Browsing by Author "Reina, Manuel"
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Item INTA MXGS Instrument Thermal Control for the ASIM Payload(50th International Conference on Environmental Systems, 7/12/2021) Reina, Manuel; Eiriz, Valvanera; Bastide, Laurent; V�zquez, Pelayo; Fern�ndez, Miguel; Mart�n, Jos� Antonio; Sabau, Lola; Rodrigo, Juana; Reglero, V�ctorINTA is a partner of the Spanish consortium on the MXGS (Modular X-Ray and Gamma-Ray Sensor) Instrument, part of the ASIM (Atmospheric Space Interactions Monitor) ESA Mission. ASIM was launched on April 2nd, 2018, with CRS-14 Falcon-9/Dragon by SpaceX, and is still operating up-to-date, anchored on the Columbus laboratory of the ISS. MXGS was designed to detect Terrestrial Gamma Flashes (TGF) due to high energy phenomena in the upper atmosphere layers, which sources and physics are the mission objectives. Low and High energy detectors with space heritage (two detectors assemblies, one with CZT and another with BGO detectors), and a coded mask in front of the instrument, provide imaging capabilities for TGF location. The Payloads and Instrumentation Area at INTA designed a thermal control subsystem based on active and passive thermal control, including thermostated heaters, MLI, surface treatments, material selection and heat pipes such as LHP (Loop Heat Pipes) and AGHP (Axial Groove Heat Pipes). Thanks to the ISS telemetry, the thermal sensors located on the MXGS assembly enable to know the temperatures seen by the instrument since the launch, and give a good overview of the thermal environment suffered during the mission lifetime. A variable environment due to the ISS orbit and attitudes, with tight temperature requirements, challenged the instrument thermal control design. Mass and envelope budget were the constraints for the structural, integration, tests and verification activities. As any space payload development program, the design included several margins to cover the uncertainties on the simulations performed to reach the actual thermal design implemented in the flight model. This paper explains the margin philosophy adopted to design the thermal control subsystem, sums up the thermal analysis results and compares the thermal sensors predictions obtained on several analysis cases with the thermal sensors reading obtained by the telemetry.Item INTA Thermal testing and Model Correlation for Mechanical Thermal Strap Test - ATHENA Instrument(50th International Conference on Environmental Systems, 7/12/2021) Fern�ndez, Miguel; Llases, Almudena Garc�a; Bastide, Laurent; Azcue, Joaqu�n; Reina, Manuel; Balado, Ana; Elvira, Javier G�mezScientific missions to study the Hot Universe does use of X-ray spectrometry, which detectors are transition-edge sensor (TES) superconductor detectors operating at millikelvin. That goal could be reached with a cryostat refrigerated by cryocoolers up to 2K, and subKelvin refrigeration is part of the Focal Plane Assembly, where the TES are. DCS (Detector Cooling System) is a demonstrator of such cryostats, designed to test the performance and the functionality of a cryogen free coolers chain. The DCS is composed by two main assemblies: Focal Plane Assembly (FPA) and a Dewar (the pressure vessel structure and radiative shields cooled by Pulse tube and Joule-Thompson coolers), which creates a 2K environment for the FPA, where an ADR cools the detectors. The radiation is managed by the intermediate cooled shields, while the conduction goes through two �radial� paths: mechanical straps and harness. Each mechanical strap is formed by four links of composite materials (GFRP and CFRP), selected according to structural and thermal requirements. The material distribution is GFRP for high temperature stages (300K to 30K) and CFRP in low temperature stages (30K to 2K). To verify the design, a dedicated thermo-mechanical test was performed, submitting the straps to temperature gradients and mechanical stress similar to the expected: two straps were tested at their temperature range (at 300K), while the cold end was at 30K. Straps under a tension of 6.000N applied at room temperature, according to the DCS design. Active thermal control, insulating shields and ancillary elements, were used to create the thermal environment, and Silicon-Diode thermal sensors used to measure the strategic spots. Strain gauge was used before the cool down to measure the deformation due to the tension and check any change due to temperature changes. This paper describes the test set-up, thermal model done and the results of such correlation.Item TuMag Optical Unit Thermal Control for a Stratospheric Balloon-borne Mission(2023 International Conference on Environmental Systems, 2023-07-16) Gonzalo, Alejandro; Reina, Manuel; Sánchez, Antonio; Fernández-Medina, Ana; Cebollero, María; Laguna, Hugo; Escribano, David; Álvarez-Herrero, AlbertoThe Tunable Magnetograph (TuMag) is an imaging tunable spectropolarimeter designed to study solar magnetic fields at high spatial resolution. It measures the state of polarization of light at three selected spectral solar lines: the Fe I at 525.02nm and 525.06nm, and the Mg I b2 at 517.27nm. TuMag is part of the post-focal instrumentation of the SUNRISE III mission whose first launch attempt was carried out from Kiruna (Sweden) in July 2022. The correct science performance of the instrument is strongly determined by the thermal stability of critical subsystems during observations. Elements such as the polarization modulator based on Liquid Crystal Variable Retarders, the LiNbO₃ etalon used to scan the spectral lines, or the three narrow bandpass filters with a ~1.5 Å FWHM mounted on a filter wheel, are required to operate within a tight temperature set-point. TuMag Thermal Control System (TCS) will guarantee the correct operational temperature for the aforementioned sub-systems at the time that provides a cooling mechanism for the detectors and minimizes thermo-elastic deformations across the optical path. It combines active and passive strategies in an architecture that profits from the unit location within the balloon gondola, which leaves only its top surface opened to the outer space. The thermal environment of a stratospheric flight is similar to that in LEO and hence typically driven by radiation. However, the presence of a 5 mbar rarefied atmosphere is shown to have an undesired effect in the thermal control performance of some of the internal elements. This impact was assessed during the thermal ground testing with the fully integrated Optical Unit, prior to its delivery to the platform. The expected TCS performance is currently being compared to the real data retrieved during the brief SUNRISE III first flight.