Dynamic Testing and Model Validation of a Capture Mechanism for Rendezvous Between a Space Tether and Payload

2006 ◽  
Author(s):  
Stephen L. Canfield ◽  
Marshall A. Norris ◽  
Seth V. Knight ◽  
Kirk F. Sorensen
Keyword(s):  
Dynamic Model ◽  
Dynamic Testing ◽  
High Energy ◽  
Low Earth Orbit ◽  
Momentum Exchange ◽  
Analysis And Design ◽  
Capture Mechanism ◽  
Upper Stage ◽  
System 2 ◽  
High Thrust

Momentum eXchange Electrodynamic Reboost, or MXER, tether systems have been proposed to serve as an “upper stage in space” [1]. A MXER tether station would boost spacecraft from low Earth orbit to a high-energy orbit quickly, like a high-thrust rocket. Then, using the same principles that make an electric motor work, it would slowly rebuild its orbital momentum by pushing against the Earth’s magnetic field without using any propellant. One of the significant challenges in developing a momentum-exchange / electrodynamic reboost tether system is in the analysis and design of the capture mechanism and its effects on the overall dynamics of the system [2]. A capture mechanism that provides nearly passive operation is presented and described in [3] and led to the fabrication of a prototype article of this mechanism. This paper will describe the process of testing this prototype in a dynamically similar environment and validating an associated dynamic model. The primary contributions of this paper will be a description of the proposed capture mechanism concept and associated testing process and the validation of a dynamic model of this mechanism.

A Comparison of Three Passive Capture Mechanisms for Tether Momentum Exchange

2007 ◽  
Author(s):  
Stephen L. Canfield ◽  
Daniel L. Chlarson ◽  
Kirk Sorensen
Keyword(s):  
High Speed ◽  
Quantitative Description ◽  
High Energy ◽  
Low Earth Orbit ◽  
Momentum Exchange ◽  
Efficient Manner ◽  
Capture Process ◽  
Upper Stage ◽  
High Thrust ◽  
Rendezvous And Docking

The Momentum-exchange/electrodynamic reboost (MXER) tether system has been proposed as a highly fuel-efficient means to enable high-energy missions to the Moon, Mars and beyond by serving as an “upper stage in space”. The MXER tether system combines electrodynamic propulsion via a conducting tether with energy storage and a transfer mechanism to boost spacecraft from low Earth orbit to a high-energy orbit quickly, like a high-thrust rocket. One of the significant challenges in developing a momentum-exchange/electrodynamic reboost tether system is the design of a mechanism that will enable a high speed rendezvous and docking process in an energy efficient manner [1]. This paper will review two elements of the process of developing an appropriate mechanism to accommodate the MXER tether capture process. The paper will begin with the derivation of a qualitative and quantitative description about the nature of the capture window due to parameteric uncertainties in the MXER tether. The paper will then present a several candidate capture mechanisms and will evaluate their performance relative to the kinematic and dynamic aspects of performing the capture process.

scholarly journals Neighboring Optimal Guidance and Constrained Attitude Control for Accurate Orbit Injection

2021 ◽  
Author(s):  
Mauro Pontani ◽  
Fabio Celani
Keyword(s):  
Attitude Control ◽  
Initial Position ◽  
Low Earth Orbit ◽  
Guidance And Control ◽  
Optimal Guidance ◽  
Combined Use ◽  
Upper Stage ◽  
Neighboring Optimal Guidance ◽  
And Control ◽  
Guidance Technique

AbstractAccurate orbit injection represents a crucial issue in several mission scenarios, e.g., for spacecraft orbiting the Earth or for payload release from the upper stage of an ascent vehicle. This work considers a new guidance and control architecture based on the combined use of (i) the variable-time-domain neighboring optimal guidance technique (VTD-NOG), and (ii) the constrained proportional-derivative (CPD) algorithm for attitude control. More specifically, VTD-NOG & CPD is applied to two distinct injection maneuvers: (a) Hohmann-like finite-thrust transfer from a low Earth orbit to a geostationary orbit, and (b) orbit injection of the upper stage of a launch vehicle. Nonnominal flight conditions are modeled by assuming errors on the initial position, velocity, attitude, and attitude rate, as well as actuation deviations. Extensive Monte Carlo campaigns prove effectiveness and accuracy of the guidance and control methodology at hand, in the presence of realistic deviations from nominal flight conditions.

On the Design and Analysis of Acoustic Horns for Ultrasonic Welding Teflon Encapsulated O-Ring

2013 ◽  
Vol 753-755 ◽  
pp. 402-406
Author(s):  
Kuen Ming Shu ◽  
Yu Jen Wang ◽  
Hoa Shen Yen
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
High Energy ◽  
Ultrasonic Welding ◽  
Ultrasonic Machining ◽  
Analysis And Design ◽  
Vital Part ◽  
Finite Element Software ◽  
Acoustic Horns

The acoustic horn plays a very vital part in high energy ultrasonic machining, and its design is critical to the quality and the efficiency of ultrasonic machining. This paper performs the analysis and design of acoustic horns for ultrasonic welding Teflon encapsulated O-ring by employing ANSYS finite element software. Firstly, the theoretical dimensions of the horns are calculated. Moreover, their natural frequencies and amplitudes are obtained through the simulations of ANSYS.

Analysis and Design of Coherent Combining of two Q-Switched Fiber Laser in Mach-Zehnder Type Cavity

2019 ◽  
Vol 40 (4) ◽  
pp. 393-400
Author(s):  
Ali Nassiri ◽  
Hafida Idrissi-Saba ◽  
Abdelkader Boulezhar
Keyword(s):  
Fiber Laser ◽  
Peak Power ◽  
High Energy ◽  
Nanosecond Pulse ◽  
High Peak ◽  
High Peak Power ◽  
Analysis And Design ◽  
Coupled Cavities ◽  
Combining Efficiency ◽  
Coherent Combining

Abstract In this work, we have developed an analytical model of an actively Q-switched Ytterbium-doped fiber laser by using two coupled cavities with amplifying fibers in Mach–Zehnder interferometer configuration. This oscillator system provides high peak power and high energy nanosecond pulse. The pulse energy is almost twice the energy of an individual fiber laser with a combining efficiency goes up 99%. This concept brings some novel perspectives for scaling the high energy and high peak power of nanosecond pulse fiber laser.

scholarly journals Dynamic Modelling Transformations for the Low Earth Orbit Satellite Particulate Environment

1991 ◽  
Vol 126 ◽  
pp. 37-40
Author(s):  
J.A.M. McDonnell ◽  
K. Sullivan ◽  
S.F. Green ◽  
T.J. Stevenson ◽  
D.H. Niblett
Keyword(s):  
Dynamic Model ◽  
Space Debris ◽  
Residue Analysis ◽  
Dynamic Modelling ◽  
Low Earth Orbit ◽  
Earth Orbit ◽  
Natural Orbital ◽  
Low Earth Orbit Satellite ◽  
Chemical Residue ◽  
Particle Velocities

AbstractA simple dynamic model to investigate the relative fluxes and particle velocities on a spacecraft’s different faces is presented. The results for LDEF are consistent with a predominantly interplanetary origin for the larger particulates, but a sizable population of orbital particles with sizes capable of penetrating foils of thickness <30μm. Data from experiments over the last 30 years do not show the rise in flux expected if these were space debris. The possibility of a population of natural orbital particulates awaits confirmation from chemical residue analysis.

Dynamic Analysis and Design of Compliant Mechanisms Using the Finite Element Method

2012 ◽  
Vol 163 ◽  
pp. 111-115 ◽  
Author(s):  
Wen Jing Wang ◽  
Li Ge Zhang ◽  
Shu Sheng Bi
Keyword(s):  
Finite Element Method ◽  
Dynamic Model ◽  
Natural Frequency ◽  
Compliant Mechanisms ◽  
Compliant Mechanism ◽  
The Finite Element Method ◽  
Dynamic Effects ◽  
Experiment System ◽  
Analysis And Design ◽  
Theoretical Results

Compliant mechanisms gain at least some of their mobility from the deflection of flexible members rather than from movable joints only. Dynamic effects are very important to improving the design of compliant mechanisms. An investigation on the dynamics and synthesis of the compliant mechanisms is presented. The dynamic model of compliant mechanisms is developed at first. The natural frequency and sensitivity are then studied based on the dynamic model. Finally, optimal design of compliant mechanism is investigated. The experimental study of natural frequency is performed. The comparison between the experiment results and the theoretical results verifies the validity of the experiment system and theoretical model.

Multi-Field Coupled Analysis on Preparation Process of CZ Crystal

2012 ◽  
Vol 268-270 ◽  
pp. 387-390
Author(s):  
Ke Liang Ren ◽  
Song Qing Zhao ◽  
Qiao Di Yang ◽  
Dong Xu Guo
Keyword(s):  
Energy Consumption ◽  
Flow Field ◽  
Dynamic Model ◽  
High Energy ◽  
Parametric Model ◽  
Coupled Analysis ◽  
Preparation Process ◽  
Model Design ◽  
Model Modification ◽  
High Energy Consumption

To consider the high energy consumption and the key components are easy to damage in CZ crystal furnace, in this paper, a multi-field coupled analysis on temperature and flow field has been carried out by using FEM software ANSYS, and the APDL language of ANSYS is used to implement the parametric model design for CZ crystal furnace. In addition, the abilities of APDL to make dynamic model modification, control calculation procedure and extract the result are exploited to simulate the preparation process of CZ crystal and get the temperature and flow field. The results can be used for guiding the producing process of CZ crystal.

scholarly journals Two-dimensional lubrication analysis and design optimization of a Scotch Yoke engine linear bearing

2006 ◽  
Vol 220 (10) ◽  
pp. 1575-1587 ◽  
Author(s):  
X Wang ◽  
A Subic ◽  
H Watson
Keyword(s):  
Dynamic Testing ◽  
Combustion Engine ◽  
Design Sensitivity ◽  
Two Dimensional ◽  
Test Rig ◽  
Analysis And Design ◽  
Lubricant Flow ◽  
Bearing Assembly ◽  
Bearing Design ◽  
Scotch Yoke Mechanism

Recent study has shown that the application of a Scotch Yoke crank mechanism to a reciprocating internal combustion engine reduces the engine's size and weight and generates sinusoidal piston motion that allows for complete balance of the engine. This paper describes detailed investigation of the performance of a linear bearing assembly, which is one of the key components of the Scotch Yoke mechanism. The investigation starts by solving Reynolds equation for the Scotch Yoke linear bearing. The two-dimensional lubricant flow is numerically simulated and the calculated results are compared with experimental results from a linear bearing test rig. The performance characteristics and a design sensitivity analysis of the bearing are presented. Dynamic testing and analysis of an instrumented linear bearing on a test rig are used to validate the numerical simulation model. The oil supply and lubrication mechanism in the linear bearing are analysed and described in detail. This work aims to provide new insights into Scotch Yoke linear bearing design. In addition, strategies for optimization of the linear bearing are discussed.

The High-Energy Particle Detector (HEPD) on Board the CSES Mission

2017 ◽  
Vol 13 (S335) ◽  
pp. 365-367 ◽  
Author(s):  
Vincenzo Vitale ◽  
Keyword(s):  
Geomagnetic Field ◽  
High Energy ◽  
Low Earth Orbit ◽  
Light Nuclei ◽  
High Energy Particle ◽  
Particle Detector ◽  
Trigger System ◽  
Energy Particle ◽  
System A ◽  
Coincidence System

AbstractThe High-Energy Particle Detector (HEPD) will measure electrons, protons and light nuclei fluxes, in low Earth orbit. This detector consists of a high precision silicon tracker, a versatile trigger system, a range-calorimeter and an anti-coincidence system. It is one of the instruments on board the China Seismo-Electromagnetic Satellite (CSES). HEPD can detect multi-MeV particles trapped within the geomagnetic field. When operated at large latitudes HEPD can also detect un-trapped solar particles and low energy cosmic rays. A detailed description of the HEPD will be given.

scholarly journals Optical Response of Metakaolin after Ultraviolet and High Energy Electron Exposure

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
B. T. Cesul ◽  
S. Mall ◽  
L. Matson
Keyword(s):  
Coefficient Of Thermal Expansion ◽  
High Energy ◽  
Low Earth Orbit ◽  
Energy Electron ◽  
Space Environment ◽  
Inorganic Polymers ◽  
High Energy Electron ◽  
Specific Strength ◽  
High Energy Electrons ◽  
Radiation Sources

Metakaolin, which is part of a class of inorganic polymers called geopolymers, is being tested currently for its use as a lightweight mirror material in spacecraft applications. Metakaolin, as with most geopolymers, has the advantages of low initial coefficient of thermal expansion, easy preparation at room temperature and pressure, and high specific strength. Even though metakaolin has been known as a structural material for millennia, it has not been properly vetted for use as a material in spacecraft applications, especially with respect to exposure to its environments. This research highlights one particular aspect of response to the space environment; that is, how do the optical properties of metakaolin change after subjugation to bombardment by ultraviolet and high energy electron radiation? These two radiation sources are common in low earth orbit and a primary cause of degradation of organic polymers in space. Photospectroscopic analysis showed that ultraviolet in combination with high energy electrons causes changes in the metakaolin which need to be accounted for due to their potential impacts on the thermal management of a spacecraft and during application in composite mirror structures.

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