
New planetary defence mission ready to blast off to double asteroid system
CBC
On Monday, if all goes as planned, a European spacecraft will blast off on a SpaceX Falcon 9 rocket and begin its two-year-long voyage to a double asteroid system beyond the orbit of Mars.
The European Space Agency's Hera mission is a follow up to NASA's successful Double Asteroid Redirection Test (DART) mission, which impacted the asteroid Dimorphos in September 2022.
The goal of that mission was to demonstrate the ability to change the orbit of an asteroid. Dimorphos is the smaller of a two-asteroid system, or binary, with Didymos being the largest.
Before the DART mission, Dimorphos orbited Didymos once every 11 hours and 55 minutes. After the impact, that orbit was shortened by 33 minutes, and a plume of debris spread more than 10,000 kilometres into space, lasting for months.
WATCH | NASA slams spacecraft into asteroid to test planetary defence
This smashing into an asteroid isn't just fun and games. It has a purpose, and that purpose is for planetary defence: to test whether we can deflect an asteroid that may one day be on its way to Earth.
Both DART and Hera are part of the Asteroid Impact and Deflection Assessment (AIDA).
"Planetary defence is an extremely important initiative worldwide because asteroid impacts are something that is proven to have happened already many times in the past [and] is something for which we have clear evidence and statistics and know is going to happen again," Hera deputy project manager Paolo Martino said.
"So the question about asteroid impact is not if, but when."
The Hera spacecraft is roughly 1.6 metres across, with solar arrays that stretch 11.5 metres once they're fully deployed.
But Hera isn't alone. Hitching a ride are two CubeSats, small spacecraft that have been increasingly used due to their size and low-cost.
One, Juventas, will determine the gravity field, internal structure and surface properties of Dimorphos.
The second, Milani, will map the asteroid, as well as determine the effects of the DART impact. It will also study any dust clouds around the pair of asteroids.
Eventually, the pair will land on Didymos and conduct further research on its surface composition.