In February, with remarkably little fanfare, NASA released a budget proposal that eliminated plans for a return to the moon, but was vague about where humans would be going next in space and when.

Speaking at the Kennedy Space Center in Florida last Thursday, President Obama attempted to fill in the details of his new vision for the space agency, including identifying the solar system destinations he foresees humans visiting in the next three decades.

“By 2025, we expect new spacecraft designed for long journeys to allow us to begin the first-ever crewed missions beyond the moon into deep space,” he said, starting with a mission to a near-Earth asteroid. “By the mid-2030s, I believe we can send humans to orbit Mars and return them safely to Earth. And a landing on Mars will follow. And I expect to be around to see it,” the president added.

Missing from the president’s plan is a return to the moon, which had been the cornerstone of the plans outlined in 2004 by President Bush. “I just have to say pretty bluntly here: We’ve been there before,” Obama said. “There’s a lot more of space to explore, and a lot more to learn when we do.”

Obama also used the speech to describe some changes to the plans rolled out in February. The biggest is the restoration of the Orion spacecraft, which was assumed to be canceled with the rest of the Constellation program after the February announcement. Orion will be retained in a scaled-down form to serve as a crew-return vehicle for the International Space Station. Orion will be launched unmanned and remain docked to the station for months at a time, serving as a “lifeboat” should crews need to evacuate the station.

The near-term benefits of keeping Orion may be more political than technical, according to Robert Walker, a former congressman who served on the science committee and advocated spending on the space program. Walker notes that language in NASA’s current appropriations bill prevents the agency from ending any aspect of Constellation at least through the end of this fiscal year. Keeping Orion in some form makes it possible to get an early start on the new plan, especially if debate over the budget stretches through the end of the year. “It’s a rather clever move by the administration,” Walker says.

Obama’s speech also revealed a plan to make a decision by 2015 on a new heavy-lift launch vehicle to support future exploration missions. The February plan included over $3 billion over the next five years performing launch-vehicle research and development, including the development of a new engine, but the plan didn’t indicate when that research would translate into a decision on a new rocket.