Hera Orbit Determination Covariance Analysis of Didymos Binary Asteroid with the Full Two-Body Problem

@misc{gramigna2026hera,
  title = {{Hera Orbit Determination Covariance Analysis of Didymos Binary Asteroid with the Full Two-Body Problem}},
  author = {Edoardo Gramigna and Riccardo Lasagni Manghi and Marco Zannoni and Paolo Tortora and Michalis Gaitanas and Ioannis Gkolias and Kleomenis Tsiganis and Ryan S. Park and Alex Meyer and Petr Pravec},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.14784},
  eprint = {2610.14784},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.14784},
  note = {CC BY-NC-ND 4.0},
}

TY  - UNPB
TI  - Hera Orbit Determination Covariance Analysis of Didymos Binary Asteroid with the Full Two-Body Problem
AU  - Edoardo Gramigna
AU  - Riccardo Lasagni Manghi
AU  - Marco Zannoni
AU  - Paolo Tortora
AU  - Michalis Gaitanas
AU  - Ioannis Gkolias
AU  - Kleomenis Tsiganis
AU  - Ryan S. Park
AU  - Alex Meyer
AU  - Petr Pravec
PY  - 2026
DA  - 2026/10/10
PB  - arXiv
DO  - 10.48550/arxiv.2610.14784
UR  - https://arxiv.org/abs/2610.14784
AB  - Standard planetary radio science analyses may be inadequate for accurately interpreting data from the Hera mission at the Didymos system due to the anticipated challenge posed by the coupling between the translational and rotational motions of the asteroids. A more precise dynamical model, the full two-body problem model, which includes a mutual gravitational potential, may be required to fit the Hera data properly. This work presents a covariance analysis of the Hera radio science experiment using this advanced model. The tested dynamical scenarios are based on recent lightcurve observations indicating that Dimorphos is in an excited non-principal axis spin state that is, on average, tidally locked. Three non-principal axis scenarios are analyzed using a multi-arc local estimation approach instead of the global one adopted in previous investigations involving non-chaotic states. The results show that tumbling or chaotic cases significantly improve the recovery of the bodies' moments of inertia due to the enhanced observability of the system's dynamics from the excited spin state. However, the local estimation approach slightly degrades the accuracy of the mass estimation by a factor of 1.3-3 and Dimorphos' relative orbit by about one order of magnitude. Developing a dedicated constrained multi-arc filter is thus required to improve the estimation accuracy of the Didymos system's dynamical state further. Nevertheless, these results still meet the Hera radio science requirements.
ER  -