VERTECS rode to orbit aboard H3 Launch Vehicle No. 6, the H3-30 test vehicle configuration, lifting off from the Japan Aerospace Exploration Agency’s Tanegashima Space Center at 9:53:59 a.m. Japan Standard Time on June 12, 2026. Once the launch vehicle delivered the nano-satellite into its designated orbit, the operations team established contact with the spacecraft through its designated ground stations, a critical first step that confirmed the separation sequence had unfolded as designed. From that moment, the commissioning schedule proceeded methodically. Engineers activated and validated the power subsystem in turn, then communications, then the attitude-control system that keeps the telescope steady against the gentle but relentless torques of orbital flight, followed by the data-processing chain and, finally, the observation instrument itself. Each stage of verification had to succeed before the next could begin, a discipline that protects a mission from masking one fault behind another.

The payoff of that patience came in the form of images. During initial operations the team commanded VERTECS to point at selected sky regions and capture exposures with its onboard visible-light camera, then downlinked the data for inspection. The results, released as multicolor composite images of the Cygnus Loop, the Lagoon Nebula, and the North America Nebula, showcase stars and glowing clouds of interstellar gas in striking detail. Beyond their aesthetic appeal, the images serve as hard engineering evidence: by pointing precisely at the intended coordinates and returning sharp frames, the satellite demonstrated the high-precision attitude-control performance that its scientific mission demands. Perhaps most striking is the efficiency. VERTECS obtained its crisp images with exposures of just one minute, whereas producing comparable images with ground-based telescopes would require hours of integration time, since Earth’s atmosphere blurs and absorbs incoming light in ways no spacecraft ever has to fight.

The scale of VERTECS’s view of the sky is what sets the mission apart. Its main camera covers a field of view of 3 degrees by 3 degrees in each wavelength band, meaning a single observation captures an area roughly 40 times the apparent area of the full Moon. Established space observatories such as the James Webb Space Telescope and the Euclid satellite, both optimized for different science goals, would require many individual pointings to tile an equivalent patch of sky. Wide-field capability is not a luxury for this mission; it is the entire point. Mapping the extragalactic background light requires summing enormous numbers of faint, unresolved sources, and a telescope that can swallow vast regions of sky in a single exposure can build the necessary map in a fraction of the observing time that narrower instruments would need.

To validate the instrument for that task, the team imaged the Boötes region, a patch of sky deliberately chosen because it contains no bright astronomical objects that could drown out the dim background signal the mission is hunting. Analysis of the resulting frame confirmed that VERTECS meets its specified spatial resolution and sensitivity requirements, matching the performance predicted during ground testing and simulation. As a final checkout exercise, the satellite’s secondary camera photographed Earth while the spacecraft communicated with an operational ground station. Because the antenna must remain pointed at the ground station during data downlinks, the Earth image doubles as proof that the attitude-control system held the spacecraft stable in a demanding operational posture, closing out the last open question about the satellite’s readiness.

With commissioning complete, the mission now pivots to its scientific heart. The extragalactic background radiation in visible wavelengths is the accumulated light of cosmic history, emitted by stars and galaxies across billions of years and stretched by the expansion of the universe. Some of that light comes from sources telescopes can individually resolve, but a portion is thought to originate from populations too faint or too diffuse to be catalogued, potentially including the first generations of stars that ended the cosmic dark ages. By measuring the total brightness and structure of this background with unprecedented coverage, VERTECS aims to constrain how the cosmic rate of star and galaxy formation evolved over time, effectively reading the energy ledger of star formation written across the entire sky.

Scientists involved in the project emphasized both the relief and the ambition that accompany the transition to routine operations. Kei Sano, an assistant professor in the Department of Space Systems Engineering at the Kyushu Institute of Technology, said the initial images mark an important first step, demonstrating that the satellite can achieve its specified observational performance in space, and that the team will now steadily accumulate and analyze observation data with the aim of producing new scientific results. Shuji Matsuura, professor of physics and astronomy at Kwansei Gakuin University, whose group led development of the observation instrument, noted that the on-orbit performance matches ground tests and simulations and said the team is deeply impressed by the beauty of astronomical images obtained with such a small telescope above the atmosphere. He added that the research group will use the expansive map of the universe built through long-term observations to take on the challenge of unraveling the mystery of the extragalactic background radiation.

Other institutional partners described the commissioning success as the culmination of years of distributed engineering effort. Takao Nakagawa, a specially appointed professor at Tokyo City University’s Advanced Research Laboratories, expressed satisfaction that the satellite is performing as expected and said his team will continue contributing to satellite operations, data reception, and analysis. Ichiro Jikuya, an associate professor at Kanazawa University who participated in introducing the attitude-control unit, said the establishment of high-precision attitude control enables the telescope to realize its full performance and marks a major milestone in the development of the satellite bus. Koji Takimoto, a project researcher at the University of Tokyo who coordinated the onboard observation instrument and developed the telescope, admitted the team remained anxious about whether the telescope would perform in orbit until the first image arrived, making the sharp early frames especially rewarding. Operations are conducted by members of the participating institutions, with observations planned to continue for a year.

The success of VERTECS carries significance well beyond its immediate science goals. Nano-satellites have traditionally been treated as platforms for technology demonstrations and student training, capable of modest engineering experiments but rarely competitive with flagship observatories. A nano-class spacecraft now certified to deliver science-grade wide-field imaging with minute-scale exposures that would consume entire nights on the ground suggests the class of vehicle can shoulder genuine astrophysical missions at a fraction of conventional cost. If the year-long survey delivers on its promise, the mission will not only chart the diffuse glow of cosmic star formation but also strengthen the case for fleets of small, specialized telescopes working in concert, an approach that could reshape how astronomy allocates its observing time in the decades ahead. For now, the team’s gratitude extends to the students, researchers, and engineers who carried the project from drawing board to orbit, and their attention has turned fully to the sky.

Subject of Research: A Japanese nano-satellite mission observing visible extragalactic background radiation to trace star and galaxy formation history

Article Title: Astronomical nano-satellite VERTECS completes initial operations and begins scientific observations

Article References: Astronomical nano-satellite VERTECS completes initial operations and begins scientific observations. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: VERTECS, nano-satellite, astronomy, extragalactic background radiation, Kyushu Institute of Technology, H3 launch vehicle, Tanegashima Space Center, visible-light telescope, star formation history, wide-field imaging, attitude control, space telescope

The problem the researchers set out to solve is genuinely hard. Their representative satellite, based on an established benchmark used in layout-optimization research, contains 53 movable equipment components modeled as cylinders and cuboids, distributed across four bearing surfaces on two structural decks, plus one fixed central exclusion region. Because each component’s vertical position is fixed by its mounting surface, the optimization must juggle 106 independent in-plane coordinates, all subject to 385 non-interference constraints that prevent any two objects from overlapping. On top of the geometry, the layout must satisfy attitude-control requirements: the center of gravity must sit within tight tolerances of its target, and the principal axes of inertia must stay closely aligned with the spacecraft’s body axes, because even small misalignments complicate the job of attitude-control thrusters and reaction wheels.

To search this vast, highly constrained space, the team turned to particle swarm optimization, an algorithm inspired by the way bird flocks and fish schools move collectively. In PSO, each candidate solution is a particle that flies through the design space, guided by its own best experience and the best solution found by the whole swarm. Standard PSO, however, has a well-known weakness: in complex, multimodal landscapes, the swarm can lose its diversity and converge prematurely on a mediocre local optimum. The researchers’ enhanced version, EPSO, counters this by applying Gaussian mutation to a small fraction of the swarm at every iteration, randomly nudging particles to new positions and re-evaluating their fitness. If a mutated particle improves, its personal best is updated, injecting fresh diversity without derailing convergence.

Getting the algorithm’s knobs right mattered. A sensitivity analysis over mutation rates from 0.02 to 0.10 showed that the lowest rate, 2 percent of particles per iteration, produced the smoothest and most stable convergence, while higher rates introduced oscillatory, erratic behavior. The team also employed a linearly decreasing inertia weight, moving the swarm from broad global exploration early on to fine local refinement later, along with velocity clamping, reflective boundary handling, and an initialization strategy that seeds the population with five elite layouts derived from a heuristic baseline and repairs any constraint violations before optimization begins.

The results were striking. Across six standard benchmark functions, including Schwefel, Rosenbrock, Rastrigin, Ackley, and Levy landscapes, EPSO consistently achieved lower objective values and far smaller standard deviations than standard PSO, in some cases reaching errors on the order of ten to the minus 160. On the real satellite problem, the team ran both algorithms 30 times under identical conditions and applied rigorous statistics, including Shapiro-Wilk normality tests and Mann-Whitney U tests. EPSO cut the average center-of-gravity deviation from 3.954 millimeters to 2.158 millimeters, a 45.4 percent improvement, reduced the normalized inertia index by 8.2 percent, and needed only about 134 iterations to converge versus roughly 172 for standard PSO, a 21.8 percent reduction. All differences were statistically significant at p below 0.001, with rank-biserial effect sizes approaching the maximum possible for center-of-gravity deviation and convergence speed.

What makes the work especially timely is its treatment of electromagnetic compatibility, an aspect of satellite design that earlier layout studies largely ignored. Cables and connectors are among the most critical pathways for electromagnetic interference aboard spacecraft: power lines, pyrotechnic firing circuits, radio-frequency links, and delicate sensor signals all share the same cramped volume. Prior research has shown that simply changing how cables are bundled can shift induced noise levels by as much as 40 decibels, so the configuration of wiring is not a detail to be left for the integration phase. The new framework makes EMC a quantitative player from the earliest design stages.

The researchers derived a physics-based penalty model from the fundamentals of near-field coupling between parallel wires, where mutual inductance and mutual capacitance both decrease as separation grows. Because an exact closed-form crosstalk expression would be too slow to evaluate across thousands of optimization iterations, they adopted an inverse-square distance weighting weighted by the electromagnetic sensitivity of each component, an engineering approximation that preserves the dominant physical trend. They then validated the model two ways: against analytical crosstalk calculations for representative component pairs, where relative errors stayed below 6 percent, and against full finite-element electromagnetic simulations in COMSOL Multiphysics. Across six layout configurations, spanning a baseline optimized layout to a worst case with sensitive components jammed against noise sources, the penalty model showed a strong linear correlation with simulated electric fields, with a Pearson coefficient of 0.92 and an R-squared of 0.85.

With the component layout frozen, the framework’s second stage routes 47 cable connections through the satellite using the A* pathfinding algorithm over a voxelized map of the interior. The routing space is discretized at 10-millimeter resolution into roughly 15,000 nodes, each classified as forbidden, constrained, or free. The step cost balances cable length, proximity to sensitive components, and bend penalties, since space-grade cables cannot be bent tighter than a 15-millimeter radius. Cables from incompatible EMC classes, such as power and pyrotechnic lines, must stay at least 30 millimeters apart. The optimal wiring design achieved zero EMC violations, a total wiring length of 11.16 meters, and 86 percent shielding effectiveness, exceeding the 85 percent target, all computed in under three seconds.

The authors are candid about the framework’s limits. The coupling between layout and routing is one-way: cable outcomes do not feed back to move components, component geometries are simplified, and the EMC model captures relative risk rather than full-wave phenomena like resonances or impedance mismatches. Full-wave simulation remains necessary for final verification. Still, as a tool for preliminary design, where engineers must rapidly explore how mass distribution, attitude control, wiring, and EMC interact, the framework fills a genuine gap, and the team points toward bidirectional layout-routing optimization and higher-fidelity electromagnetic modeling as the next frontier.

Beyond satellites, the approach could extend to any domain where dense electronics, tight spaces, and interference collide, from avionics packaging to modular system integration. In an era when constellations of hundreds of satellites are being built at unprecedented pace, algorithms that quietly solve the hidden puzzle of parts and wires may prove as consequential as the rockets that carry them.

Subject of Research: Satellite component layout optimization and EMC-aware 3D cable routing using enhanced particle swarm optimization

Article Title: A sequentially coordinated framework for satellite component layout and EMC-aware 3D cable routing using enhanced particle swarm optimization

Article References: A sequentially coordinated framework for satellite component layout and EMC-aware 3D cable routing using enhanced particle swarm optimization. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: satellite layout optimization, particle swarm optimization, electromagnetic compatibility, cable routing, spacecraft design, attitude control, A* algorithm, moment of inertia, Gaussian mutation, finite element simulation, wiring harness, Results in Engineering

The study, published in the International Journal of Aeronautical and Space Sciences, tackles a problem that has shadowed every membrane-based spacecraft concept since the earliest solar sail designs: the film itself deforms. When a sail twists under aerodynamic loading, its shape changes, and that change feeds back into the very torques that caused it. This coupling between torsional deformation and aerodynamic forces means that treating the sail as a rigid plate is not merely inaccurate, it can be fundamentally misleading. The research team, led by Shuiyuan Wu and Ming Xu with corresponding author Lincheng Li, built their analysis from the ground up, beginning with the physics of the film itself.

Their first step was to apply classical elasticity theory to calculate the torsional deformation of the thin membrane. Rather than stopping at an idealized analytical solution, the team cross-checked their results against a finite element simulation built on solid-shell elements, a numerical approach capable of capturing the behavior of structures that are thin in one dimension but extended in the other two. This dual verification matters because the deformation field directly determines how air molecules strike the surface, and therefore how much torque the sail experiences. An error of even a few degrees in the local surface inclination can shift the aerodynamic torque distribution across the entire membrane.

To translate the deformed geometry into forces, the researchers turned to the Schaaf–Chambre model, a foundational framework from the study of rarefied gas flows. At the altitudes where atmospheric sails operate, the air is so thin that molecules almost never collide with one another before hitting the spacecraft; the flow is instead governed by individual molecule-surface interactions. In this free molecular regime, the momentum transferred to the sail depends on how molecules reflect off the film, characterized by normal and tangential accommodation coefficients, and on the local angle of incidence. By integrating these molecular momentum exchanges over the deformed sail surface, the team derived the torques acting about all three axes and assembled a complete three-axis attitude dynamics model of the flexible sail.

One of the study’s quieter but more consequential findings is that the torques involved are remarkably small, all on the order of newton-meters. That may sound like good news, and in terms of structural loading it is, but it presents a severe challenge for control engineers. Actuators must respond to disturbances that are tiny, nonlinear, and constantly shifting as the membrane flexes. A controller that reacts too aggressively wastes precious energy and can excite vibrations in the film; one that reacts too sluggishly lets the sail drift off its intended attitude. The team’s answer to this dilemma is a composite scheme that pairs a radial basis function neural network, or RBFNN, with sliding mode control, a robust technique long favored for spacecraft attitude regulation.

Sliding mode control works by driving the system’s state onto a predefined sliding surface and then holding it there, offering strong guarantees against bounded disturbances. Its weakness is that it must treat unknown nonlinearities as disturbances to be overpowered, which demands larger control effort and can induce chattering. The RBFNN changes that equation. Because a radial basis function network can approximate arbitrary nonlinear functions given enough nodes, it can learn the unknown terms in the sail’s dynamics, specifically the nonlinear functions the researchers label f1(x), f3(x), and f5(x), and compensate for them directly. The simulations show that the network tracks these nonlinear terms rapidly and efficiently, effectively handing the sliding mode controller a much cleaner problem to solve.

The payoff is striking. When the RBFNN–SMC composite controller was applied, the torque required about the z-axis, Mz, dropped by as much as 55.2 percent compared with sliding mode control alone. Just as importantly, the physical motion of the sail films themselves became gentler. The rotation angles of the film segments, denoted β2, β3, and β4 in the study, were notably reduced under the hybrid scheme, with the motor rotation amplitude for β4 shrinking by 35.6 percent. For a membrane structure whose service life is limited by flexing, folding, and fatigue, smaller rotation angles translate directly into longer operational lifetimes. The researchers summarize this with an accumulated energy index, which came out lower under the composite controller, confirming that the neural network approach reduces total energy consumption rather than merely shifting it elsewhere in the system.

The implications extend well beyond a single simulation study. Atmospheric sails sit at the intersection of several pressing trends in space technology. Satellites destined for very low Earth orbit, where they can image the planet at higher resolution or serve as drag-based formation flyers, must constantly fight atmospheric drag, and sails offer a way to harness rather than resist it. Distributed drag sails have already been proposed for transverse satellite formation flying, and atmosphere-breathing electric propulsion concepts rely on the same rarefied flow physics that the Schaaf–Chambre model describes. Every one of these applications needs attitude control that is both precise and frugal, because small satellites cannot carry generous power budgets or oversized reaction hardware. A control scheme that cuts torque demand by more than half could be the difference between a feasible mission concept and an impractical one.

The study also contributes to a broader effort to model sail deformation rigorously. Previous work has examined the structural response of large solar sails during attitude maneuvers, analyzed wrinkling of solar-photon sails, and used point cloud methods to characterize sail deformation. What distinguishes the new research is its end-to-end treatment: the deformation is computed analytically, verified numerically, fed into a free molecular flow model to produce torques, and then closed into a full attitude dynamics loop where the controller must cope with the coupled torsional-aerodynamic effects. This chain matters because the coupling is precisely what makes deformable sails hard to control. A film that twists changes its own aerodynamic loading, which changes the torque, which changes the twist again. A controller blind to this loop would either fight it wastefully or be destabilized by it.

For now, the results come from simulation, and the transition to flight hardware will demand further validation, including how the neural network performs under model uncertainties, thermal-induced membrane vibrations, and the messy realities of actuator saturation. But the direction is clear. As membranes grow larger and spacecraft grow smaller, the era of treating flexible structures as rigid bodies is ending. Machine learning is increasingly finding its way into spacecraft control, from fault-tolerant attitude tracking with neural estimators to adaptive neural sliding controllers for rotorcraft and hypersonic vehicles. This study adds a compelling data point to that trend, showing that a well-trained network can shoulder the nonlinear burden of a flexing sail and leave the robust core of the controller free to do its job with a fraction of the effort. If atmospheric sails are to sweep through the thin air of low orbit in the years ahead, they may well do so with a neural network quietly trimming their course, saving energy with every gentle turn of the film.

Subject of Research: Energy-efficient neural network attitude control of deformable atmospheric sails under coupled torsional and aerodynamic effects

Article Title: Energy-Efficient RBFNN-SMC Attitude Control of Deformable Atmospheric Sail Under Coupled Torsional-Aerodynamic Effects

Article References: Wu, S., Xu, M., Li, L., Wang, H., & Meng, D. (2026). Energy-Efficient RBFNN-SMC Attitude Control of Deformable Atmospheric Sail Under Coupled Torsional-Aerodynamic Effects. International Journal of Aeronautical and Space Sciences. https://doi.org/10.1007/s42405-026-01241-4

Image Credits: AI Generated

DOI: 10.1007/s42405-026-01241-4

Keywords: atmospheric sail, attitude control, RBF neural network, sliding mode control, torsional deformation, free molecular flow, very low Earth orbit, spacecraft dynamics, membrane structures, energy efficiency, aerodynamic torque, flexible spacecraft

Writing in the open-access journal HardwareX, Bas Stijnen, Joseph Thompson, Ryan Paetzold, Eoghan Somers, and David McKeown present a fully open-source, camera-based trifilar pendulum system designed to measure the mass moment of inertia of CubeSat-class objects with impressive accuracy. The complete hardware and software package, from 3D-printed platform tiles to Python analysis code, is released under permissive licenses including CERN-OHL, CC-BY-4.0, and the MIT License, and the total cost ranges from roughly 55 euros for the bare pendulum platform to about 550 euros for a full setup with support frame and camera. The system has even earned open-source hardware certification under OSHWA UID IE000005, a formal stamp of reproducibility that few laboratory instruments can claim.

The trifilar pendulum itself is a beautifully simple piece of physics. A platform is hung from three equal-length wires and given a gentle twist. Because the platform’s centre of mass sits directly beneath the suspension point, it oscillates about the vertical axis with a period that depends on its rotational inertia, its mass, the suspension radius, and the length of the wires. The classical relation, derived under the assumptions of small-angle motion, rigid bodies, and negligible friction, links the measured oscillation period directly to the moment of inertia. What has traditionally made such setups expensive is not the pendulum but the instrumentation: precision rotary encoders or inertial sensors must be physically attached to the oscillating platform, adding mass, friction, and damping that corrupt the very quantity being measured.

The Dublin team’s key innovation is to remove contact entirely. Instead of sensors, they print two paper fiducial markers and tape them to the underside of the platform. These are not ordinary targets but N-fold markers, one with four-fold and one with five-fold rotational symmetry, selected using the MarkerLocator framework. The coprime symmetry orders allow the image-processing software to distinguish the two markers unambiguously and estimate rotational pose reliably from a single camera, even as the platform twists back and forth. A webcam or action camera mounted below the platform records the oscillation, and open-source Python software built on OpenCV, NumPy, and PyQt6 extracts the oscillation period, applies the trifilar equation, and reports the moment of inertia in kilogram metres squared, complete with an estimated measurement error.

The platform itself is assembled from nine triangular 3D-printed PLA tiles joined with brass threaded inserts and M4 screws, forming an equilateral triangular footprint roughly 407 millimetres on a side. The validated configuration handles test articles up to approximately two kilograms, a limit set not by the suspension hardware but by the stiffness of the printed platform, which can flex under concentrated loads and alter the effective suspension geometry. An optional support frame built from aluminium extrusion holds the pendulum and mounts the camera, making the system portable enough for ISO 8 CubeSat assembly cleanrooms, though the team found that suspending the platform directly from a rigid ceiling generally yields better results.

Validation was thorough and revealing. Using calibration masses with analytically known inertias, the researchers tested nine different moment of inertia values spanning from 0.15 to 6.1 times ten to the minus three kilogram metres squared, repeating every measurement five times. The results fell into three clear regimes. For inertias above three times ten to the minus three kilogram metres squared, errors stayed below five percent regardless of camera choice. In the intermediate range, errors ranged between five and fifteen percent, still acceptable for CubeSat characterisation. Below ten to the minus three, accuracy degraded sharply, sometimes exceeding forty percent with the support frame, because the inertia of the object becomes small compared with that of the platform itself, and the final answer emerges from subtracting two large, similar numbers.

Two practical findings stand out for anyone planning to build the system. First, the suspension material matters more than one might expect. Replacing steel cables with braided Dyneema fishing line, chosen for its negligible mass and bending stiffness, cut measurement errors dramatically, bringing even the lowest-inertia test case down to about 6.6 percent error. Second, camera quality matters mainly at the low end: a GoPro Hero 7 Black at fifty frames per second outperformed a basic Logitech C270 webcam by roughly ten percent for small inertias, thanks to better tracking resolution, while the two cameras performed nearly identically for larger objects. Camera distance, between fifteen and thirty centimetres below the platform, proved almost irrelevant, though the GoPro’s wide-angle fish-eye distortion introduced slight errors when markers drifted toward the frame edges.

The software also tackles a common experimental headache: imperfect centring. The trifilar equation assumes the test object’s centre of mass sits exactly over the platform centre, but real satellites are rarely so cooperative. The team implemented an optional correction based on the parallel axis theorem, subtracting the term mass times offset squared from the measured value. Verification tests with calibration masses displaced by five to twenty millimetres showed the software’s corrections matched theoretical predictions to within one part in a million of a kilogram metre squared. A free-decay experiment further confirmed that damping is negligible: the logarithmic decrement of 0.0162 corresponds to a damping ratio of just 0.00257, and the oscillation period shifted by only 0.38 percent over fifty seconds of decay.

The most convincing demonstration came with a representative CubeSat mock-up, an aluminium frame carrying four PCB-based solar panel simulators and integrated calibration masses. The pendulum measured a moment of inertia of 6.738 times ten to the minus three kilogram metres squared, within 3.7 percent of the CAD prediction of 6.996. The small discrepancy was attributed to exactly the kinds of details that make experimental measurement valuable in the first place: tape, fasteners, T-slot hardware, and assembly tolerances that no model captures perfectly. For university CubeSat programmes and small research groups, the message is clear. With a desktop 3D printer, a webcam, a kitchen scale, and freely downloadable design files and software, laboratory-grade mass property measurement is now within reach of virtually any team, and the era of guessing a satellite’s inertia may finally be drawing to a close.

Subject of Research: An open-source camera-based trifilar pendulum for measuring the mass moment of inertia of small satellites

Article Title: An open-source camera-based trifilar pendulum setup for measuring mass moment of inertia of small satellites

Article References: Stijnen, B., Thompson, J., Paetzold, R., Somers, E., & McKeown, D. (2026). An open-source camera-based trifilar pendulum setup for measuring mass moment of inertia of small satellites. HardwareX, Article e00821. https://doi.org/10.1016/j.ohx.2026.e00821

Image Credits: AI Generated

DOI: 10.1016/j.ohx.2026.e00821

Keywords: mass moment of inertia, trifilar pendulum, CubeSats, open-source hardware, fiducial markers, optical tracking, 3D printing, attitude control, small satellites, PocketQubes, HardwareX, low-cost instrumentation