Flight Configuration Research Articles

Design of an epithermal neutron velocity selection system for the Penn State Breazeale Reactor

A series of mechanical neutron choppers to operate as a velocity selection system have been developed for the Pennsylvania State Breazeal Reactor (PSBR). This chopper system will provide pulsed epithermal neutrons in the energy range of 0.5–40 eV with 2% or better energy resolution, and with a transmission of 1E-6 or better. Four different chopper geometries have been evaluated for their utility as mechanical neutron choppers. Specifically, Fermi, ring, piston, and disc choppers have been evaluated to assess their potential neutronics performance and mechanical constructability. A series of high-speed disc choppers were selected for the final design, and optimization work was performed to maximize the neutron pulse intensity. It is estimated that the optimized system will produce an epithermal neutron intensity of approximately 96 n/s. This system can also be operated in a time of flight (TOF) configuration such that the neutrons arriving at the source have a white spectrum. This operation can be accomplished by leaving the second stage of choppers in the open position, or by removing it from the beam completely. Such unique source of epithermal neutrons produced by this chopper system will have applications in both prompt and delayed epithermal neutron activation analysis (ENAA), as well as in neutron resonance transmission analysis (NRTA).

Experimental Analysis of Rotor Blade Noise in Edgewise Turbulence

This paper presents an experimental investigation into the effects of turbulence ingestion on the aerodynamic noise characteristics of rotor blades in edgewise flight. A small-scaled, two-bladed rotor was used in the study. The test utilised two turbulence-generating grids, to generate turbulence inflows with different characteristics, and to compare them to the baseline configuration of the laminar inflow. The experiments were set at forwarding edgewise flight configuration, with freestream inflow velocity ranging from 10 m/s to 22 m/s. Simultaneous measurements of far-field acoustic pressure and load were conducted, along with a separate flow measurement using particle image velocimetry. The acoustic spectra demonstrated a larger contribution to the tonal noise radiation at blade passing frequency, and to the broadband noise radiation at the mid-frequency domain, due to turbulence ingestion. However, the broadband responses in the high-frequency domain were comparable between the tested laminar and turbulence inflow cases, with similar broadband humps featuring in the acoustic spectra. The directivity patterns of the overall sound pressure level showed that the noise radiation was lowest near the plane of rotation, and highest downstream. Turbulence ingestion effects could also be seen in the elevated noise levels throughout the observation positions for the grid inflow cases, particularly at larger advance ratios.

Aerodynamic Investigation of Blended Wing Body Configuration


 A blended wing body (BWB) configuration is an unconventional aircraft design in which the wing and fuselage are blended to form an aircraft. This design concept has inherent higher aerodynamic efficiency, environmental benefits and capacities. These advantages make the BWB configuration a feasible concept for commercial transport aircraft. In the present work, a 3-D BWB model is designed in SolidWorks and fabricated using a 3D printer. The numerical and experimental analyses are carried out with this BWB geometry. Aerodynamic characteristics and flow features obtained from the open-source CFD software OpenFOAM have been studied, analyzed, and compared with the wind tunnel results. Experimental and computational data compare well and the present BWB can operate at a high angle of attack. The coefficient of lift (CL) increases with AoA up to 45º. The CL starts decreasing beyond this AoA, and the present BWB geometry stalls at around AoA = 45º. The coefficient of drag (CD) increases with the increase in AoA due to the spreading of the separated region over the geometry. Lift/Drag (L/D) variation with AoA is also studied to find the optimum flight configuration of the present BWB geometry. Sectional pressure distribution at different spanwise locations, velocity contours, pathlines, surface limiting streamlines and tuft flow visualization are also presented to investigate the flow. The studies investigate the aerodynamics, flow field and optimal flight configuration for cruising a BWB geometry.

Comparison between Eulerian and Lagrangian methods to predict brownout clouds

In this work, brownout simulations using both Lagrangian and Eulerian frames of reference are presented. The work compares results between these two methods and with experimental results. The numerical models used for the carrier and dispersed phases are presented along with the obtained results. Then, follows a description of the simulations performed for brownout clouds around aircraft at different flight configurations. Different flight configurations involve several thrust coefficients, taxiing speeds and the presence of the fuselage. Finally, analyses have been conducted on the influence on the computational efficiency of Eulerian and Lagrangian approaches, and the two models are compared in terms of parallel efficiency. Results show that Eulerian model can be more affordable in terms of computational cost.

UAV Photogrammetry in Intertidal Mudflats: Accuracy, Efficiency, and Potential for Integration with Satellite Imagery

The rapid, up-to-date, cost-effective acquisition and tracking of intertidal topography are the fundamental basis for timely, high-priority protection and restoration of the intertidal zone. The low cost, ease of use, and flexible UAV-based photogrammetry have revolutionized the monitoring of intertidal zones. However, the capability of the RTK-assisted UAV photogrammetry without ground control points, the impact of flight configuration difference, the presence of surface water in low-lying intertidal areas on the photogrammetric accuracy, and the potential of UAV/satellite Synergy remain unknown. In this paper, we used an RTK-assisted UAV to assess the impact of the above-mentioned considerations quantitatively on photogrammetric results in the context of annual monitoring of the Chongming Dongtan Nature Reserve, China based on an optimal flight combination. The results suggested that (1) RTK-assisted UAVs can obtain high-accuracy topographic data with a vertical RMSE of 3.1 cm, without the need for ground control points. (2) The effect of flight altitude on topographic accuracy was most significant and also nonlinear. (3) The elevation obtained by UAV photogrammetry was overestimated by approximately 2.4 cm in the low-lying water-bearing regions. (4) The integration of UAV and satellite observations can increase the accuracy of satellite-based waterline methods by 51%. These quantitative results not only provide scientific insights and guidelines for the balance between accuracy and efficiency in utilizing UAV-based intertidal monitoring, but also demonstrate the great potential of combined UAV and satellite observations in identifying coastal erosion hotspots. This establishes high-priority protection mechanisms and promotes coastal restoration.

The REPEATABILITY OF AIRCRAFT VIBRATION AT THE INTERNATIONAL AIRPORT OF ALMATY

The movement of air particles is a very mobile medium, which is usually chaotic or turbulent in nature. Turbulence (translated from latin "turbo" means vortex) is a state of the atmosphere in which a vortex and wind can form horizontal and vertical cracks. The influence of atmospheric turbulence on the flight of the aircraft is manifested in sudden and unexpected changes in the horizontal flight configuration. A sharp and sudden change in flight mode due to the effect of turbulence is usually called a "vibration" or bump. Vibration depends on the physical state of the atmosphere, time of year, time of day, altitude of the terrain, its orographic features and meteorological conditions. In the article, work was carried out to identify the features of vibration propagation and its relationship with meteorological parameters at the airport of Almaty in the period from 2015 to 2019. As a result, it was showed that the maximum frequency of vibration at the considered standard levels of 960-110 hPa corresponds to the cold period of the year and occurs at the height of takeoff and landing. As for the connection between air temperature and vibration, it has found that vibration is most common in the temperature range from -4 ° C to 0 ° C. It was also revealed that the frequency of vibration most often coincides in cloudless conditions, i.e. the total number of cases is 439 (00 hours) and 609 (12 hours), respectively, the frequency is 61 and 84%. During the study of the relationship between vibration and clouds, it was recorded that vibration exists only with 3 different clouds, i.e. Ci, Ac and Sc. The results of the study can be widely used in the fields of civil aviation, military aviation.

Validation of three inherently different aircraft noise calculation programs

Aircraft noise affects large areas around airports. Noise calculation programs therefore need to account for air operations with high accuracy. In this contribution, we simulated several thousand single flights with the three aircraft noise calculation programs FLULA2, sonAIR and AEDT, and compared the results among each other and with corresponding noise measurements to evaluate their accuracy. While FLULA2 and sonAIR calculations are adjusted to local conditions, AEDT was run with default settings (NPD data and standard procedural profiles) to assess its performance when using unadjusted input data. We found that results of all three programs on average agree well with measurements and with each other. sonAIR is more accurate when using flight configuration data, but also in greater distances to the airports. Exemplarily adaptations of AEDT input data to local conditions showed that such adaptations clearly improve its calculation results. It was shown that, despite their inherently different modelling approaches, (a) all three programs are on average equally capable of reproducing the sound exposure in the vicinity of airports, (b) adaptions of input data to local conditions substantially improve results and (c) sonAIR is able to reproduce single flights with higher accuracy when provided with flight configuration data.

3D ray tracing solver for communication blackout analysis in atmospheric entry missions

During the atmospheric entry phase at hypersonic speed, the radio communication from/to a space vehicle can be disrupted due to the formation of a plasma sheath within the surrounding flow field. In order to characterize such communication blackout phases, this work presents a numerical methodology combining Computational Fluid Dynamic (CFD) simulations of ionized chemically reacting entry flows by means of Computational Object-Oriented Libraries for Fluid Dynamics (COOLFluiD) and a ray tracing analysis by means of the newly developed BlackOut RAy Tracer (BORAT). The latter is based on the numerical solution of the 3D Eikonal system of equations, offering a fast, efficient and accurate method to analyse the interaction between electromagnetic signals and weakly ionised plasmas. The proposed methodology, and BORAT in particular, is first verified on popular benchmark cases and then used to analyse the European Space Agency (ESA) 2016 ExoMars Schiaparelli entry flight into Martian environment. The corresponding results demonstrate the validity of the proposed ray tracing approach for predicting communication blackout, where signals emitted from the on-board antenna undergo reflection and refraction from the plasma surrounding the entry vehicle, and the advantage of a 3D approach for analysing real flight configuration.

Determination of main performance data of an aircraft threedimensional maneuver split-S with a permissible flight envelope limiter

Due to a steady extension of the flight envelope of modern agile combat aircraft, with the growing requirements for state tests, it is increasingly necessary to study the entire flight envelope and specifically, to determine the main performance data of individual maneuvers. Currently, state tests are based on a flight full-scale experiment, which is cost-ineffective in terms of cost, duration, and limit lines of the flight envelope. The accelerating trends to update state tests are semirealistic simulation and complex simulation modeling. The article presents the various techniques to determine main performance data of a three-dimensional maneuver split-S, which include the calculation method, semirealistic simulation, and simulation modeling. The calculation method is understood as calculation formulas expressed from the system of equations for motion of the aircraft mass center. Semirealistic simulation was carried out using a flight-simulation stand by operator pilots. Simulation modeling was conducted using a complex simulation model of an aircraft, consisting of a pilot’s control actions model based on fuzzy logic. The article provides the description, advantages and disadvantages, comparison of the results of each of the techniques. The calculation method, despite its efficiency, is the most inaccurate due to the complexity and inability to define the average flight parameters. Additionally, this method does not take into consideration such factors as the aircraft flight configuration, atmospheric disturbances, the pilot’s command profile, the logic of the permissible flight envelope limiter operation. The results of semirealistic simulation showed that this method is more accurate than the calculation one, but complex and time consuming in terms of the organization and execution of experiments. The analysis of the study illustrated that the most appropriate way to determine main performance data of split-S is simulation modeling on a complex simulation model of the aircraft, because the given method considerably saves financial and time resources used on state flight tests.

Design and performance of the camera of the Micro-channel X-ray Telescope on-board the SVOM mission

The Microchannel X-ray Telescope (MXT) is part of the scientific payload of the SVOM Sino-French space mission to observe the early afterglow of gamma-ray bursts in the 0.2–10 keV energy range and localize them within 2 arcmin. For a total mass of 42 kg and a total power of 60 W, this instrument is composed of an optical system, a structural carbon fiber tube, a radiator, a camera and a data processing unit. The camera consists of a focal plane assembly with a detector ceramic board and thermoelectric coolers, a front-end electronics, a calibration wheel and a support structure. Spectral characterization tests of the focal plane assembly based on a 256 × 256 pixel pnCCD spectroscopic imager were performed in the laboratory, at the Metrology beamline of the SOLEIL synchrotron and at the PANTER X-ray facility. Energy resolution of 79 eV FWHM at 1.5 keV was demonstrated in the nominal flight configuration (−65 °C, real time event selection by the camera). The paper presents the design, the realization and the performance of the flight camera of MXT. It focuses on the technical challenges, the original implemented solutions and the custom-made setups for the validation tests.

Using a Tandem Flight Configuration between Sentinel-6 and Jason-3 to Compare SAR and Conventional Altimeters in Sea Surface Signatures of Internal Solitary Waves

Satellite altimetry has been providing a continuous record of ocean measurements with numerous applications across the entire range of ocean sciences. A reference orbit has been used since 1992 with TOPEX/Poseidon, which was repeated in the Jason missions, and in the newly launched Sentinel-6 Michael Freilich (in November 2020) to continually monitor the trends of sea level rise and other properties of the sea surface. These multidecadal missions have evolved alongside major technological advances, whose measurements are unified into a single data record owing to continuous intercalibration and validation efforts. However, the new Sentinel-6 provides synthetic aperture radar (SAR) processing, which improves the along-track resolution of conventional altimeters from a few kilometres (e.g., for Jason-3) to about 300 m. This means a major leap in sampling towards higher frequencies of the ocean spectrum, which inevitably means reconciling the assumption of a uniform Brown surface between the footprints of the larger kilometre-scale conventional altimetry and those of the finer-scale SAR altimetry. To explore this issue, this study uses the vantage point of the Sentinel-6/Jason-3 tandem phase to compare simultaneous sea surface signatures of large-scale Internal Solitary Waves (ISWs) between SAR and conventional altimetry. These waves can modulate the sea surface into arrayed sections of increased and decreased roughness with horizontal scales up to 10 km, which inflict sharp transitions between increased and decreased backscatter in the radar altimeters. It is found that Sentinel-6 can provide more detailed structures of ISWs in standard level-2 products, when compared with those from the conventional Jason-3 (similarly to previous results reported from the SAR altimeter from Sentinel-3). However, a new and striking feature is found when comparing the radar backscatter between Sentinel-6 and Jason-3, which are in opposite phases in the ISWs. These intriguing results are discussed in light of the intrinsically different acquisition geometries of SAR and conventional altimeters as well as possible implications thereof.

Accuracy analysis of UAV photogrammetry using RGB and multispectral sensors

In recent years, unmanned aerial vehicles (UAVs) have become increasingly important as a tool for quickly collecting high-resolution (spatial and spectral) imagery of the Earth's surface. The final products are highly dependent on the choice of values for various parameters in flight planning, the type of sensors, and the processing of the data. In this paper ground control points (GCPs) were first measured using the Global Navigation Satellite System (GNSS) Real-Time Kinematic (RTK) method, and then due to the low height accuracy of the GNSS RTK method all points were measured using a detailed leveling method. This study aims to provide a basic assessment of quality, including four main aspects: (1) the difference between an RGB sensor and a five-band multispectral sensor on accuracy and the amount of data, (2) the impact of the number of GCPs on the accuracy of the final products, (3) the impact of different altitudes and cross flight strips, and (4) the accuracy analysis of multi-altitude models. The results suggest that the type of sensor, flight configuration, and GCP setup strongly affect the quality and quantity of the final product data while creating a multi-altitude model does not result in the expected quality of data. With its unique combination of sensors and parameters, the results and recommendations presented in this paper can assist professionals and researchers in their future work.

Investigation of the influence of engine displacement along the aircraft wing on the propagation of a condensation trail

With the publication of this article, the authors continue their research into the interaction of vortex and condensation trails behind aircraft, which has begun in the previously published articles in the Civil Aviation High Technologies of the Moscow State Technical University of Civil Aviation. This paper presents the investigation results of the influence of engine displacement along the A320 aircraft wing on the development and propagation of a contrail. It should be clear that a contrail is a product of aviation fuel combustion in the engine and represents condensed moisture in the form of ice crystals, which is formed under certain conditions of the atmosphere. As numerous studies and observations have shown, contrails can affect the heat exchange processes in the atmosphere and deteriorate the environment contributing to the greenhouse effect. This is especially true for the areas where numerous airways pass. It was noted that inboard engine displacement or, vice versa, outboard affects the development and propagation of a contrail. Therefore, when forming the aerodynamic configuration of the future aircraft, designers should take this aspect into account. The fact is that a wake vortex, which is formed behind the aircraft, impacts the contrail in different ways, depending on the engine proximity to the vortices, trailing from the airframe. Let us point out that a wake vortex is the area of the disturbed airflow behind the aircraft, generated as a result of its movement. A contrail, interacting with a vortex one, dissipates in the atmosphere, and the substances, composing a contrail, lose their concentration. It is also significant that a contrail, interacting with a wake vortex, can reveal its structure and visualize the wake vortex propagation and decay processes. In this paper, a special computational software application, based on the discrete vortex method, was used to study the influence of engine displacement along the A320 aircraft wing on the development and propagation of a contrail. When calculating the characteristics of a wake vortex, it takes into consideration the aircraft weight, speed and altitude, flight configuration, ambient conditions, axial velocity in the vortex core and some other factors. This complex passed the required testing and the state registration. A variety of activities was undertaken to validate and verify the developed complex, confirming the operability of its programs and the reliability of the results obtained. The results obtained allow us to understand how engine displacement along the A320 aircraft wing influences the contrail development and propagation.

Gull dynamic pitch stability is controlled by wing morphing

Birds perform astounding aerial maneuvers by actuating their shoulder, elbow, and wrist joints to morph their wing shape. This maneuverability is desirable for similar-sized uncrewed aerial vehicles (UAVs) and can be analyzed through the lens of dynamic flight stability. Quantifying avian dynamic stability is challenging as it is dictated by aerodynamics and inertia, which must both account for birds' complex and variable morphology. To date, avian dynamic stability across flight conditions remains largely unknown. Here, we fill this gap by quantifying how a gull can use wing morphing to adjust its longitudinal dynamic response. We found that it was necessary to adjust the shoulder angle to achieve trimmed flight and that most trimmed configurations were longitudinally stable except for configurations with high wrist angles. Our results showed that as flight speed increases, the gull could fold or sweep its wings backward to trim. Further, a trimmed gull can use its wing joints to control the frequencies and damping ratios of the longitudinal oscillatory modes. We found a more damped phugoid mode than similar-sized UAVs, possibly reducing speed sensitivity to perturbations, such as gusts. Although most configurations had controllable short-period flying qualities, the heavily damped phugoid mode indicates a sluggish response to control inputs, which may be overcome while maneuvering by morphing into an unstable flight configuration. Our study shows that gulls use their shoulder, wrist, and elbow joints to negotiate trade-offs in stability and control and points the way forward for designing UAVs with avian-like maneuverability.

Assessment and Prediction of Impact of Flight Configuration Factors on UAS-Based Photogrammetric Survey Accuracy

Recent advances in computer vision and camera-equipped unmanned aerial systems (UAS) for 3D modeling enable UAS-based photogrammetry surveys with high spatial-temporal resolutions. To generate consistent and high-quality 3D models using UASs, understanding how influence factors (i.e., flight height, image overlap, etc.) affect the 3D modeling accuracy and their levels of significance are important. However, there is little to no quantitative analysis that studies how these influence factors interact with and affect the accuracy when changing the values of the influence factors. Moreover, there is little to no research that assesses more than three influence factors. Therefore, to fill this gap, this paper aims to evaluate and predict the accuracy generated by different flight combinations. This paper presents a study that (1) assessed the significance levels of five influence factors (flight height, average image quality, image overlap, ground control point (GCP) quantity, and camera focal lengths), (2) investigated how they interact and impact 3D modeling accuracy using the multiple regression (MR) method, and (3) used the developed MR models for predicting horizontal and vertical accuracies. To build the MR model, 160 datasets were created from 40 flight missions collected at a site with a facility and open terrain. For validating the prediction model, five testing datasets were collected and used at a larger site with a complex building and open terrain. The results show that the findings of this study can be applied to surveyors’ better design flight configurations that result in the highest accuracies, given different site conditions and constraints. The results also provide a reasonable prediction of accuracy given different flight configurations.

Similarity Relations of PID Flight Control Parameters of Scaled-Model and Full-Size Aircraft

To carry out a scaled-model flight test of a high-gain aircraft with a proportional plus integral plus derivative (PID) flight control design, the similarity relations of the flight control law parameters of scaled-model and full-size aircraft must be systematically studied. In this article, the general similarity relations applicable to commonly used flight control law configurations and feedback signals are derived and analyzed. Based on the control principle, PID control parameters are divided into two types: feedback gains and series combined dynamic elements. The general similarity relations for the control parameters of these two types of elements are derived from system similarity theory. Finally, closed-loop flight control simulations of a fighter aircraft and its scaled model are completed. The simulation results show that the scaled-model and full-size aircraft with similar PID control law parameters are physically similar, validating the similarity relation conclusions proposed in this article.

An Experimental Study of the Aeroacoustic Properties of a Propeller in Energy Harvesting Configuration

The aim of the present manuscript is to investigate the noise footprint of an isolated propeller in different flight configurations for the propulsion of a hybrid-electric aircraft. Experimental tests were performed at the Low-Turbulence Tunnel located at Delft University of Technology with a powered propeller model and flush-mounted microphones in the tunnel floor. The propeller was investigated at different advance ratios in order to study the noise impact in propulsive and energy harvesting configurations. For brevity, this work only reports the results at the conditions of maximum efficiency in both propulsive and energy harvesting regimes, for a fixed blade pitch setting. Comparing these two configurations, a frequency-domain analysis reveals a significant modification in the nature of the noise source. In the propulsive configuration, most of the energy is related to the tonal noise component, as expected for an isolated propeller; however, in energy harvesting configuration, the broadband noise component increases significantly compared to the propulsive mode. A more detailed analysis requires separation of the two noise components and, for this purpose, an innovative decomposition strategy based on proper orthogonal decomposition (POD) has been defined. This novel technique shows promising results; both in the time and in the Fourier domains the two reconstructed components perfectly describe the original signal and no phase delays or other mathematical artifices are introduced. In this sense, it can represent a very powerful tool to identify noise sources and, at the same time, to define a proper control strategy aimed at noise mitigation.

Miniature ion analyzer for applications in space weather monitoring

This article presents the results of development and testing of a simple and compact ion energy-mass analyzer. PICA (Plasma Ion Compact Analyzer) is designed as a solution for solar wind measurements, polar proton precipitation monitoring and as a miniature solution for various space plasma experiments. We introduce general ideas that lead to the development of a simple and low-cost instrument and review several operating plasma instruments. After we address our previous results in modeling a possible scheme of the instrument and indicate improvements based on the results of previous research. We introduce the details of computer modeling of an improved for space application model, the results of prototype tests and flight configuration unit preformance. During the tests we checked the energy and mass resolutions of the laboratory prototype (ΔE/E = 4% M/ΔM = 4–8). All parameters were checked for the energy range of the upper boundary of 5 keV owing to the limitations of our equipment. The analytical characteristics of the instrument allow for distinguishing the fluxes of protons and alpha particles and monitoring the main parameters of the solar wind. The flight configuration of the instrument and can be placed on 3U CubeSATs.

Modeling of iced rotor dynamics via CFD/CSD coupling

Purpose The purpose of this paper is to advance the multiphysics analysis of helicopter rotors under icing conditions by coupling the iced rotor’s aerodynamics, analyzed by CFD, with the rotor’s structural characteristics, analyzed by CSD. Design/methodology/approach The current work introduces supercomputer-based computational approaches capable of assessing the impact of ice accretion on the aerodynamics, blade dynamics, vibrations and loading of a rotorcraft. The rigid and elastic motions of the blades are accounted for through a loose coupling of the flow solver to a multibody dynamics solver. The coupling framework allows for comprehensive aeroelastic simulations of iced rotors in hover and in forward flight. Findings The flow and structural modules were validated on a full helicopter configuration in forward flight using the ROBIN experimental model. The tip structural deflections were in very close agreement with the experimental measurements. Research limitations/implications The results of the CFD analyses are limited by the available experimental results they can be compared to. In dry air CFD, three-dimensional (3D) experiments occur first and CFD is then compared to them; in icing, the opposite is true: 3D experiments (if they are ever done, as they are very expensive) chase CFD and sometimes never occur. Practical implications This paper presents an outline of how CFD and computational stress dynamics (CSD) analyses can be linked and provides a toolbox for deeper investigation of the complex flows over helicopters operating under difficult in-flight icing conditions. Social implications More and more helicopters are designed to be able to operate in hostile environments such as rescuing and saving lives over the oceans or mountains, conditions under which icing encounters cannot be avoided. Originality/value A loosely coupled CFD/CSD framework that accounts for the rotor blades structural response to aerodynamic loading and ice accretion in hover and forward flight has been presented. This versatile and cost-effective framework provides a more accurate estimation of the helicopter rotor performance and its degradation due to icing encounters during the early design stages than traditional CFD tools.

Experimental Demonstration of Test Cap Design for Space Transponder Applications

Antenna test caps allow the testing of transmit and receive functionality of complete end-to-end radio frequency (RF) space systems in flight configuration outside anechoic environment. The test caps are made of two off-centered cylinders. The upper cylinder contains a probe, corresponding port, as well as a tuning screw. The lower cylinder contains absorbing material, the antenna under test. A full design and its experimental validation are demonstrated for a Martian X-band radio science payload.