Keith's 11:00 am EDT note: Sources are reporting that the Senate Commerce Committee has finally made good on its threat and has issued a subpoena to NASA regarding materials related to the SLS decision. Prior to this several letters and a hearing were held to prompt NASA in this regard. No luck. Congress is more or less convinced that the decision regarding SLS design/architecture has already been made and they are using the tools at their disposal to force NASA/the White House to admit that this is indeed the case. Stay tuned.
NASA Has Not Delivered All Of The Documents Requested by Congress, earlier post
Senate Threatens NASA With Subpoena For Missing Documents, earlier post
Keith's 1:00 pm EDT note: According to NASA PAO "While we share the Senators' commitment to human space exploration and implementation of the Authorization Act, we also have a commitment to be responsible stewards of taxpayer dollars. The Space Launch System is the most important -- and expensive -- decision NASA will make for the next decade, and we want to get it right so we don't repeat the mistakes of the past or get pushed into making a premature decision about our nation's deep space exploration plans."