Short-Period Seismometer Development at JPLDetermining the structure of the interior of Mars has been a high priority for every Mars exploration strategy developed in the past 20 years, and is one of the primary goals of the InterMarsnet mission. Seismology is by far the most effective and detailed tool for investigating the radial and lateral distribution of density and elastic properties within a planet. Whereas long-period signals contain information from surface waves and normal modes from relatively large events, as well as the tidal response of the planet, the ability to record the high-frequency portion of the seismic spectrum (0.05 > f > 50 Hz) is essential for using the body waves of small to moderate events for probing the interior and analyzing the source characteristics of martian quakes.