The countdown to/of/for the launch of the rocket has been postponed.

[thehammer]

Should I use to, of or for?

1- The countdown to/of/for the launch of the rocket has been postponed.
2- NASA has stopped the countdown for/to/of the space shuttle mission because of technical problems.
3- The progress of time is paced by weekly fire and boat drills and the countdown of/to/for dive days remaining.

 

[emsr2d2]

I can't see any reason to use anything but the standard "countdown to" in any of them.

 

[jutfrank]

1. Only to is correct.
2. I say the whole sentence is wrong. You can't count down to a mission. You can only count down to a particular moment.
3. I can't understand much about what this sentence is supposed to mean.