ANITA2 – the Multicomponent Air Analyser on ISS – Gas Measurement Results From the ISS Air in 2023



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2024 International Conference on Environmnetal Systems


The ANITA2 (Analysing Interferometer for Ambient Air) system is a trace gas analyser designed to operate onboard the ISS to monitor the cabin atmosphere. ANITA2 can detect more than 45 of the most important trace gases in parallel. The advantages of an ANITA-type instrument include high sensitivity, accuracy, precision, and time resolution of the measurement data, as well as no consumption except electrical power and no production of waste. This also makes ANITA a steppingstone into the future, as a precursor system for crewed stations, bases, and exploration missions, including the Lunar Gateway and to/on the Moon and Mars.

Like ANITA1, that operated successfully for 11 months on-board the ISS in 2007 and 2008, the ANITA2 system was built in a contract between ESA, OHB, and SINTEF. ANITA2 was launched to the ISS in December 2021, and it has been in regular operation since March 9, 2022. At the time of writing, ANITA2 is monitoring 48 gas compounds in the ISS air.

This paper covers ANITA2's air analysis on the ISS, including extensions of the calibration to include new gases, and adaptations to new conditions after moving from an Express rack in the US Lab to the EPM rack in ESA's Columbus module on March 1, 2023. Manual non-local samples, applying ANITA2's hand pump and gas bags to feed air samples into ANITA2 for automatic gas analyses, has confirmed that the ISS air in general is well mixed. Still, the moving of the system showed marked differences in small, local cyclic variations in gases that are influenced by removal systems for carbon dioxide. This paper also describes the special actions taken to support the operational decisions for the ISS on how to handle the possible internal air pollution from a leaked external cooling liquid contaminating the space suits during spacewalks.


A. Honne, SINTEF, Norway
K. Kaspersen, SINTEF, Norway
K. A. Bakke, SINTEF, Norway
A. E. Liverud, SINTEF, Norway
J. Thielemann, SINTEF, Norway
B. Elvesæter, SINTEF, Norway
M. Gisi, OHB System AG, Germany
L. Pfeiffer, OHB System AG, Germany
A. Stettner, OHB System AG, Germany
E. Göhler, OHB System AG, Germany
R. Seurig, OHB System AG, Germany
P. Rebeyre, ESTEC, The Netherlands
ICES205: Advanced Life Support Sensor and Control Technology
The 53rd International Conference on Environmental Systems was held in Louisville, Kentucky, USA, on 21 July 2024 through 25 July 2024.


Gas Analysis, Air Analysis, FTIR, Life Support in Space, ANITA, Analysing Interferometer for Ambient Air, Trace Gas Monitoring, ISS, International Space Station, Exploration, Habitat, Real Time Monitoring, Gateway, Lunar Exploration, Human Space Flight