GrailQuest (Gamma Ray Astronomy International Laboratory for QUantum Exploration of Space-Time) is a mission concept based on a constellation (hundreds/thousands) of nano/micro/small-satellites in low (or near) Earth orbits. Each satellite hosts a non-collimated array of scintillator crystals coupled with Silicon Drift Detectors with broad energy band coverage (keV-MeV range) and excellent temporal resolution (≤ 100 nanoseconds) each with effective area \(\sim 100 \text {cm}^{2}\). This simple and robust design allows for mass-production of the satellites of the fleet. This revolutionary approach implies a huge reduction of costs, flexibility in the segmented launching strategy, and an incremental long-term plan to increase the number of detectors and their performance; this will result in a living observatory for next-generation, space-based astronomical facilities. GrailQuest is conceived as an all-sky monitor for fast localisation of high signal-to-noise ratio transients in the X-/gamma-ray band, e.g. the elusive electromagnetic counterparts of gravitational wave events. Robust temporal triangulation techniques will allow unprecedented localisation capabilities, in the keV-MeV band, of a few arcseconds or below, depending on the temporal structure of the transient event. The ambitious ultimate goal of this mission is to perform the first experiment, in quantum gravity, to directly probe space-time structure down to the minuscule Planck scale, by constraining or measuring a first-order dispersion relation for light in vacuo. This is obtained by detecting delays between photons of different energies in the prompt emission of Gamma-Ray Bursts.

GrailQuest（伽玛射线天文学国际时空量子探索实验室）是一个基于低（或近）地球轨道上的纳米/微型/小型卫星星座（数十/数千）的任务概念。每颗卫星都有一个非准直的闪烁体晶体阵列，以及具有宽能带覆盖（keV-MeV 范围）和出色的时间分辨率（≤ 100 纳秒）的硅漂移探测器，每个探测器的有效面积\(\sim 100 \text {cm} ^{2}\). 这种简单而坚固的设计允许批量生产舰队的卫星。这种革命性的方法意味着成本的大幅降低、分段发射策略的灵活性以及增加探测器数量及其性能的增量长期计划；这将为下一代天基天文设施打造一个活生生的天文台。圣杯探索被认为是一种全天监测器，用于快速定位 X 射线/伽马射线波段中的高信噪比瞬变，例如引力波事件的难以捉摸的电磁对应物。根据瞬态事件的时间结构，强大的时间三角测量技术将允许在 keV-MeV 波段中实现前所未有的定位能力，在几弧秒或以下。这项任务雄心勃勃的最终目标是进行第一个量子引力实验，通过约束或测量真空中光的一阶色散关系，直接探测到极小的普朗克尺度的时空结构。这是通过检测伽马射线暴的即时发射中不同能量的光子之间的延迟来获得的。