Space subsystems design: (navigation, control, structure and…)
Moslem Karim Abadeh; Morteza Tayefi
Articles in Press, Accepted Manuscript, Available Online from 09 April 2024
Abstract
In this study, the control of a space capsule during the re-entry phase is examined. Re-entry is one of the most important phases of a spacecraft's mission because when the spacecraft enters the Earth's atmosphere, aerodynamic forces and moments will disturb the angles of attack and side slip. These ...
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In this study, the control of a space capsule during the re-entry phase is examined. Re-entry is one of the most important phases of a spacecraft's mission because when the spacecraft enters the Earth's atmosphere, aerodynamic forces and moments will disturb the angles of attack and side slip. These disturb angles, if not controlled, can cause serious injuries to the spacecraft and its passengers. To eliminate the disturbances, moving mass controllers have been used as an operator. Moving mass controllers (MMC) control the flying device by creating an internal force. The main advantage of moving mass controllers compared to other operators such as aerodynamic surfaces and thrust jets is the non-production of turbulent aerodynamic force (which can disrupt the controller's performance) due to the creation of internal force. Another important factor is the mechanism of moving mass controllers. In this research, in addition to the cross mechanism, which is a more common mechanism, the radial mechanism has also been examined. A non-linear controller is needed in order to use the radial mechanism, and in this research, a non-linear proportional-integral-derivative controller is suggested.
Space subsystems design: (navigation, control, structure and…)
Morteza Tayefi; Ramin Kamali Moghadam
Volume 15, Issue 3 , September 2022, , Pages 1-9
Abstract
To create drag and reduce the speed of space payloads in the phase of entering the atmosphere, the payload body itself can be used as brake mechanisms without using additional tools. The approach analyzed in this paper is the separation of the nose and then the stability of the cylindrical body in horizontal ...
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To create drag and reduce the speed of space payloads in the phase of entering the atmosphere, the payload body itself can be used as brake mechanisms without using additional tools. The approach analyzed in this paper is the separation of the nose and then the stability of the cylindrical body in horizontal or vertical mode. First, by numerical solution, the cylindrical body is aerodynamically simulated in the flight conditions entering the atmosphere, and the location of the center of mass is designed to achieve static stability. Then, by developing the equations of motion of atmospheric reentry using aerodynamic coefficients and derivatives calculated by DATCOM, the flight parameters for both modes are compared and evaluated. The simulation results show that the horizontal flight is more efficient and is able to create better conditions for opening the parachute and landing. Another advantage of atmospheric reentry flight in horizontal mode is the proper distribution of aerodynamic heating and reduction of heat load in certain points of the payload.
Morteza Tayefi; Ghasem Kahe; Mijtaba Mehrafrooz
Volume 12, Issue 4 , December 2019, , Pages 69-77
Abstract
Sounding rockets provide a useful platform for the aerospace research activities in which carry out a research payload to the space and recover it in the ground. In the flight path, it does scientific experiments and acquire the result for more analysis in the ground. All of the well-known aerospace ...
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Sounding rockets provide a useful platform for the aerospace research activities in which carry out a research payload to the space and recover it in the ground. In the flight path, it does scientific experiments and acquire the result for more analysis in the ground. All of the well-known aerospace centers around the world use frequently the various forms of sounding rocket to test and evaluate their sensitive space components. Actually, space qualification process of a space module is completed sometimes through a real space flight using the sounding rocket. In this paper the performance of a MEMS based inertial measurement unit (IMU) is investigated. The investigation result shows that using appropriate filtering, MEMS based IMU can measure appropriately the dynamic behavior of the sounding rocket. These data may be used for further identification and validation tests.
M. Jafari; M. Taefi; J. Roshanian
Volume 6, Issue 2 , July 2013, , Pages 57-66
Abstract
Flight dynamic equations have an effective role in aerospace technologies. It can be as cheap and efficient means for correcting errors in the spatial position and velocity in inertial navigation systems. The Inertial navigation system is an ideal solution for motion detection with high accuracy with ...
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Flight dynamic equations have an effective role in aerospace technologies. It can be as cheap and efficient means for correcting errors in the spatial position and velocity in inertial navigation systems. The Inertial navigation system is an ideal solution for motion detection with high accuracy with fast dynamics, but the precise location and status of the system output can be significantly reduced over time. In this paper, inertial navigation system integrated with a navigation aided system based on online solving of flight dynamic equations. For this purpose, the proposed use of the Lagrangian of Kepler equations and three degrees of freedom of Newton's equations of transfer flights dynamic has been studied. Using this method, online high accuracy to be achieved by flight computer. Kalman filter algorithm is used for integrating inertial navigation and flight dynamic equations . Finally, The simulation results including position and velocity errors with regard to fly a prototype space module, for the proposed two conditions were compared and the advantages and disadvantages of each method are presented
