Hera Will Begin Braking to Reach Asteroid Dimorphos
The European Space Agency mission will adjust velocity to study the aftermath of NASA's 2022 asteroid impact.
Updated on Oct. 7, 2026 in Space
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On October 15, 2026, the European Space Agency's Hera spacecraft will rotate to face the Didymos binary asteroid system to prepare for its primary science mission. This maneuver follows the start of critical braking sequences designed to slow the car-sized probe.
Why it matters
Hera intends to collect detailed data on the asteroid Dimorphos, which NASA physically impacted in 2022. This investigation will refine scientific understanding of asteroid deflection and the structural outcomes of high-speed collisions in deep space.
The probe is currently traveling at speeds exceeding 12 kilometres per second. The first braking phase involves a 93-minute burn of three hydrazine-based thrusters, with further velocity reduction planned for October 22.
The players
European Space Agency
An intergovernmental space agency that coordinates financial and intellectual resources to conduct space exploration and planetary research.
NASA
The United States civil space agency responsible for the DART mission that impacted the Dimorphos asteroid.
The details
The spacecraft, roughly the size of a small car, utilizes three hydrazine-based thrusters—a chemical propulsion system using nitrogen-hydrogen fuel—to manage its velocity. To maintain correct orientation during these maneuvers, the probe engages its Reaction Control Thrusters, which are small thrusters used for precise attitude adjustments. Ground control facilitates this process using 35-metre deep space antennas, such as those located in New Norcia, Australia.
Timeline
2022: NASA impacted the asteroid Dimorphos.
Spring 2025: Hera performed a flyby of Mars.
2 October: A test burn was performed.
15 October: Hera rotates to face the Didymos system.
22 October: The second braking manoeuvre occurs.
The Tech Race
This mission follows the kinetic impact demonstration achieved by the DART spacecraft. Hera now aims to provide the necessary diagnostic data to confirm the effectiveness of that initial planetary defense experiment.
These maneuvers are automated deep-space operations that do not affect terrestrial infrastructure. Data gathered from the Didymos system will eventually provide the public with a clearer scientific assessment of planetary defense capabilities.
The takeaway
The success of this mission rests on the precise execution of multi-stage braking burns throughout late October. Observers should track the upcoming October 22 maneuver for confirmation that the spacecraft remains on course for its scheduled arrival at the Didymos system.
Further reading
For more on planetary exploration missions, visit the Space section.
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