Introduction

The European Space Agency's (ESA) Hera mission is blazing a trail through the cosmos, recently completing a pivotal maneuver as it embarks on its ambitious journey to the Didymos binary asteroid system. Launched on October 7, 2023, Hera has already made significant strides in its mission.

Deep-Space Maneuvers

On October 23, Hera ignited its three orbital control thrusters for a full 100 minutes, initiating its first deep-space maneuver and altering its velocity by about 146 m/s. This was followed by a second, shorter burn on November 6, lasting 13 minutes and boosting its speed by an additional 20 m/s. Collectively, these maneuvers have successfully set Hera on a path for a crucial gravity assist at Mars scheduled for March 2025.

Deep-space maneuvers require meticulous planning, as Sylvain Lodiot, Hera's Spacecraft Operations Manager, explains: "The first, larger burn does most of the work. Then, after precisely measuring the spacecraft's trajectory, we execute a second, smaller burn to correct any inaccuracies and provide the rest of the required boost."

Prior to these deep-space maneuvers, the team conducted three successful test burns at ESA's European Space Operations Center (ESOC) in Germany. They employed deep-space tracking facilities located in Spain, Argentina, and Australia to measure Hera’s trajectory and velocity with high precision.

“Post-burn analysis indicates that everything went remarkably well," remarked Francesco Castellini from ESOC's Flight Dynamics team. "We are planning a tiny corrective maneuver on November 21 to fine-tune Hera's trajectory as it approaches Mars.”

The Cosmic Boost from Mars

The trajectory of Hera has been strategically designed to take advantage of Mars's gravitational influence. Pablo Muñoz from ESOC's Mission Analysis team noted, "We are fortunate that Mars is positioned perfectly to assist Hera, enabling us to utilize its gravity to speed up the spacecraft's journey to Didymos and conserve fuel at the same time."

In addition to this celestial assistance, the Hera mission is set to conduct some opportunistic scientific studies during the Mars flyby. The craft is scheduled to pass within a mere 300 km of Deimos, one of Mars's two moons, providing scientists with a unique opportunity to study this intriguing celestial body up close.

The Path Ahead

Following the Mars encounter, Hera will execute another deep-space maneuver in February 2026, leading to several rendezvous maneuvers between October and December 2026, bringing it into close proximity with the asteroids.

At Didymos, Hera will embark on a groundbreaking investigation aimed at answering pivotal questions about binary asteroid systems and the aftermath of NASA's DART mission, which successfully impacted Didymos's moonlet Dimorphos in 2022. Key queries include: How and why do these binary systems form? Did the DART impact result in a crater or reshape the entire asteroid? What secrets lie within Dimorphos’s internal structure?

A Flourishing Era for Asteroid Research

ESA's asteroid teams are in a bustling period, marked by the successful launch of Hera and the initiation of plans for the Ramses mission, targeted at asteroid Apophis.

In conjunction with mission developments, the ESA's Near-Earth Object Coordination Center continues its vital work in the discovery and analysis of new asteroids. They have recently achieved an impressive milestone by identifying the tenth asteroid ever discovered before it could impact Earth.

Next week, ESA’s Planetary Defense Office will convene at ESOC in Germany, collaborating with experts from across Europe and beyond to enhance strategies for accurately measuring the sizes of potentially hazardous near-Earth asteroids.

As Hera ventures further into the abyss of space, the excitement and intrigue surrounding asteroid research is sure to swell—stay tuned for more updates from the frontiers of cosmic exploration!