The DESTINY+ Dust Analyser (DDA) for in-situ Cosmic Dust Measurements

The DESTINY+ mission, led by the Japan Aerospace Exploration Agency (JAXA), offers a distinctive opportunity for in-situ measurements of cosmic dust. Scheduled for launch in 2028, the spacecraft will use electric propulsion during its interplanetary trajectory toward its target, the active asteroid (3200) Phaethon. A high-speed flyby of Phaethon, with a relative velocity of 35 km/s, is a key mission objective.

The mission's primary scientific payload, the Destiny Dust Analyser (DDA), is being developed by the University of Stuttgart, Germany, in partnership with von Hoerner Sulger GmbH. The DDA’s goal is to characterize the cosmic dust environment encountered along the trajectory through in-situ analysis of individual dust particles. These dust populations range from space debris and interplanetary/interstellar dust to ejecta particles from the lunar surface and Phaethon itself. During the flyby, should Phaethon exhibit activity, dust particles originating from its interior may also be analyzed.

Equipped with a trajectory sensor, the DDA measures the primary surface charge, trajectory, and velocity of individual dust grains. It further conducts compositional analysis via time-of-flight (TOF) mass spectrometry of the impact plasma generated when dust grains collide with the instrument’s target. The charge generated in the impact plasma is also measured, offering additional insights into particle properties.

This paper outlines the DDA’s instrument configuration, provides an update on its development status, and demonstrates its performance using recent TOF mass spectra. Testing has included both positive and negative polarity modes, enabling comparisons of anion and cation mass spectra. Such comparisons are particularly valuable for analyzing organic-rich dust particles.