Joan-Pau Sanchez Cuartielles

Passive sorting of asteroid material using solar radiation pressure

Understanding dust dynamics in the vicinity of asteroids is key for future science missions and, in the long term, for asteroid exploitation. This paper analyzes the feasibility of manipulating asteroid material by means of solar radiation pressure. A novel method is proposed for passively sorting material as a function of its grain size or density, where solar radiation pressure is used as a passive in situ mass spectrometer. A simplified analysis shows that, in principle, this method allows an effective sorting of regolith material. This could have immediate applications for a sample return mission, and for industrial-scale in-situ resource utilization to separate and concentrate regolith according to particle size or composition.

Alternating orbiter strategy for asteroid exploration

This paper proposes the use of highly non-Keplerian trajectories enabled by solar radiation pressure and devices with variable area or reflectivity to map and characterize small asteroids. Strategies alternative to hovering involving a combination of retrograde and prograde orbits, together with inversions of the orbit direction by either maneuvers or exploiting the natural dynamics, are presented and analyzed. As opposed to terminator orbits, this alternating orbiter strategy allows direct overflies of the subsolar point and other equatorial regions. A simple cost comparison demonstrates a significant improvement with respect to traditional hovering strategies. Additional orbits of interest for hopper spacecraft are also discussed. Finally, various possible implementations of variable-area spacecraft that could provide the required solar radiation pressure control are suggested and discussed.

Opportunities for Asteroid Retrieval Missions

Recently, significant interest has been devoted to the understanding of minor bodies of the Solar System, including near-Earth and main belt asteroids and comets. NASA, ESA and JAXA have conceived a series of missions to obtain data from such bodies, having in mind that their characterisation not only provides a deeper insight into the Solar System, but also represents a technological challenge for space exploration. Near Earth Objects in particular have also stepped into prominence because of two important aspects: they are among the easiest celestial bodies to reach from the Earth and they may represent a potential impact threat. This increased interest has encouraged the research community to propose further asteroid engineering projects, such as NEO retrieval missions, taking advantage of the synergies with current minor bodies search campaigns and asteroid manipulation technology development initiatives.

Micro-to-Macro: Astrodynamics at Extremes of Length-scale

This paper investigates astrodynamics at extremes of length-scale, ranging from swarms of future ‘smart dust’ devices to the capture and utilisation of small near Earth asteroids. At the smallest length-scales families of orbits are found which balance the energy gain from solar radiation pressure with energy dissipation due to air drag. This results in long orbit lifetimes for high area-to-mass ratio ‘smart dust’ devices. High area-to-mass hybrid spacecraft, using both solar sail and electric propulsion, are then considered to enable ‘pole-sitter’ orbits providing a polar-stationary vantage point for Earth observation. These spacecraft are also considered to enable displaced geostationary orbits. Finally, the potential material resource available from captured near Earth asteroids is considered which can underpin future large-scale space engineering ventures. The use of such material for geoengineering is investigated using a cloud of unprocessed dust in the vicinity of the Earth-Sun L1 point to fractionally reduce solar insolation.