In fall 2022, after a 7-million-mile journey, NASA's DART spacecraft will slam into a small asteroid to test deflection techniques. Years later, the European Space Agency's Hera probe will arrive to meticulously assess the impact's effects.
One proven strategy for countering asteroid threats involves subtly altering their paths. To validate this approach, NASA and the European Space Agency (ESA) jointly developed the DART (Double Asteroid Redirection Test) mission, successfully launched on November 24, 2021, aboard a SpaceX Falcon 9 from Vandenberg Space Force Base in California.
In fall 2022, DART will target the binary asteroid system Didymos, featuring a 780-meter-diameter primary orbited by a 160-meter "moonlet," Dimorphos. The spacecraft will intentionally collide with Dimorphos to shift its orbit, with the change measured via variations in the system's brightness.
A compact Italian Cubesat, LICIacube from the Italian Space Agency, will detach 10 days prior to document the event up close. We've covered this aspect before; here, we spotlight the mission's third key element.
ESA's Hera spacecraft will precisely map the DART impact crater and deliver invaluable data.
Originally slated to observe the impact live, funding delays from ESA member states pushed back Hera's timeline. Project scientist Michael Küppers now anticipates a October 2024 launch, reaching the asteroids by late 2026 or early 2027. This delay could prove advantageous, allowing dust to settle for clearer observations.
Building on LICIacube's images, Hera will reveal the asteroids' shapes, masses, compositions, and chemistries—details currently unknown despite known orbits and sizes. Experts suspect Didymos is a loosely bound rubble pile, possibly mirrored in Dimorphos, a hypothesis Hera will test. Such data is essential for refining future deflection strategies.
Hera's findings will empower planetary defense experts to design effective missions against Earth-impacting asteroids.
