4th IAA Conference on Dynamics and Control of Space Systems (DyCoSS)

Keynote Speech

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Keynote Speaker

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Arun K. Misra is the Thomas Workman Professor in the Department of Mechanical Engineering at McGill University in Montreal, Canada. His research interests lie in the areas of spacecraft dynamics, space robotics, space structures and tethered satellites. He is a Fellow of the American Institute of Aeronauticsand Astronautics (AIAA) as well of the American Astronautical Society (AAS). He has been elected to the International Academy of Astronautics (IAA) and the Canadian Academy of Engineering (CAE). He is a Co-Editor of the journal Acta Astronautica.


Topic: Spacecraft dynamics near a binary asteroid system

Dynamics of a spacecraft around an asteroid is very interesting due to the irregular shape of the asteroids. There have been several studies on the orbital and attitude dynamics of a spacecraft orbiting an asteroid. However, there have been relatively fewer studies on spacecraft dynamics near a binary asteroid system. Many asteroids occur in pairs and there is a plan to send a spacecraft mission to a binary asteroid system in the near future. This paper examines the dynamics of a spacecraft near such a binary system. The three-body problem involving the binary asteroids and the spacecraft has some similarity with the classical three-body problem, but the details can be very different. It is found that in this system more than five Lagrangian-like points can exist. Furthermore, it is also noted that the stability behavior of the orbits around these Lagrangian-like points can be different compared to the conventional CRTBP. The effects of the second and fourth order terms in the gravitational potential are examined. The effect of the solar radiation pressure on the dynamics is also investigated.


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Dr. BONG WIE is Professor of Aerospace Engineering at Iowa State University. He received MS and PhD degrees in aeronautics and astronautics from Stanford University in 1978 and 1981, respectively. In 2006, the AIAA presented Professor Wie with the Mechanics and Control of Flight Award for his innovative research on advanced control of complex spacecraft such as agile imaging satellites equipped with CMGs, solarsails, and large space structures.  He is the author of two AIAA textbooks: “Space Vehicle Dynamics and Control” and“Space Vehicle Guidance, Control, and Astrodynamics.” He has published 200 technical papers, 75 journal articles, and holds three U.S. patents on CMG steering logic. During the past several years, he has been actively involved in astrodynamics, guidance, and control research for deflecting or disrupting hazardous near-Earth Objects.  He was the PI of NIAC Phase 1 and 2 projects (“An Innovative Solution to NASA's NEO Impact Threat Mitigation Grand Challenge and Its Flight Validation Mission Design”)from 2011 through 2014.


Topic: New Two-Phase ZEM/ZEV Feedback Guidance for Marsand Lunar Powered Descent & Landing with Hazard Avoidance and Retargeting

This talk presents a new, yet simple, two-phase ZEM/ZEV (Zero-Effort-Miss/Zero-Effort-Velocity) feedback guidance law that prevents the possibility of Mars or lunar surface collision during powered descent & landing. The conventional single-phase ZEM/ZEV guidance law is mainly intended for orbital intercept or rendezvous maneuvers without such a surface collision avoidance constraint, and it assumes an independent control acceleration along each axis. However, the single-phase ZEM/ZEV guidance law, employed for powered descent soft landing maneuvers with an inherent constraint on the magnitude of the control thrust vector, often exhibits unacceptable surface collisions.  Consequently, a new two-phase ZEM/ZEV guidance law is proposed for Mars or lunar landing maneuvers, and it basically consists of: i) Phase-1 ZEV mode and ii) Phase-2 ZEM/ZEV mode. The Phase-1 ZEV mode attempts to mainly control the vertical descent rate to prevent the surface collision possibility, by using the maximum available thrust force and with less active control of both down range and cross range.  The effectiveness of the proposed new approach will be demonstrated by using illustrative examples of lunar and Mars soft landings.


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Guang Meng is the Associate Dean of Shanghai Academyof Spaceflight Technology. His research interests include dynamics andvibration control of mechanical systems, nonlinear vibration, and micro electromechanical systems. He received the Ph.D. degree from Northwestern Polytechnical University, Xi’an, China, in 1988. In 1993, he was a Professor and the Director of the Vibration Engineering Institute, Northwestern Polytechnical University. From 1989 to 1993, he was also a Research Assistant with Texas A&M University, College Station, an Alexander von Humboldt Fellow with the Technical University of Berlin, Berlin, Germany, and a Research Fellow with the University of New South Wales, Sydney, Australia. From 2000 to2008, he was with Shanghai Jiao Tong University as the Cheung Kong Chair Professor, an Associate Dean, and the Dean of the School of Mechanical Engineering.


Topic: Micro-vibration Control of FY-4 Meteorological Satellite

The spacecraft is developing towards ultra-high precision, ultra-high stability and hyper-spectral sensing directions.Micro-vibration in satellite platform can significantly degrade the performance of payload, so that the micro-vibration analysis, control, measurement and experiment is very important to all kinds of high performance satellites. Considering the main vibration source on the FY-4 satellite and the requirement of the sensitive payload, the vibration suppression isolators are adopted to both vibration source and the sensitive payload. The parameters and sensitivity of the isolator unit is studied to give basic vibraiton suppression design guide line. Based on the isolator unit, the research on the hexapod vibration isolation chasis for flywheel is carried out both theoritically and experimentally. For the sensitive payload vibration isolation, a three-pointsupport using isolator and damper is proposed and the vibration isolation performance is studied. The vibraiton isolation of the interferometer can be seemed as second level vibraion isolation and can further reduce the vibraiton. The low-frequency suspension system and ultra-quiet labotary are used to fulfill the micro-vibration experiment on ground. The on-orbit vibration measurement system is carried on FY-4 satellite and the real data shows that themicro-vibraiton level can be suppressed to under 0.1mg which meet the satellite requirement. The micro-vibration suppression and experiment technique are of great significance and can also be used to other similar satellite.


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Filippo Graziani has been professor of Astrodynamics at Aerospace Engineering School of Sapienza University of Roma for thirty five years till 2012 when he retired and has been dean of the School from 2004 to 2010. He is Member of the International Academy of Astronautics (IAA) and Member of IAA Trustees Board. His didactical and research activity has been mainly directed towards the“hands-on”space educational programs.

He participated in the main Italian space programs starting with the San Marco satellites in 1970 and he was the team leader of the Italian University Satellites Program (UNISAT) with the aim of  designing, manufacturing, launching micro satellites with his students. Ten micro satellites have been launched since 2000.

In 2012 he founded the company GAUSS (Group of Astrodynamics for the Use of Space Systems) as a spin-off of the Aerospace Engineering School, active in the space technology field and he is President and CEO. He is author of more than 200 technical papers on Astrodynamics and Space Systems. He is Co-Editor of Acta Astronautica since 2009. He received the“Utkin Golden Medal” for international relationship between Russia and Italy for University Satellites Launches and the “M.K.Yangel -100 years Golden Medal for the contribution to the development of space science in the world.


Topic: GAUSS Activities on Attitude and Orbital Control Systems

To Be Completed.


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Professor Chen is a research fellow of National Innovation Institute of Defense Technology, a corresponding member of International Academy of Astronautics(IAA), a member in International Astronautical Federation (IAF), a member in the robotics committee of Chinese Society of Astronautics, and an editorial board member in some major journals like International journal of Mechanics and Materials in Design, Journal of Astronautics, and Aerospace China. Prof. Chen took in charge of developing Tian-Tuo (TT) series micro/nano satellites (10 satellites divided into 3 sets). Under his leadership, his team accomplished Tian-Yuan 1 on-orbit refueling satellite flight test, which is the second time in the world after the United States. He established advanced overall design theory of flight vehicles featuring multi-disciplinary design optimization(MDO). Prof. Chen published 7 monographs and more than 180 academic papers, in which there are about 94 papers indexed by SCI. Prof. Chen was selected in New Century Talent Supporting Project by the Ministry of Education in 2008, and financially supported by National Fund for Distinguished Young Scholars and National Defense Science and Technology Excellent Youth Talent Fund.


Topic: Research on Micro-/Nano-Satellite System Design and Dynamics Development

With the characteristics of small size, light weight, short-development period, effective and flexible launch mode, micro-/nano-satellite has become an important part of space systems and is one of an important development directions of space technology. This report will firstly introduce the overview of “Tiantuo” satellite team from National University of Defense Technology. The “Tiantuo” satellite team has successively developed and launched 10 micro-/nano-satellites, and obtained a large number of original achievements represented by the “TT” series Micro-/Nano-satellites. In view of the problems encountered in the development of micro-/nano-atellite, this report will analyze the significance of the system design and dynamics research for micro-/nano- satellites. Then, this report will introduce the research achievements of “Tiantuo” team in the field of micro-/nano-satellite system design and dynamics research, including multi disciplinary optimization design (MDO) of satellite, high-precision filter algorithms for micro-nano-satellites, dynamics and control for spacecraft formation, spacecraft formation coordinated control, etc. And then, this report will introduce the verification results of “Tiantuo” team in the field of micro-/nano-satellites, including basic information and innovative achievements for projects like “Tiantuo 1”, “Tiantuo 3” and “Tianyuan 1”. Finally, this report will forecast the future development tendency of micro-/nano-satellite.


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Eberhard Gill, born 1961 in Germany, received a diploma in physics and holds a PhD in theoretical astrophysics of the Eberhard-Karls-University Tuebingen, Germany. He holds a Master of Space Systems Engineering of the Delft University of Technology.

He has been working as researcher at the German Aerospace Center (DLR) from 1989 to 2006 in the field of precise satellite orbit determination, autonomous navigation and spacecraft formation flying. He has developed a GPS-based onboard navigation system for the BIRD microsatellite. Dr. Gill has been Co-Investigator on several international missions, including Mars94-96, Mars-Express, Rosetta, Equator-S and Champ and acted as Principal Investigator on the PRISMA formation flying satellite mission. Since 2007, he holds the Chair of Space Systems Engineering at the Faculty of Aerospace Engineering of the Delft University of Technology. The chair has developed the nano-satellites Delfi-C3 and Delfi-Next, successfully operating since their launches in 2008 and 2013. In 2013, he has been appointed also as department head Space Engineering at the faculty. The research interests of Dr. Gill are miniaturized space systems, navigation, distributed space systems and Systems Engineering.

Dr. Gill has authored or co-authored more than 250 journal articles and conference papers and four text books: Relativity and the Earth's Rotation (Springer 1990), Satellite Orbits (Springer 2000), Applied Space Systems Engineering (McGraw-Hill 2009) and Distributed Space Missions for Earth System Monitoring (Springer 2013). He holds three patents on GNSS applications, attitude control systems and Formation Flying. He has been awarded Senior Scientist of DLR in 2006. Dr. Gill has been cluster lead of MISAT, a large research program on Micro-Systems Technology. He is chairman to several conferences, editor of text books and Journals. Dr. Gill served as research advisor for universities and as board member for research institutions. In 2008-2011, he has been program director of the SpaceTech post-graduate program. In 2014, he has been appointed full member of the International Academy of Astronautics (IAA). Since 2015, he is also founding Director of the TU Delft Space Institute.


Topic: Proximity Operations of Distributed Space Systems

Where are we today and what are the prospects for proximity operations of space systems? Applications of proximity operations and associated missions have gone a long way, starting with expensive operations of Gemini in the mid-sixties, extending to the demonstration of autonomous serving capabilities today and reaching out to unprecedented functionalities, such as in-orbit assembly in the future.


Such progress goes along with rapid development of technology on sensor and actuator level, areas such as distributed computing, but also enhanced operations and innovative space architectures. The keynote will not only address the progress on applications and technology, but also cover regulatory and international aspects, which will play an ever-increasing role for critical future space applications such as counter-space activities as well as active space debris removal.


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Professor Lin Liu is currently working at the School of Astronomy and Space Science at Nanjing University. He is a specialist on celestial mechanics and astrodynamics. He is recognized as one of the founders of astrodynamics in China. For all his life, he is dedicated to the researches concerned with celestial mechanics, and studies and applications of astrodynamics. In recent years, he has made important contributions to many Chinese space activities, such as the Shenzhou spacecraft and the moon explorations.

Most of his original work are concerned with Chinese space activities. In the last decades, he focused on orbital mechanics of deep space probes. He is the leader of many research projects. He is the author of over 250 journal papers, and more than 10 books and one translated work. He is the receiver of the major achievement award at the National Conference on Science in 1978. He is the receiver of the Zhang Yuzhe award. he has won the second class Science and Technology Progess Award of Ministry of Education for three times. He was a council member of Chinese Astronomical Society and was the president of the committee of celestial mechanics and satellite dynamics. He was a council member of Chinese Society of Astronautics. He was in the editorial board of many journals such as Journal of Astronautics, Chinese Journal of Space Science, etc. Currently, he serves as a member of the editorial board of Acta Astronomica Sinica, and an academic committee member of the Center of Space Exploration, Ministry of Education, an invited expert of the National Astronomical Observatories of the Chinese Academy of Sciences, an associated member of COSPAR, etc.

  To honor Prof. Lin Liu’s contribution, the asteroid 261936 is renamed as his name by the IAU minor planet center.


Topic: A Review on the Orbital Mechanics and Its Applications

Orbits are fundamental to space systems. They are involved in many aspects of space missions, from orbit design to launch trajectories, and from ground station observations to various applications. Usually, there are three stages for a practical study concerned with orbits: (1) proper choice of the dynamical model; (2) accurate solutions to the model; (3) relate the solutions to real systems to reflect the dynamics of the orbits.

Spacecraft are actually artificial small bodies in the solar system. As to the fundamental models for their orbits, according to current studies and experiences, there are two such models --- the perturbed two-body problem and the perturbed restricted three-body problem.

For orbiters around one center body, based on the widely used mean element method, our group proposes its improved form – the quasi-mean element method. Using this method, we are able to avoid the singularities of the solution. This method is already used in many applications including orbit design, ground observation, and onboard control. For other types of orbiters, our group also gives some special solutions, which are used by lunar exploration missions and some related space missions. In a word, these solutions are currently used in many practical applications of our space system, including orbit design, orbit control, orbit determination and orbit prediction.

Currently, for satellites, our group has already obtained complete analytical solutions truncated at the second order. One problem remains to be solved is the model for surface forces acting on the satellites, i.e., the solar radiation pressure and the atmosphere. Especially for the atmosphere, accurate description of the force is crucial for low-altitude (~100 – 200 km) applications, such as the precise decay prediction of various spacecraft and space debris. Focusing on this problem, under the condition of no accurate information from theories and ground simulations, we discuss the possibility to build force models for h=100 – 200km by sending satellites to this height.