This paper presents a high-level control architecture for robotic spacecrafts. The design of this architecture focuses on future On-Orbit Servicing missions. Part of it is a component framework that improves software reuse in space applications and enables real-time communication between different components of a satellite which is essential for on-orbit servicing. Further, this architecture su...

Purpose Each production process in construction is closely connected with the question of costs and deadlines. In every project an investor or customer, as well as the construction company, has to meet the planned completion date and the estimated costs associated with the construction. In practice, determining the duration of construction at minimum costs is still not based on the reliable cal...

Aircraft hydraulic systems are composed of several components connected and distributed along the aircraft. Monitoring leakage of these components are time consuming tasks, and often cover only some parts of the system. The objective of this work is to present a method to estimate hydraulic leakage and recommend maintenance and servicing tasks using aircraft standard sensors such as fluid tempe...

This paper deals with a tool which may help maintenance manager to schedule maintenance activities. To help him, we show that by using events which can be observed on a process, like maintenance events, we can predict failures before they occur. Principles are based on the hypothesis that failure is preceded by a typical sequence of events. We also show that Hidden Markov Models can be used acc...

The far-UV throughput of WFPC2 was monitored on March 23, 2002 for any signs of unexpected throughput degradation following Servicing Mission 3b. No significant changes were detected.

The notion of service-enhanced product brings new perspectives for value creation and differentiation in manufacturing. The existence of complex and highly customized products, the inclusion of business services that add value to the product typically require the collaboration of multiple stakeholders. It is natural that each stakeholder has its own set of values and preferences and as a result...

The ACS/WFC detector consists of two CCDs, each of which is read out through two amplifiers. While reading each quadrant of the detector, the electronic crosstalk between the amplifiers induces faint, typically negative, mirror-symmetric ghost images on the other three quadrants. The effect is strongest for high-signal offending (source) pixels. Analysis of pre-SM4 crosstalk showed that its imp...

64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 standing army of technicians and engineers, plus exhaustive training for the astronauts who carry out the work. And then there’s the $500 million price tag for a shuttle flight. These huge costs led to an agreement in the late 1990s among Congress, N...