Figure. Clockwise from upper left, MARS node configuration,  array of 4 nodes with varying shielding thickness, flight hardware, location of single nodes on GLADIS box.
Figure. Clockwise from upper left, MARS node configuration, array of 4 nodes with varying shielding thickness, flight hardware, location of single nodes on GLADIS box.

Objectives

  • Provide an array of persistent, ubiquitous sensors that monitor the total dose radiation on the host spacecraft for 3-D rad modeling. The concept is to provide a radiation state-of-health measurement like that of a thermistor.
  • Validate SWORD modeling.

Approach

  • Hybrid microcircuit which directly measures accumulated total ionizing dose in a silicon test mass since power-up, technology developed by Aerospace and transitions to Teledyne.
  • Persistent sensor – 100% duty cycle
  • Low Size, Weight, and Power (SWAP) small telemetry requirement:
    5.4 x 5.4 x 1.9 cm, 110g, 30 mW avg., 66 bits/sample/sensor
  • An array of micro-dosimeters is flown on the STP-H4 host experiment (GLADIS), several nodes on the exterior and one on the interior. First flight of technology post industry transition.
  • A co-located array of four dosimeters with varying amount of shielding to look at different energy levels
  • Nodes connect to a simple central data collector that collates data for distribution to host platform data handling system.

Deliverable/Value/Accomplishment

  • Flight of an array of micro-dosimeters placed on the interior and exterior of a host spacecraft will provide radiation depth-dose profile in the vehicle, which can be directly compared with SWORD calculations using rad. transfer and mass modeling
  • Spacecraft Design Aid
    • Enables verification of space vehicle radiation design models ( e.g.. SWORD, SPENVIS)
    • Critical for highly exposed applications
    • Deep dielectric discharges
    • Determine amount of shielding
  • Launch Plans: MARS delivered to STP-H4 payload complement for launch on HTV-4 (Tanegashima, Japan) in Aug 2013 for flight on International Space Station