(Georgia Institute of Technology, 2022-06-08)
Kotani, Kohei
Today, the demand for big data, such as high-resolution images, has been rapidly increasing in space missions. However, the means to achieve multi-Gbps transmission is limited to ethernet, coax, or FFC in CubeSat design. This research describes the development of a lightweight and low-power consumption high-speed communication system suitable for small satellites. A high volume of data from two high-resolution cameras is transmitted to a Raspberry Pi Compute Module 4 running Linux using a fiber-optic link as an interconnect, and the dual images are displayed on a monitor. The FPGA with a high-speed transceiver is extensively used to achieve high-speed communication. It is also verified that the fiber-optic module operates at up to 6.25 Gbps with a power consumption of 90 mW. This research includes the hardware and software development details. All the materials, including the schematics, PCB design, and programming codes, can be found in the Github repository. Furthermore, this thesis includes the discussion of fiber-optic module usage in the space environment and comparing fiber-optic with ethernet, coax, and FFC, along with the selection guides CubeSat developers can refer to. The final deliverable of this research is the high-speed fiber-optic interconnection designed to fit into a CubeSat platform, demonstrating the dual-image display from two HD cameras. The prototype can be extended to implement high-volume data applications such as stereo imaging for proximity operations, free-space inter-satellite links, and high-speed intra-satellite communications for CubeSat platforms.
(Georgia Institute of Technology, 2020-01-10)
Hunter, Richard Anthony John
Fast, high-cadence translunar pathfinder missions hold great promise for advancing NASA's scientific observation, prospecting, and technology validation objectives through increased lunar exploration.
This research applies high-performance computing to characterize direct injection lunar trajectories over a broad parameter space, and in so doing, demonstrates the viability of lunar pathfinder missions using the near-future commercial launch market. The results are intended to provide mission designers with an accurate, versatile reference for preliminary planning, including optimal departure epochs, and pertinent performance dependencies.
Characterized herein are statistical distributions for the performance demands of optimally phased translunar missions, over an 18.6 year Earth-Moon nodal cycle, to a range of tailored lunar arrival architectures, for 0 – 24 kg small satellite payloads capable of supporting pathfinder objectives.
This characterization is based upon a TLI stage with flight proven propulsion technology, high fidelity orbital dynamics, and direct injection flyby, orbit insertion and landing architectures compatible with both dedicated and ride share commercial launches.