The Small-Body Dynamics Toolkit (SBDT) v5.0 is a collection of primitive-body-specific trajectory design and analysis tools written in MATLAB®. The SBDT gives the user the capabilities to propagate, analyze, and visualize spacecraft trajectories and the dynamical environment near realistic asteroid, comet, or small planetary-moon models. The various component functions provided can be put together through user-created scripts, functions, or tools to perform a wide variety of trajectory analyses, including close-proximity encounter design, Monte Carlo studies, stability analysis, geometric analyses, and fuel budget calculations.

The latest release of the SBDT, version 5.0, supports three types of gravity models (point mass, constant density, or spherical harmonic), three types of primitive-body shapes (sphere, ellipsoid, or arbitrary polyhedron), a solar radiation pressure (SRP) model, and several comet outgassing models. The dynamic models available in version 5.0 include the two-body, Hill, circular-restricted three-body, elliptic-restricted three-body, and four-body problems (for modeling binary asteroid systems), all of which allow for irregular gravity and SRP acceleration. One of the most significant aspects of the SBDT design is that all of the functions work equally well with any of the shape, gravity, or force models described above. A set of data format standards has been applied across the toolkit such that all SBDT functions execute so long as the data structure is correctly populated. A number of convenient utility functions are also provided for converting between different gravity and shape model types and for applying random deformations to the shape and gravity to support Monte Carlo studies.

The software is applicable to design and analysis of encounter phase activities during the early mission development phases and for support of research work in this area. To date, the SBDT has been used in support of several mission proposals and a few dozen research papers.

This work was done by Stephen B. Broschart, Gregory Lantoine, Thomas A. Pavlak, and Eugene G. Fahnestock of Caltech; and Loic Chappaz of Purdue University for NASA's Jet Propulsion Laboratory. This software is available for license through the Jet Propulsion Laboratory, and you may request a license here. NPO-49707