Search Results

This paper reports on the approach followed for the TCS verification of the payload AMS-02 (Alpha Magnetic Spectrometer), aiming at the qualification of the entire system, in steps, for the space environment. AMS-02 is a state-of-the-art experiment composed by a stack of seven different particle detectors, each of them having its own electronics and control equipments. It will be installed on the International Space Station Starboard segment S3 of the main Truss, and will be a 6500 kg payload, with a power consumption of 2000 W. The verification philosophy is driven by the need to qualify the flight hardware and by the necessary confirmation and correlation of the thermal mathematical models, based on experimental data. The hardware used on AMS-02 is derived from the state-of-the-art ground based detectors for high energy physics, hence not yet proven for operations in vacuum and in extreme thermal environment.

The ASI (Italian Space Agency) AGILE satellite has been launched on April, 23rd 2007 by a PSLV rocket from Shrikariota spaceport, in India. Its payload, called AGILE as well (for Astro-rivelatore Gamma a Immagini LEggero) is an instrument for near-earth space research: its scientific instrumentation has optimal imaging capabilities in both the gamma-ray energy range (30 MeV - 30 GeV) and hard X-ray range (15 - 45 keV). It will study all the phenomena occurring in the high energy spectrum, such as: Active Galactic Nuclei, Gamma Ray Bursts, Gamma-ray Galactic Diffuse Emission, and more. The first 10 months in orbit are reviewed, in light of the thermal control system performance compared with the numerical and experimental predictions.

The future Mars rover thermal design presents a unique challenge to the thermal engineers: the need arises for a thermal control system able to keep rover elements within their operational and non-operational temperature ranges in the face of extreme environmental conditions, characterized by broad day/night temperature excursions, cold biased conditions and long periods in standby modes induced by dust storms. A thermal device is needed, which allows the removal of excess heat from dissipating units during the Martian day and to keep them above their minimum operational/survival temperature during night. Moreover the scientific goals introduce strict requirements in terms of allowable internal components temperature ranges and thermal stability, which the candidate device has to fulfill against wide-ranging power dissipation modes. Such a device has been called Variable Thermal Conductance Device, or ‘Heat Switch’.

The Alpha Magnetic Spectrometer (AMS-02) is a particle physics detector designed to be installed on the International Space Station for at least 3 years, in order to measure charged cosmic rays, and to search for dark matter, missing matter and antimatter. The silicon Tracker is the centre of AMS. It measures particle trajectories through AMS-02 strong magnetic field with a micron accuracy. The heat dissipated by the whole experiment is rejected to deep space by means of four radiators [4–5]: the two Tracker radiators assure the heat dissipation for the above mentioned silicon Tracker, and the two Main radiators reject to space all the heat dissipated by the power, command and control units. The four radiators have been designed, analyzed by means of detailed thermal mathematical models and finally constructed and tested. This paper focuses on the thermal mathematical models tuning to best fit the provided test data.

The Alpha Magnetic Spectrometer (AMS) is a particle physics detector designed to measure charged cosmic rays spectra and high energy photons on board of the International Space Station (ISS). The large acceptance (0.5 m2sr), the long mission duration (3 years) and the state of the art particle identification techniques will allow AMS to provide the most sensitive search up to date for the existence of anti matter nuclei and for the origin of dark matter. AMS02 now is in its final integration phase at CERN. To verify the functional performance of the detectors and of the key subsystems of the Thermal Control System under vacuum condition and to validate the thermal mathematical model of AMS02 a system level thermo-vacuum test will be performed in the Large Space Simulator (LSS) of ESA at ESTEC (the Netherlands).

A Heat Switch has been developed, namely a device able to autonomously regulate its own thermal conductance in function of the equipment dissipation and environmental heat sink conditions. It is based on a Loop Heat Pipe (LHP) technology, with a passive bypass valve which diverts the flow to the Compensation Chamber when needed for regulation purposes. The target application is the potential use on a Mars Rover thermal control system. The paper recalls the Heat Switch design, and reports the results of an extensive test campaign on the ground demonstrator. The performance of the device was found extremely satisfying, and often exceeded the system requirements.

This paper updates on the Thermal Control System (TCS) of AMS (Alpha Magnetic Spectrometer). The Shuttle fleet grounding, after Columbia accident February 2003, has caused a delay in the AMS-02 project schedule, allowing to put additional effort on the TCS design optimization. This paper accounts for two-years extended numerical simulations, leading to a stable TCS baseline design. AMS (shown in Figure 1) is to be installed on the International Space Station (ISS) Starboard segment of the Truss, where it shall acquire data for three years with the Superfluid Helium magnet powered ON. After Superfluid Helium tank is depleted, operations continue taking data with instruments not requiring the magnetic field of the super-conducting magnet; this allows a fine characterization of the spectrum of atoms nuclei, for Solar System human exploration purposes. AMS payload has a mass of about 6500 kg, and a power budget of about 2kW.