Session
Session VII: Communications
Abstract
Three CubeSats flown in the past two years have successfully mapped Globalstar performance over the altitude range 100 km to 700 km. The Globalstar constellation provides “Anywhere and Anytime” visibility to satellites and is ideal for CubeSats, constellations, and formation flying missions. Globalstar capacity is designed for 2500 channels per Globalstar satellite, potentially enabling hundreds to thousands of simultaneous communication to satellites. Capacity would then extend from the ground to potentially above the Globalstar LEO constellation at 1400km. TSAT (2U) made real-time plasma density and diagnostic measurements in the Extremely Low-Earth Orbit (ELEO) ionospheric region 350 to 110 km for new in-situ Space Weather mapping. TSAT heated at a rate of 20 degrees/min. on reentry at 110 km (reentry physics), yet it maintained a good real-time link with ground stations in Canada and Venezuela where it is believed to have re-entered. The NSL Globalstar flight products now permit new experiments to ELEO orbits in addition to releasing drop radiosondes to explore the Upper Atmosphere (Mesosphere) coupling with the lower atmosphere. Preliminary results are presented from the Globalstar Experiment and Risk Reduction Satellites (GEARRS1 and GEARRS2). GEARRS1 (3U) was launched from the ISS and verified the Globalstar CDMA protocol and Duplex SMS messaging. GEARRS2 (3U) was launched with an Atlas rocket on May 20, 2015 into a 350 by 700 km orbit and the Simplex communication and instrumentation operated well for 9 months beyond the mission expected lifetime (high TRL and radiation tolerant). Improved global coverage maps of the Simplex and Duplex performance are presented. Global maps of Duplex RF pulse data indicate that the Duplex may have good global coverage when on a 3 axis stabilized satellite to permit necessary connect time. Using a small permanent magnet for attitude control, the two patch antennas (1.616 GHz) and loss-cone energetic particle detector point up and down the earth’s magnetic field lines. The three SSD detectors mapped the precipitating and trapped particle flux in the aurora zone, the SAMA, the trapping boundary, and the internal penetrating radiation dose. Several new Globalstar flight radios are manifested for launch with three axis stabilization, so that Duplex large file transfer can be characterized. TSAT and GEARRS data indicate a strong side lobe link that may reach to high MEO altitudes
Globalstar Link: From Reentry Altitude and Beyond
Three CubeSats flown in the past two years have successfully mapped Globalstar performance over the altitude range 100 km to 700 km. The Globalstar constellation provides “Anywhere and Anytime” visibility to satellites and is ideal for CubeSats, constellations, and formation flying missions. Globalstar capacity is designed for 2500 channels per Globalstar satellite, potentially enabling hundreds to thousands of simultaneous communication to satellites. Capacity would then extend from the ground to potentially above the Globalstar LEO constellation at 1400km. TSAT (2U) made real-time plasma density and diagnostic measurements in the Extremely Low-Earth Orbit (ELEO) ionospheric region 350 to 110 km for new in-situ Space Weather mapping. TSAT heated at a rate of 20 degrees/min. on reentry at 110 km (reentry physics), yet it maintained a good real-time link with ground stations in Canada and Venezuela where it is believed to have re-entered. The NSL Globalstar flight products now permit new experiments to ELEO orbits in addition to releasing drop radiosondes to explore the Upper Atmosphere (Mesosphere) coupling with the lower atmosphere. Preliminary results are presented from the Globalstar Experiment and Risk Reduction Satellites (GEARRS1 and GEARRS2). GEARRS1 (3U) was launched from the ISS and verified the Globalstar CDMA protocol and Duplex SMS messaging. GEARRS2 (3U) was launched with an Atlas rocket on May 20, 2015 into a 350 by 700 km orbit and the Simplex communication and instrumentation operated well for 9 months beyond the mission expected lifetime (high TRL and radiation tolerant). Improved global coverage maps of the Simplex and Duplex performance are presented. Global maps of Duplex RF pulse data indicate that the Duplex may have good global coverage when on a 3 axis stabilized satellite to permit necessary connect time. Using a small permanent magnet for attitude control, the two patch antennas (1.616 GHz) and loss-cone energetic particle detector point up and down the earth’s magnetic field lines. The three SSD detectors mapped the precipitating and trapped particle flux in the aurora zone, the SAMA, the trapping boundary, and the internal penetrating radiation dose. Several new Globalstar flight radios are manifested for launch with three axis stabilization, so that Duplex large file transfer can be characterized. TSAT and GEARRS data indicate a strong side lobe link that may reach to high MEO altitudes
