ESA’s Hera Spacecraft Embarks on Two-Year Mission to Study Asteroid Deflection
On Monday, a European Space Agency (ESA) spacecraft called Hera blasted off from Cape Canaveral, Florida, beginning a two-year journey to an asteroid that was knocked off course by NASA's DART mission in 2022. This mission is part of a larger effort to explore how humanity might deflect potentially dangerous asteroids from hitting Earth in the future.
Hera is headed for Dimorphos, a small moon orbiting the asteroid Didymos. In 2022, NASA deliberately crashed a probe into Dimorphos as part of its Double Asteroid Redirection Test (DART), successfully altering its orbit by several metres.
Although neither asteroid poses any real threat to Earth, the test was crucial for proving that a similar strategy could be used to prevent future asteroid impacts.
Hera mission to investigate impact of 2022 DART
The main goal of the Hera mission is to take a closer look at Dimorphos to better understand the impact of NASA's collision. The spacecraft will study the crater created by DART’s impact and assess the structure and composition of the asteroid.
Naomi Murdoch, a scientist involved in the mission, explained the importance of the data: “We need to understand what these asteroids are made of. Are they blocks of rock? Are they made of sand inside?”
In addition to its primary mission of studying Dimorphos, Hera will also pass by Mars’ moon Deimos during its journey, using the opportunity to gather additional data with its scientific instruments.
How will the mission investigate the asteroid?
By gathering more information about the asteroid’s makeup, scientists hope to refine their techniques for future asteroid deflection attempts. The size and composition of asteroids can vary widely, making it necessary to understand what works best for different types of objects. ESA’s Hera mission will provide the detailed data needed to improve this planetary defence strategy.
The mission, part of ESA’s broader Space Safety program, will deploy small CubeSats to gather additional data, including information on the asteroid’s mass and structure. These mini-satellites will orbit and eventually land on Dimorphos, further enhancing the study of its physical properties.
“Planetary defence is an inherently international endeavour,” said ESA Director General Josef Aschbacher. “Hera is a bold step in scaling up ESA’s engagement in planetary defense.”
The spacecraft’s journey is being closely monitored by the European Space Operations Centre in Germany, and the mission is expected to provide crucial insights by the time it reaches the asteroid in December 2026.
Hera mission will not be directly controlled from Earth
One of the key features of the mission is its use of autonomous navigation technology. Hera will attempt to navigate around the asteroids without direct control from Earth, relying on visual tracking of surface features.
This could be an essential step forward for future space missions, allowing spacecraft to operate more independently in deep space.
The DART mission proved that it’s possible to change an asteroid’s course, but there’s still much to learn about how to make this process more reliable. Hera's detailed study of the aftermath of the DART impact will help scientists develop a repeatable strategy for planetary defence.
