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Nanospacecraft could enable detailed characterization of many asteroids in a small timeframe by launching multiple spacecraft simultaneously to visit a large set of targets. To be able to characterize as large of a set of asteroids as possible, however, visits to individual asteroids would be limited to flybys, which would have to be autonomous. As an additional challenge, due to the limitations of nanospacecraft and a massively parallel architecture, Earth-based localization and communication infrastructure, such as the Deep Space Network, cannot be relied upon. We have developed an optical instrument prototype and an image simulation system for autonomous asteroid flybys and 3D multispectral mapping using nanospacecraft. The final system is targeted to fit into a single CubeSat unit (a 10 cm cube) and to have the mass of less than 1 kg. The images are used for structure from motion algorithms to determine the quality of 3D reconstruction to be expected from this mission. We are presenting the instrument design, the simulation system, and the simultaneous localization and mapping system developed for nanospacecraft asteroid flybys.

We propose a distributed close-range survey of hundreds of asteroids representing many asteroid families, spectral types and sizes. This can be implemented by a fleet of nanospacecraft (e.g., 4–5-unit CubeSats) equipped with miniature imaging and spectral instruments (from near ultraviolet to near infrared). To enable the necessary large delta-v, each spacecraft carries a single electric sail tether which taps the momentum from the solar wind. Data are stored in a flash memory during the mission and downlinked at an Earth flyby. This keeps deep-space network telemetry costs down, despite the large number of individual spacecraft. To navigate without the use of the deep-space network, optical navigation is required to track stars, planets and asteroids. The proposed mission architecture is scalable both scientifically and financially. A fleet of 50 spacecraft will be able to obtain images and spectral data from 200 to 300 near-Earth and main belt asteroids. It allows study of those asteroid families and spectroscopic types for which currently no close-range observations are available. This paper presents science objectives, overall science traceability matrix, example targets and technical challenges associated with the mission. We open to discuss preliminary requirements, mission and spacecraft designs.