EQUULEUS (EQUilibriUm Lunar-Earth point 6U Spacecraft) will be the world's smallest spacecraft to explore the Earth-Moon Lagrange point. It is being jointly developed by JAXA (Japan Aerospace Exploration Agency) and the University of Tokyo, and will be launched by NASA's Space Launch System Exploration Mission-1. The spacecraft will fly to a libration orbit around the Earth-Moon L2 point (EML2) and will demonstrate low-energy trajectory-control techniques within the Sun-Earth-Moon region for the first time by a nano-class spacecraft. EQUULEUS also carries three scientific observation missions: imaging of Earth's plasmasphere by extreme ultraviolet wavelength, lunar impact flash observation on the far side of the moon, and micrometeoroid flux measurements in the cis-lunar region. While all these missions have their own scientific objectives, they will also contribute to future human activity and/or infrastructure development in the cis-lunar region. Most parts of the spacecraft system use commercial off-the-shelf components, or are designed based on the experiences of various past space missions, with the exception of the newly developed water resistojet propulsion system. EQUULEUS uses X-band frequency for deep space telecommunication. Japanese deep space antennas (64-m and 34-m) will be nominally used for spacecraft operation, and support from the deep space network of JPL (Jet Propulsion Laboratory) is also being planned, especially for the initial phase of operation. The spacecraft will fly to EML2 in less than one year, and will remain there for scientific observations until shortly before the depletion of the onboard propellant, when the spacecraft will leave the orbit for space-debris compliance.

中文翻译：

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6U CubeSat 的地月拉格朗日点任务：EQUULEUS

EQUULEUS（EQUilibriUm Lunar-Earth point 6U Spacecraft）将是世界上最小的探索地月拉格朗日点的航天器。它由 JAXA（日本宇宙航空研究开发机构）和东京大学联合开发，将由 NASA 的太空发射系统探索任务 1 发射。该航天器将飞往围绕地月 L2 点 (EML2) 的平动轨道，并将首次通过纳米级航天器在日地月区域内展示低能轨迹控制技术。EQUULEUS 还承担三项科学观测任务：通过极紫外波长对地球等离子体层进行成像，在月球背面进行月球撞击闪光观测，以及在顺月区域测量微流星体通量。虽然所有这些任务都有自己的科学目标，但它们也将为顺月地区未来的人类活动和/或基础设施发展做出贡献。航天器系统的大部分部件都使用商用现成组件，或者是根据过去各种太空任务的经验设计的，但新开发的防水喷气推进系统除外。EQUULEUS 使用 X 波段频率进行深空通信。日本深空天线（64 米和 34 米）将名义上用于航天器的运行，来自 JPL（喷气推进实验室）深空网络的支持也正在计划中，特别是在运行的初始阶段。航天器将在不到一年的时间内飞往 EML2，