## 5 Juno Trajectory Geometry
The greatest encounter with the Earth happened at 19:21 universal time coordinated (UTC) on 9 October 2013 [27]. The outer cruise phase lasted from L + 823 days to the beginning of the Jupiter approach phase, which occurred six months after Jupiter orbit insertion (JOI) (L + 1614 days or JOI \(-\) 182 days). This portion of the trip lasted for a total of 791 days, which was more than 2 years [25]. While preparing for JOI, the spacecraft's instruments were restricted in their operations near JOI due to orbital insertion preparations. The Jupiter Approach phase lasted for the last six months of the trip before JOI. TCM began at JOI \(-\) 5 months, and the DSN coverage increased due to these more regular movements. The 26-month Outer Cruise period preceded the 178-day Jupiter Approach phase. Just before JOI, which began three months later, the project was entirely prepared for the 1.3-year scientific orbit. The JOI critical sequence began at JOI \(-\) 4 days, at which point the phase concluded [24; 28]. After traveling 1740 million miles over five years, Juno finally reached Jupiter on 4 July 2016 and immediately entered a polar orbit with a period of 53 days that stretched from just over Jupiter's cloud tops to the furthest limits of the planet's magnetosphere [29]. The JOI critical sequence was included in the scope of the JOI phase. It started four days in advance of the commencement of the orbit insertion maneuver and continued for one hour after it began. The JOI phenomenon happened when the spacecraft was closest to Jupiter and slowed it down to the point where Jupiter pulled it into an orbit for 53.8 days. This was the second most important event of the mission. To correct any JOI maneuver execution mistakes, a cleaning burn was performed at JOI + 8.6 days while the phase was in progress for capturing orbits. During the JOI phase, there was never a break in the DSN broadcast [30]. Orbit 0 through Orbit 35 were all included in the Science Orbits phase. Orbit N is defined as the region beginning at apojove (AJ) N-1 and continuing to apojove N, and it also involves perijove (PJ) N. The process of assigning orbit numbers began before the Science Orbits phase. Orbit 0 is defined as lasting from PJ0 to AJ0, which included a JOI \begin{table}
\begin{tabular}{l l l} \hline
**Activity Name** & **Start Date** & **End Date** \\ \hline Pre-Launch & 2 August 2011 & 5 August 2011 \\ Launch & 5 August 2011 & 8 August 2011 \\ Inner Cruise 1 & 8 August 2011 & 10 October 2011 \\ Inner Cruise 2 & 10 October 2011 & 28 May 2013 \\ Inner Cruise 3 & 28 May 2013 & 5 November 2013 \\ Earth Flyby (short event) & 9 October 2013 & 9 October 2013 \\ Quiet Cruise & 5 November 2013 & 5 January 2016 \\ Jupiter Approach & 5 January 2016 & 30 June 2016 \\ Jupiter Orbit Insertion (JOI) & 1 July 2016 & 5 July 2016 \\ Capture Orbits & 5 July 2016 & 19 October 2016 \\ Period Reduction Maneuver & 19 October 2016 & 20 October 2016 \\ Orbits 1-2 & 20 October 2016 & 9 November 2016 \\ Science Orbits & 9 November 2016 & 11 October 2017 \\ Deorbit & 11 October 2016 & 16 October 2017 \\ Extended Mission & 1 August 2021 & 30 September 2025 \\ \hline \end{tabular}
\end{table} 
Table 1: Activity phases of the Juno mission (TBD time zone). cleaning maneuver that took place at JOI + 8.6 days. Orbit 1 encompassed PJ1 and extended from AJ0 to AJ1 in its entirety. Orbit 2 encompassed PJ2 and extended from AJ1 to AJ2 in its entirety. Orbit 3 encompassed PJ3 and extended from AJ2 to AJ3 in its entirety. Before the JOI keep-out zone was established, the early orbital research baselines were established in Orbits 0, 1, 2, and 3. The first scientific experiment took place in Orbit 4. It began at AJ3 and continued through AJ4, taking in PJ4 along the way (including the first OTM at PJ4 + 7.5 h). The orbital period was shortened from about 53 days to approximately 43 days as a result of the flyby of Ganymede (the largest satellite of Jupiter) (PJ34) [31; 32].