Payload Bay Research Articles

Hydrodynamic Analysis of Payload Bay Berthing for Underwater Vehicles

Hydrodynamic Analysis of Payload Bay Berthing for Underwater Vehicles

Research on Moulding Technology of Composite Payload Bay Frame

This paper describes a large-size grid closed cavity composite payload bay frame moulding technology, focusing on the process research of the moulding process scheme, mould design scheme and layering curing mode. The research shows that: the moulding of large-size grid closed cavity composite frame can be realized by layering the layer of each unit separately and integral co-curing. Through the process research, the key technology of integral autoclave curing and individual silicon rubber pressurization has been broken through to meet the requirements of even and stable pressure at all positions in the of moulding process of composite products. The residual internal stress can be effectively removed after several cycles’ temperature variation, and then the dimensional accuracy of the frame tends to be stable in a specific temperature range. The vertical bar position deviates from 0.3mm-0.8mm, and the deviation of the frame’s thickness is ±2%. The overall flatness of the plane where the installation interfaces of all key equipment are located is better than 0.2mm. The testing shows that the mechanical properties of the specimen are better than the design index, meeting the user's requirements

Autonomous Mars Rover Design using SOLIDWORKS and User Interface development via Internet of Things

Abstract: In this paper, an autonomous Mars Rover is designed using the software SOLIDWORKS and a mechanical model is developed with in-depth simulations to analyse the functions of the vehicle. Furthermore, a graphical user interface is also developed based on the principles of Internet of Things using Node-Red to control and monitor the rover remotely. The red planet, i.e.; Mars, has been the centre of attraction for over 2 decades now, with astrophysicists and engineers working in unison to build devices and launch shuttle programs to understand and learn about the planet and gather more intelligence. This paper proposes the detailed development of a 6-wheeled rover that could explore the terrains of Mars, featuring a stereo vision system that could provide live video coverage and a robotic arm that can facilitate investigation of the surface, in an attempt to contribute to and fulfil the human race’s mission to Mars. It employs multiple onboard sensors that can acquire necessary data pertaining to the environmental conditions and actuators that enable functionality, with the sensors and actuators integrated onto a control system based on microcontrollers and microprocessors such as Arduino and Raspberry Pi. The rover also has a provision of a payload bay in its rear which enables it to carry loads. The SOLIDWORKS tool from Dassault systèmes is used to design and model the rover and carry out static analysis and motion studies. The GUI developed in the further sections allows overall voice control for the user and makes the task of monitoring the rover a much simpler task by eliminating the complexity that rises due to multiple control platforms. Keywords: Mars Rover, Graphical User Interface (GUI), Chassis, Mastcam, Actuators, Internet of Things (IoT), Nitinol, Payload

Icarus: In-situ monitoring of the surface degradation on a near-Sun asteroid

Icarus is a mission concept designed to record the activity of an asteroid during a close encounter with the Sun. The primary science goal of the mission is to unravel the nontrivial mechanism(s) that destroy asteroids on orbits with small perihelion distances. Understanding the destruction mechanism(s) allows us to constrain the bulk composition and interior structure of asteroids in general. The Icarus mission does not only aim to achieve its science goals but also functions as a technical demonstration of what a low-cost space mission can do. The proposed space segment will include a single spacecraft capable of surviving and operating in the harsh environment near the Sun. The spacecraft design relies on the heritage of missions such as Rosetta, MESSENGER, Parker Solar Probe, BepiColombo, and Solar Orbiter. The spacecraft will rendezvous with an asteroid during its perihelion passage and records the changes taking place on the asteroid’s surface. The primary scientific payload has to be capable of imaging the asteroid’s surface in high resolution using visual and near-infrared channels as well as collecting and analyzing particles that are ejected from the asteroid. The payload bay also allows for additional payloads relating to, for example, solar research. The Icarus spacecraft and the planned payloads have high technology readiness levels and the mission is aimed to fit the programmatic and cost constraints of the F1 mission (Comet Interceptor) by the European Space Agency. Considering the challenging nature of the Icarus trajectory and the fact that the next F-class mission opportunity (F2) is yet to be announced, we conclude that Icarus is feasible as an F-class mission when certain constraints such as a suitable launch configuration are met. A larger mission class, such as the M class by the European Space Agency, would be feasible in all circumstances.

Investigation of material response to atmospheric re-entry exposure of sub-structural Ti-6Al-4V components recovered from Space Shuttle Columbia

Aluminum and titanium char-layer deposits discovered on overhead windows recovered from the Space Shuttle Columbia accident revealed unexpected material response. It was observed that titanium melted and deposited before aluminum: behavior inconsistent with their relative melting temperatures. In close proximity to the windows, payload bay door (PLBD) latch rollers, containing Ti-6Al-4V, exhibited significant thermal damage that could not be explained by re-entry heating alone. The roller was considered a likely source of the deposition as damage was localized to the titanium region and the component was evaluated to identify features of ignition and/or combustion. A second examination was conducted on arc-jet samples obtained from a previous work that studied Ti-6Al-4V combustibility in a simulated re-entry environment. The samples were compared to the analysis of the PLBD roller and both exhibited features suggestive of titanium combustion. The PLBD roller possessed microstructural similarities to the arc-jet specimens that reacted more aggressively to the simulated environment.

The vertical variability of black carbon observed in the atmospheric boundary layer during DACCIWA

Abstract. This study underlines the important role of the transported black carbon (BC) mass concentration in the West African monsoon (WAM) area. BC was measured with a micro-aethalometer integrated in the payload bay of the unmanned research aircraft ALADINA (Application of Light-weight Aircraft for Detecting IN situ Aerosol). As part of the DACCIWA (Dynamics–Aerosol–Chemistry–Cloud Interactions in West Africa) project, 53 measurement flights were carried out at Savè, Benin, on 2–16 July 2016. A high variability of BC (1.79 to 2.42±0.31 µg m−3) was calculated along 155 vertical profiles that were performed below cloud base in the atmospheric boundary layer (ABL). In contrast to initial expectations of primary emissions, the vertical distribution of BC was mainly influenced by the stratification of the ABL during the WAM season. The article focuses on an event (14 and 15 July 2016) which showed distinct layers of BC in the lowermost 900 m above ground level (a.g.l.). Low concentrations of NOx and CO were sampled at the Savè supersite near the aircraft measurements and suggested a marginal impact of local sources during the case study. The lack of primary BC emissions was verified by a comparison of the measured BC with the model COSMO-ART (Consortium for Small-scale Modelling–Aerosols and Reactive Trace gases) that was applied for the field campaign period. The modelled vertical profiles of BC led to the assumption that the measured BC was already altered, as the size was mainly dominated by the accumulation mode. Further, calculated vertical transects of wind speed and BC presume that the observed BC layer was transported from the south with maritime inflow but was mixed vertically after the onset of a nocturnal low-level jet at the measurement site. This report contributes to the scope of DACCIWA by linking airborne BC data with ground observations and a model, and it illustrates the importance of a more profound understanding of the interaction between BC and the ABL in the WAM region.

Design And Development of Man Portable Back Packable Multi-Purpose Drone

This report mainly presents the concepts, design and analysis of a ‘Man Portable Back Packable Multi Purpose Drone (MPBPMD)’ which has many applications in different areas for different operations. The technology employed in the design of this ‘MPBPMPD’ is adapted from the mechanism of tilt rotor, which can be fabricated as rotor MAV, similar to helicopters and hovercrafts. The main objective of this aircraft design is to provide payload bay which can be installed with multiple payloads like a camera which can be used for surveillance or a speaker to control the animals in the reserved forest, etc. The MPBPMPD will be equipped with Auto pilot for a better operational control and navigation of the aircraft even at the places with less Launch distance using its VTOL capability. The wing attach/detach mechanism technique is also used to provide the aircraft with better portability. The complete aircraft should fit in a backpack, so that the complete model can be carried easily for better portability.

Conceptualization and Prototyping of Unmanned Amphibious Aerial Vehicle for Water Quality Assessment

Unmanned Amphibious Aerial Vehicles (UAAV) are gaining significant interest in accessing remote water bodies and an ideal tool for limnologist in water quality assessment. In this article, conceptualization of UAAV by inculcating the principle of hovercraft and multirotor system is carried out in a systematic approach. The unconventional configuration of UAAV makes the conceptual stage as a challenging task in the design process. In order to overcome the challenges and strapped configuration of vehicle design, the authors exploited the design process, Thirteen conceptual models are evolved and the best UAAV design model is selected based on stability, provision for accommodating payload, endurance, air cushioning effect for effective gliding along the water bodies, payload carrying capacity and modularity in construction. In addition, design of payload bay, selection of material, estimation of endurance and center of gravity calculations are carried out for those designs. The finalized conceptual models are constructed and performance of amphibious vehicles is investigated for varying the payload. The conglomerate designs of UAAV are evaluated for the design requirements and the computational fluid dynamic (CFD) analysis is performed to measure its performance characteristics. The experimental prototype of UAAV is custom built to demonstrate the competency of UAAV through flying in air and hovering in water. The test results suggested that, the developed UAAV has tremendous impact on minimizing the efforts of human being in inspecting remote water bodies in proficient way.

Flexible Firepower Moves Closer

Tests on payload bays that will adapt to carry different weapons systems

The MetNet vehicle: a lander to deploy environmental stations for local and global investigations of Mars

Abstract. Investigations of global and related local phenomena on Mars such as atmospheric circulation patterns, boundary layer phenomena, water, dust and climatological cycles and investigations of the planetary interior would benefit from simultaneous, distributed in situ measurements. Practically, such an observation network would require low-mass landers, with a high packing density, so a large number of landers could be delivered to Mars with the minimum number of launchers.The Mars Network Lander (MetNet Lander; MNL), a small semi-hard lander/penetrator design with a payload mass fraction of approximately 17 %, has been developed, tested and prototyped. The MNL features an innovative Entry, Descent and Landing System (EDLS) that is based on inflatable structures. The EDLS is capable of decelerating the lander from interplanetary transfer trajectories down to a surface impact speed of 50–70 m s−1 with a deceleration of < 500 g for < 20 ms. The total mass of the prototype design is ≈ 24 kg, with ≈ 4 kg of mass available for the payload.The EDLS is designed to orient the penetrator for a vertical impact. As the payload bay will be embedded in the surface materials, the bay's temperature excursions will be much less than if it were fully exposed on the Martian surface, allowing a reduction in the amount of thermal insulation and savings on mass.The MNL is well suited for delivering meteorological and atmospheric instruments to the Martian surface. The payload concept also enables the use of other environmental instruments. The small size and low mass of a MNL makes it ideally suited for piggy-backing on larger spacecraft. MNLs are designed primarily for use as surface networks but could also be used as pathfinders for high-value landed missions.

Shuttle MMOD Impact Database

The Shuttle Hypervelocity Impact Database documents damage features on each Orbiter from micrometeoroids (MM) and orbital debris (OD). Data is divided into tables for crew module windows, payload bay door radiators and thermal protection systems along with other miscellaneous regions. The database contains nearly 3000 records, with each providing impact feature dimensions, location on the vehicle and relevant mission information. Additional detail on the type and size of particle that produced the damage site is provided when sampling data and definitive spectroscopic analysis results are available. Relationships assumed when converting from observed feature sizes in different shuttle materials to particle sizes will be presented.

An Innovative Short Arm Centrifuge for Future Studies on the Effects of Artificial Gravity on the Human Body

In July 2013, the German Aerospace Center (DLR) in Cologne, Germany, commissioned its new medical research facility :envihab. One central element of the facility is a new type of short radius centrifuge called DLR-SAHC 1 (formerly known as :enviFuge), which has been developed in collaboration with AMST Systemtechnik GmbH, Ranshofen, Austria. The shift of subjects above heart-level on a short arm centrifuge allows unique studies on, e.g., the cardiovascular regulation in surroundings with a high gradient of artificial gravity. Equipped with the capacity to move the four nacelles along the acceleration axis simultaneously and independently from each other, the centrifuge allows the possibility to perform up to four complex trials in parallel. The maximal acceleration is 6 g at the foot level and each nacelle can accomodate an up to 150kg payload. Additional equipment can be mounted on two payload bays with a capacity of 100kg each. Standard features of the centrifuge include a motion capturing system with six cameras and two triaxial force plates to study the kinematics of physical exercise (e.g., squatting, jumping or vibration training) under increased gravity. Future projects involving SAHC 1 will allow the development and testing of potential countermeasures and training methods against the negative effects of weightlessness in space on human physiology. Due to the centrifuge’s capability to hold heavy equipment, carrying out a variety of non-human life science experiments requiring complex and heavy hardware is also fully feasible.

Modeling of the Acoustic Response of Payload Bays Within Launch Vehicle Fairings

Acoustic shielding treatments are necessary to prevent damage to the payload during launch. This paper discusses three modeling approaches used to analyze the efficacy of such treatments. Results from acoustic modeling studies based on an analytical model, a finite element model, and experimental testing are presented here. Payload bay pressure distributions and frequency response functions are developed using simple two-dimensional scale models. The two-dimensional finite element models demonstrate good agreement with analytical and experimental results and show the potential for three-dimensional full-scale finite element modeling to handle more complex acoustic load conditions.

Eos is out of this world—literally

When the space shuttle Endeavour launched on its 25th and final flight, AGU member and astronaut Andrew J. Feustel took with him a special bit of cargo: an issue of Eos. The accompanying photograph with the image of Eos, taken on 23 May 2011, shows the 15 February issue of Eos floating in front of one of the International Space Station windows. Below and left of the issue is the wing of Endeavour; also visible is the radiator panel on the shuttle's payload bay door. The thin blue line to the right of the issue is Earth's atmosphere. The STS‐134 mission, the second to last space shuttle mission, launched on 16 May and returned to Earth on 1 June. It delivered the Alpha Magnetic Spectrometer (a particle physics experiment module) to the International Space Station along with two communications antennas, a high‐pressure gas tank, and parts for the two‐armed Special Purpose Dexterous Manipulator (Dextre) robot. The final shuttle mission, STS‐135, launched on 8 July.

Swarm Heuristic for Identifying Preferred Solutions in Surrogate-Based Multi-Objective Engineering Design

Exploring the entire Pareto frontier of high-fidelity multidisciplinary problems can be prohibitive due to the excessive number of expensive evaluations required. The use of surrogate models offers promise toward managing such problems, which are restricted by a computational budget. In this paper, the kriging-assisted user-preference multi-objective particle swarm heuristic is presented, in which less accurate but inexpensive surrogate models are used cooperatively with the precise but expensive objective functions to alleviate the computational burden. A userpreference module is integrated into the optimization framework, which guides the swarm toward preferred regions of the Pareto frontier, thereby focusing all computing effort on identifying only solutions of interest to the designer. While providing a logical criterion to prescreen candidates for precise evaluation, the additional guidance provided by user-preferences guarantees an accelerated convergence rate. To depict the proficiency of the proposed framework, a suite of test problems, including the multidisciplinary cross-sectional design of a semimonocoque fuselage enclosing a pressurized cabin and payload bay, is presented.Aparametric model is described that is capable of generating a broad range of double-lobe fuselage designs. The superiority of the kriging-assisted user-preference multi-objective particle swarm optimization algorithm over more traditional search methods to efficiently manage high-fidelity discontinuous design problems is highlighted.

The Shuttle Radar Topography Mission—A New Source of Near-Global Digital Elevation Data

The Shuttle Radar Topography Mission (SRTM) has generated a homogeneous near-global digital elevation model (DEM) of the Earth using single-pass radar interferometry. The crew of Space Shuttle Endeavour (STS-99) operated the modified dual-antenna synthetic aperture radar systems for 11 days in February 2000. SRTM acquired both C-band and X-band synthetic aperture radar data, collecting 3D data using a 60-metre mast extending from the shuttle payload bay, containing additional C-band and X-band receiver antennas.SRTM DEM data have a horizontal resolution of 1 arc second (30 m at the equator) and vertical resolution of 10 m (C-band radar). SRTM-1 (1 arc second) data are available for US territories only, with subsampled SRTM-3 (3 arc second) data provided for the rest of the world. The USGS is responsible for archiving the data, with 3 arc second data being made freely available on a continent-by-continent basis. All data processing was completed in July 2004. Comparison of SRTM DEM data with older GTOPO and altimetric DEMs shows a significant improvement in horizontal and/or vertical resolution, similar to that achieved by ASTER. The SRTM DEM data provide a useful new resource, especially in areas where limited topographic data are available.

Space Shuttle UHF communications performance evaluation

Computational investigations and experimental measurements were performed to evaluate the Space Shuttle UHF communication system performance for payload bay antenna at the proposed new location. To insure adequate communication coverage at relocated new location, the link margin for the Extravehicular Activity (EVA) astronauts and between Space Shuttle Orbiter and International Space Station (SSO-ISS) during rendezvous were analyzed. The multipath effects from the vehicle structures surrounding the antenna were investigated. The Radio Frequency (RF) electromagnetic radiation to the Orbiter Docking System (ODS) pyrotechnics was also analyzed to ensure the EMC/EMI compliances.

Multibody system model of a cargo airship to study the load exchange process

Projected cargo airships for the transport of large loads exceed the dimensions of existing aircrafts and gave rise to various technical problems. One important task in an airship mission is the loading and unloading of the heavy and spacious load from the payload bay of the airship.In order to study the dynamics of the load exchange process, mathematical models of the airship including the oscillating load frame are developed. The hull together with the load frame represent a multibody system. Crucial aspects contributing to the dynamics of the system are the floatation of the flying crane and nonlinear couplings between hull and load frame. Furthermore, added masses of the surrounding air are considered. Oscillations of the load frame are excited by wind loads, airship maneuvers and winding up the cables.

Vibro-acoustic noise control treatments for payload bays of launch vehicles: Discrete to fuzzy solutions

Sound transmitted through an enclosing structure into a cavity has been minimised by optimising the locations, numbers and properties of tuned mass dampers placed on the structure and Helmholtz resonators placed in the cavity. Most of the results presented in the literature show the effect of a few well selected acoustic or vibration absorbers on simple vibro-acoustic systems, whereas the results presented here indicate the trends that occur when a few absorbers are replaced by a large number. The results indicate that for low numbers of absorbers, the result of the optimal configuration is to reduce the response of discrete modes, and for a large number of absorbers the result of the optimal configuration is a tendency for the vibro-acoustic energy to be smeared over a range of frequencies, which is similar to the results seen in fuzzy structures. The enormous computational task was achieved using a distributed computing network and an asynchronous parallel genetic algorithm.

A tool for the optimisation of vibro-acosutic systems using a parallel genetic algorithm and a distributed computing network

An asynchronous parallel genetic algorithm (GA) was used in conjunction with a distributed computing network to optimise the locations and parameters for combined Helmholtz resonators and tuned mass dampers, called passive vibro-acoustic devices (PVADs), placed on the walls of a composite cylinder model of the payload bay in a rocket used to launch satellites. The vibro-acoustic response was calculated using modal coupling theory with the modal response calculated using commercial finite element software. Binary and integer representations of the chromosomes in the genetic algorithm were used in the optimisation, and it was found that the integer representation converged twice as fast as the binary representation. Optimisations were conducted with a varying number of PVADs. The use of the distributed computing environment reduced the time taken to conduct the optimisation to 3 days compared to 75 days on a single desktop computer.