The search for life on Europa

由于没有被广泛接受的生命定义，目前在我们太阳系内的搜索集中在我们最熟悉的形式上。以前的欧罗巴飞行任务已经揭示了海底的明确证据，很可能是由潮汐加热和动态辐射环境维持的。木星系统的磁层模型表明，在木星磁场中加速的粒子驱动了大量的有机化学。这种环境很可能满足我们所知的生命的关键要求。然而，同样可能支持隐藏的生物过程的辐射环境也对未来的行星探测任务有效载荷构成了威胁。高粒子辐照度会影响探测器/电子元件的性能，从而显著降低科学仪器的性能。重要的是要对所涉及的物理过程进行建模，以充分理解和说明它们将对整体科学能力产生的影响。2015年，美国宇航局选择了包括木卫二快艇在内的木卫二木星系统任务进行月球探测。在此之后，目前正在考虑一个着陆器，通过验证月球在海洋上的存在及其特征来关注月球的宜居性，同时确定已经和将在月球上发生的地质和生物过程。着陆器可能会为部署最近开发的分析仪器提供机会，以核实与寻找生命有关的关键生物特征的存在。拉曼光谱是一种快速、非破坏性的散射技术，它提供了关于样品的分子/化学成分的信息。由于最近在仪器小型化和坚固性方面的进步，第一台部署在太空中的拉曼光谱仪将于2020年发射，作为外部火星漫游者任务有效载荷的一部分。一旦登上火星表面，拉曼激光光谱仪(RLS)将被用于识别有机化合物和寻找生命迹象。RLS(和NASA的Mars2020拉曼仪器)的发展使拉曼光谱仪被认为是NASA木卫二着陆器任务的主要科学仪器。然而，需要努力通过优化探测器性能、辐射缓解和操作模式来提高拉曼仪器设计的整体辐射硬度。该项目涉及为木卫二着陆器任务开发仪器包(基于典型的任务科学要求)。将模拟和调查辐射环境对分析仪器性能的影响(因此是一次飞行任务的科学目标)。还有必要使用辐射环境模拟设施(实验)和适当的模拟样品来验证每种拟议仪器配置的性能，以充分了解所涉及的关键设计权衡。

As there is no widely accepted definition of life, the current search within our solar system focuses on the form that we're most familiar with. Previous Europa missions have revealed clear evidence of subsurface oceans most likely sustained by tidal heating and the dynamic radiation environment. Magnetospheric models of the Jovian system suggest a large amount of organic chemistry that has been driven by particles accelerated in Jupiter's magnetic field. This environment likely satisfies the critical requirements for life as we know it.However, the same radiation environment that may support hidden biological processes also pose a threat to future planetary exploration mission payloads. High particle irradiances can affect the performance of detectors/electronic components, significantly reducing the scientific instruments' performance. It is important to model the physical processes involved to fully understand and account for the impact that they will have on overall scientific capability. In 2015, NASA selected the Europa Jupiter System Mission, including Europa Clipper, for the exploration of the moon. Following this, a lander is currently being considered, focussing on the habitability of the moon by verifying the presence on the ocean and its characteristics, whilst determining the geological and biological processes that have and will take place on the moon. The lander will potentially provide an opportunity for the deployment of recently developed analytical instruments to verify the presence of key biological signatures associated with the search for life. Raman spectroscopy is a rapid, non-destructive scattering technique that provides information about the molecular/chemical composition of a sample. Due to recent advances in instrument miniaturisation and robustness, the first Raman spectrometer to be deployed in space will be launched in 2020 as part of the ExoMars rover mission payload. Once on Martian surface, the Raman Laser Spectrometer (RLS) instrument will be used to identify organic compounds and search for signs of life. The development of RLS (and NASA's Mars2020 Raman instruments) has led to a Raman spectrometer being considered as a primary science instrument for NASA's Europa Lander mission. However, effort needs to be focused on improving the overall radiation hardness of Raman instrument designs, through optimising detector performance, radiation mitigation and operating modes.This project involves developing an instrument package for a Europa lander mission (based on typical mission science requirements). The impact that the radiation environment will have on analytical instrument performance (hence the science goals of a mission) will be modelled and investigated. It is also necessary to verify performance of each proposed instrument configuration using radiation environment simulation facilities (experimental) and suitable analogue samples to gain a full understanding of the critical design trade-offs involved.