日本宇宙航空研究开发机构（JAXA）正推进名为「火星卫星探测」（MMX）的任务，预计于2026年发射，目标是从火星的卫星「火卫一」（Phobos）采集至少10克样品并于2031年送回地球。若任务成功，这将是人类首次将火星卫星的岩石带回地球。这些样品有助于解开火星两颗卫星究竟是巨型撞击抛射物凝聚而成，抑或是被火星重力捕获的外太阳系小行星之谜。
MMX探测器将面临严峻的航行与通讯挑战。由于地球与火星间存在长达20分钟的讯号延迟，探测器必须依赖高精准度的自主导航系统进行降落与起飞决策。火卫一微弱但不可忽视的重力使得著陆极为精细，降落过程中探测器会比对地形并避开险境。此外，由法德航太机构联合开发的「IDEFIX」探测车将先一步部署至火卫一表面进行约100天的先遣勘测，为母船的安全降落铺路。
抵达火卫一表面后，探测器将运用机械手臂钻探并透过气体辅助采样装置收集尘埃样品。由于历来陨石撞击火星喷出的物质会覆盖于火星卫星上，科学家预期采得样品中约有0.1%包含来自火星本土的碎屑。此项耗资约3.45亿美元的任务不仅标志著日本28年来首次发射火星探测器，在工程上也将验证未来火星来回航行及取样的核心关键技术。
The Japan Aerospace Exploration Agency (JAXA) is preparing the Martian Moons eXploration (MMX) mission, scheduled to launch in 2026, with the primary objective of collecting at least 10 grams of samples from Phobos and returning them to Earth by 2031. If successful, this will mark the first time samples from a Martian moon are brought to Earth. The returned material could finally resolve the longstanding debate over whether Mars' moons formed from debris ejected by a giant impact or were outer solar system asteroids captured by Martian gravity.
The mission must overcome significant spaceflight and communication challenges, particularly a communication delay of up to 20 minutes with Earth that necessitates high-precision autonomous navigation for descent and landing. Given Phobos' unique gravity profile, hovering is not fuel-feasible, requiring real-time terrain matching and hazard avoidance during the descent sequence. Additionally, the French-German IDEFIX rover will be deployed prior to the main landing to scout the surface for approximately 100 days, ensuring operational safety.
Once landed on Phobos, the spacecraft will gather core samples using a robotic drill and retrieve fine surface dust via a specialized gas-stream mechanism. Because meteorite impacts on Mars have historically coated its moons with ejecta, scientists estimate that roughly 0.1 percent of the collected material will consist of Martian debris. Costing roughly $345 million, this mission represents Japan's first Mars mission in 28 years and serves as a vital engineering testbed for future interplanetary round-trip travel and sampling technologies.