In Star Trek III, the mission was to take Bones to Vulcan to release Spock's Katra. Why did it suddenly turn to going to the Genesis planet? They didn't know about Kruge yet.
Sarek specifically tells Kirk that he must bring them both to Vulcan, so I suspect that having Spock's body brought as well was necessary to lay the Katra to rest properly. Even McCoy in the bar was trying to get to to the body.
I would expect that Kirk figured he'd have to go hunting for a torpedo tube floating around somewhere in the Mutara sector. I would guess this is why the title is called a "Search for Spock". Turns out a search was not necessary.
And the fact that they actually found a living body for Spock meant that Fal-tor-pan was suddenly an option.
Why would anyone even think Spock's body was there? By all accounts it should've burned up in the atmosphere. Even David and Saavik were surprised to find the torpedo tube. And when Saavik announces to Kirk that there is "a certain Vulcan" there, he seems surprised.
So I believe Kirk was expecting to have to return to the Genesis area, and have to calculate the last known trajectory from where he previously shot the tube. A bit of a needle in a haystack "search for Spock" that he was planning to undertake. That's why time was of the essence: the longer they wait, the farther away it will be.
In the filming script, the Grissom scenes came first, so Kirk knows the tube soft landed from the first log entry "The news of Spock's tube has shaken me". The rewrote the captains log when they reordered in editing.
ah, interesting!In the filming script, the Grissom scenes came first, so Kirk knows the tube soft landed from the first log entry "The news of Spock's tube has shaken me". The rewrote the captains log when they reordered in editing.
So, indeed.... why Genesis?
So what was Spock's plan? I think he had no idea that Kirk would shoot his body into space. I think Spock expected his body and soul to be taken home for its final resting place.
All of those quotes are in reference to the katra existing within McCoy, and the need to go to Vulcan to separate them. Nothing to do with the body.
So since the scenes are in the wrong order, all the characters know that, at the very least, Spock's intact dead body is on the planet. And Spock's katra senses that his body has been regenerated, which is why it keeps telling McCoy to go back.
Normally, you would have established explicit instructions about burial beforehand, but I think the nature of Spock's death gives us an out. Starfleet regulations on the disposal of highly irradiated bodies might supersede any wishes of the deceased.