A. A. M. Delil

Development of a Mechanically Pumped Two-Phase CO2 Cooling Loop for the AMS-2 Tracker Experiment

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Moveable Thermal Joints for Deployable or Steerable Spacecraft Radiator Systems

A possible solution to handle the heat dissipated by the batteries of the Columbus Polar Platform is to equip each battery ORU (Orbital Replacement Unit) with a dedicated heat pipe radiator. Such a radiator, being stowed during launch, has to be deployed in orbit and might be chosen to be steerable to achieve maximum radiator performance, hence minimum radiator size. In such radiator systems the coupling between battery and deployable or steerable radiator has to Incorporate a rotatable or flexible thermal joint. Drivers for the design of such joints are a low thermal resistance, hence a limited temperature drop across the joint to optimize radiator size, and a small deployment/retraction torque or steering torque.

Thermal Modeling Issues Concerning the Mechanically Pumped Two-Phase CO2 Cooling for the AMS-2 Tracker

This paper discusses the thermal modeling activities as a design and development tool for the Tracker Thermal Control System, the mechanically pumped, carbon dioxide thermal management system for the AMS-2 Silicon Tracker. Main modeling topics are: radiator sizing and condenser development, set-point control and pre-heating issues with respect to the spatial and temporal temperature gradient requirements of the Tracker.

Quality Monitoring in Two-Phase Heat Transport Systems for Large Spacecraft

Two-phase heat transport systems are currently considered for the thermal management of future large power spacecraft. The monitoring of the quality, being the relative vapour mass content, of the two-phase mixture at various locations in the system, is valuable - possibly indispensable - for the proper operation of such a system. This paper reviews concepts for quality monitoring. Only a few concepts turn out to be suitable for spacecraft applications. Promising concepts are based on the capacitance, sonic velocity and index of refraction. These concepts are described and quantitatively analyzed. Applicability, advantages, restrictions and some hardware aspects are discussed.

Development Status of the Mechanically Pumped Two‐Phase CO2 Cooling Loop for the AMS‐2 TTCS

The Alpha Magnetic Spectrometer AMS is an international experiment, led by Nobel Prize laureate Samuel Ting (MIT), searching for anti‐matter, dark matter and lost matter. It is a particle detector for high‐energy cosmic rays, consisting the sub‐detectors: (Silicon) Tracker, Time of Flight (ToF) system, Veto Counters, Transition Radiation Detector (TRD), Synchrotron Radiation Detector (SRD), Ring Imaging Cherenkov Counter (RICH), Anti‐Coincidence Counter, and Electromagnetic Calorimeter. The demonstration experiment AMS‐1 has successfully flown in June ’98 on the Space Shuttle Discovery (STS91). The paper focuses on TTCS issues.

Sensors and Components for Aerospace Thermal Control and Propellant Systems

Various aspects of different sensors and components, (being) developed or fine-tuned for aerospace thermal control and propellant systems, are discussed, i.e.: rotatable radial heat pipe joints, vapour quality sensors, controllable valves, condensers, flow metering assemblies and propellant gauges.

Development of Liquid Flow Metering Assemblies for Space

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In-Orbit Demonstration of Two Phase Heat Transport Technology Status of TPX II:Reflight of the European Two-Phase Experiment

In order to demonstrate two-phase heat transport system technology in orbit, the Dutch-Belgian two-Phase eXperiment TPX was successfully flown as Get Away Special G557, aboard STS60, February 1994. Based on TPX conclusions and lessons learned, a reflight experiment TPX II is being developed in order to usefully fill the gap between TPX and possible future full-scale Capillary Pumped Loop flights. The characteristicss of TPX II, intended to fly early 1998, are discussed in detail: configuration and component changes, updates of objectives/scenario, current status, results of pre-launch (components) testing and outlook.

Sensors and components for aerospace thermal control, life sciences and propellant systems

Various aspects of different sensors and components, (being) developed or fine-tuned for aerospace thermal control and propellant systems, are discussed: rotatable radial heat pipe joints, vapour quality sensors, controllable valves, condensers, flow metering assemblies and propellant gauges.

Development of liquid flow metering assemblies for space

As it is impossible to directly use commercial liquid flow meters in space, a study was done for the European Space Agency to adapt commercial flow meter assemblies for spacecraft applications. The activities led to the selection of two commercial units, which were re-designed and adapted for use in spacecraft single-phase (water) and two-phase (ammonia) thermal control loops. These flow meter assemblies were tested according to an agreed test programme, that included performance and calibration tests in a test bench (developed during the study), vibration and EMC/EMI testing. The results are discussed to assess to what extent the study objectives were met. Recommendations for future work are given.