2019.A.3.3. A design trajectory strategy for Phobos small satellite mission


Pierpaolo Nigido (1)
Michel Grassi (1)
Raffaele Votta (2)
Alberto Fedele (3)

  1. University of Naples “Federico II”, Italy
  2. Italian Aerospace Research Center (CIRA), Italy
  3. Italian Aerospace Research Center (CIRA)




Phobos, Design Trajectory


The present work is the result of a study about a preliminary design of a trajectory for an interplanetary mission to Phobos. In particular, this work relies on on-going activities being developed at the Italian Aerospace Research Center (CIRA) in the framework of the fagship studies aimed to write thenew National Aerospace Research program. Matching a general interest of scientic community on the exploration of Martian moons, an innovative low-cost exploration mission by means of CubeSat platform is proposed. In particular, Phobos’ surface is covered by a regolith layer > 10 m thick, which may be adopted as construction material or 3D-printing powder; furthermore, Phobos may also provide a location for a staging base to support human missions on Mars surface. An innovative payload will be boarded on the CubeSat in order to measure Phobos’ surface features. A trajectory for this mission has been provided, in order to minimize the overall DeltaV required for all the phases of the transfer from Earth to Mars to Phobos: this way, the cost of the mission is signicantly reduced or a larger scientic payload is available. The interplanetary transfer analysis from Earth to Mars has been carried out by solving Lambert’s problem, for a given range of departure dates. The position and velocity of the departure and arrival planets have been computed for several combinations of dates so that “Porkchop plots” have been generated by means of a proper developed code. The best solution in terms of V, and consequently the best choice of departure and arrival dates, has been found. This procedure has been applied for dierent mission scenarios. The launch constraints have been considered on departure, as well as those on arrival, imposed by the fact that, the spacecraft must match Mars position considering, at the same time, even Phobos’ motion: some trade-ff analyses have been carried out to obtain the most convenient arrival strategy. In this regard, the B-plane concept has been introduced in order to perform the Mars insertion: key parameters are the inclination and right ascension of ascending node of the arrival orbit with respect to those of Phobos. A highly elliptical capture orbit has been proposed in order to optimize the plane- change maneuver and the subsequent circularization and rendezvous maneuvers. After the rendezvous, stable Quasi-Satellite Orbits have been proposed taking into account Phobos’ gravitational field.


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