Cardús D
Baylor College of Medicine, Department of Physical Medicine and Rehabilitation, Houston, TX 77030-3405, USA.
J Gravit Physiol. 1994 May;1(1):P19-22.
The history of manned space flight has repeatedly documented the fact that prolonged sojourn in space causes physiological deconditioning. Physiological deterioration has raised a legitimate concern about man's ability to adequately perform in the course of long missions and even the possibility of leading to circumstances threatening survival. One of the possible countermeasures of physiological deconditioning, theoretically more complete than others presently used since it affects all bodily systems, is artificial gravity. Space stations and spacecrafts can be equipped with artificial gravity, but is artificial gravity necessary? The term "necessary" must be qualified because a meaningful answer to the question depends entirely on further defining the purpose of space travel. If man intends to stay only temporarily in space, then he must keep himself in good physical condition so as to be able to return to earth or to land on any other planetary surface without undue exposure to major physiological problems resulting from transition through variable gravitational fields. Such a situation makes artificial gravity highly desirable, although perhaps not absolutely necessary in the case of relative short exposure to microgravity, but certainly necessary in interplanetary flight and planetary landings. If the intent is to remain indefinitely in space, to colonize space, then artificial gravity may not be necessary, but in this case the consequences of long term effects of adaptation to weightlessness will have to be weighed against the biological evolutionary outcomes that are to be expected. At the moment, plans for establishing permanent colonies in space seem still remote. More likely, the initial phase of exploration of the uncharted solar system will take place through successive, scope limited, research ventures ending with return to earth. This will require man to be ready to operate in gravitational fields of variable intensity. Equipping spacecrafts or space stations with some means of artificial gravity in this initial phase is, therefore, necessary without question. In a strict sense artificial gravity is conceived as a means of replacing natural gravity in space by the centripetal acceleration generated by some sort of rotating device. Rotating devices create an inertial force which has effects on bodies similar to those caused by terrestrial gravity, but artificial gravity by a rotation device is not the same as terrestrial gravity, as we shall see. Present research in artificial gravity for space exploration is projected in two main directions: artificial gravity for whole space stations and artificial gravity produced by short arm centrifuges designed for human use in space.
在太空中长期停留会导致生理机能衰退。生理机能的恶化引发了人们对人类在长期任务中充分发挥能力的担忧，甚至担心这可能导致威胁生存的情况。生理机能衰退的一种可能对策是人工重力，从理论上讲，它比目前使用的其他方法更为全面，因为它会影响身体的所有系统。空间站和航天器可以配备人工重力，但人工重力是必需的吗？“必需”这个词必须加以限定，因为对这个问题的有意义回答完全取决于对太空旅行目的的进一步界定。如果人类只是打算在太空中短暂停留，那么他必须保持良好的身体状况，以便能够返回地球或在任何其他行星表面着陆，而不会因穿越可变引力场而过度暴露于重大生理问题。在这种情况下，人工重力是非常可取的，尽管在相对较短时间暴露于微重力环境下可能并非绝对必要，但在星际飞行和行星着陆时肯定是必需的。如果意图是在太空中无限期停留、殖民太空，那么人工重力可能不是必需的，但在这种情况下，必须权衡适应失重的长期影响与预期的生物进化结果。目前，在太空中建立永久殖民地的计划似乎仍然遥不可及。更有可能的是，对未知太阳系的初步探索阶段将通过连续的、范围有限的研究任务进行，最终返回地球。这将要求人类准备好在强度可变的引力场中操作。因此，在这个初始阶段，为航天器或空间站配备某种人工重力手段无疑是必要的。严格来说，人工重力被设想为通过某种旋转装置产生的向心加速度来取代太空中的自然重力。旋转装置会产生一种惯性力，其对物体的影响类似于地球重力所产生的影响，但正如我们将看到的，旋转装置产生的人工重力与地球重力并不相同。目前用于太空探索的人工重力研究主要朝着两个方向进行：为整个空间站提供人工重力以及由专为人类在太空中使用的短臂离心机产生人工重力。
