Session
Weekend Session 3: Science/Mission Payloads - Research & Academia I
Location
Utah State University, Logan, UT
Abstract
NinjaSat is a 6U CubeSat-sized X-ray observatory to be launched into the low Earth orbit at an altitude of 550 km, and is scheduled for launch this October. NinjaSat is equipped with two 1U-sized gas X-ray detectors (GMC) and is expected to operate mainly for astronomical observations of bright X-ray objects in the sky, such as neutron stars and black holes.
Since high voltages are applied to the gas cells of GMC, two radiation belt monitors (RBM) will also be installed to protect GMC from electrical discharges potentially caused by excessively high rate of charged particles. NinjaSat RBM will play a fail-safe function in the voltage suppression operation of GMC in the auroral zone and South Atlantic Anomaly, and also protect GMC from charged particles such as protons and electrons that arrive unexpectedly due to solar flares or other low-Earth orbit radiation events.
RBM uses a 9 mm x 9 mm Si-PIN photodiode as a charged particle sensor. By taking advantage of the difference in sensor response to protons and electrons, the sensor is designed to simultaneously count charged particle rates at multiple energy thresholds so that GMC protection function will operate even if either the proton or electron rate increases. RBM can count up to about 10 kcps with almost no loss of counts, and proton beam tests have confirmed that the response performance is sufficient to protect GMC against excessively high charged particle rates above 10 Mcps without choking the circuitry.
The flight models of the RBM have passed the thermal vacuum and vibration tests last year. The developed RBM occupies only about 6% of the 1U CubeSat size in volume and weighs only 70g. In addition, since the RBM uses inexpensive, commercially available sensors, it could be installed on small satellites other than NinjaSat with relatively small development resources.
Development of Radiation Belt Monitors for the 6U CubeSat X-Ray Observatory NinjaSat
Utah State University, Logan, UT
NinjaSat is a 6U CubeSat-sized X-ray observatory to be launched into the low Earth orbit at an altitude of 550 km, and is scheduled for launch this October. NinjaSat is equipped with two 1U-sized gas X-ray detectors (GMC) and is expected to operate mainly for astronomical observations of bright X-ray objects in the sky, such as neutron stars and black holes.
Since high voltages are applied to the gas cells of GMC, two radiation belt monitors (RBM) will also be installed to protect GMC from electrical discharges potentially caused by excessively high rate of charged particles. NinjaSat RBM will play a fail-safe function in the voltage suppression operation of GMC in the auroral zone and South Atlantic Anomaly, and also protect GMC from charged particles such as protons and electrons that arrive unexpectedly due to solar flares or other low-Earth orbit radiation events.
RBM uses a 9 mm x 9 mm Si-PIN photodiode as a charged particle sensor. By taking advantage of the difference in sensor response to protons and electrons, the sensor is designed to simultaneously count charged particle rates at multiple energy thresholds so that GMC protection function will operate even if either the proton or electron rate increases. RBM can count up to about 10 kcps with almost no loss of counts, and proton beam tests have confirmed that the response performance is sufficient to protect GMC against excessively high charged particle rates above 10 Mcps without choking the circuitry.
The flight models of the RBM have passed the thermal vacuum and vibration tests last year. The developed RBM occupies only about 6% of the 1U CubeSat size in volume and weighs only 70g. In addition, since the RBM uses inexpensive, commercially available sensors, it could be installed on small satellites other than NinjaSat with relatively small development resources.
