I need a little bit of help on how to destroy the four beam weapons the battleship has before it jumps.
My missiles never seem to lock on quick enough, I don't have near enough ammunition to destroy all four beam weapons and it always faces the Colossus fully battle ready.
It's got so bad that I've taken time off the game so I don't get too annoyed with it.
Any tips or strategies would be very much appreciated.

That mission is really painful. What I usually do is:
*Load as many nukes as possible.
*Divert all power to the engines and close in on afterburners until the lock-on begins. Then divide power between engines and shields.
*fire double nukes at one beam weapon until it goes down. Two volleys should be enough, BUT ALL MISSILES MUST CONNECT. After destroying two beams, call in support ship, but do not wait for it until you're out of nukes.
*the most trouble is caused by the array of flak guns at the "spike wall". SDG might help here, but only if you're confident that you have enough time.
It really is a difficult mission and a lot depends on a chance (particularly, if you see that your nukes detonate but don't deal any damage, or do only half damage, restart immediately)

Don't forget to order your wing to "Attack Subsystem" for one of the beams. They took down one for me pretty darn quick. That let me target another one. We had 2 down in no time, which is all you really need to do.

Yup, make sure its firing two missiles at once. On normal difficulty about 4 should take out one beam turret, so lock, fire, wait for the cooldown to end, fire again, move to next target. Keep the supply ship around at all times, and divert your energy to shields when your targeting and slow down so you have plenty of time

Also, try to shoot your Helios while facing the Sathanas, not from "behind" the arm spikes when you fly by it.
I can't find a schematics or representative screenshot on the Internet, so MSPaint will have to do because I'm at work :D

Best... art... ever

No smiley face in the "Right" pic though. I missed the smiley. The smiley would have been so happy. Why do you hate the smiley? Has it hurt you in the past? Do you now wish it nothing but pain? It is a sad smiley now... I really hope you are happy...

Well, Shivans are Pr0gam3rR00x0r so when they get hit, they tend to just shut up and take it.
But when they're ahead, they brag. A lot!

Hey guys, thanks for the posts, I can now take out two of the four beam cannons, still can't do all four, but Command seems happy enough ^_^

yea, you don't need all 4 to complete the mission. it'll make it harder for you later if you don't though.

Destroying all four is a remarkable feat. I've managed to do it once, but it took countless retries!
You need to refit your wing (I really can't remember if you even got one) with Helios only (no trebuchets) and while giving them the "attack subsystem" command with the beam cannon targeted, you go to take out the other one.
As soon as they finish with one, inmediately assign them the other. You have to use EVERY ship, even the escort.
Doable... but really hard!
(no pics today, sorry :D )