Planetary-Defense Missions
Missions that test or study how to deflect a hazardous asteroid — DART, Hera, and their forerunners.
- DARTCompletedNASA / JHU APL
NASA's Double Asteroid Redirection Test — the first full-scale planetary-defense demonstration. The spacecraft deliberately crashed into Dimorphos, the small moon of asteroid Didymos, in 2022, measurably shortening its orbit and proving that a kinetic impactor can deflect an asteroid.
- Type
- Impactor (planetary defense)
- Launched
- 2021-11-24
- HeraActiveESA
ESA's follow-up to DART and the European half of the AIDA collaboration — it is cruising to the Didymos–Dimorphos system to survey the crater DART left and measure Dimorphos's mass, turning the DART experiment into a well-characterised deflection.
- Type
- Rendezvous · orbiter (planetary defense)
- Launched
- 2024-10-07
- Don Quijote (concept)Concept / proposedESA (concept study)
An early-2000s ESA planetary-defense concept — a two-spacecraft study in which an impactor (Hidalgo) would strike an asteroid while an orbiter (Sancho) measured the deflection. It was never built, but it prefigured the AIDA/DART–Hera approach.
- Type
- Impactor + orbiter (concept)
- AIM (concept)Concept / proposedESA (concept study)
ESA's Asteroid Impact Mission — the original European orbiter half of the AIDA collaboration, meant to observe the DART impact in real time. It was not funded in 2016, but its science was largely revived and reshaped as the Hera mission.
- Type
- Rendezvous · orbiter (concept)