MENCA onboard the Indian Mars Orbiter Mission

Anil Bhardwaj , S.V. Mohankumar , Tirtha Pratim Das , Smitha V. Thampi , P. Pradeepkumar , P. Sreelatha , Sundar B. , Amarnath Nandi , Dinakar Prasad Vajja , M.B. Dhanya , Neha Naik , G. Supriya ,R. Satheesh Thampi , G. Padma Padmanabhan ,

1Space Physics Laboratory, Vikram Sarabhai Space Centre

The MENCA (Mars Exospheric Neutral Composition Analyser) is one of the science instruments onboard the Mars Orbiter Mission, India’s first mission to Mars. MENCA is a quadrupole mass spectrometer, and is also equipped with a Bayard Alpert gauge for total pressure measurements. The quadrupole mass spectrometer is being used to measure the exospheric composition of Mars. In this article, the theory of quadruple mass spectrometery is briefly discussed followed by description of the MENCA instrument. The various processes involved in the characterization and calibration of this mass spectrometer are also described.