NASA has told lawmakers that it could build a heavy-lift rocket
incorporating the space shuttle’s main engines, giant external
tank and taller versions of the shuttle's solid-rocket boosters
— but not within Congress' budget and timetable. The NASA
report, mandated by an authorization bill that became law last
October, drew a tart response on Thursday from two leading
senators who helped push the bill through Congress. Sen. Bill
Nelson, D-Fla., and Sen. Kay Bailey Hutchinson, R-Texas, told
NASA Administrator Charles Bolden in a letter that the law "is
not an optional, advisory document." They told NASA that plans
to build a heavy-lift rocket and a new space capsule to carry
astronauts by the end of 2016 "should be carried out, unless the
agency can demonstrate why they are infeasible or impossible to
perform." The NASA Authorization Act of 2010 directed the space
agency to get started this year on a multipurpose crew
exploration vehicle and a heavy-lift rocket initially capable of
hauling 70 to 100 metric ton