This paper presents a power-centric systems-engineering approach for PlanarSats and for atto-, and femto-class spacecraft where surface-limited power dominates design. We review agency practices (The National Aeronautics and Space Administration (NASA), European Space Agency (ESA), Japan Aerospace Exploration Agency (JAXA)) and the American Institute of Aeronautics and Astronautics (AIAA) framework, then extend them with refined low-power subcategories and a log-linear method for selecting phase- and class-appropriate power contingencies. The method is applied to historical and conceptual PlanarSats to show how contingencies translate into required array area, allowable incidence angles, and duty cycle, linking power sizing to geometry and operations. We define the operational power envelope as the range of satellite orientations and conditions under which generated power meets or exceeds mission requirements. Consistent with agency guidance, sizing is performed to the maximum expected value (MEV) (CBE plus contingency); when bounding or stress analyses are needed, we report the maximum possible value (MPV) (Maximum Possible Value) by applying justified system-level margins to the MEV. Results indicate that disciplined, phase-aware contingency selection materially reduces power-related risk and supports reliable, scalable PlanarSat missions under severe physical constraints. ... Read more

This paper introduces a power-driven systems engineering methodology for the early-phase design of highly miniaturized satellites: PlanarSats. We derive an analytical framework linking power requirements, contingency policies, solar-cell performance, and subsystem integration to determine the absolute minimum satellite size. Through idealized and detailed case studies, we explore the trade-offs inherent in subsystem selection and integration constraints. Sensitivity analysis identifies critical factors affecting minimum area and operational envelopes. Our framework provides a clear tool for balancing functionality, reliability, and physical limits in next-generation ultra-small satellite missions.
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Delfi-PQ is a pioneering 3P PocketQube developed at Delft University of Technology, measuring 50x50x178 mm and weighing 545 g. Launched on January 13th 2022, it remained operational until its deorbit in January 2024, demonstrating nearly two years of sustained in-orbit functionality. Its architecture features a standardized core that supports reusable hardware and software across multiple subsystems, while an innovative structural design maximizes the limited internal volume. This paper presents results in orbit, the lesson learnt and a detailed hardware development cost analysis of a 3P PocketQube. Cost containment was a central mission objective. Using commercial off-the-shelf components, modular subsystem design, and iterative manufacturing, the Delfi-PQ team maintained tight budget control. Multiple hardware revisions allowed lessons learnt at each stage to be quickly integrated back into the design cycle. A detailed cost breakdown shows that a standardized core can substantially reduce non-recurring engineering expenses, making advanced pico-satellite development feasible within academic constraints. During its mission, Delfi-PQ encountered substantial thermal swings (up to 75◦C), yet consistently maintained full functionality. Although some limitations in battery protection arose from specific design choices, the paper documents which components performed reliably in space and how others deteriorated over time, offering critical guidance for future teams. In addition, the inclusion of a laser reflector payload designed to enhance tracking accuracy| and the structural innovations required to optimize space usage are discussed. A global network of amateur radio operators, together with the ground station in Delft, regularly received telemetry throughout the mission. This support was vital for tracking spacecraft health, investigating anomalies, and refining subsystem performance: the extended reliability of Delfi-PQ underscores the value of cost-conscious engineering, modular architectures, and strategic community partnerships to extend the service life of the mission. In summary, Delfi-PQ demonstrates that a lean yet robust satellite design based on modular principles, iterative development, and close collaboration| can reliably operate over extended mission durations. By presenting a full cost breakdown and comprehensive mission results, this paper offers practical insights for institutions aiming to deploy similarly innovative, affordable PocketQubes for advanced research and education. ... Read more

As satellite technology advances, there has been a notable trend towards miniaturization, leading to the development of increasingly smaller satellites such as femtosatellites and attosatellites. A new emerging form of such satellites is often called ChipSat, with unique designs that utilize both surfaces of a single plane to maximize functionality within limited dimensions. Initially, the term ChipSat referred to system–on–a–chip satellites but it has since expanded to include centimeter and millimeter scale spacecraft. To provide a clearer terminology, this paper introduces the term “PlanarSat” for such a planar spacecraft. Despite the challenges in deployment and the constraints, such as cost, size, access to space, and capabilities, of miniaturized subsystems, these satellites represent a significant shift in space technology, aiming for cost-effective solutions and innovative mission capabilities. This study reviews thirty sub-100-gram satellites, analyzing their design, deployment, and potential for future advancements in a comparative manner. In this study, satellite independence was defined based on system-wise independence, highlighting operational autonomy irrespective of physical connections. The survey’s findings highlight technological advancements and potential applications for these very small spacecraft, which are pushing the boundaries of what is feasible with smaller satellites and how these satellites were or planned to be delivered to orbit. The analysis results provide a basic cost comparison, providing information on hardware and launch costs, taking the instantaneous data rate as a reference point, underscoring the need for a new systems engineering approach to the design of such satellites. ... Read more

With the rapid growth of operational satellites and debris in congested areas, such as Low Earth Orbit, moving in the traffic is becoming key also due to new regulations potentially coming into play. This paper presents a selection of current guidelines that can play a major role in small satellite mission design and presents the Delfi-Twin mission, conceived to demonstrate Space Traffic Management capabilities. The mission s made by two small satellites which will operate as a formation using differential drag as control strategy. On-board orbit determination will be employed to speed-up the availability of high-accuracy ephemeris and improve their dissemination to other operators. Miniaturized commercial receivers have been evaluated in an emulated orbital scenario to assess the performances of future on-board orbit determination system, providing some insights on existing problems related to commercial receivers not designed for operating in space. ... Read more

Sporadic-E (Es) layers can strongly perturb HF/VHF propagation and create intermittent interference, motivating higher-revisit monitoring at the frequencies most affected. EsTRACE (Es-layer TRAnsient Cloud Explorer) is a PlanarSat mission concept that transmits sequential beacons in the 28/50 MHz amateur bands using FT4 (weak-signal digital) and CW (continuous wave) waveforms and leverages distributed amateur receiver networks for near-real-time SNR mapping. This paper documents the early-phase spacecraft design from the Bid/proposal phase (Bid), through the Conceptual Design Review (CoDR), to the Preliminary Design Review (PDR), using a power-first sizing loop that couples link-budget closure to duty cycle and solar-array area under a free-tumbling, batteryless constraint. The analysis supports conceptual feasibility of the architecture under stated antenna and ground-segment assumptions; on-orbit demonstration and measured RF/antenna characterization are identified as required future validation steps. ... Read more

The Lunar Gateway is an essential element of deep space infrastructure that provides a multi-purpose long-duration cislunar platform. As such, it also provides an opportunity for Mars-forward use and technology development. Building on an analysis of NASA's Moon to Mars (M2M) Program objectives, architecture documentation, and Gateway's existing capabilities and requirements, this paper will recommend ways to utilize the Gateway as a testbed for future missions and operational concepts, and hardware to fill gaps in enabling future human Mars exploration. Areas of assessment include extending human life, enhancing quality of life on deep space missions, establishing a sustainable cislunar ecosystem, international partnership and commercial opportunities around the Moon. This paper is a condensed version of the final report produced by the Lunar Gateway Team Project for the International Space University’s Space Studies Program 2024. It aims to define the Gateway's role in advancing capabilities for sustainable lunar exploration while serving as a springboard for future missions to Mars. The results of this study will advise recommendations to NASA's Gateway Program on leveraging the lunar outpost for Mars and beyond. ... Read more

Current monitoring systems to detect sporadic E use ground-based setups, ionosondes, and the network of GNSS satellites in order to assess the phenomenon of sporadic E. This paper aims to monitor sporadic E using a miniature space-based platform in an atypical way. The setup consists of multiple radio-amateur beacon systems aboard satellites, each having a specific modulation and transmission scheme. This Radio Amateur Beacon System for the Investigation of the Ionosphere (RABSII) is coupled to a GNSS receiver, revealing the location of the platform. Multiple beacon data streams are sequentially sent from a satellite platform towards the Earth. By receiving and comparing the Signal-to-Noise ratios of these streams using a dedicated ground-based radio-amateur network of receiving stations, the presence of sporadic E can be determined, and a location-based model can be built. The advantage of this miniaturized, low-power, low-cost instrument is its ability to be put on any satellite platform in the future in order to map sporadic E. ... Read more

The 16U4SBSP mission concept is based on using a swarm of CubeSats to perform a scaled demonstration of SpaceBased Solar Power (SBSP) from Earth orbit. In this demonstration mission, seven identical spacecraft of 16U format are used to provide wireless energy in the kW-scale using Radio-Frequency (RF) Wireless Power Transfer (WPT), and the spacecraft in the swarm are designed to be suitable to both space-to-ground or space-to-space WPT applications. The main objective of the mission is to validate the general concept of providing SBSP using a swarm of satellites instead of a monolithic configuration, as well as some of the involved miniaturized technologies, in view of full-scale missions which could serve users in remote areas with low power requirements or support emergency operations in blackout zones affected by unpredicted hazards (e.g. natural disasters). More in general, the mission would represent a low-cost precursor towards MW-GW scale SBSP to supply clean and affordable energy from space to large areas on the Earth surface. A pre-Phase A study of the mission, funded by the European Space Agency (ESA) through the Sysnova campaign “Innovative Missions Concepts enabled by Swarms of CubeSats”, has led to encouraging results on the feasibility of the mission concept. This paper summarizes the main results of the 16U4SBSP pre-Phase A study, including the mission design and the possible way forward to the following steps in mission implementation (Phase A and later). A summary of the spacecraft system design and mission analysis is presented, as well as a short description of the mission CONOPS (concept of operations). Particular focus is given to the available options and objectives of the SBSP demonstration, and to the proposed solutions for RF power beaming, formation flying maintenance and end-of-life operations for compliance to the new ESA regulations on space debris mitigation. ... Read more

The 16U4SBSP mission concept is based on using a swarm of CubeSats to perform a scaled demonstration of Space-Based Solar Power (SBSP) from Earth orbit. In this demonstration mission, seven identical spacecraft of 16U format are used to provide wireless energy in the kW-scale using Radio-Frequency (RF) Wireless Power Transfer (WPT), and the spacecraft in the swarm are designed to be suitable to both space-to-ground or space-to-space WPT applications. The main objective of the mission is to validate the general concept of providing SBSP using a swarm of satellites instead of a monolithic configuration, as well as some of the involved miniaturized technologies, in view of full-scale missions which could serve users in remote areas with low power requirements or support emergency operations in blackout zones affected by unpredicted hazards (e.g. natural disasters). More in general, the mission would represent a low-cost precursor towards MW-GW scale SBSP to supply clean and affordable energy from space to large areas on the Earth surface. A pre-Phase A study of the mission, funded by the European Space Agency (ESA) through the Sysnova campaign “Innovative Missions Concepts enabled by Swarms of CubeSats”, has led to encouraging results on the feasibility of the mission concept.

This paper presents in detail the final outcome of the pre-Phase A design effort for the 16U4SBSP spacecraft. The trade-off studies conducted to select all sub-systems and components are presented and their final outcomes detailed and justified, together with the technical budgets and the main areas of attention for the spacecraft design. Particularly critical for the success of the mission are the choices related to: the power transmission payload (DC-RF converter, transmitting antenna and heat dissipation system); the ADCS subsystem and in particular the sensors required to provide sufficient accuracy in the knowledge of the 3-axis attitude (both absolute and relative to the other spacecraft in the swarm); the relative navigation system, based on inter-satellite link between the spacecraft in the swarm and on a beacon link to the receiving station on ground, for efficient beaming coordination; the main propulsion system for continuous formation flying control through the whole mission lifetime; the electric power system, based on orientable solar arrays by means of a SADA mechanism and a set of batteries with sufficient capacity for beaming the required amount of power while in eclipse conditions. ... Read more

The Da Vinci Satellite is a 2U CubeSatellite that is being developed with the goal to inspire and enthuse the youth to learn more about technology and space travel. The team at Delft University of Technology consists of over 80 Bachelor and Master students from disciplines such as Aerospace Engineering, Computer Science, Electrical Engineering and Applied Physics. There are also multiple Precision Engineers part of the team, that have joined from the Leiden Instrumenten Maker School (LIS) in the Netherlands. Through working on the satellite and educational modules, the multidisciplinary team focuses on demystifying space and making it a fun and engaging subject for children in primary schools and high schools. That is why the satellite harbours two novel custom-made payloads on board; the Dice Payload and the BitFlip Payload.

The Dice Payload consists of a small chamber with five small aluminium dice of different colours, which will be used by primary school children. In collaboration with the LIS, a special mechanism has been designed to ‘roll the dice’ in microgravity and clamp them such that a picture of the numbers can be taken with the Earth as a backdrop. After the design, manufacturing, and assembly of the parts, the payload underwent a series of tests. These tests have included multiple 0g flight tests and a vibration test. Through the extensive testing, there have been iterative design changes to improve the payload’s overall performance and design.

The second payload of the Da Vinci Satellite is the BitFlip Payload. This novel payload recently has been tested in a proton accelerator facility at the Paul Scherrer Institute. This subsystem is a stack of PCB’s with SRAM that has been designed for high school students. High school students can send a picture of themselves to the satellite where the data will be stored on the SRAMs. Because of the radiation environment in LEO and the susceptibility of the memory, bitflips will occur. These changes in the information from a 1 to a 0 (or the other way around), will result in the information of the picture being changed. When the picture has been compressed using a compression algorithm such as GIF, JPEG, or PNG interesting effects can occur. Once the student will receive the altered picture, they will be able to compare it with the original and learn about space, radiation, compression algorithms, and electronics. ... Read more

In recent years, the trend towards satellite miniaturization has led to a considerable rise in picosatellite missions in Low Earth Orbit (LEO). Due to their size, identifying and tracking small objects poses significant challenges. While the detectability of individual picosatellites has been proven, the potential implications of clusters flying in formation remain unexplored. Therefore, the Delft University of Technology is starting a pioneering mission involving multiple picosatellites to improve Space Situational Awareness (SSA) by demonstrating the capabilities and limits of both inspace and ground-based tracking means. This paper outlines a high-level mission analysis investigating the feasibility of this formation-flying mission: in the proposed model, the autonomy of each satellite is enhanced by integrating a Global Navigation Satellite System (GNSS) receiver, which enables independent orbital determination and facilitates the validation of satellite position data against other tracking systems. The mission concept involves deploying a cluster of two identical 3P PocketQubes, launched as a single spacecraft into a near-circular orbit. Following deployment, they will be separated using springs, considering factors such as relative velocity, direction, and angle to carefully study the release process. Additionally, their relative distance is controlled using differential drag, i.e. adjusting the satellite drag area by deploying solar panels at varying angles. Through the integrated use of STK and MATLAB, two mission control sequences are defined: the former, characterized by satellite propagation stopping conditions based solely on relative distance, and the latter, in which they are based on both relative distance and relative velocity. Their comparison reveals the latter as the most effective strategy: despite the challenge of controlling satellite distance during close passes (conjunctions), the optimal sequence prioritizes maximizing time in close proximity. This approach reduces the average relative velocity and minimizes the duration of the high drag configuration, resulting in a significant extension of the mission lifetime. The simulations, along with a power budget, support the definition of both mission and GNSS receiver payload requirements. Finally, a suitable candidate is selected from among miniaturized GNSS space receivers and tested through multiple hardware-in-the-loop simulations, using a GNSS signal simulator. These simulations aim at verifying the accuracy of receiver positioning measurements and assessing power consumption. The results of this paper represent the cornerstone of a disruptive mission, providing insights into the future development of satellite control optimization strategies to minimize collision risk. Furthermore, the remarkable payload test results, while reliable, underscore the need to improve testing systems to reduce position errors and achieve higher tracking accuracy for LEO picosatellites equipped with GNSS receivers. ... Read more

The 16U4SBSP mission aims to demonstrate Space-Based Solar Power (SBSP) using a CubeSat (CS) swarm from Earth orbit. This mission employs seven 16U CSs to deliver 1 kW-scale wireless energy via Radio-Frequency (RF) beaming, adaptable for space-to-ground and space-to-space applications. The goal is to validate SBSP provision using a satellite swarm and to explore miniaturized technologies for future large-scale missions. A pre-Phase 0 study funded by the European Space Agency (ESA) through the Sysnova campaign has shown encouraging feasibility results. This paper presents a study on the formation flying and orbital dynamics of a CS mission, using a model that includes Earth’s gravitational perturbations, solar radiation pressure (SRP), atmospheric drag, and lunar and solar gravity. The swarm configuration consists of seven CSs, with one at the center and six in a hexagonal arrangement. The Concept of Operations (CONOPS) is divided into three phases: deployment and acquisition, maintenance, and disposal. CSs are deployed at 30-second intervals, followed by a one-day Launch and Early Orbit Phase (LEOP) for subsystem checks. A 1000-meter formation is initially established, then reduced to 100 meters for the first half of the mission and 10 meters for the second half, maintained by a bang-bang limit-cycle controller. A disposal strategy compliant with ESA’s Space Debris Mitigation Requirements is outlined. The analysis characterizes propellant consumption at various altitudes, proposes optimal initial conditions and launch dates, and performs a trade-off analysis, resulting in a detailed mission characterization and baseline definition. The work presented in the paper proves the feasibility of the 16U4SBSP mission, which would supply clean energy from space through wireless power transfer. ... Read more

The Delft University of Technology has been working on Delfi–PQ, a 3P PocketQube developed by Aerospace Engineering students during their education. The satellite, while being only 50x50x178 mm and having a mass of 545 g, shares the same problems and requirements as larger satellites. Delfi–PQ was launched on January 13th, 2022, and stayed operational till it decayed on January 9th, 2024. This paper presents the design concept, development, and cost of Delfi–PQ to help other teams in their development. This paper will provide a detailed overview of the hardware cost of Delfi–PQ. This cost breakdown will be from multiple angles; system costs, components, structural pieces, and the cost of a specific function in a subsystem. Such a detailed breakdown can be used for future satellite cost modeling and create a foundation for other institutions for their satellite projects. ... Read more

This chapter provides an overview of the command and data handling system (CDHS) in small satellites and CubeSats. The chapter presents first analysis of radiation effects, specifically targeted at this subsystem, to justify components and architecture choices. Improvements in radiation testing strategies are also presented, specifically for small satellites. State-of-the-art components are then presented, providing an overview of the current market and the most common architectures. An overview of past and current missions is also presented, providing a clear mapping of the presented state-of-the-art components and architectures to guide future designs. High-level design considerations are also presented to help the reader follow some of the current trends in the sector. This chapter, overall, aims at presenting the most common approaches for the CDHS system and comparing this with traditional satellites, showing where the main differences lay with component selection and testing strategies being the fundamental points driving the architecture choices. ... Read more

The Da Vinci Satellite project is a non-profit initiative started at the Delft University of Technology to inspire and enthuse the youth to learn more about technology and space travel. The team does this by focussing on demystifying space and making it a fun and engaging subject. The non-profit student team is divided into different sub teams, two of which are the technical team and the educational team. The technical team has been building a 2U CubeSat with two payloads that have been designed to support educational packages for children from primary schools and high schools. The educational team works to make these educational modules available for schools all around the world such that children have the opportunity to interact directly with space via The Da Vinci Satellite. ... Read more

The last years saw the diffusion of nano, pico and femto satellite missions launched by multiple entities thanks to the launch cost reduction and the electronics miniaturization. Such missions usually present limited capabilities in terms of precise orbit determination and extremely small radar and optical cross-sections. Often these missions carry one or more laser retro-reflectors for precise orbit determination but precise orbital measurements cannot be found in the literature. Miniaturized GNSS receivers are also often carried out but due to the experimental nature of such missions, the reliability and time span of such measurements is limited, leaving radar tracking as the only reliable tracking method. Due to the size of such satellites, the signal-to-noise ratio of such radar measurements is typically low and satellite identification (when launched on ride-share launches with a hundred or more other satellites) proves difficult and time-consuming. Being these very small satellites at the edge of the radar detection capabilities and not providing independent orbit determination means, their position uncertainty could be quite significant, leading to an increased orbit collision perceived risk. With this paper, we present a dedicated small satellite formation, made by multiple nano and pico satellites to evaluate the space surveillance network tracking capabilities and limits. The formation is made by a 3U CubeSat to be deployed as part of a rideshare launch. The satellite would be equipped with multiple means to track it, including a GNSS receiver, a set of multiple laser retro-reflectors, and LEDs for optical, laser, and radar tracking, allowing to characterize also different detection means in terms of capabilities. Such a satellite is made of two independent smaller satellites that can be un-docked in orbit upon command, reducing the satellite size and cross-section. This would push the detection limit for the space surveillance networks starting from an already acquired object and with limited clutter around it. Independent laser and GNSS tracking would allow ground measurement validation and validate position estimations. Further pico-satellites would be deployed by each sub-satellite to further push the detection limits and validate up to which size objects are trackable (still optically, radar and GNSS), thanks to miniaturized GNSS receivers already flown by several other missions. Sub-satellite separation is implemented upon command to ensure the process can be followed and executed at lower altitudes to limit the orbital lifetime of eventually hard-to-track small objects that could worsen the space debris problem. Ground characterization (in terms of optical and radar properties) will be performed, also including polarimetric measurements used to identify the separate satellites. All these technologies together would contribute to creating a unique tool to estimate the tracking capabilities of multiple instruments, specifically tailored for very small objects, the hardest to track, as compared to other characterization activities performed on much bigger objects. ... Read more

The Delft University of Technology has been working on Delfi-PQ, a 3 P P ocketQube d eveloped b y Aerospace Engineering students during their education. The satellite, while being only 50x50x178 mm and having a mass of 545 g, shares the same problems and requirements of bigger satellites. This paper presents the design concept, development, and testing of Delfi-PQ to help other teams in their development. All the combined information will help to generate a big picture for institutions to start their own small satellite mission. ... Read more

PocketQubes are a form factor of highly miniaturized satellites with a body of one or more cubic units of 5 cm. In this paper, the characteristics of PocketQubes in terms of their constraints and their (potential) utility are treated. To avoid space debris and limit collision risk, the orbits of PocketQubes need to be constraint. An analysis of orbital decay characteristics has been carried out which, considering existing space regulations and a pro-active attitude, PocketQubes should preferably be launched in low Earth orbits below 400 km altitude. Due to technical constraints, such as form factor, power and attitude control, the domain of applications for single PocketQube missions is limited. Still, they can act as low-cost training and technology demonstration platforms. To make PocketQubes an attractive platform for other types of missions, not only the launch cost, but also the development, production and operations cost should be significantly lower than CubeSats. When the PocketQube platform matures and produced in high numbers, networks of PocketQubes can enable new applications. Applications considered feasible are in the field of (but not limited to) continuous surveillance using optical instruments, gravity field monitoring using precise orbit determination, in-situ measurements of the space environment, low data rate or bandwidth communication services and inexpensive probes around other celestial bodies. ... Read more

This paper presents the design, integration and testing of a pico satellite, Delfi-PQ, a 3P PocketQube developed by Delft University of Technology, expected to be launched at the end of 2020. The main goal of this project is creating a miniaturized platform for future space missions with performances comparable to CubeSats, taking advantage of the miniaturization of electronic components and their integration. Education of aerospace engineering students is a second key goal of the project, where students involved in the project as part of their curricular activities. ... Read more