Ensuring crew health and safety is a prime concern in spacecraft and other closed manned habitats. Therefore ESA (European Space Agency) has a long term research and development programme where SINTEF is developing advanced air quality monitoring technology in co-operation with Kayser-Threde GmbH. The key technologies applied are FTIR (Fourier Transform Infra-Red spectroscopy) and PLS (Partial Least Squares), a family of multivariate statistical methods applied for calibration.The air quality monitoring system ANITA (Analysing Interferometer for Ambient Air) has been constructed for early detection of toxic, harmful or unpleasant gases. The system applies off-the-shelf or modified FTIR hardware and specially developed analysis software. The software includes novel compensation methods for hardware insufficiencies, allowing simultaneous moni¬toring of over 30 possible air contaminants in the presence of water vapour, carbon dioxide, and methane. In a blind sample test campaign for NASA, the system was ranked first with substantial distance to the competitors.ANITA was successfully launched on the Space Shuttle STS 118 in August 2007. After installation in the US lab Destiny on the ISS (International Space Station) in September, the system was monitoring the trace gas dynamics in the ISS cabin air until August 2008. The system represents a versatile air quality monitor, allowing for the first time the detection and monitoring of trace gas dynamics, with high time resolution, in a spacecraft atmosphere. Other possible application areas for such systems and techniques include monitoring of indoor air and industrial processes.This presentation is the first out of two parts. The second part addresses ANITA’s operation on the ISS and the measurement results.This first part describes the instrument, the measurement task, the system calibration and testing, preparations for flight, and installation on the ISS.