Mechanical Design of Distributed Solar Sail Deployment Systems

2019 ◽  
Author(s):  
Ni Li ◽  
Salla Kim ◽  
Jason Lin ◽  
Benjamin De La Torre ◽  
Manhong Wong ◽  
...  
Keyword(s):  
Theoretical Analysis ◽  
Mechanical Design ◽  
Experimental Tests ◽  
Solar Sail ◽  
Space Travel ◽  
Coordinated Motion ◽  
Solar Sails ◽  
Solar Sailing ◽  
Future Space ◽  
Propulsion Force

Abstract Solar sailing has been increasingly considered for future space missions as an alternative method of propulsion, since it uses radiation pressure exerted by sunlight on a large mirrored surface for thrust and it does not require propellants such as chemicals or compressed gasses. For decades, single solar sail designs and deployment mechanisms have been studied and implemented in several CubeSats with the purpose of propulsion or deorbiting. Recently, a distributed four sail design has been proposed. The distributed four sails would have the potential to not only provide the spacecraft with propulsion force for space travel, but also control the attitude of the spacecraft by the coordinated motion of the four sails. Considering the large dimensions of the sails, it is necessary for the solar sails to be effectively stowed before launch and then deployed in a controlled manner in space. In this paper, the mechanical design of a deployment system that can stow and deploy four independent triangular solar sails with the ability to rotate after deployment will be presented. To demonstrate the effectiveness and the feasibility of the design, a prototype has been developed and validated through theoretical analysis and experimental tests.

Electron Exposure Measurements of Candidate Solar Sail Materials

2005 ◽  
Vol 127 (1) ◽  
pp. 125-130 ◽  
Author(s):  
Tesia L. Albarado ◽  
William A. Hollerman ◽  
David Edwards ◽  
Whitney Hubbs ◽  
Charles Semmel
Keyword(s):  
Solar Sail ◽  
Reaction Mass ◽  
Space Environment ◽  
Back Surface ◽  
Unique Form ◽  
Polymeric Substrate ◽  
Solar Sails ◽  
Solar Sailing ◽  
Optical And Mechanical Properties ◽  
Exposure Measurements

Solar sailing is a unique form of propulsion where a spacecraft gains momentum from incident photons. Since sails are not limited by reaction mass, they provide continual acceleration, reduced only by the lifetime of the lightweight film in the space environment and the distance to the Sun. Practical solar sails can expand the number of possible missions that are difficult by conventional means. The National Aeronautics and Space Administration’s Marshall Space Flight Center (MSFC) is concentrating research into the utilization of ultra lightweight materials for spacecraft propulsion. Solar sails are generally composed of a highly reflective metallic front layer, a thin polymeric substrate, and occasionally a highly emissive back surface. The Space Environmental Effects Team at MSFC is actively characterizing candidate sails to evaluate the thermo-optical and mechanical properties after exposure to electrons. This paper will discuss the preliminary results of this research.

Investigating the Design Space for Solar Sail Trajectories in the Earth-Moon System

2011 ◽  
Vol 4 (1) ◽  
pp. 26-44 ◽  
Author(s):  
Geoffrey G. Wawrzyniak ◽  
Kathleen C. Howell
Keyword(s):  
Design Space ◽  
Solar Sail ◽  
Mission Design ◽  
South Pole ◽  
Low Thrust ◽  
Solar Sails ◽  
Moon System ◽  
Solar Sailing ◽  
The Earth ◽  
Lunar South Pole

Solar sailing is an enabling technology for many mission applications. One potential application is the use of a sail as a communications relay for a base at the lunar south pole. A survey of the design space for a solar sail spacecraft that orbits in view of the lunar south pole at all times demonstrates that trajectory options are available for sails with characteristic acceleration values of 1.3 mm/s or higher. Although the current sail technology is presently not at this level, this survey reveals the minimum acceleration values that are required for sail technology to facilitate the lunar south pole application. This information is also useful for potential hybrid solar-sail-low-thrust designs. Other critical metrics for mission design and trajectory selection are also examined, such as body torques that are required to articulate the vehicle orientation, sail pitch angles throughout the orbit, and trajectory characteristics that would impact the design of the lunar base. This analysis and the techniques that support it supply an understanding of the design space for solar sails and their trajectories in the Earth-Moon system.

Electron Exposure Measurements of Candidate Solar Sail Materials

Solar Energy ◽  
2003 ◽  
Author(s):  
Tesia L. Albarado ◽  
William A. Hollerman ◽  
David Edwards ◽  
Whitney Hubbs ◽  
Charles Semmel
Keyword(s):  
Solar Sail ◽  
Reaction Mass ◽  
Space Environment ◽  
Back Surface ◽  
Unique Form ◽  
Polymeric Substrate ◽  
Solar Sails ◽  
Solar Sailing ◽  
Optical And Mechanical Properties ◽  
Exposure Measurements

Solar sailing is a unique form of propulsion where a spacecraft gains momentum from incident photons. Since sails are not limited by reaction mass, they provide continual acceleration, reduced only by the lifetime of the lightweight film in the space environment and the distance to the Sun. Practical solar sails can expand the number of possible missions that are difficult by conventional means. The National Aeronautics and Space Administration’s Marshall Space Flight Center (MSFC) is concentrating research into the utilization of ultra lightweight materials for spacecraft propulsion. Solar sails are generally composed of a highly reflective metallic front layer, a thin polymeric substrate, and occasionally a highly emissive back surface. The Space Environmental Effects Team at MSFC is actively characterizing candidate sails to evaluate the thermo-optical and mechanical properties after exposure to electrons. This paper will discuss the preliminary results of this research.

Agoraphilic navigation algorithm in dynamic environment with obstacles motion tracking and prediction

Robotica ◽  
2021 ◽  
pp. 1-19
Author(s):  
H. S. Hewawasam ◽  
M. Yousef Ibrahim ◽  
Gayan Kahandawa ◽  
T. A. Choudhury
Keyword(s):  
Free Space ◽  
Motion Tracking ◽  
Dynamic Environment ◽  
Experimental Tests ◽  
Cluttered Environments ◽  
Navigation Algorithm ◽  
Prediction Module ◽  
Future Space ◽  
Free Spaces ◽  
Advanced Development

Abstract This paper presents a new algorithm to navigate robots in dynamically cluttered environments. The proposed algorithm uses basic concepts of space attraction (hence the term Agoraphilic) to navigate robots through dynamic obstacles. The new algorithm in this paper is an advanced development of the original Agoraphilic navigation algorithm that was only able to navigate robots in static environments. The Agoraphilic algorithm does not look for obstacles (problems) to avoid but rather for a free space (solutions) to follow. Therefore, it is also described as an optimistic navigation algorithm. This algorithm uses only one attractive force created by the available free space. The free-space concept allows the Agoraphilic algorithm to overcome inherited challenges of general navigation algorithms. However, the original Agoraphilic algorithm has the limitation in navigating robots only in static, not in dynamic environments. The presented algorithm was developed to address this limitation of the original Agoraphilic algorithm. The new algorithm uses a developed object tracking module to identify the time-varying free spaces by tracking moving obstacles. The capacity of the algorithm was further strengthened by the new prediction module. Future space prediction allowed the algorithm to make decisions considering future growing/diminishing free spaces. This paper also includes a bench-marking study of the new algorithm compared with a recently published APF-based algorithm under a similar operating environment. Furthermore, the algorithm was validated based on experimental tests and simulation tests.

Automatic tool with adaptive suspension system for high-quality inspection of underwater risers

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Vivian Suzano Medeiros ◽  
Alan Conci Kubrusly ◽  
Raphael Lydia Bertoche ◽  
Miguel Andrade Freitas ◽  
Claudio Camerini ◽  
...  
Keyword(s):  
Control System ◽  
Oil And Gas ◽  
Pipe Wall ◽  
Mechanical Design ◽  
Experimental Tests ◽  
Gas Production ◽  
Suspension System ◽  
Inspection System ◽  
High Definition ◽  
Content Type

Purpose The inspection of flexible risers is a critical activity to ensure continuous productivity and safety in oil and gas production. The purpose of this paper is to present the design and development of a novel automatic underwater tool for riser inspection that fits the most commonly used riser diameters and significantly improves inspection quality and reduces its operating costs. Design/methodology/approach The mechanical and electronic design of the inspection system is discussed, as well as its embedded sensors and control system. The tool is equipped with a suspension system that is able to adapt to the riser diameter and negotiate obstacles on the pipe wall. Numerical simulations were carried out to analyze the mechanical design, and a hardware-in-the-loop simulation was developed for tuning the control system. Further, experimental results are presented and discussed. Findings Experimental tests in laboratory tanks and shallow seawater have confirmed the effectiveness of the tool for detailed real-time inspection of underwater pipelines. Practical implications The use of the proposed tool will potentially reduce the time and costs for riser inspection, currently performed by divers or high-cost ROVs. Originality/value The authors present a reliable tool able to perform automatic inspections up to 250 m deep in less than 30 min, equipped with a high-definition visual inspection system, composed of full-HD cameras and lasers and a suspension mechanism that can negotiate sharp obstacles in the pipe wall up to 25 mm high. The tool uses a comprehensive control system that autonomously performs a full inspection, collecting sensors data and returning safely to the surface. Its robust design can be used as basis for several other nondestructive techniques, such as ultrasound and X-ray.

Mechanical Design of Antichiral-Reentrant Hybrid Intravascular Stent

2018 ◽  
Vol 10 (10) ◽  
pp. 1850105 ◽  
Author(s):  
Xiao Li Ruan ◽  
Jie Jie Li ◽  
Xiao Ke Song ◽  
Hong Jian Zhou ◽  
Wei Xing Yuan ◽  
...  
Keyword(s):  
Large Scale ◽  
Mechanical Design ◽  
Experimental Tests ◽  
Building Blocks ◽  
Industrial Applications ◽  
Mechanical Effect ◽  
Parametric Models ◽  
Element Analysis ◽  
Specific Strength ◽  
Intravascular Stents

Chiral and reentrant metastructures with auxetic deformation abilities can serve as the building blocks in many industrial applications because of their light weight, high specific strength, energy absorption properties. In this paper, we report an innovative tubular-like structure by a combined mechanical effect of antichiral and reentrant. 2D antichiral-reentrant hybrid structures consisting of circular nodes and tangentially-connected ligaments are predesigned and fabricated using laser cutting technology with high-resolution. The elastic properties and auxeticity of the plane structure are analyzed and compared based on finite element analysis (FEA) and experimental results. For the first time, the antichiral-reentrant hybrid intravascular stents with the auxetic feature are proposed and parametric models are devised with good geometrical structure demonstrated. A series of large-scale stents are manufactured with stereolithography apparatus (SLA) additive manufacturing technique, and their mechanical behaviors are investigated in both experimental tests and FEA. As the selected antichiral-reentrant hybrid stents with tailored expansion ability are subjected to radial loading by the dilation of the balloon, stents undergo identifiable deformation mechanism due to the beam-like ligaments and circular node elements in the varied geometrical design, resulting in the distinct stress outcomes in plaque. It is also demonstrated that the antichiral-reentrant hybrid stents with tunable auxeticity possess robust mechanical properties through implantation inside the obstructed lesion.

scholarly journals Nrf2 contributes to the weight gain of mice during space travel

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Takafumi Suzuki ◽  
Akira Uruno ◽  
Akane Yumoto ◽  
Keiko Taguchi ◽  
Mikiko Suzuki ◽  
...  
Keyword(s):  
Gene Knockout ◽  
Disease Model ◽  
Space Station ◽  
Extreme Environment ◽  
Space Research ◽  
Plasma Metabolites ◽  
Space Travel ◽  
Future Space ◽  
Nrf2 Signaling Pathway ◽  
Induced Stresses

AbstractSpace flight produces an extreme environment with unique stressors, but little is known about how our body responds to these stresses. While there are many intractable limitations for in-flight space research, some can be overcome by utilizing gene knockout-disease model mice. Here, we report how deletion of Nrf2, a master regulator of stress defense pathways, affects the health of mice transported for a stay in the International Space Station (ISS). After 31 days in the ISS, all flight mice returned safely to Earth. Transcriptome and metabolome analyses revealed that the stresses of space travel evoked ageing-like changes of plasma metabolites and activated the Nrf2 signaling pathway. Especially, Nrf2 was found to be important for maintaining homeostasis of white adipose tissues. This study opens approaches for future space research utilizing murine gene knockout-disease models, and provides insights into mitigating space-induced stresses that limit the further exploration of space by humans.

scholarly journals A Novel Self-Deployable Solar Sail System Activated by Shape Memory Alloys

Aerospace ◽  
2019 ◽  
Vol 6 (7) ◽  
pp. 78 ◽  
Author(s):  
Gianluigi Bovesecchi ◽  
Sandra Corasaniti ◽  
Girolamo Costanza ◽  
Maria Elisa Tata
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Environmental Conditions ◽  
Solar Sail ◽  
Operating Conditions ◽  
Small Scale ◽  
Space Vehicles ◽  
Solar Sails ◽  
Suitable Material ◽  
Transfer Mechanisms

This work deals with the feasibility and reliability about the use of shape memory alloys (SMAs) as mechanical actuators for solar sail self-deployment instead of heavy and bulky mechanical booms. Solar sails exploit radiation pressure a as propulsion system for the exploration of the solar system. Sunlight is used to propel space vehicles by reflecting solar photons from a large and light-weight material, so that no propellant is required for primary propulsion. In this work, different small-scale solar sail prototypes (SSP) were studied, manufactured, and tested for bending and in three different environmental conditions to simulate as much as possible the real operating conditions where the solar sails work. Kapton is the most suitable material for sail production and, in the space missions till now, activated booms as deployment systems have always been used. In the present work for the activation of the SMA elements some visible lamps have been employed to simulate the solar radiation and time-temperature diagrams have been acquired for different sail geometries and environmental conditions. Heat transfer mechanisms have been discussed and the minimum distance from the sun allowing the full self-deployment of the sail have also been calculated.

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