Hera spacecraft to return to asteroid Didymos following NASA’s DART redirection test

Two years after a NASA spacecraft crashed into the asteroid Dimorphos, another mission to map the rocks of space is about to begin. Researchers say the data collected will strengthen Earth's planetary defenses against asteroid threats.

In 2022, NASA's Double Asteroid Redirection Test (DART) spacecraft collided with the asteroid Dimorphos, which was orbiting its parent asteroid Didymos, at a speed of 6.6 kilometers per second.

The mission was an attempt to show that it was possible to change the direction of an object on a collision course with Earth, and subsequent observations from Earth showed that Dimorphos was successfully redirected.

The European Space Agency (ESA) is currently preparing to launch its Hera spacecraft in order to determine exactly how it was affected. Hera is about the size of a small car and weighs 1,081 kilograms when fully fueled. It was launched from Cape Canaveral, Florida, on a SpaceX Falcon 9 rocket on October 7, and is scheduled to pass Mars next March on its way to the asteroid, but it won't reach its final destination until October 2026. It will be.

The original concept for this project was for Hera to be present when DART collided with Dimorphos, but funding delays made that impossible. Nevertheless, changes in the asteroid's orbit have been observed from Earth, and Hera's current work is to collect more data about Dimorphos so that future collisions could divert the object onto a collision course with Earth. The goal is to help scientists better understand how to plan for the future.

Diego Escorial OlmosHera, who works on the Hera mission at ESA, said DART and Hera are the cornerstone of the planetary defense system, but they are also needed to improve observations, provide as much warning as possible of incoming threats, and improve the spacecraft's impactor. says further efforts are needed. .

“It's simple physics,” Olmos says. “If it's huge, you need something huge to hit it. Then again, it's a timing game, and it's also basic physics. If you discovered an asteroid 100 years ago; We just give an asteroid a little push that takes 100 years to integrate, and by the time it passes, it misses us.”

Hera is equipped with a wide range of sensors, including thermal and hyperspectral cameras, LIDAR, and radar, which will also be used to map the asteroid.

The mission will also carry two small satellites, or CubeSats, called Juventas and Milani. Rather than orbiting the asteroid, these would fly in front of it, performing mop-up flights at progressively smaller and more dangerous distances to collect data. Both are expected to eventually land on the asteroid for a closer look, after doing what they can from afar.

Alan Fitzsimmons Researchers at Queen's University Belfast, UK, say the mission could “take us on the path to effective planetary defense” and show how impacts from spacecraft affect asteroids of different compositions. It is said that construction of a model for this will begin. But this is also the first detailed study of a binary asteroid, making Dimorphos the smallest asteroid ever measured in detail. “You can't avoid getting new science at the same time,” he says.

Krisa Avderidou Researchers at Britain's University of Leicester say more data will be needed to develop a reliable planetary defense system, but the chances of that being needed are slim.

“You can demonstrate as much as you like on these missions, but the exact results depend heavily on the materials involved,” she says. “So the big thing we need to do, both from the ground and on space missions, is to study a large number of objects and understand their material and surface properties. There are many more types of asteroids. ”