North Korea has announced booster-stage drop areas for its upcoming satellite launch. They earlier said they want to launch satellites to sun-synchronous 97 degree orbit, but the second stage drop zone would indicate a 73 degree orbit.
Three scenarios have been proposed:
Second stage changes direction prior to burn; stage 3 in line with stage 2, 73 deg orbit. (me)
Restartable second stage changes direction after main burn; makes second burn to reach 73 deg; third stage in line with first stage direction; 97 deg orbit. (Credit: Marco Langbroek ).
Second stage changes direction prior to burn; third stage further changes direction prior to its burn; 97 deg orbit, but with orbital plane further east. (Credit:Bob Christy and @LH2NHI )
Here is a more detailed breakdown:
|Stage 1 burnout and sep||Stage 1 burnout and sep||Stage 1 burnout and sep|
|Fairing sep||Fairing sep||Fairing sep|
|Stage 2 yaw 24 deg||Stage 2 yaw 17 deg||Stage 2 yaw 24 deg?|
|Stage 2 burn||Stage 2 burn||Stage 2 burn|
|Stage 2 yaw 45 deg|
|Stage 2 sep from 3||Stage 2 sep from 3||Stage 2 sep from 3|
|Stage 2 yaw 90 deg|
|Stage 2 restart 1.9 km/s|
|Stage 3 burn 3.6 km/s||Stage 3 burn 3.6 km/s||Stage 3 burn 4.2 km/s|
|Stage 3 sep from payload||Stage 3 sep from payload||Stage 3 sep from payload|
|1st S Eq Crossing||132E||118E||122E|
|dV relative to A||0.0||1.9||0.6 km/s|
|Impulse relative to A||0.0||1.9 x M2||0.6 km/s x M3|
Note that scenario B involves a much larger impulse (big delta-V on the massive stage 2) compared to C (smaller delta-V on the much less massive stage 3).