• An American suicide spacecraft called DART will smash into the moonlet of an asteroid in a planetary defense test
  • This test, the first of this kind, is scheduled to occur in 2022
  • Hera, a European spacecraft, will later orbit the asteroid to determine if its course has changed due to the impact

Humanity's first attempt at deflecting an asteroid from its path by ramming a spacecraft into it will involve a joint effort by American and European to see if potentially devastating collisions with Earth can be averted.

The test-run of a pioneering planetary defense mission is called AIDA (Asteroid Impact and Deflection Assessment) involving an American and European spacecraft. The impactor spacecraft called DART (Double Asteroid Redirection Test) will attempt to slam into a tiny moonlet called Dimorphos, which orbits the asteroid 65803 Didymos, in 2022.

Didymos is nearly 1 mile (780 meters) in diameter while Dimorphos is 525 feet (160 meters) wide, or roughly the span of the St. Louis Arch. They are located about 1.0 to 2.3 AU (astronomical unit) from the sun. Didymos (1996 GT) is classified as an Apollo-type near-Earth object (NEO).

DART is being built by NASA and the Johns Hopkins Applied Physics Laboratory (APL). It's being developed under the auspices of NASA's Planetary Defense Coordination Office.

The European spacecraft Hera is scheduled to launch arrive at Didymos in 2026 to scan Dimorpohs, using instruments to validate impact and asteroid deflection models. It will also make a detailed characterization of the impact crater made by the DART impactor.

Building Hera is a joint project between the European Space Agency (ESA) and Germany's OHB SE, the third-largest company in Europe's space sector.

ESA said the Hera spacecraft will blast-off aboard an Ariane 6 launch vehicle from French Guyana in 2024 to perform close-up investigation of the result of DART's impact with Dimorphos. Hera will take along two CubeSats for close-up views of Dimorphos.

By gathering details of Dimorphos’s mass, composition and the crater left by DART, Hera will allow researchers to assess the effectiveness of the deflection technique in as full a manner as possible. The result will validate if a kamikaze spacecraft can indeed deflect an oncoming asteroid from a potentially devastating collision with Earth.