In October 2022, a binary asteroid system will be coming relatively close to the Earth, giving the European Space Agency and NASA the opportunity to carry out the Asteroid Impact & Deflection Assessment (AIDA) mission and see what humans can do against asteroid threats.

An international collaboration, AIDA will involve the German Aerospace Center, the John Hopkins University Applied Physics Laboratory and Observatoire de la Cote d' Azur, working alongside the ESA and NASA. The mission's primary goal is to test how well the agencies can strike a near-Earth asteroid off-course through impact from a spacecraft. Deflection resulting from the impact will then be measured and characterized to further fine-tune efforts for dealing with asteroids.

Referred to as Didymos, the asteroid pair features a main body half a mile long and a secondary body a tenth of a mile in length. The smaller asteroid orbits around the main body and is informally known as the Didymoon. When Didymos comes close to the Earth, ESA and NASA will be aiming for Didymoon, with NASA's Double Asteroid Redirection Test (DART) taking the lead. ESA's Asteroid Impact Mission (AIM) will be standing by although the two missions will be carried out at the same time.

As both part of AIDA, the DART and AIM missions will be working together to study Didymoon. After DART crashes into the smaller Didymos asteroid, AIM will be making before-and-after comparisons of the Didymoon's body and orbit to determine if the impact had an effect.

"The results will allow laboratory impact models to be calibrated on a large-scale basis, to fully understand how an asteroid would react to this kind of energy," explained Ian Carnelli, AIM mission manager for the ESA.

How AIDA turns out will also give involved agencies a baseline to refer to for planning future defense strategies. Whether or not the impact bumps off Didymoon from its current orbit, the mission will still shed light on the kind of force required to affect the path of a coming asteroid. Should a real threat occur, the team behind AIDA will be able to apply what they've learned from the first mission, allowing them to come up with a technique that will work.

Should either DART or AIM be unable to perform its role during the joint campaign, the other will continue on and achieve its individual goals. Facilities will also be observing from the ground to contribute to the mission.