This story is thoroughly enjoyable but deeply flawed. It's absolutely worth reading if you read Ender's Game. However, I'm not sure it's worth continuing past this. 
 Biggest flaws: 
 They manage to go from data to peer-reviewed scientific publication with distribution to politicians and move them to act in four days. 
 The aliens are called Piggies and Buggers. Intensely juvenile and condescending. The one(s) trying to see them as equals (Ra-Men) should make an effort to call them by a less demeaning name.