Analysing Interferometer for Ambient Air explained

Analysing Interferometer for Ambient Air (ANITA) is a trace gas monitoring system for the International Space Station (ISS). Monitoring air quality on ISS helps provide adequate life support for the crew. ANITA is developed by OHB and SINTEF under contract of ESA.

Working principle

ANITA is based on Fourier-Transform-Infrared-Spectroscopy FTIR. Each measured gas absorbs light in a certain frequency, these spectral lines are analysed and a gas concentration is calculated.

Development

ANITA-1 was operating from Sept 2007 until Aug 2008 on board the ISS. It weighed >55kg which was distributed in 2 Middeck Locker Inserts and a Laptop. Power consumption was approx. 150W. It was able to measure more than 32 trace gases on board the ISS.^{[1] [2]}

ANITA-2 launched on SpaceX CRS-24 in Dec. 2021. It has been significantly reduced in size (1 Middeck Locker Insert) and mass (<38kg). The total power consumption is approx. 80W. It features WiFi Connection and a Touch Screen for a more versatile use. Compared to ANITA-1 it has a significantly increased (~factor 4) Signal to Noise Ratio allowing lower detection limits. ANITA-2 is calibrated to detect 37 gases, mostly with a detection limit well below 1ppm.^{[3] [4]} ANITA-2 was installed in an Express Rack inside the Destiny Lab by Matthias Maurer January 5, 2022.^[5] ANITA-2 is running nearly continuously on board the ISS since March 2022 and is monitoring the gas environment.

Usage

Using ANITA-1 Freon 218 was able to be detected on board the ISS, which was probably leaking from a Russian cooling loop.^[6]

External links

• Overview of the project ANITA-2 at the website of SINTEF

Notes and References

1. Stuffler, T., et al. ANITA air monitoring on the international space station part 1: The mission. No. 2008-01-2042. SAE Technical Paper, 2008.
2. Honne, A., et al. "ANITA Air monitoring on the international space station part 2: air analyses." SAE International Journal of Aerospace 1.1 (2009): 178.
3. Gisi, Michael, et al. "ANITA2 Trace Gas Analyser for the ISS-Flight Model Finalization and ground test results." 49th International Conference on Environmental Systems, 2019.
4. Stuffler, Timo, et al. "ANITA2 Flight Model Development-A status report of the multicomponent ISS Air Analyser." 47th International Conference on Environmental Systems, 2017.
5. Web site: Analysing Interferometer for Ambient Air (ANITA-2) Installation in Destiny Lab Express Rack. www.esa.int.
6. Web site: Prima Klima oder dicke Luft auf der ISS?. www.esa.int.