Orbits of the Heart: The Science Behind "Star Rider"

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Alcon's Journal # 13
For a vessel like the 3137, which needed to perform exploration missions involving frequent changes in trajectory, acceleration, and deceleration, neither of these futuristic technologies could be used. Instead, we relied on the preliminary practicality of controlled nuclear fusion and the well-established propellant propulsion technology. The gaseous giant planets in the outer solar system, primarily composed of hydrogen and helium, served as excellent materials for fusion engines and a source of propellant. Jupiter and Uranus became our supply stations.
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Fusion energy itself isn't a new concept—the Sun is a massive fusion reactor. Humanity demonstrated nuclear fusion upon detonating the hydrogen bomb, but achieving controlled fusion remains a significant challenge. The most promising approaches involve Inertial confinement fusion (ICF) and magnetic confinement fusion (MCF), though current technology can sustain controlled fusion reactions only for a few seconds or minutes. Recent breakthroughs have extended this duration beyond 1000 seconds, marking a crucial step toward viable fusion power.

For spacecraft propulsion, fusion engines typically use plasma propulsion, where high-temperature plasma is expelled to generate thrust. However, in Star Rider, DSF3137 frequently maneuvers, requiring significant thrust. Plasma-based propulsion, while fast, produces relatively low thrust. Thus, transferring fusion-generated energy into traditional propellant-based thrust would be more effective. Consequently, in the story, the crew often discusses replenishing propellant rather than fuel, as fusion fuel consumption is minimal compared to propellant mass.