The Fine Details of the Phoenix Robotic Arm
The Phoenix’s Robotic Arm (RA), built by the Jet Propulsion Laboratory, is highly critical to the Mars operation that is now fully in operation, intended to dig trenches, scoop samples of soil and water ice. Once this is accomplished, data of samples will be sent to the two instruments- the TEGA and MECA—for more detailed chemical and geological analysis. An excellent piece of work, the RA can operate in four different directions: up and down, side to side, back and forth, and a complete rotation.
The TEGA, or Thermal and Evolved Gas Analyzer, consists of a combination of a mass spectrometer instrument, in addition to a high temperature furnace, for the analyzing of samples of ice and soil. The robotic arm’s operation will consist of samples delivered to a hopper, designed to feed just a bit of soil or ice into eight tiny little ovens—the size of an ink cartridge in a ballpoint pen—with the ovens used only once. A process called scanning calorimetry will begin, which is used to help the mission scientists understand the samples’ chemical characters where they will be able to see clues for past biological processes. At this point, the scoop will run through the dug furrows to obtain the sample fragments—enough for a scientific study on the platform.
The second step is the MECA process, the Microscopy, Electrochemistry, and Conductivity Analyzer, is also built by the Jet Propulsion Laboratory, and characterizes the Mars’ soil in the same manner as a gardener tests his soil for chemicals. The soil is dissolved in water, and the wet chemistry lab (WCL) determines the pH of the soil, things such as magnesium and sodium cations, along with many other things. The MECA looks through a microscope to examine the soil grains in order to figure out their origin and mineralogy. Before the RA delivers soil samples to a wheel which contains 69 different substrates which are designed to distinguish between different adhesion mechanism, magnets, sticky polymers, and buckets for bulk sampling.
The size of the RA on the Phoenix is almost 8 feet, with an elbow joint in the middle. This will allow the arm to trench about 1.6 feet below the surface of Mars, just deep enough to find the proposed water-ice samples. If it is found, the moveable scoop located at the end of the RA has sharp prongs and serrated blades to tear the exposed materials, with the blades scraping the fractured soil.
This entry was posted on Thursday, May 29th, 2008 at 9:39 am and is filed under Mission Objectives, Space Agency News, The Gear to Get There. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
