the minor-planet moon Dimorphos of the double asteroid Didymos in September 2022 to assess the potential of a spacecraft impact to deflect an asteroid from a collision course with Earth. In October, NASA declared DART a success, confirming it had shortened Dimorphos' orbital period around Didymos by about 32 minutes. Planned missions Currently, several asteroid-dedicated missions are planned by NASA, JAXA, ESA, and CNSA. NASA's Lucy, launched in 2021, would visit eight asteroids, one from the main belt and seven Jupiter trojans; it is the first mission to trojans. The main mission would start in 2027. ESA's Hera, planned for launch in 2024, will study the results of the DART impact. It will measure the size and morphology of the crater, and momentum transmitted by the impact, to determine the efficiency of the deflection produced by DART. NASA's Psyche would be launched in 2023 or 2024 to study the large metallic asteroid of the same name. JAXA's DESTINY+ is a mission for a flyby of the Geminids meteor shower parent body 3200 Phaethon, as well as various minor bodies. Its launch is planned for 2024. CNSA's Tianwen-2 is planned to launch in 2025. It will use solar electric propulsion to explore the co-orbital near-Earth asteroid 469219 Kamoʻoalewa and the active asteroid 311P/PanSTARRS. The spacecraft will collect samples of the regolith of Kamo'oalewa. Asteroid mining The concept of asteroid mining was proposed in 1970s. Matt Anderson defines successful asteroid mining as "the development of a mining program that is both financially self-sustaining and profitable to its investors". It has been suggested that asteroids might be used as a source of materials that may be rare or exhausted on Earth, or materials for constructing space habitats. Materials that are heavy and expensive to launch from Earth may someday be mined from asteroids and used for space manufacturing and construction. As resource depletion on Earth becomes more real, the idea of extracting valuable elements from asteroids and returning these to Earth for profit, or using space-based resources to build solar-power satellites and space habitats, becomes more attractive. Hypothetically, water processed from ice could refuel orbiting propellant depots. From the astrobiological perspective, asteroid prospecting could provide scientific data for the search for extraterrestrial intelligence (SETI). Some astrophysicists have suggested that if advanced extraterrestrial civilizations employed asteroid mining long ago, the hallmarks of these activities might be detectable. Mining Ceres is also considered a possibility.