White House and Congress to work on mars plan, Nasa chief says

WASHINGTON - The Obama administration will work with Congress in developing a plan for sending astronauts to Mars and will release it in the "coming months," the head of the National Aeronautics and Space Administration said today.

NASA Administrator Charles Bolden, a former space shuttle commander, resisted senators' efforts at a Washington hearing on the agency's fiscal 2011 budget to announce specific missions and deadlines. The administration has drawn opposition for proposing to scrap a program to return astronauts to the moon and describing a Mars mission as only a long-range goal.

"The steps are pretty complex and complicated" to go to Mars, Bolden told a Senate Commerce, Science and Transportation subcommittee. "Two weeks after budget rolling out, I'm not capable of giving you a plan."

After the hearing, Bolden told reporters that development of the plan would be "evolutionary." He declined to elaborate.

The United States already operates robotic rovers on the Martian surface and has put unmanned craft in orbit around the planet. Obama plans to fund an expansion of that exploration work.

Bolden faced opposition at the hearing from Democrats and Republicans to President Barack Obama's plan to end the Constellation program to develop rockets and spacecraft for a return to the moon by 2020. Constellation would have set the stage for an eventual Mars trip.

With the scheduled end of the space shuttle program this year, the administration risks ceding U.S. space leadership without a firm plan, senators said.

"By eliminating plans for a heavy-lift vehicle and a spacecraft" in the proposed budget, "the U.S., this senator fears, will be on the sidelines," said Sen. Bill Nelson, D-Fla., who is the panel's chairman.

Bolden highlighted one deadline: he said it was NASA's plan to assist U.S. commercial companies in developing space vehicles that could be used to ferry astronauts to the International Space Station as soon as 2015. The administration's spending plan sets aside $6 billion for the commercial effort.

If Congress agrees to shut down Constellation, NASA should continue some rocket and capsule development, Bolden said. Nelson has said he is concerned about relying solely on commercial companies to fly astronauts to the space station.

Obama's budget supports the development of rocket systems that eventually might take U.S. astronauts back into deep space. In preparation for those trips, the administration envisions using robotic ships to find locations for future landings and test out new technology.

Americans need specific goals and missions to be inspired, said Senator David Vitter of Louisiana, the subcommittee's senior Republican.

"You don't accomplish great things without a clearly defined mission, and this budget has no clearly defined mission," he said.

The U.S. may lose valuable workers with needed skills if NASA employees and contractors aren't given a better idea of how the agency will proceed on human space flight, said Michael Snyder, a space shuttle engineer.

"You're looking at a significant net loss of experience that won't be re-established," he said.