ESA's Hera Spacecraft Begins Critical Braking Maneuvers Ahead of Dimorphos Rendezvous

Photo by Léa Claisse on Pexels

Mission Background and the Path to Didymos

Hera launched from Cape Canaveral Space Force Station in Florida on October 7, 2024, embarking on a planetary defense mission to investigate the site of NASA's 2022 DART impact. The mission aims to closely study the binary asteroid system following that collision.

To reach its destination, Hera navigated deep-space maneuvers alongside a spring 2025 Mars flyby that shifted the spacecraft's trajectory and increased its speed. Ahead of its scheduled braking maneuvers, Hera traveled at speeds exceeding 12 kilometers per second relative to Earth.

Executing the Braking Burns

Preparation for the deceleration phase began on October 2, 2026, when Hera successfully completed a brief preparatory test burn for the initial braking maneuver, known as BRM-1.

The primary deceleration occurs on October 15, 2026, when Hera is scheduled to execute a continuous 93-minute braking burn. During this maneuver, the spacecraft will fire three Orbit Control Thrusters simultaneously to decelerate toward the Didymos asteroid system, reducing its velocity relative to the asteroids by a few hundred meters per second. One week after completing this 93-minute burn, Hera is scheduled to perform a shorter burn to fine-tune its adjusted orbit.

Photo by ESA & Science Office on Wikimedia Commons

Upcoming November 2026 Rendezvous

The braking burns pave the way for Hera's rendezvous with Didymos and its moon Dimorphos in November 2026.

Upon reaching the asteroid system, the spacecraft will spend six months investigating the impact site, providing key findings to advance planetary defense research.