CubeSats can encounter a myriad of difficulties in space like cosmic rays, temperature<br/>issues, and loss of control. By creating better, more reliable software, these problems can be<br/>mitigated and increase the chance of success for the mission. This research sets out to answer the<br/>question: how do we create reliable flight software for CubeSats? by providing a concentrated<br/>list of the best flight software development practices. The CubeSat used in this research is the<br/>Deployable Optical Receiver Aperture (DORA) CubeSat, which is a 3U CubeSat that seeks to<br/>demonstrate optical communication data rates of 1 Gbps over long distances. We present an<br/>analysis over many of the flight software development practices currently in use in the industry,<br/>from industry leads NASA, and identify three key flight software development areas of focus:<br/>memory, concurrency, and error handling. Within each of these areas, the best practices were<br/>defined for how to approach the area. These practices were also developed using experience<br/>from the creation of flight software for the DORA CubeSat in order to drive the design and<br/>testing of the system. We analyze DORA’s effectiveness in the three areas of focus, as well as<br/>discuss how following the best practices identified helped to create a more reliable flight<br/>software system for the DORA CubeSat.

As part of NASA’s Artemis program, NASA intends to construct the Lunar Gateway space station in a near rectilinear halo orbit (NRHO) about the L2 Lagrange point of the Earth-Moon system in the near future. Gateway will help facilitate astronaut landings on the surface of the Moon and support numerous scientific endeavors. One of these scientific endeavors is FARSIDE. FARSIDE is a radio telescope array concept that will be deployed on the surface of the far side of the moon. Because of this, FARSIDE will require an orbiter, such as Gateway, to act as a communication relay to be able to communicate with ground stations on Earth. This thesis analyzes how the Lunar Gateway space station can assist FARSIDE with its communication with Earth and how unintentionally scattered radio signals from FARSIDE could affect the telescope’s astronomical observations. It provides insight into the optimal deployment latitude on the lunar surface for FARSIDE. The thesis first begins with a literature review of the circular restricted three body problem (CR3BP) and halo orbit calculations. This is followed by an analysis of an example halo orbit for the distance, elevation angle, and azimuth angle it has viewed from two possible sites for FARSIDE over one period of its trajectory. Using this same approach, an analysis of the Lunar Gateway’s NRHO trajectory over one year was performed along with an analysis of the scattered radio flux from ground stations on Earth and the flux leakage from Gateway. Three different possible deployment latitudes for FARSIDE were investigated: the equator, 30 degrees, and -30 degrees. The analysis in this thesis ultimately showed that a deployment latitude below the equator would be the preferable choice to maximize the visibility of Lunar Gateway from FARSIDE considering the geometry of the Lunar Gateway’s orbit.