INTA MXGS Instrument Thermal Control for the ASIM Payload


INTA 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.


Manuel Reina, INTA
Valvanera Eiriz, INTA
Laurent Bastide, ISDEFE
Pelayo V�zquez, INTA
Miguel Fern�ndez, INTA
Jos� Antonio Mart�n, INTA
Lola Sabau, INTA
Juana Rodrigo, GACE IPL University of Valencia
V�ctor Reglero, GACE IPL University of Valencia
ICES202: Satellite, Payload, and Instrument Thermal Control
The 50th International Conference on Environmental Systems was held virtually on 12 July 2021 through 14 July 2021.


MXGS, Thermal Control, ASIM