David Gondelach is a PhD student at the Surrey Space Centre (SSC) under supervision of Dr Roberto Armellin. Before joining the University of Surrey, he obtained a M.Sc. (cum laude) in aerospace engineering at Delft University of Technology, graduating on low-thrust trajectory design. In 2015 he started his PhD at the University of Southampton and was a visiting student at the Universidad de La Rioja in Spain. His research at the SSC focuses on the prediction and analysis of orbits for space situational awareness, for example the re-entry prediction of GTO rocket bodies and stability analysis of Galileo disposal orbits. During his PhD he worked on the ESA project "Technology for Improving Re-Entry Predictions of European Upper Stages through Dedicated Observations" and participated in the 9th Global Trajectory Optimization Competition (GTOC9) with the Mission Learners team.
Astrodynamics and celestial mechanics:
- Re-entry prediction of GTO rocket bodies
- Stability analysis of MEO disposal orbits
- Multi-revolution perturbed Lambert solvers
- Uncertainty propagation
- Semi-analytical propagation
to the high sensitivity of the final state to variations of the initial velocity. In this work two
different solvers based on high order Taylor expansions and an analytical solution of the J2
problem are presented. In addition, an iteration-less procedure is developed to refine the
solutions in a dynamical model that includes J2 ? J4 perturbations. The properties of the
proposed approached are tested against transfers with hundreds of revolutions including those
required to solve the Global Trajectory Optimisation Competition 9.
prediction of rocket bodies in eccentric orbits
based on TLE data, Mathematical Problems in Engineering 2017 7309637 Hindawi Publishing Corporation
impact risks to the Earth's surface when they re-enter the Earth's at-
mosphere. To mitigate these risks, re-entry prediction of GTO rocket
bodies is required. In this paper, the re-entry prediction of rocket bod-
ies in eccentric orbits based on only Two-Line Element (TLE) data
and using only ballistic coefficient (BC) estimation is assessed. The
TLEs are preprocessed to filter out outliers and the BC is estimated
using only semi-major axis data. The BC estimation and re-entry pre-
diction accuracy are analyzed by performing predictions for 101 rocket
bodies initially in GTO and comparing with the actual re-entry epoch
at different times before re-entry. Predictions using a single and mul-
tiple BC estimates and using state estimation by orbit determination
are quantitatively compared with each other for the 101 upper stages.
ground population. Predictions are particularly difficult for objects in highlyelliptical
orbits, and important for objects with components that can survive
re-entry, e.g. rocket bodies (R/Bs). This paper presents a methodology to
filter two-line element sets (TLEs) to facilitate accurate re-entry prediction
of such objects. Difficulties in using TLEs for precise analyses are highlighted
and a set of filters that identifies erroneous element sets is developed. The
filter settings are optimised using an artificially generated TLE time series.
Optimisation results are verified on real TLEs by analysing the automatically
found outliers for exemplar R/Bs. Based on a study of 96 historical
re-entries, it is shown that TLE filtering is necessary on all orbital elements
that are being used in a given analysis in order to avoid considerably inaccurate
- Gondelach, D. J. and Armellin, R. (2018). Element sets for high-order Poincaré mapping of perturbed Keplerian motion. Celestial Mechanics and Dynamical Astronomy, 130(10):65. https://doi.org/10.1007/s10569-018-9859-z.
- Armellin, R., Gondelach, D., and San Juan, J. F. (2018). Multiple revolution perturbed Lambert problem solvers. Journal of Guidance, Control, and Dynamics, 41(9):2019–2032. https://doi.org/10.2514/1.G003531
- Gondelach, D. J., Armellin, R., and Lidtke, A. A. (2017). Ballistic coefficient estimation for reentry prediction of rocket bodies in eccentric orbits based on TLE data. Mathematical Problems in Engineering, 2017. Article ID 7309637. https://doi.org/10.1155/2017/7309637.
- Gondelach, D. J., Armellin, R., Lewis, H. G., San Juan, J. F., and Wittig, A. (2017). Semianalytical propagation with drag computation and flow expansion using differential algebra. In Proceedings of the 27th AAS/AIAA Space Flight Mechanics Meeting, February 5-9, 2017, San Antonio, TX. Univelt, Inc., San Diego.
- Lidtke, A. A., Gondelach, D. J., Armellin, R., Colombo, C., Lewis, H. G., Funke, Q., and Flohrer, T. (2016). Processing two line element sets to facilitate re-entry prediction of spent rocket bodies from the geostationary transfer orbit. In Proceedings of the 6th International Conference on Astrodynamics Tools and Techniques, Darmstadt, Germany.
- Gondelach, D. J., Lidtke, A., Armellin, R., Colombo, C., Lewis, H. G., Funke, Q., and Flohrer, T. (2016). Re-entry Prediction of Spent Rocket Bodies in GTO. In Proceedings of the 26th AAS/AIAA Space Flight Mechanics Meeting, February 14-18, 2016, Napa, CA. Univelt, Inc., San Diego.
- Gondelach, D. J., and Noomen, R. (2015). Hodographic-Shaping Method for Low-Thrust Interplanetary Trajectory Design, Journal of Spacecraft and Rockets, Vol. 52, No. 3, pp. 728-738. https://doi.org/10.2514/1.A32991