Peace walker help!

Im up to the second fight with peace walker, i think its mission 25 and i can not win! When it starts to launch and it only gives you a minute to stop it fro launching i nearly alwayse lose and it launches! And in the actual fight its life goes down sooo slowly! Any ideas? Also does this game have 26 missions or 33? Thanks alot :D

hey if you have a ps3 i ncan play with you through adhoc party......psn is blackstace

equip battle camo, take 2 rocket launcher (I had C.G. and RPG7) and a machinegun.

keep one of the launchers with ammo for whenever the peace walker goes into launch mode.

hit him with the other when he's not and use the machinegun when his EM pulse is on or you're waiting for supply.

just make sure you have a rocket launcher with ammo at all times