Terrestrial Balloon 10-Mbps to 1-Gbps Communications using Commercial Satellites and NASA TDRSS

A Ka-band satellite communications flight terminal will be designed for use by NASATerrestrial Balloons to provide 10-Mbps to 1-Gbps satellite communications transmit links and low data rate command receive links using either commercial Ka-band satellites or NASA TDRSS satellites. The transmit Ka-band frequenciesof NASA TDRSS satellites go up to 27.5-Ghz and are adjacent to the commercial Ka-band satellite frequencies starting at 27.5-Ghz, so this single Ka-band flight terminal will be able to tune to both the NASA TDRSS and commercial Ka-band satellite frequencies. This Ka-band flight terminal will be shown to have a lower size, weight, and power (SWaP) to the existing NASA Balloon satcom terminals.A relatively low-cost 2-dimensional electronic beamforming antenna will be tested for its capability to point a high-gain antenna beamat the existing commercial or TDRSS Ka-band satellites in geostationary orbit (GEO) as the terrestrial balloon is moving slowly in relation to those GEO satellites. Testing will also be performed on the ability of this same beamforming antennato point at and track existing O3b middle Earth orbit (MEO) and TeleSat and SpaceX low Earth orbit (LEO) Ka-band satellites that will be moving much faster relative to the balloon.The performance of thisKa-band flight terminal will change dramatically from 10-Mbps to 1-Gbps depending on which Ka-band satellite and which satellite beam in which GEO, MEO, or LEO orbit the balloon's terminal decides to access. Software defined radio (SDR) waveform firmware and flight radio hardware will be tested through a channel simulatorthat uses software to simulatea moving NASA Balloonsuccessfully closing satcom links throughsatellites with differentlink characteristics. Beam to beam handovers, frequency channel interference mitigation, and the different Doppler shift compensation needed for the differentGEO, MEO, and LEO orbits will be tested in these simulations of the SDR firmware and hardware.