The European Space Agency's Hera spacecraft has officially launched on its long-awaited mission to investigate the aftermath of NASA's Double Asteroid Redirection Test (DART), which intentionally crashed its spacecraft, DART, to shift the orbit of the asteroid Dimorphos.
This bold maneuver took place on September 26, 2022, when DART targeted Dimorphos, which is part of the binary asteroid system Didymos, with the aim of altering its orbital path—a test of our planet's ability to defend against potentially catastrophic asteroid collisions. The results were impressive; researchers determined the impact shortened Dimorphos' orbital period around Didymos by 33 minutes, much more than the initial goal of 73 seconds. The collision also generated significant debris, sending material thousands of kilometers out from the impact site.
On October 7, 2024, the Hera spacecraft was launched aboard a SpaceX Falcon 9 rocket from Cape Canaveral, Florida, at 10:52 AM ET. This launch was significant, not just because of the technology involved but also due to the tense circumstances surrounding it. Just before the launch, Hurricane Milton was nearing landfall along the Gulf Coast, but promisingly, liftoff went smoothly.
Hera’s primary mission, as described by NASA and ESA officials, is to perform what one might call a "crime scene investigation" on Dimorphos, with its arrival expected in December 2026. This spacecraft is equipped with 12 scientific instruments, including advanced cameras, thermal imagers, and radar systems, which will allow for unprecedented observations of this asteroid.
Throughout its mission, Hera will undertake detailed examinations of Dimorphos, focusing on several key areas: its size, mass, shape, and the characteristics of the crater left behind from the DART impact. This is portrayed as the world's first detailed look at the changes brought about by the kinetic impact method of asteroid deflection.
While en route to Dimorphos, Hera will carry out various flybys, including one past Mars next year, which will provide it with observational opportunities of the Martian moon Deimos. Its planned swing beyond Mars will not only facilitate additional scientific discoveries but also allow Hera to gain the extra velocity required to reach its destination efficiently.
The mission has dual goals: not only to gather data on Dimorphos but also to test new deep-space technologies. Hera will deploy two CubeSats, Milani and Juventas, to assist with its examinations. Milani will investigate the surface mineralogy and the dust clouds surrounding Dimorphos, whereas Juventas will perform the first-ever subsurface radar imaging of the asteroid, probing to reveal internal structures beneath its exterior.
ESA’s Planetary Defense Office Director, Richard Moissl, emphasized the importance of Hera by stating, "Hera's ability to closely study its asteroid target will be just what is needed for operational planetary defense. You can envision scenarios where reconnaissance missions are immediately dispatched to assess whether any follow-up actions are needed to deflect an asteroid. We could be practicing this soon with our upcoming missions, ready to react if necessary."
Hera is expected to provide detailed insights not only for future planetary defense initiatives but also on how to leverage the kinetic impact method effectively. By the end of this promising mission, scientists hope to make the Didymos binary pair the best-documented asteroids in history, contributing significantly to the global asteroid tracking and defense efforts.
It's important to note the overarching goal of these missions: to transform the threat of asteroid impacts from something unavoidable and catastrophic to something predictable and manageable. This aligns with broader international efforts by various space agencies, including NASA, ESA, and Japan's JAXA, to track near-Earth objects (NEOs) and develop strategies to prevent potential disasters.
"This mission is key to advancing our scientific knowledge on asteroids," shared Hera mission scientist Michael Kueppers. "By enhancing our detection capabilities, we can build resilient strategies against future threats from space. The knowledge gained from Hera's findings will help refine our defense tactics, empowering us to protect our planet effectively."
Following years of collaboration and technological advancements, the launch of Hera marks only the beginning of its ambitious two-year cruise to the Didymos binary asteroid system. With anticipation building, space enthusiasts and scientists alike eagerly await the wealth of information Hera promises to bring back—insights which could dramatically reshape our terrestrial defenses against the myriad potential threats lurking beyond our atmosphere.
