High Speed X-Ray Imaging
NASA’s Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) mission (aka Mars Insight Lander) was designed to study the Red Planet. The Mars Insight Lander’s Heat Flow and Physical Properties Package instrument, HP3, used a self-propelled penetrator device called the mole to dig as much as five meters into the Martian surface.
The mole was a critical piece of the Mars Insight Lander’s HP3 hardware, housing both a high-impact hammering mechanism and sensitive electronic sensors. During development, the mole was tested in a variety of Mars surface simulants under various conditions including earth-ambient, low ambient temperature (<-50°C), low ambient pressure (<10 mbar), and low ambient temperature and pressure. In certain environmental conditions the mole’s forward progress slowed or even reversed. The mole would dig successfully on earth but not in the simulated Mars environment.
Researchers at RMD, helped NASA’s Jet Propulsion Laboratory (JPL) investigators troubleshoot the probe through X-ray cineradiography, using RMD’s sophisticated high-speed x-ray imaging camera designed to acquire high resolution X-ray movies at speeds exceeding 100,000 frames per second. A portable Mars environment was created at RMD’s Watertown, MA, facility using ‘Mars equivalent soil’ inside a vacuum chamber and X-ray movies were taken of the mole’s hammering mechanism. The attached image shows the X-ray movies of the entire mole, and a close-up of its hammering mechanism, during operation captured at 3,000 X-ray images per second. These experiments allowed RMD’s engineers to compare actual and modeled behavior of the otherwise invisible internal workings of the mole.