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Practically every kind of mass analyzer has been subjected to miniaturized design of some form or another. Magnetic sector analyzers were used in the double-focusing and gas chromatography-mass spectrometry (GC-MS) instruments designed by Alfred Nier and Klaus Biemann, respectively, in the two Viking missions to Mars launched in 1975. 1, 2 Permanent magnets used in these instruments provided a very low power design with a total mass of 600 kg. In the Nier instrument, mass scanning was achieved by sweeping the accelerating and electrostatic energy analyzer (ESA) voltages, with two collectors recording ions in 1–7 amu and 7–49 amu mass range. The GC-MS instrument had a mass range from 12 to 200 u. More recently, a novel sector instrument based upon a crossed field (ExB) design by Diaz et al. 3 has been developed as a residual gas analyzer