In Japan, reports are circulating that the satellite may be launched in April. My guess is that it will be on April 15.http://kcna.kp/en/article/q/6e77e0f02f8280bf26786dc3112818b2.kcmsf
https://twitter.com/yonhapnews/status/1648449563496427521Was there any public intel on what kinds of launch vehicle can we expect them to use?
Its looks to be in the same weight/size class as Kwangmyongsong-4. Return of Unha-3 maybe? There has been rapid work at the launch pad at Sohae since late April (https://www.38north.org/2023/05/sohae-satellite-launching-station-launch-pad-construction-resumes/) so it might be ready to support a launch campaign in coming months.
North Korea is targeting a May 31-June 11 launch window for carrying out its first spy satellite launch, according to Japanese media outlets:https://www.reuters.com/world/asia-pacific/north-korea-notified-japan-plan-launch-satellite-between-may-31-june-11-nhk-2023-05-28/https://www.reuters.com/world/asia-pacific/north-korea-notified-japan-plan-launch-satellite-between-may-31-june-11-nhk-2023-05-28/
Thanks to a tip from @martyn_williams I took a look at the warning areas for the upcoming (NET May 31) North Korean recon sat launch. The map below shows the launch site, polygonal warning areas and (orange lines) my fit to the trajectories. (1/n)...
I think the first and second warning areas correspond to first stage and nose fairing impact zones, and correspond to a -5650 x 150 km x 93.9 deg (sub)orbit (apogee not well constrained).
Then the second stage makes a 'dog leg' yaw change to head southeast, firing at 1st stage apogee to a -5240 x 500 km x 75.7 deg orbit with impact east of the Phillipines. This trajectory has an apogee over 127.1E 26.1N.
The third stage will fire at second stage apogee, likely to reach a 500 x 500 km x 76 deg orbit. The reason for the change in direction is to avoid flying over S Korea during the launch.But the reason for a 76 deg final orbit is unclear to me.
The third stage will need a delta-V of 3550 m/s to match the trajectory I derive and reach a circular orbit. This is a pretty normal value. For example, a solid upper stage of Isp 270s could orbit a 250 kg sat and 50 kg empty stage with 850 kg of propellant, all plausible nos.
The planned trajectory of the North Korean satellite launch, as estimated by me based on debris warning areas, passes 500 km above the Okinawa region - higher than the International Space Station. The only landmass it goes directly over is the uninhabited island of Irisuna-jima.
It is possible that the second stage could shut down early, or that the yaw manuever prior to stage 2 ignition could go off course, so it is not completely *impossible* for debris from the launch to hit the Okinawa region. But it is very, very unlikely.
Thus, I consider Japanese goverment hyperventilation about the launch to be rather excessive.
This side-on illustration shows the second and third stage planned trajectories; you can see that the planned path is way out in space as it passes over Okinawa