ESA F-Class Comet Interceptor: Trajectory design to intercept a yet-to-be-discovered comet

Joan Pau Sánchez (1) , David Morante (2) , Pablo Hermosin (2) , Daniel Ranuschio (1) , Alvaro Estalella (1) , Dayana Viera (1) , Simone Centuori (2) , Geraint Jones (3, 4) , Colin Snodgrass (5) , Anny Chantal Levasseur-Regourd (6) , Cecilia Tubiana (7)

1 SATM - School of Aerospace, Transport and Manufacturing
2 Deimos Space S.L.U.
3 MSSL - Mullard Space Science Laboratory
4 CPS - Centre for Planetary Sciences [UCL/Birkbeck]
5 SUPA School of Physics and Astronomy [Edinburgh]
6 PLANETO - LATMOS
7 IAPS - Istituto di Astrofisica e Planetologia Spaziali - INAF

Comet Interceptor (Comet-I) was selected in June 2019 as the first ESA F-Class mission. In 2029+, Comet-I will hitch a ride to a Sun-Earth L2 quasi-halo orbit, as a co-passenger of ESA's M4 ARIEL mission. It will then remain idle at the L2 point until the right departure conditions are met to intercept a yet-to-be-discovered long period comet (or interstellar body). The fact that Comet-I target is thus unidentified becomes a key aspect of the trajectory and mission design. The paper first analyses the long period comet population and concludes that 2 to 3 feasible targets a year should be expected. Yet, Comet-I will only be able to access some of these, depending mostly on the angular distance between the Earth and the closest nodal point to the Earth's orbit radius. A preliminary analysis of the transfer trajectories has been performed to assess the trade-off between the accessible region and the transfer time for a given spacecraft design, including a fully chemical, a fully electric and a hybrid propulsion system. The different Earth escape options also play a paramount role to enhance Comet-I capability to reach possible long period comet targets. Particularly, Earth-leading intercept configurations have the potential to benefit the most from lunar swing-by departures. Finally, a preliminary Monte Carlo analysis shows that Comet-I has a 95–99% likelihood of successfully visit a pristine newly-discovered long period comet in less than 6 years of mission timespan.

Mots clés: Comet-I; Trajectory design; Hybrid propulsion trajectories; Third body effects; Lunar swing-by

Domaines: Planète et Univers [physics]

Joan Pau Sánchez, David Morante, Pablo Hermosin, Daniel Ranuschio, Alvaro Estalella, et al.. ESA F-Class Comet Interceptor: Trajectory design to intercept a yet-to-be-discovered comet. Acta Astronautica, 2021, 188 (November), pp.265-277. ⟨10.1016/j.actaastro.2021.07.014⟩. ⟨insu-03298829⟩