design space pruning heuristics and global optimization method for ...

the sample problem reduces the number of asteroid sequences from 3072 to 512. This
eliminates only two asteroid sequences with feasible solutions, both for the following
order: Earth – Group 4 – Group 1 – Group 2/3. The maximum final mass for each of
these two sequences, however, is only 608 kg and 524 kg, which ranks these solutions
59 th and 105 th out of the now 117 feasible asteroid sequences.
The next metric considered is the change in inclination between the orbits of two
asteroids. Figure 20 plots the maximum final mass for each leg-by-leg asteroid pair, over
the date range considered, as a function of the absolute value of the inclination change
between the starting and ending body (no differences were found in the results if a
distinction was made between positive and negative inclination changes). As will be true
for all similar plots presented, only asteroid pairs that were actually analyzed are plotted.
For example, four of the eight Group 4 asteroids yielded no feasible Leg 1 trajectories,
and were therefore not considered in analyzing subsequent Leg 2 and Leg 3 trajectories.
For Leg 1, because there were only eight possible pairs, additional Group 4 asteroids
were randomly selected and analyzed in order to add more data points. Furthermore, any
asteroid sequences that resulted in a maximum final mass of less than 500 kg were
deemed infeasible and appear as 0 kg in the plots.
Maximum Final Mass (kg)
1500
Leg 1
1250
Leg 1 (added)
1000
750
500
250
0
0.00 20.00 40.00 60.00
Inclination Change (deg)
Maximum Final Mass (kg)
1200
Leg 2
1000
800
600
400
200
0
0.00 20.00 40.00 60.00
Inclination Change (deg)
Maximum Final Mass (kg)
1000
900
Leg 3
800
700
600
500
400
300
200
100
0
0 10 20 30 40
Inclination Change (deg)
Figure 20: Maximum final mass for each asteroid sequence as a function of inclination change.
For Leg 1 and Leg 2, there is a perceptible correlation between final mass and
inclination change, where smaller values of inclination change result in larger values of
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