WASHINGTON â€" U.S. Senator Kay Bailey Hutchison (R-Texas) introduced legislation Wednesday that would keep NASA flying the space shuttle program two years beyond its planned 2010 retirement.

The proposed bill would also require the space agency to study options for a heavy-lift launcher that could be ready to deliver U.S. astronauts to the International Space Station by the end of 2013 and beyond low Earth orbit by the end of 2018.

Hutchison's bill, if enacted, would deal a setback to U.S. President Barack Obama's plan to retire NASA's space shuttle fleet after four more flights and rely on Russia, and eventually commercial U.S. firms to deliver crew and cargo to the orbiting outpost.