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Radu Rugescu

Radu Rugescu

Presently university professor, married (daughter and son), born in Bucharest, Romania, E. U. on March 26, 1944 am affiliated since 1969 with University “Politehnica” of Bucharest (UPB), successively as assistant professor to full professor, with expertise in Space Technology and Astronautics, specifically Propulsion, Thermochemistry, Astrodynamics, Optimization, Statistics, Programming, Robotics and Manufacturing Technology. I taught in Romanian, English and German languages at UPB and IPSA, Paris.After I was awarded with the Doctor in Science degree at UPB in Aerodynamics and Fluid Mechanics, I performed specializations in Germany and USA and won a William Fulbright grant at Texas A
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Papers by Radu Rugescu

Research paper thumbnail of NERVA Romanian Non-orbital Entry-Return Vehicle Assessor Project
NERVA Romanian Non-orbital Entry-Return Vehicle Assessor Project
57th International Astronautical Congress, Oct 2, 2006
Research paper thumbnail of Project SEATTLER for renewable electricity
The objective of the research described in this paper was to develop numerical simulations and to... moreThe objective of the research described in this paper was to develop numerical simulations and to compare the results with laboratory experiments in new, promising zones of aeroacoustics, considered fruitful for the environmental technologies, particularly related to aerodynamic noise suppression. When noise measurements are not being conducted, the cold air turbine embedded in the tower can be used as an efficient, eco-friendly source of energy. Named SEATTLER from Solar Energy Actuator for Tall Tower Low-cost Electricity Research, this moderately tall tower creates a considerable air acceleration and allows the aerodynamic noise to be definitely perceived. Numeric simulations applied on this architecture reveal astonishing air velocities well over 100 m/s in the test chamber area.
Research paper thumbnail of Application of Solar Energy
InTech eBooks, Feb 6, 2013
Research paper thumbnail of Thethers as Far Mission Descent-Return Tools
Space tethers are investigated as possible future reusable competitive-cost tools for non-gasdyna... moreSpace tethers are investigated as possible future reusable competitive-cost tools for non-gasdynamic descent, landing, takeoff and return from target celestial bodies. The Moon, Mars and a distant planet satellite like Titan are first taken into account as sample mission objectives. The investigation is focused on the mechanical usefulness of the system in comparison with the heavy duty mass expelling energy requirements of equivalent gasdynamic propulsion systems. The two potential categories are (a) the free tether release and return systems and (b) two fixed-points elevator systems. The first one is a further development of the already proposed partial descent system from the Earth ISS adapted to be maneuvered from a robot, remotely flying unmanned spacecraft, up to a complete descent. The second type is an extraterrestrial extension of the proposed Earth based space elevator system and is numerically investigated. Specific deployment techniques prove fitting descent on target bodies with and without an atmosphere. For the case of the Earth, Moon, Europa and similar planetary satellites a free deployment mode is proposed, considering the feasibility of Lunar based, manned deployment maneuvers as solutions of the future. A number of hard technical requirements still remain to be investigated and solutions found, regarding for instance the control of errors in correlation with system dynamics. It proves that, for some of the sample missions analyzed and particularly for the Moon, Europa and Rhea the tethered systems are nevertheless more likely to reach a convenient exploitation stage than the future Earth based space elevator system. This is due to the negligible atmosphere and the low gravity of these moons. It is supposed that the manufacturing technology of light strings will properly mature. The constant reluctance towards tether systems can only be overcome when significant advantages from the use of space tethers, in this case for distant planetary missions, are proved. The interest lays in the potential for descent and landing to, or return from the surface of the Moon, Europe, Titan or other satellites in the solar system, by avoiding large mass expenses, induced by the conventional rocket propulsion.
Research paper thumbnail of Loads during Anchoring Dynamics from Earth Orbit
Loads during Anchoring Dynamics from Earth Orbit
57th International Astronautical Congress, Oct 2, 2006
Research paper thumbnail of Human Arm Control in Weightlessness and ISS Experiment on Alteration of Graphical Skills
Human Arm Control in Weightlessness and ISS Experiment on Alteration of Graphical Skills
57th International Astronautical Congress, Oct 2, 2006
Research paper thumbnail of Debris Hazards Mitigation and Retrieval for Space Elevators
Debris Hazards Mitigation and Retrieval for Space Elevators
57th International Astronautical Congress, 2006
Research paper thumbnail of TRANSIT Code for Air Turbine Flows of Solar-Gravity Draught Power Plants
TRANSIT Code for Air Turbine Flows of Solar-Gravity Draught Power Plants
Research paper thumbnail of Orbital Injection Errors and Sensor Requirements for NERVA Space Launchers
Orbital Injection Errors and Sensor Requirements for NERVA Space Launchers
Applied Mechanics and Materials, Jun 1, 2013
The input module of the NERVA space launcher guidance system consisting of the inertial and senso... moreThe input module of the NERVA space launcher guidance system consisting of the inertial and sensor platform is responsible for the basic accuracy if the ascent trajectory and injection efficiency. The sample rate magnitude and data filtering along the real time trajectory are the only tools available for improving the guidance accuracy up to the level of requirements to secure admissible orbital injection error and the subsequent flight corridor during the orbital ascent. Analysis of the NERVA-1 flight telemetry flow from the onboard inertial platform raises the problem of the optimal selection of the onboard sample rate and of the rate of telemetry, which are not identical. The orbit injection errors are chosen from the orbit altitude constraints and subsequent accuracy requirements for the inertial sensors are derived. They show that the accuracy requirements are moderate and may be covered with almost conventional sensors. To improve the flight guidance accuracy the rocket motor chamber pressure and thrust are measured and observation of the preflight zero drift, recording noise and of the high level of embedded noise during both powered and coast atmospheric flight is performed. Simple filtering based on frequency Fourier analysis is delivered with conclusions regarding the intelligent algorithm enhancement that are developed and implemented on the next generation of flight research drone missiles RT-759M NERVA-2, right in preparation. The main rationale of that algorithm stands in the method of discriminating between false and true information on each measuring point immediately after the data are delivered by the sensors. Learning procedure from previous preflight recordings and from gradual accumulation of concurrent data streams subjected to FF spectral analysis are combined to improve data filtering, for immediate release to the next module of the autopilot. The rate of sampling is optimized from the analysis of the previous flight, inertial data records and test stand pressure and thrust records that show the level of noise. The behavior of the electronics under the dynamical loads of the rocket flight, involving overloads of more than 20 g-s and the level of vibration during the real flight and other sources of measuring errors are also focused in the research. During simulated work of the sensor platform the algorithm has been acceptably validated and prepared for real flight test performance. Information important for the NERVA autopilot design activity is structured through the multiple variance approach.
Research paper thumbnail of Misbehavior in High Temperature Equilibrium of Water-Gas Reaction
Misbehavior in High Temperature Equilibrium of Water-Gas Reaction
Applied Mechanics and Materials, Dec 1, 2012
The observation that the chemical equilibrium between the combustion products of solid propellant... moreThe observation that the chemical equilibrium between the combustion products of solid propellant samples within static calorimeters is unexpectedly freezing at high temperatures is proved through a general numerical simulation of the isochoric cooling with chemical reactions between the gaseous products. A proprietary, direct linearization method of thermochemical computation is used that enables following any chemical reaction in equilibrium with high convergence. The observed chemical freezing within calorimeters is proved.
Research paper thumbnail of Plenary lecture IX: unexpected high temperature chemical freezing during slow isochoric cooling
Plenary lecture IX: unexpected high temperature chemical freezing during slow isochoric cooling
International Conference on Mathematical and Computational Methods in Science and Engineering, Nov 7, 2008
ABSTRACT
Research paper thumbnail of Intricacy of the Transit Manifold Concept Paid-off by Computational Accuracy
Intricacy of the Transit Manifold Concept Paid-off by Computational Accuracy
Applied Mechanics and Materials, Jun 1, 2013
Despite its intricacy the numerical method applied within the TRANSIT code proved successful in d... moreDespite its intricacy the numerical method applied within the TRANSIT code proved successful in describing discontinuous, non-isentropic flows in rocket engines and solar-gravitational towers for green energy. A number of 0-D approaches are known to render some results in demonstrating the feasibility of the solar tower concept, or in unsteady simulation of transient phases in rocket engines. Computational efficiency is demonstrated by CFD simulation of the starting transients in ADDA solid rocket engines and in the SEATTLER solar mirror tower. The code is exclusively directed to unsteady flow simulations in slender channels. The wave front model scheme covers the dual behavior of fully non-isentropic flow with mass addition and mixing in the thrust chamber or blunt heat addition in a heater and fully isentropic through the exhaust nozzle or gravity draught in a tall tower. Along the tower of the solar-gravity draught power plants small perturbation discontinuous flows are covered. Code robustness is demonstrated during runs on the PC.
Research paper thumbnail of Estimation of radial acoustic wave propagation in relative motion
Estimation of radial acoustic wave propagation in relative motion
International Conference on Mathematical and Computational Methods in Science and Engineering, Nov 7, 2008
ABSTRACT
Research paper thumbnail of First Flight Experiment with the NERVA-1 Inertial Platform
First Flight Experiment with the NERVA-1 Inertial Platform
Applied Mechanics and Materials, Jun 1, 2013
The guidance system of the NERVA small space launcher is based on the six degrees-of-freedom info... moreThe guidance system of the NERVA small space launcher is based on the six degrees-of-freedom information delivered by an inertial platform. Due to the main scope of the project sponsored by the Romanian Ministry of Education, Research, Youth and Sports to build a cost-effective space launcher, the inertial platform was built with extensive use of on-the-shelf, low cost inertial sensors and equipment. Concerns regarding the behavior and reliability of the sensing block were solved during the first flight experiment in June 2010, on-board the military, unguided drone missile RT-759-01 NERVA-1 and the results are described. The behavior of the electronics under the dynamical loads of the rocket flight, involving overloads of more than 20 g-s and the level of vibration during the real flight was the focus of the flight test, the first ever performed in Romania. The data were broadcast through a eight channel telemetry chain and received on the ground in two different locations for reliability enhancement. The data acquisition performed very well and supplied the basis for further development of the more accurate orbital injection guidance system of the NERVA launcher of small satellites in LEO.
Research paper thumbnail of Orthonormality and Spectral Analysis for Robotics and Astrodynamics
Orthonormality and Spectral Analysis for Robotics and Astrodynamics
Solid State Phenomena, Jun 1, 2010
A rigid transform of the E3 space into itself stands as the basis of a complete description of me... moreA rigid transform of the E3 space into itself stands as the basis of a complete description of mechanical motions of solid bodies, where the orthogonal and normalized character (orthonormality) of the transform matrix are used as a postulate. However, the orthonormality is in fact a consequence of the condition of rigidity. The demonstration is outlined through the spectral analysis for application in the engineering of robots and astrodynamics. The problem posed is to directly find, in a general and confident manner, the elements of the rotation matrix when the direction and magnitude of the rotational displacement are given, which is an inverse design problem. Previously solved in 2-D, this problem is now extended to 3-D problems of mechanics and an implicit suggestion is made for the n-D mechanics.
Research paper thumbnail of Reentry Design Solution for a Hypersonic Small Capsule
Reentry Design Solution for a Hypersonic Small Capsule
Applied Mechanics and Materials, Jul 1, 2013
Restriction and selection criteria of inertial guidance sensors and system for a small recoverabl... moreRestriction and selection criteria of inertial guidance sensors and system for a small recoverable capsule from onboard a hypersonic, atmospheric reentering rocket vehicle have attracted a specific research on the reentry design and challenges, with emphasize on the overall cost reduction and an optimal balance between the performances and costs under the given exploitation constraints. A simplified method for attitude control is derived that shows an easy accommodation in the capsule, given its high mass constraints, and convenient applicability for the class of small payloads under investigation. The palled experiments and investigating methodology is shown, as the result of the ORVEAL contract research team of ADDA-Association Dedicated to Development in Astronautics research organization, under the sponsorship of Romanian UEFISCDI authority for scientific research.
Research paper thumbnail of Goddard's 85 Years Optimal Ascent Problem Finally Solved
Goddard's 85 Years Optimal Ascent Problem Finally Solved
57th International Astronautical Congress, Oct 2, 2006
Research paper thumbnail of Ultra long orbital tethers behave highly non-Keplerian and unstable
WSEAS Transactions on Mathematics archive, Mar 1, 2008
Large twin tethers are investigated as possible competitive-cost tools for non-gasdynamic descent... moreLarge twin tethers are investigated as possible competitive-cost tools for non-gasdynamic descent, landing, takeoff and return from target celestial bodies and as passive tools for debris retrieval from orbit. The particular behavior of orbiting bodies connected with long cables is a recent preoccupation in astrodynamics and proves being full of unexpected results. The investigation here presented is focused on the non-Keplerian behavior of such large tether systems, considered in a first approximation as rigid or very stiff and massless. The investigation starts with the feasibility of non-gasdynamic orbital deployment of twin tethers without any involvement of expensive rocket propulsion means. The free tether release systems are associated to a horizontal impulsive separation (HIS) and eventual friction-free deployment to the desired length. This horizontal deployment seems to supply the most productive means of continuous separation and departure of masses in orbit. The relative motion during separation is studied and the observation is made that a considerable kinetic moment of the system preserves during all eventual phases of the flight. After the friction-free deployment the extending cable is instantly immobilized at the so-called connection moment. From here after the tether length remains constant. The evolution of the deployed tether is followed in order to record the specific behavior when the length of the tether is extremely great. The motion of the two connected masses and of the mass center proves completely non-Keplerian, beginning with the libration around local vertical due to the considerable residual kinetic moment at connection. A practical application of the quasi-vertical libration is in orbital passive debris collector, when a sandwich composite large panel is orbited for long periods of time for collecting small mass, high velocity Earth orbit debris. The most promising and controversial application of such long tethers resides in the anchoring technique to achieve the skeleton of a future space elevator. The stability of motion is an important aspect which is approached my numerical simulations.
Research paper thumbnail of Beginnings of Space Propulsion Research in Romania
Beginnings of Space Propulsion Research in Romania
54th International Astronautical Congress of the International Astronautical Federation, the International Academy of Astronautics, and the International Institute of Space Law, 2003
Up to 1960 the single Romanian experimental investigations on rocket engines were those of Prof. ... moreUp to 1960 the single Romanian experimental investigations on rocket engines were those of Prof. Hermann Oberth in Medias and Sighisoara, who had later moved in Germany and had been undisputedly recognized as the founder of Astronautics. A long eclipse on this type of investigations was imposed after the war and it happened that only in 1962 a research program on rocket engines could, on a limited base, be established, with encouragements from the same Prof. Oberth. The program was initiated by the author at the chair of Aviation, directed at that time by acad. Elie Carafoli, president of IAF between 1968 and 1972, pending on the “Politehnica” University in Bucharest, led by acad. George Baranescu, later in the United States. The MRE program was aimed to develop a series of small thrust, liquid propellant rocket engines and of a suited remotely controlled test stand for these engines and is here firstly described, emphasizing early Romanian academic preoccupations in space propulsion. The successful first test firing of the MRE-1 motor was recorded on April 9, 1969. This early endeavor led to promising results, unfortunately cut down by the military directed interests of the outgun government, prior to end in an actual proprietary space vehicle construction. The presentation also comprises a short, amateur 2x8-mm color movie of the test firing of the engine in Bucharest. Romanian state-of-the-art in 1962 It was down to 1910 that the Romanian high school boy Hermann Oberth began to put in practice his first ideas on rocket propulsion, as his childhood friend and pear Emma Glatz had told us after 70 years in Sighisoara, Romania. Years had past meanwhile, Oberth had finished his known projects in Germany, and none other significant Romanian investigations in rocket propulsion were noticed until 1962. It was in that year of 1962 that a team of very young students, led by the author, initiated at the University “Politehnica” of Bucharest a limited research program in rocket propulsion. It was not only financially limited as limited by the known restrictions imposed after the war to the aeronautical industry in Romania, once a remarkably well-developed aircraft
Research paper thumbnail of General and Debris Hazards Evaluation for Future S
General and Debris Hazards Evaluation for Future S
56th International Astronautical Congress of the International Astronautical Federation, the International Academy of Astronautics, and the International Institute of Space Law, 2005
Research paper thumbnail of NERVA Romanian Non-orbital Entry-Return Vehicle Assessor Project
NERVA Romanian Non-orbital Entry-Return Vehicle Assessor Project
57th International Astronautical Congress, Oct 2, 2006
Research paper thumbnail of Project SEATTLER for renewable electricity
The objective of the research described in this paper was to develop numerical simulations and to... moreThe objective of the research described in this paper was to develop numerical simulations and to compare the results with laboratory experiments in new, promising zones of aeroacoustics, considered fruitful for the environmental technologies, particularly related to aerodynamic noise suppression. When noise measurements are not being conducted, the cold air turbine embedded in the tower can be used as an efficient, eco-friendly source of energy. Named SEATTLER from Solar Energy Actuator for Tall Tower Low-cost Electricity Research, this moderately tall tower creates a considerable air acceleration and allows the aerodynamic noise to be definitely perceived. Numeric simulations applied on this architecture reveal astonishing air velocities well over 100 m/s in the test chamber area.
Research paper thumbnail of Application of Solar Energy
InTech eBooks, Feb 6, 2013
Research paper thumbnail of Thethers as Far Mission Descent-Return Tools
Space tethers are investigated as possible future reusable competitive-cost tools for non-gasdyna... moreSpace tethers are investigated as possible future reusable competitive-cost tools for non-gasdynamic descent, landing, takeoff and return from target celestial bodies. The Moon, Mars and a distant planet satellite like Titan are first taken into account as sample mission objectives. The investigation is focused on the mechanical usefulness of the system in comparison with the heavy duty mass expelling energy requirements of equivalent gasdynamic propulsion systems. The two potential categories are (a) the free tether release and return systems and (b) two fixed-points elevator systems. The first one is a further development of the already proposed partial descent system from the Earth ISS adapted to be maneuvered from a robot, remotely flying unmanned spacecraft, up to a complete descent. The second type is an extraterrestrial extension of the proposed Earth based space elevator system and is numerically investigated. Specific deployment techniques prove fitting descent on target bodies with and without an atmosphere. For the case of the Earth, Moon, Europa and similar planetary satellites a free deployment mode is proposed, considering the feasibility of Lunar based, manned deployment maneuvers as solutions of the future. A number of hard technical requirements still remain to be investigated and solutions found, regarding for instance the control of errors in correlation with system dynamics. It proves that, for some of the sample missions analyzed and particularly for the Moon, Europa and Rhea the tethered systems are nevertheless more likely to reach a convenient exploitation stage than the future Earth based space elevator system. This is due to the negligible atmosphere and the low gravity of these moons. It is supposed that the manufacturing technology of light strings will properly mature. The constant reluctance towards tether systems can only be overcome when significant advantages from the use of space tethers, in this case for distant planetary missions, are proved. The interest lays in the potential for descent and landing to, or return from the surface of the Moon, Europe, Titan or other satellites in the solar system, by avoiding large mass expenses, induced by the conventional rocket propulsion.
Research paper thumbnail of Loads during Anchoring Dynamics from Earth Orbit
Loads during Anchoring Dynamics from Earth Orbit
57th International Astronautical Congress, Oct 2, 2006
Research paper thumbnail of Human Arm Control in Weightlessness and ISS Experiment on Alteration of Graphical Skills
Human Arm Control in Weightlessness and ISS Experiment on Alteration of Graphical Skills
57th International Astronautical Congress, Oct 2, 2006
Research paper thumbnail of Debris Hazards Mitigation and Retrieval for Space Elevators
Debris Hazards Mitigation and Retrieval for Space Elevators
57th International Astronautical Congress, 2006
Research paper thumbnail of TRANSIT Code for Air Turbine Flows of Solar-Gravity Draught Power Plants
TRANSIT Code for Air Turbine Flows of Solar-Gravity Draught Power Plants
Research paper thumbnail of Orbital Injection Errors and Sensor Requirements for NERVA Space Launchers
Orbital Injection Errors and Sensor Requirements for NERVA Space Launchers
Applied Mechanics and Materials, Jun 1, 2013
The input module of the NERVA space launcher guidance system consisting of the inertial and senso... moreThe input module of the NERVA space launcher guidance system consisting of the inertial and sensor platform is responsible for the basic accuracy if the ascent trajectory and injection efficiency. The sample rate magnitude and data filtering along the real time trajectory are the only tools available for improving the guidance accuracy up to the level of requirements to secure admissible orbital injection error and the subsequent flight corridor during the orbital ascent. Analysis of the NERVA-1 flight telemetry flow from the onboard inertial platform raises the problem of the optimal selection of the onboard sample rate and of the rate of telemetry, which are not identical. The orbit injection errors are chosen from the orbit altitude constraints and subsequent accuracy requirements for the inertial sensors are derived. They show that the accuracy requirements are moderate and may be covered with almost conventional sensors. To improve the flight guidance accuracy the rocket motor chamber pressure and thrust are measured and observation of the preflight zero drift, recording noise and of the high level of embedded noise during both powered and coast atmospheric flight is performed. Simple filtering based on frequency Fourier analysis is delivered with conclusions regarding the intelligent algorithm enhancement that are developed and implemented on the next generation of flight research drone missiles RT-759M NERVA-2, right in preparation. The main rationale of that algorithm stands in the method of discriminating between false and true information on each measuring point immediately after the data are delivered by the sensors. Learning procedure from previous preflight recordings and from gradual accumulation of concurrent data streams subjected to FF spectral analysis are combined to improve data filtering, for immediate release to the next module of the autopilot. The rate of sampling is optimized from the analysis of the previous flight, inertial data records and test stand pressure and thrust records that show the level of noise. The behavior of the electronics under the dynamical loads of the rocket flight, involving overloads of more than 20 g-s and the level of vibration during the real flight and other sources of measuring errors are also focused in the research. During simulated work of the sensor platform the algorithm has been acceptably validated and prepared for real flight test performance. Information important for the NERVA autopilot design activity is structured through the multiple variance approach.
Research paper thumbnail of Misbehavior in High Temperature Equilibrium of Water-Gas Reaction
Misbehavior in High Temperature Equilibrium of Water-Gas Reaction
Applied Mechanics and Materials, Dec 1, 2012
The observation that the chemical equilibrium between the combustion products of solid propellant... moreThe observation that the chemical equilibrium between the combustion products of solid propellant samples within static calorimeters is unexpectedly freezing at high temperatures is proved through a general numerical simulation of the isochoric cooling with chemical reactions between the gaseous products. A proprietary, direct linearization method of thermochemical computation is used that enables following any chemical reaction in equilibrium with high convergence. The observed chemical freezing within calorimeters is proved.
Research paper thumbnail of Plenary lecture IX: unexpected high temperature chemical freezing during slow isochoric cooling
Plenary lecture IX: unexpected high temperature chemical freezing during slow isochoric cooling
International Conference on Mathematical and Computational Methods in Science and Engineering, Nov 7, 2008
ABSTRACT
Research paper thumbnail of Intricacy of the Transit Manifold Concept Paid-off by Computational Accuracy
Intricacy of the Transit Manifold Concept Paid-off by Computational Accuracy
Applied Mechanics and Materials, Jun 1, 2013
Despite its intricacy the numerical method applied within the TRANSIT code proved successful in d... moreDespite its intricacy the numerical method applied within the TRANSIT code proved successful in describing discontinuous, non-isentropic flows in rocket engines and solar-gravitational towers for green energy. A number of 0-D approaches are known to render some results in demonstrating the feasibility of the solar tower concept, or in unsteady simulation of transient phases in rocket engines. Computational efficiency is demonstrated by CFD simulation of the starting transients in ADDA solid rocket engines and in the SEATTLER solar mirror tower. The code is exclusively directed to unsteady flow simulations in slender channels. The wave front model scheme covers the dual behavior of fully non-isentropic flow with mass addition and mixing in the thrust chamber or blunt heat addition in a heater and fully isentropic through the exhaust nozzle or gravity draught in a tall tower. Along the tower of the solar-gravity draught power plants small perturbation discontinuous flows are covered. Code robustness is demonstrated during runs on the PC.
Research paper thumbnail of Estimation of radial acoustic wave propagation in relative motion
Estimation of radial acoustic wave propagation in relative motion
International Conference on Mathematical and Computational Methods in Science and Engineering, Nov 7, 2008
ABSTRACT
Research paper thumbnail of First Flight Experiment with the NERVA-1 Inertial Platform
First Flight Experiment with the NERVA-1 Inertial Platform
Applied Mechanics and Materials, Jun 1, 2013
The guidance system of the NERVA small space launcher is based on the six degrees-of-freedom info... moreThe guidance system of the NERVA small space launcher is based on the six degrees-of-freedom information delivered by an inertial platform. Due to the main scope of the project sponsored by the Romanian Ministry of Education, Research, Youth and Sports to build a cost-effective space launcher, the inertial platform was built with extensive use of on-the-shelf, low cost inertial sensors and equipment. Concerns regarding the behavior and reliability of the sensing block were solved during the first flight experiment in June 2010, on-board the military, unguided drone missile RT-759-01 NERVA-1 and the results are described. The behavior of the electronics under the dynamical loads of the rocket flight, involving overloads of more than 20 g-s and the level of vibration during the real flight was the focus of the flight test, the first ever performed in Romania. The data were broadcast through a eight channel telemetry chain and received on the ground in two different locations for reliability enhancement. The data acquisition performed very well and supplied the basis for further development of the more accurate orbital injection guidance system of the NERVA launcher of small satellites in LEO.
Research paper thumbnail of Orthonormality and Spectral Analysis for Robotics and Astrodynamics
Orthonormality and Spectral Analysis for Robotics and Astrodynamics
Solid State Phenomena, Jun 1, 2010
A rigid transform of the E3 space into itself stands as the basis of a complete description of me... moreA rigid transform of the E3 space into itself stands as the basis of a complete description of mechanical motions of solid bodies, where the orthogonal and normalized character (orthonormality) of the transform matrix are used as a postulate. However, the orthonormality is in fact a consequence of the condition of rigidity. The demonstration is outlined through the spectral analysis for application in the engineering of robots and astrodynamics. The problem posed is to directly find, in a general and confident manner, the elements of the rotation matrix when the direction and magnitude of the rotational displacement are given, which is an inverse design problem. Previously solved in 2-D, this problem is now extended to 3-D problems of mechanics and an implicit suggestion is made for the n-D mechanics.
Research paper thumbnail of Reentry Design Solution for a Hypersonic Small Capsule
Reentry Design Solution for a Hypersonic Small Capsule
Applied Mechanics and Materials, Jul 1, 2013
Restriction and selection criteria of inertial guidance sensors and system for a small recoverabl... moreRestriction and selection criteria of inertial guidance sensors and system for a small recoverable capsule from onboard a hypersonic, atmospheric reentering rocket vehicle have attracted a specific research on the reentry design and challenges, with emphasize on the overall cost reduction and an optimal balance between the performances and costs under the given exploitation constraints. A simplified method for attitude control is derived that shows an easy accommodation in the capsule, given its high mass constraints, and convenient applicability for the class of small payloads under investigation. The palled experiments and investigating methodology is shown, as the result of the ORVEAL contract research team of ADDA-Association Dedicated to Development in Astronautics research organization, under the sponsorship of Romanian UEFISCDI authority for scientific research.
Research paper thumbnail of Goddard's 85 Years Optimal Ascent Problem Finally Solved
Goddard's 85 Years Optimal Ascent Problem Finally Solved
57th International Astronautical Congress, Oct 2, 2006
Research paper thumbnail of Ultra long orbital tethers behave highly non-Keplerian and unstable
WSEAS Transactions on Mathematics archive, Mar 1, 2008
Large twin tethers are investigated as possible competitive-cost tools for non-gasdynamic descent... moreLarge twin tethers are investigated as possible competitive-cost tools for non-gasdynamic descent, landing, takeoff and return from target celestial bodies and as passive tools for debris retrieval from orbit. The particular behavior of orbiting bodies connected with long cables is a recent preoccupation in astrodynamics and proves being full of unexpected results. The investigation here presented is focused on the non-Keplerian behavior of such large tether systems, considered in a first approximation as rigid or very stiff and massless. The investigation starts with the feasibility of non-gasdynamic orbital deployment of twin tethers without any involvement of expensive rocket propulsion means. The free tether release systems are associated to a horizontal impulsive separation (HIS) and eventual friction-free deployment to the desired length. This horizontal deployment seems to supply the most productive means of continuous separation and departure of masses in orbit. The relative motion during separation is studied and the observation is made that a considerable kinetic moment of the system preserves during all eventual phases of the flight. After the friction-free deployment the extending cable is instantly immobilized at the so-called connection moment. From here after the tether length remains constant. The evolution of the deployed tether is followed in order to record the specific behavior when the length of the tether is extremely great. The motion of the two connected masses and of the mass center proves completely non-Keplerian, beginning with the libration around local vertical due to the considerable residual kinetic moment at connection. A practical application of the quasi-vertical libration is in orbital passive debris collector, when a sandwich composite large panel is orbited for long periods of time for collecting small mass, high velocity Earth orbit debris. The most promising and controversial application of such long tethers resides in the anchoring technique to achieve the skeleton of a future space elevator. The stability of motion is an important aspect which is approached my numerical simulations.
Research paper thumbnail of Beginnings of Space Propulsion Research in Romania
Beginnings of Space Propulsion Research in Romania
54th International Astronautical Congress of the International Astronautical Federation, the International Academy of Astronautics, and the International Institute of Space Law, 2003
Up to 1960 the single Romanian experimental investigations on rocket engines were those of Prof. ... moreUp to 1960 the single Romanian experimental investigations on rocket engines were those of Prof. Hermann Oberth in Medias and Sighisoara, who had later moved in Germany and had been undisputedly recognized as the founder of Astronautics. A long eclipse on this type of investigations was imposed after the war and it happened that only in 1962 a research program on rocket engines could, on a limited base, be established, with encouragements from the same Prof. Oberth. The program was initiated by the author at the chair of Aviation, directed at that time by acad. Elie Carafoli, president of IAF between 1968 and 1972, pending on the “Politehnica” University in Bucharest, led by acad. George Baranescu, later in the United States. The MRE program was aimed to develop a series of small thrust, liquid propellant rocket engines and of a suited remotely controlled test stand for these engines and is here firstly described, emphasizing early Romanian academic preoccupations in space propulsion. The successful first test firing of the MRE-1 motor was recorded on April 9, 1969. This early endeavor led to promising results, unfortunately cut down by the military directed interests of the outgun government, prior to end in an actual proprietary space vehicle construction. The presentation also comprises a short, amateur 2x8-mm color movie of the test firing of the engine in Bucharest. Romanian state-of-the-art in 1962 It was down to 1910 that the Romanian high school boy Hermann Oberth began to put in practice his first ideas on rocket propulsion, as his childhood friend and pear Emma Glatz had told us after 70 years in Sighisoara, Romania. Years had past meanwhile, Oberth had finished his known projects in Germany, and none other significant Romanian investigations in rocket propulsion were noticed until 1962. It was in that year of 1962 that a team of very young students, led by the author, initiated at the University “Politehnica” of Bucharest a limited research program in rocket propulsion. It was not only financially limited as limited by the known restrictions imposed after the war to the aeronautical industry in Romania, once a remarkably well-developed aircraft
Research paper thumbnail of General and Debris Hazards Evaluation for Future S
General and Debris Hazards Evaluation for Future S
56th International Astronautical Congress of the International Astronautical Federation, the International Academy of Astronautics, and the International Institute of Space Law, 2005

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