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This paper presents life test data of two controlled pump assemblies continuously running since September 1993. The tests, running on FLUOROCARBON CCIF2 - CCIF2, are still in progress (Current date May 1997). One pump operates at the design point, the other one at 3 different RPM's. Reliability considerations lead to a novel, sensorless, brushless DC motor of very high reliability. Given is an outline of the extensive environmental test compaign and Micro-G tests, with results. Pump performance data taken prior and after the environmental tests, performances after 1 and 3 years of continuous operation are given and compared. Up to now, after 3 years of operation no pump degradation can be detected. A pre-runner of the above pumps, featuring the same bearing design is continuously running since November 1990 with no observable degradation.

This paper presents the final results of a technology contract initiated by ESA at the end of 1990 to develop a controlled pump unit for use on board spacecraft and space vehicles. The main features required for the CPA were the adaptability to any working environment (vacuum or pressurised compartment, operation in any mission phase) with a high degree of reliability and efficiency, the compatibility with a wide range of fluids and the usability as a component of both single phase and two phase cooling loops. The final design of the assembly is presented and discussed. The main part of the presentation is devoted to the description of the tests performed to qualify the design and to the presentation and discussion of their results.

In parallel to the detailed quantitative analyses performed by ERNO and ESTEC Material Division (subject of another paper), ESTEC carried out a thermal visual inspection of EURECA thermal control hardware aiming at understanding what kind of impact the LEO environment can have on materials and design configurations. The first part of the paper deals with the findings of the inspection. A brief description of the EURECA TCS design is given first, followed by the observations on the after-flight configuration. Some discrepancies between the as-designed and as-built configurations as well as the impact of the orbital environment on the hardware characteristics are the most significant outcome of the inspection. The cooling loop and its components were not directly inspected at ESTEC. The relevant activities are still on going at ERNO (EURECA prime contractor) and NASA. This paper includes all information available at the date of issue. Further results will be presented at the conference.

Microgravity problems are considered here from the standpoint of engineers that are requested to maintain a very low level of self induced vibrations generated by a pump package. The request to conceive a mathematical model for the evaluation of the total dynamic force generated and transmitted from the package to the interfacing structure has induced a lot of activities and studies in this field. Investigations about internal sources of vibration have been made by means of analytical techniques and experimental evaluations. Preliminary results and considerations are presented.