Professor Vaios Lappas

Biography

Vaios graduated with a Bachelor in Aerospace Engineering from Ryerson University, Toronto, Canada in 1998. His thesis involved designing a Single Stage to Orbit Simulator merging animation and modelling techniques. He went on to do a Masters of Space Studies at the International Space University, Strasbourg, France and graduated in 1999. His master’s thesis took place at the Systems Engineering Division of NASA’s Goddard Space Flight Center (GSFC) and Vaios worked on flight dynamics analyses for the Space technology ST-5 nanosatellite program. Vaios went on to do his PhD in 1999 at the Surrey Space Centre, School of Electronics and Physical Sciences, University of Surrey. He completed his PhD in October 2002 on ‘A Control Moment Gyroscope (CMG) based Attitude Control Subsystem (ACS) for Agile Small Satellites’. During his PhD Vaios also worked on the attitude control of the SNAP-1 nanosatellite program and was a teaching assistant for various courses. From 2002 till the end of 2004 Vaios was a research fellow at the Surrey Space Centre, working on various topics including CMGs, solar sail systems design, solar sail attitude control and Mars ascent vehicles, research that was funded by the European Space Agency. Since December 1, 2004 Vaios was appointed lecturer in Attitude/Orbit Control Systems.

Research Interests

Research in Space systems at Surrey is dominated by practical results. Having contributed to the design and launch of 26 spacecraft (2006) SSC has a strong practical perspective in space research. Vaios’s research is mainly focused on 3 areas: (i) attitude control and determination (ii) advanced concepts and (iii) propulsion.

Control Moment Gyroscopes (CMGs)

Vaios has developed these small yet powerful actuators for the next generation of agile spacecraft. CMGs are usually complex and expensive and have flown on space stations and military spacecraft. Developments in microelectronics and mechatronics has enabled a new approach towards the design of smaller, affordable and low cost CMGs. Vaios demonstrated the viability of CMGs for small satellites and designed the first commercial small satellite CMGs currently in orbit on the Turkish BILSAT-1 microsatellite. This project was funded by SSTL, ESA and the Turkish Academy of Sciences (TUBITAK). Under funding from ESA Vaios is leading the design of an improved and scalable CMG design for small satellites. Vaios is working closely with Prof. Bong Wie on the development of these CMGs along with various singularity avoidance algorithms.

Solar Sails

Solar Sails have become one the ‘hottest topics’ in the space community and specifically in the systems design and attitude control aspects. Solar Sails come with the promise of propelling spacecraft with unprecedented ΔVs without ‘propellant’. Solar Sails work as protons reflect on a large reflector surface. Vaios has been the PI and study manager for a miniature 5 x 5 m micro sail for a study funded by ESA. Micro Solar Sails come with the promise of low cost propellantless systems that do not have the technology challenges of large solar sails (design, dynamics, control, manufacture) and can be used in formations to study niche science objectives such as monitoring the Earth’s geomagnetic tail. On the other spectrum Vaios participated in an ESA funded studied managed by Kayser Threde and dealt with the conceptual design of a 245 x 245 m solar sail called the Interstellar Heliopause Probe (IHP). Surrey was responsible for the small satellite platform design and the overall spacecraft/sail GNC system. Vaios is also working closely together with Prof. Bong Wie on various systems and ACS concepts for Solar Sails.

Combined Energy Storage and Attitude Control Systems (CEACS)

CEACS comes with the promise of reducing the mass of a spacecraft, which has high power and ACS requirements. Vaios is the PI on a USAF contract which is studing the sizing, design and proof of concept of such technology for small satellites. Further, Vaios with his PhD student David Richie are working on the same research contract for the USAF on studying various control algorithms for a large scale CEACS system developed by the USAF in the Air Force Research Laboratories in Kirkland, NM, USA.

UAV’s

Unmanned Aerial Vehicles have become important tools for reconnaissance and robotic missions. Vaios is researching systems and algorithms for autonomous systems using a 3-m UAV helicopter. The ‘ICARUS’ vehicle will also be used to demonstrate robust algorithms for terminal descent Mars Lander simulations.

Mars Landers and Mars Ascent Vehicles

Vaios has worked on the system design and GNC algorithms for Mars landers and ascent vehicles with MSc and PhD students. This research was funded by the ESA Aurora program.

Spacecraft Simulator

Space engineering despite progress made in low cost design is still and expensive and complex business. A spacecraft simulator based on a 3-axis air bearing is being designed at Surrey. George Prassinos is leading this effort which will include propulsion and CMG modules for agile 3-axis control.

1-m Resolution Small Satellites

Funded by SSTL this research activity explores the technological shortcomings on developing the next generation of 1-m resolution Earth Observation spacecraft. Based on the known concept of the Dobson telescope Surrey is studying the technology for future use. George Prassinos is currently conducting his MPhil on this subject.

Formation Flying/Coulomb and Lorentz Formations

Surrey and Cornell Universities are working together on a research grant by ESA ACT (Ariadna) on formation flying missions using Lorentz and Coulomb charging techniques. Mini Saaj, a research fellow from Surrey is actively working on a hybrid combination of the two techniques under supervision by Vaios and Mason Peck, Assistant Professor, Cornell University.

Propulsion

Propulsion is a key research area at Surrey. Micro-resistojet thrusters have been mastered at Surrey, many of them having flown on UoSAT-12, SNAP and DMC spacecraft. Vaios is supervising two PhD students on electric propulsion: Peter Shaw working on Plasma Pulsed Thrusters and Angelo Grubisic working on micro hollow cathode tubes.

Research Collaborations

Vaios work closely with Prof. Bong Wie (Arizona State University), Mason Peck (Cornell), Prof. Jozef van der Ha (consultant), Prof. N. Uzunoglou (NTUA), Prof. E. Sarris (Democritus-Thrace) and Jerry Fausz (USAF). Internally Vaios works with all academics in SSC and is assisting Dr. Craig Underwood on the Palmsat program.

Publications

Teaching

Vaios teaches undergraduate and postgraduate courses in the School of Electronics. These include Spacecraft Dynamics and Control (EE3.dyc), Launch Vehicles and Propulsion (EEM.lvp), Satellite Subsystems (EE3.sbs) and Control Engineering (EE3.ctl). Vaios also supervises undergraduate and postgraduate students in topics such as: attitude control, micro UAVs, Mars Lander dynamics and control, solar sail attitude control.

PhD Students

Vaios is currently supervising 3 PhD students: Peter Shaw on PPTs, Angelo Grubisic on micro-HCT, David Richie on CEACS, Alice Darbyshire on CMGs and he also has worked with Sajjad Ashgar (CMGs) and Stephen Wokes (solar sails) who are supervised by Dr. Palmer and Prof. Mark Roberts.

Awards

• AIAA Utah Small Satellite Student Competition (3rd Place), 2000
• IAF Student Competition (1st place) 2001
• Canadian Space Agency Caroline Babin award (2000)
• Best paper, co-author with Jozef van der Ha, AAS Astrodynamics Specialist Conference (lake tahoe), 2006
• Scholaships: EUMETSAT, SSTL, EPSRC, Canadian Space Agency, ESA
• Grants (royal Society, UniS, Institute for Advanced Studies)

Consulting

• Vaios consults for the Hellenic Space Systems company.