Nelson again tells NASA to get heavy-lift done

U.S. Sen. Bill Nelson, D-Florida, and Sen. Kay Bailey Hutchison, R-Texas, wrote a three-page letter Thursday to NASA Administrator Charles Bolden disputing the agency's contention that it can't build the heavy-lift rocket at the cost and deadline ordered.

The senators argued basically that building on the foundation of Ares and Orion would make the new rocket affordable.

"We specifically rejected the notion of relying on major new developments in launch vehicle design - the schedule and cost risks associated with such an approach have been the Achilles' heel of too many prior efforts to develop new launch systems at too great a cost," the senators wrote.

Read the senators' letter.

Read our story about what NASA told Congress and how Congress reacted.