Irrespective of the merits of the lawsuit, it's really politically tone deaf on DARPA's part to award this contract given
the current political climate, the written objections of Congress and the fact that it's budgetary silly season.
Isn't being contrarian (aka advocatus diaboli) pretty much part of DARPA's mission charter though?
Well, not in that manner.
But I think marauder has it wrong. OrbitalATK probably filed the suit to prevent the awarding of the contract. If the government halted awarding contracts simply because a wounded party filed suit, nothing would ever get done. Heck, it would become common practice to simply file suit all the time to wound your competitors. Also, just because a couple of members of Congress object to a contract does not mean that they are right and everybody else is wrong. They might be full of baloney.
I'm not saying that this contract by DARPA is a good idea. I'm just saying that if DARPA thinks it is a good idea, these things should not be deterrents to action.