WASHINGTON -- Florida lawmakers on Wednesday introduced legislation to extend the shuttle beyond its scheduled retirement this year and speed government development of a heavy-lift rocket.

The bill is designed to counter President Barack Obama's budget for NASA, which proposes abandoning the Constellation program to return people to the moon and would continue plans to retire the shuttle, Local 6 news partner Florida Today reported.

Obama wants to rely on Russian and commercial rockets to ferry supplies and people to the International Space Station, which he has proposed extending from 2015 to 2020.

But Reps. Suzanne Kosmas, D-New Smyrna Beach, and Bill Posey, R-Rockledge, said the country should rely on government space vehicles such as the shuttle and the next rocket. The bill they introduced Wednesday mirrors one introduced March 3 by Sen. Kay Bailey Hutchison, R-Texas.

"This bill is intended to maintain a robust human spaceflight program that will protect Space Coast jobs, enhance our national security and generate scientific and technological advances that boost our economy," Kosmas said.

Their proposed legislation calls for funding two shuttle flights a year and making the fleet's retirement dependent on the availability of a replacement vehicle or until the shuttle is no longer needed for the space station.

Extending the shuttle would close the several-years gap between the shuttle's retirement and development of the next rocket capable of carrying people. The extension would be an alternative to depending on Russian rockets or unproven commercial rockets.

But one of the big questions is money. A NASA official said Tuesday that shuttle fleet operations cost $200 million a month, or about $2.4 billion a year. Another question is safety, with some safety experts arguing that it's time to ground the aging fleet.

"We need a plan to close the space gap that actually maintains America's ability to send American astronauts into space," Posey said.

Obama has scheduled a space summit in Florida on April 15 to discuss his plans with experts.

Posey will participate in a news conference today calling on NASA Administrator Charles Bolden to explain how the president's proposed budget would maintain uninterrupted U.S. access to space.