Hera Mission Advances Toward Mars Flyby and Didymos Exploration

The Hera mission, a remarkable endeavor by the European Space Agency (ESA), has taken a significant stride towards its ambitious goal of exploring the Didymos asteroid system. Following its successful launch on October 7, 2024, Hera has executed an important deep-space burn, positioning it for a vital gravity assist from Mars in March 2025.

On October 23, the spacecraft’s trio of orbital control thrusters came to life, performing an intense 100-minute burn that altered Hera’s speed by approximately 146 m/s. This maneuver is a prime example of the intricate dance of deep-space navigation, where precision and adaptability are paramount. A supplemental burn, lasting 13 minutes, followed on November 6, adding another 20 m/s to the spacecraft’s velocity, ensuring it stays on its pre-calculated trajectory.

“Deep-space maneuvers are often split into parts,” remarked Sylvain Lodiot, the Hera Spacecraft Operations Manager. “The first, larger burn does most of the work. Then, after precisely measuring the spacecraft’s trajectory, we use the second, smaller burn to correct any inaccuracies and provide the needed boost.” This meticulous approach highlights the critical nature of real-time data analysis in space exploration, where every second and millimeter counts.

The ESA control team at the European Space Operations Centre (ESOC) in Germany has been integral to these maneuvers. Using deep-space antennas located in Spain, Argentina, and Australia, they closely monitored the changes in Hera’s velocity during each stage of the process. “We are now analyzing Hera’s new trajectory following the second burn,” stated Francesco Castellini from ESOC’s Flight Dynamics team. “It appears to have gone very well. We will execute a much smaller correction maneuver of a few tens of cm/s on November 21 to fine-tune the trajectory for the upcoming Mars flyby.”

The planned flyby of Mars is not merely a navigational assist; it’s a significant scientific opportunity as well. Hera will make a close approach to Deimos, one of Mars’s moons, allowing scientists to study this small celestial body from a distance of just 300 km. This presents researchers with a rare chance to gather data that can lead to insights about the moon’s composition and geophysical characteristics.

Pablo Munoz from ESOC’s Mission Analysis team expressed the strategic advantage of the mission, stating, “We are very fortunate that Mars is in the right place at the right time. This design uses Mars’s gravity to boost Hera’s speed, allowing it to reach Didymos months ahead of schedule.” Such gravity assists are pivotal in space exploration, enabling spacecraft to conserve fuel and time, essential factors in long-duration missions.

Looking to the future, Hera is scheduled to undertake another deep-space maneuver in February 2026, leading to a series of rendezvous operations between October and December 2026. These operations will facilitate a close approach to Didymos, where Hera aims to investigate the aftermath of NASA’s DART mission, which demonstrated the capability of deflecting an asteroid—a step towards planetary defense.

During its rendezvous, Hera will delve into pressing questions surrounding binary asteroid systems, such as the internal structure of Dimorphos and the nature of the crater created by DART’s impact. The insights gained could revolutionize our understanding of asteroids and their potential threat to Earth.

Moreover, ESA’s asteroid research continues to flourish, with discussions around future missions like Ramses, aimed at exploring Apophis—an asteroid that has garnered attention due to its close approaches to Earth. The Near-Earth Object Coordination Centre is actively engaged in asteroid discovery and monitoring, recently aiding in identifying the tenth asteroid known to have impacted Earth.

In a broader context, the ESA’s Planetary Defence Office is taking proactive steps to mitigate potential asteroid threats. Next week, it will host a workshop at ESOC, bringing together international experts to improve measurement techniques for identifying potentially hazardous near-Earth objects. Supported by the European Commission, this collaborative effort emphasizes the importance of global cooperation in ensuring the safety of our planet.

As the Hera mission progresses towards its objectives, it not only showcases human ingenuity in space exploration but also represents an important step in our understanding of celestial dynamics and the potential hazards that lie beyond our atmosphere.