WASHINGTON — NASA Administrator Charles Bolden told reporters Feb. 6 that the U.S. space agency would continue to work on heavy-lift rocket technology — possibly including elements of the now-canceled Ares 5 — in preparation for sending astronauts beyond low Earth orbit by 2030.

“It is my intent to work diligently toward developing a heavy-lift launch capability for the United States,” Bolden said during a news conference at the Kennedy Space Center, Fla., two days before the Space Shuttle Endeavor launched to the international space station. “Ideally, I would like to be flying a heavy-lift launch capability between 2020 and 2030. Now whether or not we’ve matured to a point by then that … the next NASA administrator will feel comfortable that it’s OK to put humans on that heavy-lift launch vehicle, I can’t say right now.”

President Barack Obama on Feb. 1 sent Congress a $19 billion NASA budget proposal for 2011 that cancels the Moon-bound Constellation program and promises to keep operating the international space station through 2020 and to pay the private sector to transport astronauts to and from the orbital outpost.

Bolden said that before NASA shuts down the Constellation program, which includes the Orion Crew Exploration Vehicle, Ares 1 rocket and Ares 5 heavy-lift launch vehicle, agency officials would “scrub” the program for technologies worth continued development, including those that could eventually lead a new heavy-lift capability.

“If I’m able to negotiate with Congress appropriately, we may actually end up carving out some subsystems that are in the current Constellation program because they are advanced technology and they are things we will need to develop any heavy-lift launch system,” he said.

But before NASA can decide on a revised heavy-lift launch architecture, the agency must work with Congress and the administration to establish clear destinations for manned space exploration beyond low Earth orbit, Bolden said.

“My first negotiation with Congress and the White House and everybody else is do we all agree that Mars is the ultimate destination in the solar system. I think it is,” he said.

Bolden referred to the so-called Flexible Path option detailed in the findings of a White House-appointed panel tasked last year with reassessing U.S. human spaceflight plans. Flexible Path proposes abandoning NASA’s Moon-first focus in favor of lunar flybys and visits to asteroids and the moons of Mars.

The panel, led by former Lockheed Martin chief Norm Augustine, found Flexible Path attractive because it would allow NASA to learn to operate in free space for hundreds of days before committing to sending astronauts to Mars.

However, the Augustine panel’s Flexible Path scenario assumed NASA would continue development of the Orion crew capsule for missions beyond low Earth orbit, and quickly begin development of Ares 5 or an alternate heavy-lift launch vehicle.

“In the best case, the heavy-lift vehicles themselves would not be available until the beginning of the 2020s, but the first stage or core could be accelerated, perhaps by a year or two,” the Augustine panel states in its Oct. 22 final report, adding that the first stage of Ares 5 or any other heavy-lift concept that the panel reviewed would be “more than capable of launching an Orion” to low Earth orbit should a commercial alternative for such launches fail to materialize.

The Augustine panel’s Flexible Path scenario suggested NASA could develop a heavy-lift capability based on a lighter but still-capable variant of Ares 5 by the early 2020s if Obama were willing to increase NASA’s human spaceflight budget by $3 billion by 2014 and commit to inflationary growth thereafter.

This so-called less-constrained budget scenario would have allowed NASA to retire the space shuttle in early 2011, continue funding the space station through 2020, pursue a commercial crew alternative to Ares 1 for low Earth orbit and still begin exploring the solar system with lunar flybys and visits to near-Earth objects and the moons of Mars by the early 2020s, according to the report.

Obama’s budget plan includes billions of dollars less for human space exploration that the Augustine panel recommended and cancels the Constellation program in its entirety, including development of Orion and Ares 5. In place of a Constellation program previously expected to surpass $5.5 billion annually in the years ahead, Obama is proposing to spend $3.1 billion over five years on heavy-lift and other propulsion research as part of an overhauled and more modest Exploration Systems Mission Directorate budget. NASA officials defending Obama’s proposal said it provides a greater amount of near-term funding for heavy-lift rocket research and development than the Constellation budgets put forward by former President George W. Bush before he left office in early 2009.

“We were not previously going to be investing in heavy-lift technology until 2016 in any meaningful way, anything over about $100 million,” NASA Deputy Administrator Lori Garver said during a Feb. 1 budget briefing at the American Association for the Advancement of Science here. “This budget puts $3 billion between now and then into heavy-lift technology, starting with about a half-billion dollars in 2011. We anticipate being much farther ahead than we would have been, with actual hardware we’ll be testing, certainly maybe with flight demonstrations well before we would have even started any significant funding with heavy lift.”

Obama’s 2010 budget proposal, sent to Congress last spring, held spending on Ares 5 to about $25 million annually through 2014, a drastic departure from Bush’s final budget, which called for spending $2.5 billion on the rocket through 2013.

While Obama’s 2011 budget proposal devotes a total of $3.1 billion to a new heavy-lift and propulsion research and development effort, NASA officials have not said how much of that money would be spent on heavy-lift technologies, such as new first-stage rocket engines, versus in-space propulsion and other “foundational, basic propulsion research” mentioned in NASA budget charts.

These charts said NASA’s projects could include commercial, academic and international partnerships.

Bolden said greater reliance on international partnerships would be one of the biggest changes NASA would see under his leadership.

“We’re going to put international partners in the critical path, which means they may develop a system that we know how to do, but we don’t know how to do it as well as they do,” Bolden said.

Bolden also told reporters that while Obama’s proposal would not see U.S. astronauts leave low Earth orbit for “the next couple of decades,” the president’s approach would allow NASA to develop “game-changing” technologies with the help of international partners that could hasten NASA’s ambition to explore the solar system.

“I think we can speed our ability to get to places beyond low Earth orbit,” Bolden said during the news conference. “We’re not destroying anything, and in fact we probably are not even impeding our ability to get there, we may get there more rapidly, by opening up the partnership to international partners. That makes available to me other types of propulsion systems, or other types of spaceflight systems that I may not be able to develop with the rapidity that I would like. So we may in fact be able to get to some of these destinations quicker. It’s too early to know.”