Biofilms are problematic on Earth due to their ability to both degrade the materials upon which they grow and promote infections. Remarkably, 65% of infections and 80% of chronic diseases on Earth are associated with biofilms. The impact of biofilms is even greater in space, as the crew's lives and mission success depend on nominal operation of mechanical systems which can be interrupted by material damage associated with biofilm growth. Furthermore, the isolated confined environment nature of spaceflight may increase the rates of disease transmission. In the case of the International Space Station (ISS), biofilms are an identified problem on the Environmental Control and Life Support System (ECLSS), namely on the water processor assembly (WPA). In late 2019, the bacterial component of the Space Biofilms experiment launched to ISS to (i) characterize the mass, thickness, morphology, and gene expression of biofilms formed in space compared to matched Earth controls, (ii) interrogate the expression of antimicrobial resistance genes, and (iii) test novel materials as potential biofilm control strategies for future ECLSS components. For this, 288 bacterial samples were prepared prior to the launch of the Northrop Grumman CRS-12 mission from NASA's Wallops Flight Facility. The samples were integrated into the spaceflight hardware, BioServe's Fluid Processing Apparatus (FPA), packed in sets of eight in Group Activation Packs (GAP). Half of these samples were activated and terminated on orbit by NASA astronauts Jessica Meir and Christina Koch, while the remaining half were processed equivalently on Earth. The spaceflight bacterial samples of Space Biofilms returned on board the SpaceX CRS-19 Dragon spacecraft in early 2020. We here describe the test campaign implemented to verify the experiment design and confirm it would enable us to achieve the project's scientific goals. This campaign ended with the Experiment Verification Test (EVT), from which we present example morphology and transcriptomic results. We describe in detail the sample preparation prior to flight, including cleaning and sterilization of the coupons of six materials (SS316, passivated-SS316, lubricant impregnated surface, catheter-grade silicone with and without a microtopography, and cellulose membrane), loading and integration of growth media, bacterial inoculum, and the fixative and preservative to enable experiment termination on orbit. Additionally, we describe the performance of the experiment on board the ISS, including crew activities, use of assets, temperature profile, and experiment timeline; all leading to a successful spaceflight experiment. Hence, this manuscript focuses on the steps implemented to ensure the experiment would be ready for spaceflight, as well as ISS and ground operations, with results presented elsewhere. The processes discussed here may serve as a guideline to teams planning their own gravitational microbiology experiments. This material is based upon work supported by the National Aeronautics and Space Administration under Grant No. 80NSSC17K0036.

生物膜在地球上是有问题的，因为它们能够降解它们生长的材料并促进感染。值得注意的是，地球上 65% 的感染和 80% 的慢性病与生物膜有关。生物膜的影响在太空中甚至更大，因为机组人员的生命和任务的成功取决于机械系统的正常运行，而机械系统的正常运行可能会因与生物膜生长相关的物质损坏而中断。此外，太空飞行的孤立密闭环境性质可能会增加疾病传播率。就国际空间站 (ISS) 而言，生物膜是环境控制和生命支持系统 (ECLSS)，即水处理器组件 (WPA) 上的一个已识别问题。2019 年底，太空生物膜实验的细菌成分发射到国际空间站，以（i ) 与匹配的地球对照相比，表征太空中形成的生物膜的质量、厚度、形态和基因表达，( ii ) 询问抗菌素耐药性基因的表达，以及 ( iii )) 测试新材料作为未来 ECLSS 组件的潜在生物膜控制策略。为此，在美国宇航局瓦勒普斯飞行设施的诺斯罗普·格鲁曼公司 CRS-12 任务发射之前，准备了 288 个细菌样本。这些样品被集成到航天硬件 BioServe 的流体处理设备 (FPA) 中，以一组八组的形式包装在组激活包 (GAP) 中。这些样本中有一半是由美国宇航局宇航员杰西卡·梅尔和克里斯蒂娜·科赫在轨道上激活和终止的，而剩下的一半在地球上进行了同等处理。太空生物膜的航天细菌样本于 2020 年初在 SpaceX CRS-19 龙飞船上返回。我们在此描述了为验证实验设计并确认它将使我们能够实现该项目的科学目标而实施的测试活动。该活动以实验验证测试 (EVT) 结束，我们从中展示了示例形态学和转录组学结果。我们详细描述了飞行前的样品制备，包括对六种材料（SS316、钝化 SS316、润滑剂浸渍表面、导管级硅胶（带和不带微观形貌）以及纤维素膜）的试样的清洁和消毒、装载和集成生长培养基、细菌接种物以及固定剂和防腐剂，以使实验在轨道上终止。此外，我们描述了国际空间站上的实验性能，包括机组人员活动、资产使用、温度分布和实验时间表；所有这些都导致了成功的太空飞行实验。因此，这份手稿重点介绍了为确保实验为太空飞行、国际空间站和地面操作做好准备而实施的步骤，结果在别处展示。这里讨论的过程可以作为团队规划自己的重力微生物学实验的指南。本材料基于美国国家航空航天局资助的第 80NSSC17K0036 号资助的工作。