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Laboratory for Atmospheric and Space Physics

INSPIRESat-4

The Satellite Research Centre at Nanyang Technological University is currently developing the Atmospheric Coupling and Dynamics Explorer (ARCADE) Mission, which is flying a hall effect thruster to progressively lower the altitude from an initial 500 km to 250 km. ARCADE is also the fourth satellite in the INSPIRE (International Satellite Program in Research and Education) satellite series with joint development from Forschungszentrums Jülich, Germany; LASP, University of Colorado USA;  IIST, India and NCU, Taiwan. ARCADE is a 27U spacecraft carrying an ionospheric plasma payload which will make ion temperature, velocity, density and electron temperature measurements. The satellite will be launched along with six other Singaporean satellites on a Singapore dedicated PSLV in 2022 into a near equatorial orbit. Since the final altitude is expected to be < 300 km, the ARCADE/INSPIRESat-4 mission provides an excellent opportunity to study the equatorial ionosphere at low altitudes where the ion and electron density are much higher. The mission is expected to provide new information on plasma irregularities along the magnetic equator. The mission is also a technology demonstration of a gridded ion thruster with Iodine fuel developed by French Startup ‘Thrust Me’. Another addition to the mission is a Spatial Heterodyne Interferometer Infra-Red Imager for imaging the Mesosphere and Lower thermosphere region between 60-120 km. The SHI instrument will provide temperature information and help for understanding the dynamics of the equatorial MLT region.

ARCADE carries an ion propulsion thruster to lower its orbit to less than 300 km to make in-situ ionospheric measurements. The thruster is expected to enable the mission to survive under 300 km for a duration of 6 months or more. The mission objectives of the ARCADE mission are as follows:

  • In-situ measurement of plasma irregularities along the magnetic Characterize the formation and evolution of ionospheric anomalies like plasma bubbles and its effects on GPS signal scintillation.
  • Perform in-situ measurements of ionospheric plasma below 300 km in
  • Quantify the role of wave dynamics in the upward and downward coupling of the MLT region and its influence on the dynamics and variability of the MLT
  • Image the equatorial region at a high resolution.

The ARCADE mission carries the following payloads.

1.   Compact Ionosphere Probe (CIP)

The Compact Ionosphere Probe (CIP), developed by Space Payload Laboratory at NCU, is a successor to the Advanced Ionospheric Probe aboard the FORMOSAT- 5 satellite. CIP is an all-in-one plasma sensor that performs in-situ measurements of the ionospheric plasma compositions, ion concentrations, velocities, and temperatures to explore the terrestrial ionosphere. The CIP instrument is being flown in a mid-latitude orbit in the INSPIRESat-1 mission and in a polar sun-synchronous orbit on the INSPIRESat-2 mission. Together with INSPIRESat-4 in an equatorial orbit, a constellation of such instruments is expected to be operational by Q3 of 2022 providing ionospheric measurements at a range of altitudes and local times.

2.   ATMOLITE

AtmoLITE is a highly miniaturized limb sounder utilizing a monolithic spatial heterodyne interferometer for day and nighttime atmospheric temperature sounding developed at Forschungszentrums Jülich, Germany. Atmospheric temperature profiles are obtained by limb-sounding O2 A-Band emissions at a wavelength of 762 nm from a low Earth orbit3. It is a complete remote sensing instrument with optics, detector, electronics, structure, and a radiator.