## 5 Juno Trajectory Geometry
### Trajectory Components  
A sequence of trajectory rectification maneuvers must be performed on the Juno spacecraft to ensure that it is guided to the appropriate target points along the reference trajectory. These maneuvers must be performed without breaching the mission's pointing, power, or other limitations [22]. Juno's travel route from Earth to Jupiter is shown in Figure 1. There was an August 2011 launch for the Juno spacecraft. The mission was on course to enter Jupiter's orbit on 4 July 2016, after which it was maneuvered back toward Earth for a rendezvous on its way to Jupiter, which is confirmed by [29; 34]. It is essential to mention that we are providing our analysis between August 2011 (start of analysis interval), the launch phase, and January 2023 (end of analysis interval). The latter is the last date of data that NASA has provided, as the next release of data was available in the second half of 2023. As seen in Figure 1, the spacecraft moved around the Sun, firing its main engine twice at a distance beyond Mars' orbit. Figure 1: Illustration of the Juno spacecraft’s trajectory around the solar system barycenter (SSBC) between August 2011 (SoI—Start of Interval), through Jupiter orbit insertion (JOI: July 2016), and January 2023 (EoI—End of Interval). A blue line marks the Earth's trajectory. The flyby of the Earth took around two years after launch and was built up by these deep space maneuvers. Each X marker in the figure represents the first sample at the start of the Earth new year. An Earth flyby helped Juno gain the momentum to cruise straight into Jupiter's orbit. In July 2016, Juno arrived at orbit around Jupiter. Juno's trajectory is shown by the (red) line. The start of the interval is symbolized by a red circle, while the black box represents the last date of the analyzed time interval. A green line represents Jupiter's orbit. A red star and the Juno Orbit Insertion with a purple diamond object symbolize the solar system barycenter (SSBC). Because the JOI process took just around five days, the diamond object moves very little around the orbit in the scale of years. It can be noticed that when it was on its way back to Earth after a deep-space maneuver, Juno stayed inside the ecliptic, but when it was traveling to Jupiter from Earth, it strayed outside of the ecliptic. As soon as it reached Jupiter, Juno performed a significant maneuver to enter a capture orbit that lasted for 78 days. This JOI burn took about 33 min and sent Juno into a polar, elliptical orbit with Jupiter (see Figures 1 and 2). During the following perijove passage, which occurred on 19 October 2016, Juno executed a period reduction maneuver (PRM) that lasted about 34 min. The goal of this maneuver was to bring the orbital period down to just under 11 days so that the research portion of the mission could begin. Because any problems that may have occurred during the PRM execution were scheduled to be fixed during the first 11-day orbit, the first science orbit occurred during the second 11-day orbit. The orbit of capture was considered Orbit 1, the orbit of clean-up was considered Orbit 2, and the first main scientific orbit was considered Orbit 3. After each science orbit, a maneuver occurred four hours after the perijove to achieve the proper circumstances for the subsequent perijove (discussed later). After the main scientific phase of each orbit had been completed (about three hours after perijove), an orbit trim maneuver (OTM) took place. Figure 3 depicts Juno's trajectory in the last quarter of the overall analyzed time interval. In July 2016, Juno arrived at Jupiter and immediately commenced an elliptical orbit around the planet's poles. The Juno probe investigated regions of the galaxy that have never been scrutinized before because of its unique orbital path. As discussed earlier, the Juno spacecraft was successfully launched onto a heliocentric trajectory in August 2011.