Apply for MSCA E-Sailors Doctoral Researchers Positions at Tartu Observatory
The application period is from 3 December, 2025 to 31 January, 2026.
The Electric solar wind Sail doctors (E-Sailors) is a challenge-based Doctoral Network funded by the European Union’s Horizon Europe Marie Skłodowska-Curie Actions (MSCA). The network aims to advance Electric solar wind sail (E-sail) from Low Earth Orbit (LEO) demonstration missions to the operational environment of the solar wind. The project network includes 8 universities including FMI, where E-sail was invented, and 4 companies.
E-sail is a highly innovative and potentially disruptive propellantless propulsion system. An operational E-sail consists of hair-thin and kilometres-long wires, or tethers, which are charged at a high voltage creating an electrostatic sheath (electric sail) which deflects solar wind particles and generates the propulsive effect in interplanetary environment. Successful and rapid development and deployment of the technology will ensure EU's leadership in the exploration and exploitation of deep space, the next commercial space frontier.
The programme is designed to achieve the following training objectives for our doctoral candidates (DC):
- Equip them with core scientific skills and specialised knowledge in designing experiments for demonstrating space technologies and developing space missions;
- Provide them with a wide range of transferrable skills, such as Open Science and FAIR, communicating science to public, advocacy, networking etc.;
- Develop their business and entrepreneurship skills, such as IPR management, preliminary business planning, pitching to investors, starting start-ups.
This DC position “E-Sailor 1” will be responsible for advancing the ESTCube-LuNa concept in terms of supporting the E-sail experiment design with high-fidelity orbital simulations. In accordance, the DC shall be responsible for establishing the deep space E-sail mission design. In the scope of the E-Sailors DN as a whole, E-Sailor 1 will set requirements for the E-Sail payload and nano spacecraft platform and establish the E-sail characterization with radio frequency (RF) ranging and Langmuir probes. The PhD study shall enable the doctoral candidate to be trained as a leader of future missions, capable of inventing and defining experiments and communicating requirements to engineering teams.
E-Sailor 1 will work on simulation software Electric Sail Mission Expeditor (ESME) which can simulate the Coulomb drag interaction (the phenomenon that creates the E-sail force) between the solar wind and electrostatic sheath around the E-sail tether(s). The DC will be responsible for the following tasks.
1) E-Sailor 1 will be tasked to develop high-fidelity simulations of the ESTCube-LuNa E-sail experiments. Currently, the ESTCube-LuNa E-sail experiment has been simulated over two approaches. One simulation is over realistic Coulomb drag interaction developed in ESME where the spacecraft is placed in the solar wind conditions of 1 AU but not integrated in orbit propagator (this provides the thrust estimate). Second simulation is developed in General Mission Analysis Tool (GMAT) software where the thrust is emulated with an electric thruster and the spacecraft is placed in orbit around the Moon (this provides the orbital change estimate). The first paper of E-Sailor 1 will focus on simulating the full ESTCube-LuNa E-sail experiment in ESME where an orbit propagator will be implemented by another E-Sailor DC.
2) E-Sailor 1 will be tasked to simulate the ionospheric conditions in ESME and replicate the Foresail-1p experiment sequence. The Foresail-1p mission, developed by Aalto University, with an E-sail payload, developed by the FMI. E-Sailor 1 shall analyse Foresail-1p E-sail experiment through robust simulation studies in ESME as well as identify other relevant mission profiles in accordance with mission. Foresail-1p will operate in the LEO ionosphere where the E-sail works as the “plasma brake” for deorbiting.
3) E-Sailor 1 will be tasked to develop a new space plasma physics mission concept. For the future application of ESTCube-LuNa-style mission, we are considering a space plasma physics concept where a fleet of nano spacecraft would characterize the solar wind interaction with the Earth’s magnetic field (however, we are open for different innovative concepts to emerge). The E-sail will be used for keeping the relative and absolute positions of the fleet and the Langmuir probe is already a valuable solar-wind instrument. In addition, we propose to equip the new concept with a miniature magnetometer on a boom (e.g. similar to the one of Foresail-2 mission concept).
Hosts: University of Tartu, Tartu Observatory (Estonia), Finnish Meteorological Institute (Finland) and company Spacecraft Anatomy OÜ (Estonia)
Supervisor: Dr. Aditya Savio Paul (UT)
Co-supervisor(s): Prof. Mihkel Pajusalu (UT), Prof. Pekka Janhunen (FMI), Dr. Iaroslav Iakubivskyi (SA)
This DC position “E-Sailor 11”, is dedicated to the research, development, and implementation of advanced visual navigation algorithms on embedded systems, specifically microcontroller (MCU) and field-programmable gate array (FPGA) platforms. The project contributes to the broader ESTCube-LuNa mission, which aims to demonstrate novel plasma brake and E-sail technologies in lunar orbit while advancing autonomous spacecraft navigation capabilities. The doctoral work will require a strong combination of algorithmic innovation, embedded hardware design, system-level integration, and experimental validation.
E-Sailor 11 will work in close collaboration with E-Sailor 12 at Riga Technical University (RTU), Latvia, whose focus is the design, evaluation, and optimization of the navigation algorithms on high-performance, PC-based pipelines. E-Sailor 11 will adapt these algorithms for real-time execution on resource-constrained flight hardware. In addition, the candidate will receive access to photorealistic synthetic datasets, hardware-in-the-loop simulators, and real-time rendering tools through collaboration with E-Sailor 15 at RTU, enabling rigorous testing under realistic mission conditions.
From the point of view of on-board execution, the following functions will be developed and implemented by E-Sailor 11:
1. Simplified MCU-based lunar orbit propagator. Building on uplinked orbital elements and the onboard time reference, the propagator will compute an approximate position of ESTCube-LuNa within its lunar orbit. The propagated state, combined with the known spacecraft attitude, will predict the expected presence and location of major celestial bodies (Moon, Earth, Sun) in the TCN camera images. This prediction capability is essential for cross-checking observations, identifying anomalies, and maintaining navigation robustness, particularly when outdated orbital elements, persistent perturbations, or E-sail maneuvers introduce trajectory deviations. The propagator is also crucial for identifying eclipse periods, when the Earth, Sun, or both are occluded by the Moon, thus informing power, thermal, and communication strategies.
2. FPGA-based image classification and object position determination. E-Sailor 11 will design and implement a high-performance, low-latency FPGA pipeline capable of processing imagery from the spacecraft’s five onboard cameras. The goal is to identify which images contain which celestial body and to estimate each object’s apparent size and location within the image. These measurements will then be transformed into the spacecraft reference frame to enable accurate triangulation. The FPGA solution will contribute directly to autonomous attitude estimation by complementing star tracker data, Sun sensor outputs, and gyroscope readings. This task constitutes one of the most technically challenging aspects of the project, requiring deep expertise in digital hardware design, fixed-point arithmetic, computer vision, and real-time system constraints.
3. Orbital triangulation, attitude determination, and Kalman filtering. Using the extracted line-of-sight information and newly calculated object positions, the system will perform triangulation to refine the spacecraft’s orbital state. These estimates, fused with attitude measurements from multiple sensors, will feed into an onboard Kalman filter. The filter will integrate new observations with the current state estimate, improving robustness, reducing drift, and enabling autonomous navigation even during communication gaps or partial sensor outages. This subsystem embodies the full integration of algorithmic theory, embedded implementation, and system-level validation.
We consider the visual navigation implementation on FPGA to be the most novel and scientifically significant contribution of the E-Sailor 11 project. We foresee the following development steps:
a) Develop the FPGA gateware architecture, including image classification modules, object detection kernels, and coordinate transformation stages, optimised for radiation-tolerant, resource-constrained hardware. b) Develop comprehensive testbenches and verify designed FPGA components in simulation, ensuring functional correctness, timing closure, and pipeline stability. c) Validate simulation results through algorithmic cross-comparison with CPU-based implementations developed jointly with E-Sailor 12. d) Design an end-to-end test setup and perform screen-in-the-loop experiments, in which flight-representative cameras observe photorealistic rendered scenes in a controlled environment, reproducing diverse illumination and geometric conditions. e) Use Git for rigorous version control, documentation, and traceability in accordance with scientific reproducibility and space-mission development standards.
Overall, this doctoral topic offers a unique opportunity to contribute to next-generation autonomous navigation systems for deep-space missions. It combines theoretical research with hands-on, hardware-validated implementation, preparing the candidate for high-level careers in academia, space systems engineering, or advanced embedded vision technologies.
Secondment: The DC will also be co-supervised by Dr. Jaan Viru while spending 6 months at CrystalSpace (Estonia).
Hosts: University of Tartu, Tartu Observatory, Company Nanocraft SIA (Latvia)
Supervisor: Dr. Aditya Savio Paul
Co-supervisor(s): Prof. Mihkel Pajusalu, Dr. Andris Slavinskis, Dr. Jaan Viru
This DC position “E-Sailor 14”, shall advance the ESTCube-LuNa mission concept by developing, analyzing, and validating control algorithms for the first-ever demonstration of the electric sail (E-sail) in the solar wind. In addition to contributing to this near-term mission, the doctoral candidate will conduct forward-looking research into advanced control strategies tailored for future large-scale deep space missions employing full E-sail architectures. The work encompasses theoretical modelling, algorithm development, simulation studies, and mission-level performance analysis, positioning the candidate at the center of a cutting-edge, rapidly developing field in space propulsion and autonomous spacecraft control.
Full-scale E-sail missions rely on remote units located at the distal ends of the long, charged E-sail tethers. These remote units include small thrusters that enable fine control of tether tension, spin-plane orientation, and overall sail deployment, working in conjunction with the sail’s charge modulation system. However, the ESTCube-LuNa demonstration mission does not include such remote units, which imposes unique constraints on deployment dynamics and in-flight control. Without the ability to actively reorient the spin plane, the system becomes largely inertially fixed, requiring new approaches to achieve the desired E-sail behavior in the varying environment of lunar orbit and, prospectively, the solar wind. Developing, analysing, and validating these novel methods constitutes the scientific core of the E-Sailor 14 project.
The doctoral candidate will be responsible for the following tasks:
1. Analyze inertially fixed spin-plane E-sail maneuverability and thrust/torque behavior in lunar orbit. This includes developing high-fidelity dynamical models of the spacecraft–tether system, quantifying achievable maneuvers, evaluating control authority under realistic perturbations, and characterizing expected thrust and torque profiles during various phases of the mission. Special attention will be given to how solar wind variability, plasma interactions, and the absence of remote units influence control performance. The results will form the foundation for mission feasibility assessments and control design.
2. Implement E-sail control methods in the open-source Electric Sail Mission Expeditor (ESME). The candidate will integrate new and existing control algorithms into ESME’s simulation framework, contributing to its development as a community tool for modelling E-sail missions. This task involves software engineering, validation of numerical stability and accuracy, and designing reproducible simulation campaigns that can be used both within the project consortium and by external researchers.
3. Design multiple approaches for E-sail deployment, spin-plane orientation, and spin-rate control.
Doctoral research will explore innovative concepts such as differential voltage modulation, asymmetrical tether charging, dynamic spin-up strategies, and alternative deployment sequences compatible with the ESTCube-LuNa hardware limitations. These approaches will be evaluated for robustness, feasibility, and efficiency under operational constraints, ultimately identifying viable pathways for demonstrating controlled E-sail operation without remote units.
4. Provide detailed control studies on the most suitable applications of each spin control method. The candidate will perform extensive performance analyses, examining stability margins, sensitivity to uncertainties, potential failure modes, and mission-level benefits of each control strategy. These studies will help determine which methods are best suited for near-term E-sail demonstrations, which are promising for full-scale deep space missions, and how the design of future E-sail systems should evolve to maximise performance and reliability.
Overall, this doctoral project offers a unique opportunity to shape the future of propellantless deep-space propulsion. It combines theoretical spacecraft dynamics, cutting-edge control system design, numerical simulation, and mission-level analysis—preparing the candidate for advanced careers in space mission design, plasma-based propulsion, and autonomous spacecraft control.
Hosts: University of Tartu, Tartu Observatory and company Aurora Propulsion Technologies OY (Finland)
Supervisor: Dr. Aditya Savio Paul (UT)
Co-supervisor(s): Prof. Mihkel Pajusalu (UT), Dr. Perttu Yli-Opas (APT)
How to apply
All the application documents must be submitted via DreamApply by the deadline: https://estonia.dreamapply.com/courses/course/1495
Kindly refrain from questions about the status of the selection process. We will inform you as soon as there is an update.
Candidates whose application is not compliant with the requirements below will not be considered.
Application deadline: 31 January, 2026 at 11:59 PM EET
Expected starting date: 1 May, 2026
Applications and enclosures received after the deadline will not be considered.
Requirements for PhD position
Master’s degree in aerospace engineering, space technology, physics, mechanical engineering, computer science or closely related field. Copies of bachelor's and master's diplomas and academic transcripts/diploma supplements (with translations, if applicable) must be submitted. Candidates may apply prior to obtaining their master’s degree and submit the most recent master’s transcript, but cannot receive an employment contract before having obtained the master’s degree. Master’s graduation documents must be submitted by 1st April at the latest.
Curriculum vitae
Excellent command of written and spoken English. More information on language requirements - https://ut.ee/en/sisu/phd-language-requirements
Copy of passport
Motivation letter – explaining the following topics:
Research experience and independent work experience evident through technical projects, theses, publications, or technical reports. This includes the evidence of innovative thinking or novel approaches to technical problems, the ability to synthesize information from multiple sources to advance understanding and demonstrated curiosity and persistence in pursuing technical challenges.
- Strong academic and development track record with demonstrated proficiency in orbital mechanics and propagators (GMAT, STK, or similar), propulsion systems, spacecraft dynamics, space systems, space mission and environment analyses, cubesats, small spacecraft systems, space plasma physics, software development and version control (Git), simulation software development (experience in multiple fields are considered beneficial).
- Familiarity with simulation software and numerical methods and proficiency in programming languages (Rust, Python, MATLAB, C/C++, or similar) for simulation and data analysis.
- Experience in managing multiple concurrent tasks and priorities independently and track record of meeting project deadlines and delivering results without constant supervision.
- Proven ability to work autonomously on complex technical problems and demonstrated problem-solving skills in technical/engineering contexts.
- Leadership experience in terms of leading or significantly contributing to multi-month technical projects and taking initiative in research or development activities.
- Experience working with interdisciplinary and international teams while maintaining individual accountability, such as driving projects forward without extensive guidance.
- Example of at least one practical project completed within the deadline with minimal supervision, and evidence of self-motivation and proactive problem-solving. Please submit description of personal contributions and level of independence, project outcomes and impact, and references in terms of publications, theses, technical reports, simulations, analysis, code samples, or documentation (multiple references are considered beneficial).
The primary workplace will be in Tartu, Estonia. Therefore, candidates from outside the EU must be eligible to obtain a visa. The position is expected to start in the first half of 2026.
Residency history of the last 36 months and main activity (work, studies, etc.) in the country of the host organization of last 36 months.
As events are foreseen, applicants must be ready to travel.
Letter of recommendation, and contact details of at least one academic or professional reference
Please download and complete this form and submit it together with the required application documents:
Eligibility requirements
- The applicant must have MSc degree or equivalent.
- The applicant must not already be in possession of a doctoral degree at the date of the recruitment.
- At the time of recruitment, the researcher must not have resided or carried out their main activity (work, studies, etc.) in Estonia for more than 12 months in the three years immediately prior to the recruitment date. Compulsory national service and/or short stays such as holidays are not considered.
Applicants can be of any nationality within the laws of the EU to enter the EU countries. Candidates may apply for multiple positions offered within E-Sailors, but should carefully choose the ones that they apply for.
Responsibilities
- Undertake innovative and independent research in terms of developing new concepts or improving existing methodologies. Carry out literature review, hypothesis development, and experimental design.
- Adapt, develop and learn new tools, software, and methodologies independently.
- Present and publish research in both academic and non-academic audiences. Attend and participate in academic and non-academic conferences, events and seminars.
- Communicate results in professional written English thorough reports and publications.
- Work independently while effectively communicating progress and challenges.
- Work in international teams and on interdisciplinary problems, while also identifying and addressing technical challenges independently.
- Stay current with relevant literature and technologies.
- Actively contributes to the public engagement and outreach activities of the project.
- The above job descriptions are not exhaustive, the PhD candidate may be required to undertake other tasks, which are broadly in line with the above duties and responsibilities.
- Full-time employment (40 hours per week) with a 100% in-person workload for 4 years (no remote or part-time possibility).
Benefits
- Competitive funding scheme, with a minimum gross monthly salary approximately of EUR 2600 (Estonia, Latvia) and EUR 2900 (Finland), topped by additional mobility allowances as well as optional family allowances (if applicable).
- While the MSCA Doctoral Network programme lasts 3 years, doctoral studies at the University of Tartu may continue for up to 4 years. The salary on the 4th year is less than on the previous years and it does not include the monthly allowances for mobility nor family. The exact gross salary on the 4th year depends on the minimum salary of junior research fellows at the University Tartu at that time (currently, it is EUR 2100 per month).
- Covered tuition costs, research costs and funding for short term mobility (i.e. conference attendance).
- Interdisciplinary and international research projects.
- Participate in 3 network-wide training schools.
- Personal and Career Development Plan.
- Early-stage researcher position, with corresponding social and medical benefits in Estonia.
- Becoming a Marie Skłodowska-Curie PhD fellow.
More information can be found from the E-Sailors project web page – esailors.ut.ee
E-Sailors project has received funding from the European Union’s Horizon Europe research and innovation program under the MARIE SKŁODOWSKA-CURIE grant agreement no 101227277.
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