// NSString *myF15MissilesParticleSystemPath = [[NSBundle mainBundle] pathForResource:@"myF15MissilesParticle" ofType:@"sks"];
// myF15MissilesParticleSystem = [NSKeyedUnarchiver unarchiveObjectWithFile:myF15MissilesParticleSystemPath];
myF15MissilesParticleSystem = [SKEmitterNode nodeWithFileNamed:@"myF15MissilesParticle.sks"];