Didymos Gravity Science through Ground-based and Satellite-to-Satellite Doppler Tracking
- 1University of Bologna, DIN - Aerospace Division, Forlì, Italy (paolo.tortora@unibo.it)
- 2ESA/HQ, 75738 Paris Cedex 15, France
- 3ESA/ESAC, Villanueva de la Cañada (Madrid), Spain
- 4ESA/ESTEC, 2200 AG Noordwijk, The Netherlands
- 5Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, CS 34229, 06304 Nice Cedex 4, France
Hera is ESA’s contribution to an international effort supported by ESA and NASA named Asteroid Impact and Deflection Assessment (AIDA). NASA’s DART mission will first perform a kinetic impact on Didymos secondary, nicknamed Didymoon, then Hera will follow-up with a detailed post-impact survey, to fully characterize this planetary defense technique. Two CubeSats will be deployed by the Hera spacecraft once the Early Characterization Phase has completed.
The Hera spacecraft communicates with the ground station on the Earth by means of a standard two-way X-band system. The microwave signal is sent to the S/C from a ground antenna and coherently retransmitted back to Earth, where Doppler (the key observable for gravity science) and range measurements are obtained. In addition, Hera will track the two CubeSats by means of a space-to-space inter-satellite link (ISL). This represents a very nice add-on to the gravity investigation carried out by means of Hera tracking observables as the Doppler effect that affects the inter-satellite link contains the information on the dynamics of the system, i.e. masses and gravity field of Didymos primary and secondary.
We describe here the mission scenario for the gravity science experiments to be jointly carried out by the three mission elements, i.e. Hera, CubeSat#1 (named Juventas) and CubeSat#2, via Ground-based and Satellite-to-Satellite Doppler Tracking. Also, our results and achievable accuracy for the estimation of the mass and gravity field of Didymos primary and secondary are presented.
How to cite: Tortora, P., Gai, I., Lombardo, M., Zannoni, M., Carnelli, I., Kueppers, M., Martino, P., and Michel, P.: Didymos Gravity Science through Ground-based and Satellite-to-Satellite Doppler Tracking, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-12800, https://doi.org/10.5194/egusphere-egu2020-12800, 2020