Search

Nanosatellite missions represent a promising option for the exploration of the near-Earth asteroid population since they provide low-cost versatile platforms for scientific observations. This paper describes the preliminary orbital and navigation analyses for the DustCube mission, which was pre-selected to reach the binary asteroid system Didymos on-board ESA’s AIM spacecraft. Possible candidate orbits that exploit the binary nature of the system are identified and traded off to produce a preliminary concept of operations. The overall feasibility of the proposed scenario is then addressed by integrating the spacecraft trajectories in a realistic dynamical environment, evaluating their sensitivity to state errors, and estimating the accuracy of the orbit determination system. Preliminary results suggest that autonomous navigation of a Cubesat platform within a binary asteroid system is technically feasible. The proposed solution, which combines an initial parking orbit at the L4 equilibrium point with a Distant Retrograde Orbit for proximity operations, is shown to be consistent with the estimated orbit determination accuracy and allows to fulfil the mission requirements.

To accurately estimate the mass of a comet, is a challenging task, given the complexity of its dynamical environment, and particularly so while close to perihelion, where the coma emissions are stronger. This study describes an operational approach for simultaneous orbit determination and mass estimation of a cometary target, using detailed dynamical models and combining measurements from multiple instruments. The testbed for the proposed approach is represented by the Proteus mission towards the main belt comets 288P and 238P-Read, for which formal uncertainties for the mass and other parameters of interest are estimated though a covariance analysis. It will be shown that the required relative accuracy of 10% in mass estimation can be achieved for both cometary targets under realistic operational conditions.

Nanosatellites are a promising option for the exploration of the solar system and near-Earth objects, providing an agile, reduced cost and mass solution for interplanetary missions. This paper summarises the efforts done during the Phase A study aimed at assessing the feasibility of a nanosatellite-based mission concept for a 3U CubeSat to the vicinity of the binary asteroid 65803 Didymos. The nanosatellite is meant to be part of the Asteroid Impact Mission (AIM) which is the European element of the NASA-ESA jointly developed Asteroid Impact & Deflection Assessment (AIDA) mission. The inclusion of a scientific optical payload based on a Nephelometer, the selected orbital and navigation strategy, together with the differences found between the Beyond-Earth space environments (radiation, micrometeoroids, ejected material, illumination conditions, communications access) and a typical LEO polar environment, unveils new technical challenges to be faced along interplanetary missions. These challenges have been identified and analysed to be included within the DustCube concept of operations, are described in this manuscript.