I have tried many times, many different ways, to have shooting stars coming out of cakes but they always fall over.  I never cover my cakes in fondant so I don't have the extra support of the fondant covered cake.  

Any help or suggestions would be great!

Place them in coffee stir/straws.
 

I have tried drinking straws, but the wires seem to twist and turn  and not stay where I put them.  How would you get them to stay in place and not turn?

Maybe a blob of modelling paste in the end of the straw would hold the wire in place.

Or you could try using slightly thicker wire and thinner fondant/gumpaste stars - it may just be that the weight is too great, and a lighter, stronger combination will work.
 

is gumpaste lighter than fondant?  I have made them really thin, but then the wire shows through.