# Hera Mission: A New Benchmark in Planetary Defense and Space Exploration
In a pioneering advancement for space exploration and planetary defense, the European Space Agency (ESA) is getting ready to dispatch the **Hera spacecraft** to the **Didymos binary asteroid system**. This mission signifies the first instance where a spacecraft will investigate a small celestial object that is part of a multi-satellite configuration. The mission is not only distinctive due to its target—a binary asteroid system—but also because it innovatively employs **CubeSats** for operations in close proximity.
As **Patrick Michel**, the principal investigator of the Hera mission, highlighted:
> “This is the first occasion on which we send a spacecraft to a small body, which is indeed a multi-satellite system, featuring one main spacecraft and two CubeSats performing closer proximity operations. This has never been accomplished.”
## The Hera Mission: An In-Depth Perspective
The Hera mission is part of a collaborative international initiative aimed at testing strategies for planetary defense. It follows NASA’s **Double Asteroid Redirection Test (DART)**, which successfully impacted **Dimorphos**, the smaller component of the Didymos binary asteroid system, in 2022. DART’s objective was to showcase the viability of altering an asteroid’s path through kinetic impact—a vital step in creating techniques to shield Earth from possible asteroid hazards.
Hera, named after the Greek goddess of marriage, is set to arrive at the Didymos system in 2026 to evaluate the consequences of DART’s collision. The spacecraft will offer detailed measurements of the crater formed by DART and collect data regarding the dynamics, composition, and structure of the binary system. This will assist scientists in understanding the effectiveness of the kinetic impact method and refining models for upcoming planetary defense initiatives.
### A Multi-Satellite Configuration: Hera and Its CubeSats
What distinguishes Hera from prior missions is its deployment of two **CubeSats**, known as **Juventas** and **Milani**. These compact, shoebox-sized satellites will be released from the primary Hera spacecraft to conduct close-range operations within the Didymos system. The CubeSats will engage with ground teams through radio communications with the Hera mothership, enabling real-time data transfer and coordination.
*Artist’s representation of the Hera spacecraft alongside its two deployable CubeSats, Juventas and Milani, situated near the Didymos binary asteroid system. The CubeSats will interact with ground teams through radio links with the Hera mothership. Credit: ESA-Science Office*
The CubeSats will undertake various operations:
– **Juventas** will be equipped with a radar tool to explore the internal composition of Dimorphos, yielding insights into the asteroid’s make-up and density.
– **Milani** will investigate the surface composition of both Didymos and Dimorphos, aiding researchers in understanding the materials constituting these celestial objects.
This multi-satellite strategy marks a pioneering moment in space exploration, representing a major advancement in the utilization of small, cost-efficient spacecraft for intricate missions. CubeSats have been utilized in low Earth orbit and interplanetary missions previously, but never in such an organized approach around a minor body in deep space.
### The Debris Challenge: A Controversial Topic
A prominent concern regarding the Hera mission is the possible presence of debris in the Didymos system, particularly following DART’s impact on Dimorphos. The **Hubble Space Telescope** detected a debris field surrounding the system a few months after the impact, prompting safety inquiries for Hera and its CubeSats as they near the asteroid.
**Ignacio Tanco**, ESA’s flight director for Hera, voiced caution concerning the debris:
> “For me, the debris issue is a source of… I wouldn’t categorize it as concern, but definitely as precaution. It’s something we’ll need to handle carefully when we arrive.”
In contrast, **Michael Kueppers**, a scientist at ESA, maintains a more positive outlook, likening the situation to ESA’s **Rosetta mission**, which adeptly navigated around an active comet from 2014 to 2016. Kueppers is confident that the debris field surrounding Didymos is not likely to present a major threat to Hera, yet Tanco’s apprehensions emphasize the inherent dangers of working in such an unpredictable environment.
This divergence in views—between the cautious stance of engineers and the hopeful perspective of scientists—highlights the intricacies of space missions. While scientists are eager to collect data and expand the frontiers of exploration, engineers must focus on ensuring the safety and longevity of the spacecraft.
### A Prolonged Journey
