Source: Space Politics

The Senate Commerce, Science and Transportation Committee is unhappy with NASA. Earlier this week, the space agency provided lawmakers with a progress report on plans for the heavy lift rocket and a multipurpose crew vehicle specified in the 2010 NASA Authorization Act. Essentially, NASA said it could not meet cost and schedule requirements that would have both systems operational by Dec. 31, 2016. On Wednesday, the Commerce Committee reacted, informing NASA it must comply with the guidelines because they are the law. On Thursday, U.S. Senator Bill Nelson, a Florida Democrat, and U.S. Sen. Kay Bailey Hutchison, a Texas Republican, wrote NASA Administrator Charles Bolden informing him the assumptions in the progress report could not be justified.
http://www.spacepolitics.com/2011/01/13/nelson-hutchison-and-hall-respond-to-nasa-report/