I think I've finished my first revision
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@@ -1155,9 +1155,9 @@
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uniform distribution within those bounds.
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A unit launch direction is then also chosen as a 3-length vector of uniform random
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numbers, then normalized. This unit vector is then multiplied by a uniform random
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number between 0 and the square root of the maximum launch $C_3$ specified by the
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user to generate an initial $\vec{v_\infty}$ vector at launch.
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numbers and normalized. This vector is then multiplied by a uniform random number
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between 0 and the root of the maximum launch $C_3$ specified by the user to generate
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an initial $\vec{v}_\infty$ vector at launch.
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Next, the times of flight of each phase of the mission is then decided. Since launch
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date has already been selected, the maximum time of flight can be calculated by
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@@ -1288,17 +1288,17 @@
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a tuning parameter to determine the size of the tails and width of the distribution
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set to $1.01$, but easily tunable.
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The perturbation function, then steps through each parameter of the mission,
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generating a new mission guess with the parameters modified by the above Pareto
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distribution. After this perturbation, the NLP solver is then called again to find
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a valid solution in the vicinity of this new guess. If the solution is better than
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the current basin solution, it replaces that value and the drill counter is reset to
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The perturbation function then steps through each parameter of the mission,
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generating a new guess with the parameters modified by the Pareto distribution.
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After this perturbation, the NLP solver is then called again to find a valid
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solution in the vicinity of this new guess. If the solution is better than the
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current basin solution, it replaces that value and the drill counter is reset to
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zero. If it is better than the current total best, it replaces that value as well.
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Otherwise, the drill counter increments and the process is repeated. Therefore, the
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drill patience allows the mission designer to determine a maximum number of
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iterations to perform without any improvements in a row before ending a given drill
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loop. This process can be repeated essentially ''search patience`` number of times
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in order to fully traverse all basins.
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iterations to perform without improvement in a row before ending the drill loop.
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This process can be repeated essentially ''search patience`` number of times in
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order to fully traverse all basins.
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\chapter{Results Analysis} \label{results}
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@@ -1436,8 +1436,11 @@
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with Mars after three and one half years to rendezvous in mid-December 2027.
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Unfortunately, the launch energy required to effectively used the gravity assist with
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Mars at this time is quite high. The $C_3$ value was found to be $60.4102$ kilometers
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per second squared. However, for this phase, the thrusters are almost entirely turned
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off, allowing for a nearly-natural trajectory to Mars rendezvous.
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per second squared. However, for this phase, the thrust magnitudes are quite low,
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raising slowly only as the spacecraft approaches Mars, allowing for a nearly-natural
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trajectory to Mars rendezvous. Note also that the in-plane thrust direction was neither
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zero nor $\pi$, implying that these thrusts were steering thrusts rather than
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momentum-increasing thrusts.
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\begin{figure}[H]
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\centering
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@@ -1518,11 +1521,11 @@
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previous trajectory. However, this time the launch energy is considerably lower, with a
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$C_3$ value of only $40.4386$ kilometer per second squared. Rather than employ an almost
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entirely natural coasting arc to Mars, however, this trajectory performs some thrusting
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at about the apoapsis point of its orbit in order to raise the periapsis enough to
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rendezvous at roughly the same incidence angle in Mars' orbit, but one revolution ahead.
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In this case, the launch was a bit earlier, occurring in November of 2023, with the Mars
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flyby occurring in mid-April of 2026. This will prove to be helpful in comparison with
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the other result, as this mission profile is much longer.
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almost entirely in the velocity direction, increasing its orbital energy in order to
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achieve the same Mars rendezvous. In this case, the launch was a bit earlier, occurring
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in November of 2023, with the Mars flyby occurring in mid-April of 2026. This will prove
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to be helpful in comparison with the other result, as this mission profile is much
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longer.
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\begin{figure}[H]
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\centering
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@@ -1565,9 +1568,11 @@
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Finally, this mission also has a third phase. The Jupiter flyby provides quite a strong
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$\Delta V$ for the spacecraft, allowing the following phase to largely be a coasting arc
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to Saturn almost one revolution later. Because of this long coasting period, the mission
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length increases considerably during this leg, arriving at Saturn in December of 2037,
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over 8 years after the Jupiter flyby.
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to Saturn almost one revolution later. During the most efficient part of the journey,
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some thrust in the velocity direction accounts for a little bit of orbit-raising, but
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the phase is largely natural. Because of this long coasting period, the mission length
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increases considerably during this leg, arriving at Saturn in December of 2037, over 8
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years after the Jupiter flyby.
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However, there are many advantages to this approach relative to the other trajectory.
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While the fuel use is also slightly higher at $530.668$ kilograms, plenty of payload
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