to guide the kite towards the ground station while reeling in the tether. At an altitude of 30m the kite will transition into hovering mode and the rotors will land the aircraft at the designated landing spot. As can be seen in the figure, the main rotors have two blades and are located at the wingtips of the main wing to minimise impact on lift generation. During nominal flight, these two blades will be fixed in the longitudinal direction of the kite, minimising aerodynamic drag while flying the figures of eight. The rotors are positioned at an offset of 1.0 m from the wing to reduce interaction between the outflow from the rotors and the main wing. A smaller rotor at the tail is installed to give stability while hovering and produce energy while in nominal flight.

This week, we have focused on bringing the aerodynamics, structures, stability & control and power & propulsion subsystems together. This has led to a complete system with an estimated total mass of 68.5 kg and a rated power output of the system of 93 kW at a reference velocity of 14.5 m/s. The next two weeks, we will aim to document our design and the deliverables in the report, use the feedback from our tutor and the customers to improve the design and prepare the symposium presentation.

25 - Design of a Low-Noise, Medium-Range Airliner

Aircraft and noise have been inseparable concepts since the invention of manned flight. Over the last couple of years noise has become a more and more governing criterion in the development of new aircraft. The objective for this project was to design a low-noise airliner capable of transporting 110 passengers over at least 1500 nautical miles. The end result, the SRJ110, sets an industry wide standard with respect to low-noise operations paired with high fuel efficiency, low purchase price and excellent performance figures.

Render of the SRJ110

The SRJ110 has been designed with respect to low noise pollution from day one. Several noise mitigation measurements were investigated for application on the aircraft. One of the most notable noise mitigation measure is the placement of the engines. Mounting the engines on top of the wing yields a significant noise reduction due to the shielding of fan noise by the wing. The aircraft makes use of the latest generation of geared turbofans which allows the engine fan to rotate at a lower speed, reducing noise and boosting engine efficiency. In order to make sure the passengers are not affected by the close location of the engines to the fuselage, the aircraft is equipped with active noise and vibration suppression technology (ANVS). This excellent noise performance comes hand in hand with high fuel efficiency. Fuel consumption is equal to 2.52 l/100km per passenger; up to 18% lower than the new generation of Embraer E2 jets. Emission of harmful pollutants such as CO2 and NOx are significantly reduced, contributing to the sustainability of the aircraft. Take-off and landing performance are improved too, allowing operations from short runway airports such as London City. This high performance package also comes at a significantly lower purchase price compared to the competition, without making sacrifices to important customer parameters such as cruise speed, passenger comfort and aircraft reliability. During the final stage of the project special care will be put into fine-tuning the aircraft performance figures and filling remaining engineering budget. The design team will be delighted to present the final design of the SRJ110 during the symposium on June 6th, 2017.

26 - Lunar Exploration Access Point (LEAP) - The conceptual design of a lunar habitat for four astronauts staying on the Moon for one year.

In 1969, Apollo 11 proved that mankind can send astronauts to the Moon and safely bring them back to Earth. The International Space Station (ISS) proves that it is possible to sustain life in space for extended durations. The advancement of technology and our inert drive to explore bring us to new frontiers and enable us to overcome new challenges. The challenge of today is to settle outside of our planet’s protection and see if the achievements of Apollo and the ISS can be combined to establish a semi-permanent outpost on the Moon. This initiated Project LEAP; the Lunar Exploration Access Point.

The challenge for LEAP is to sustain the life of astronauts on the Moon and to organise a mission so the required facilities and units can be sent to the Moon when needed.

Sustaining life, in essence, is the engineering of a habitat, that can host four astronauts for a duration of one year. The hostile lunar environment poses a threat to human life and the machinery sent. Thermal control, meteorite shielding, radiation protection, atmospheric control and many more are key functions of the habitat to create an Earth-like environment in the vacuum of the Moon. It is a particularly difficult task to generate the required living space for four astronauts for one year. Currently, there is no launcher capable of delivering a payload large enough to meet all demands for this mission. Therefore, the second challenge of LEAP is to identify the logistics necessary to establish an operational lunar habitat.

Our work so far has focussed on producing a detailed design of the habitat and solving the logistical challenges on a conceptual level. At first, we identified human needs and technical constraints and translated them to requirements for the habitat. As a result, the habitat consists out of a central dome, a high-tech aluminium structure that acts as a central node, and two inflatable structures which generate most of the living space. In total, the habitat features 130m2 of living space and has a gross wet mass of 27.5 tonnes. The three modules will, therefore, be delivered to the Moon by two Space Launch Systems in their own missions; Giant Leap 1 & 2. Prior to this, the missions Small Step 1, 2 & 3 deliver all machinery to develop the lunar infrastructure needed. After these five missions, the first astronauts are expected to arrive on the Moon in 2035. From there on, annual resupply missions will provide the astronauts with everything they need from Earth, and an annual exchange of astronaut crews ensures a continuous mission.

Finally, sustainability is a key driver in the project. With a total estimated mission cost of around 47B EUR, the placement of humans on another celestial body, and the environmental impact of rocketry, the project bears great responsibilities to not only the Earth and humanity but also the Moon and its future inhabitants. As the habitat’s detailed design is concluded, the last few weeks of the DSE will be spent on further defining the auxiliary missions and the human operations in and around the habitat. It is up to future DSE groups to venture into the detailed design of all the missions of Project LEAP.