Japan's Hayabusa2 achieves first-ever laser ranging experiment with an asteroid

Japan's Hayabusa2 spacecraft achieved a historic first on July 5, 2023, with a successful laser-ranging experiment during a flyby of asteroid Torifune. This milestone, conducted by the Japan Aerospace Exploration Agency (JAXA), represents a significant advancement in space exploration capabilities. The experiment utilized Hayabusa2's LIDAR laser altimeter (LALT) instrument, which measured distances, asteroid density, surface reflectance, and levitating dust particles.

The LALT instrument, originally developed for JAXA's lunar orbiter Kaguya, played a crucial role in the probe's navigation and provided valuable data on asteroid Ryugu's surface topography. The laser was fired twice, at 6:29 p.m. (2:29 a.m. PDT; 5:29 a.m. EDT) and 56.5 seconds and 57.5 seconds before the flyby, from distances of approximately 20 km and 15 km.

Despite the challenges of directing the laser at a small target while traveling at 5.3 km/s, the mission team's extensive preparation ensured the experiment's success. Laser ranging, a technique used to add scale to spacecraft images and accurately determine the size of astronomical objects, is essential for improving orbital predictions and planetary-defense assessments.

This information is not only crucial for space exploration but also for identifying potentially hazardous asteroids. The successful laser-ranging experiment marks a significant step forward in our ability to gather crucial information about celestial objects, even as spacecraft travel at high velocities.