Hamacher H
Deutsche Forschungsanstalt fur Luft- und Raumfahrt (DLR), Koln, Germany.
Microgravity Sci Technol. 1996;9(3):152-7.
Since the early eighties Spacelab has been the primary platform for experimentation under the state of virtually weightlessness (microgravity) in spaceflight. The International Space Station (ISS), planned to be operational by end of the century, will extend the scientific opportunities of Spacelab in many respects, e.g. by offering the opportunity for long lasting and continuous microgravity investigations. Stringent design and operational requirements have been defined for the ISS to keep residual accelerations as low as possible. These guidelines are based on investigations (Langbein, Alexander, and others) of upper allowable residual accelerations for most physical phenomena involved in space experiments. To meet these requirements, severe perturbations from operating the Station (reboosts to correct the orbit, docking maneuvers, etc.) are grouped outside dedicated microgravity-experiment phases. For the microgravity-phases, stringent criteria on upper limits of residual accelerations are specified. Recent predictions for the present ISS concept indicate that additional measures have to be taken. The results of the microgravity-studies on Spacelab missions (D-1, D-2, etc.) contain a wealth of valuable information for developing optimal design principles. Passive measures must be applied first ('perturbation reduction at the source' and timelining) before considering complex active isolation concepts which should be reserved for high sensitive investigations only.
自20世纪80年代初以来，太空实验室一直是在太空飞行中几乎失重（微重力）状态下进行实验的主要平台。计划在本世纪末投入使用的国际空间站（ISS）将在许多方面扩展太空实验室的科学机会，例如通过提供进行长期和连续微重力研究的机会。为国际空间站定义了严格的设计和运行要求，以尽可能降低残余加速度。这些指导方针是基于对太空实验中涉及的大多数物理现象的最大允许残余加速度的研究（朗贝恩、亚历山大等人）制定的。为了满足这些要求，空间站运行产生的严重扰动（轨道修正助推、对接操作等）被安排在专门的微重力实验阶段之外。对于微重力阶段，规定了残余加速度上限的严格标准。对当前国际空间站概念的最新预测表明，必须采取额外措施。太空实验室任务（D-1、D-2等）的微重力研究结果包含了大量用于制定最佳设计原则的宝贵信息。在考虑复杂的主动隔离概念之前，必须首先采取被动措施（“从源头上减少扰动”和时间安排），而复杂的主动隔离概念应仅用于高灵敏度研究。
