Bortoluzzi D, Benedetti M, Baglivo L, De Cecco M, Vitale S
Department of Mechanical and Structural Engineering and INFN, University of Trento, via Mesiano 77, 38123 Trento, Italy.
Rev Sci Instrum. 2011 Dec;82(12):125107. doi: 10.1063/1.3658479.
In the frame of many scientific space missions, a massive free-falling object is required to mark a geodesic trajectory, i.e., to follow inside a spacecraft an orbit that is determined only by the planetary gravity field. The achievement of high-purity geodesic trajectories sets tight design constraints on the reference sensor that hosts and controls the reference body. Among these, a mechanism may be required to cage the reference body during the spacecraft launch and to inject it into the geodesic trajectory once on-orbit. The separation of the body from the injection mechanism must be realized against the action of adhesion forces, and in the worst case this is performed dynamically, relying on the body's inertia through a quick retraction of the holding finger(s). Unfortunately, this manoeuvre may not avoid transferring some momentum to the body, which may affect or even jeopardize the subsequent spacecraft control if the residual velocity is too large. The transferred momentum measurement facility (TMMF) was developed to reproduce representative conditions of the in-flight dynamic injection and to measure the transferred momentum to the released test mass. In this paper, we describe the design and development of the TMMF together with the achieved measurement performance.
在许多科学太空任务中，需要一个巨大的自由落体来标记测地线轨迹，即在航天器内部沿着仅由行星引力场决定的轨道运行。实现高纯度测地线轨迹对承载和控制参考体的参考传感器提出了严格的设计约束。其中，可能需要一种机构在航天器发射期间将参考体锁定，并在轨道上一旦就位就将其注入测地线轨迹。必须克服附着力的作用实现参考体与注入机构的分离，在最坏的情况下，这是通过快速缩回夹持指依靠参考体的惯性动态完成的。不幸的是，这种操作可能无法避免将一些动量传递给参考体，如果残余速度过大，这可能会影响甚至危及后续的航天器控制。开发了转移动量测量设施（TMMF）来再现飞行中动态注入的代表性条件，并测量传递给释放的测试质量的动量。在本文中，我们描述了TMMF的设计和开发以及所实现的测量性能。
