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Mars base illustration
Human missions to Mars has long been a desire of NASA. Now, there’s growing acceptance of that long-term goal, but less understanding of the best way to achieve it in a budget-constrained era. (credit: NASA)

The uncertain road to Mars

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If you don’t know where you’re heading, the saying goes, any road will take you there. That’s been the criticism sometimes levied at NASA’s human spaceflight program by those who believe it to be wandering aimlessly with a lack of focus.

In fact, the situation is somewhat different. There is a broad and growing consensus that NASA’s human spaceflight program has, and should have, the goal of sending humans to Mars, and to do so by the mid 2030s. That was the goal laid out four years ago this month by President Obama in a speech at the Kennedy Space Center, and one that even Congressional critics of the administration’s space policy seem willing to support.

“I don’t even like the term ‘exploration’ any more. We’re ‘pioneering,’” Bolden said.

What’s less certain is not the long-term destination, but the path to get there. NASA has argued that its Asteroid Redirect Mission (ARM) is the next step on a path that is gradually beginning to take shape, a case that NASA officials, including administrator Charles Bolden, will likely make at this week’s Humans to Mars Summit in Washington. That approach, though, faces criticism from some who disagree on the plan’s lack of emphasis on the Moon, while others wonder if NASA will have sufficient funding to carry it out on schedule.

NASA’s plans come into focus

The first step in NASA’s path to Mars is the ARM, a concept that, a year after its introduction, is still struggling to win support (see “After a year, NASA’s asteroid mission still seeks definition”, The Space Review, March 31, 2014). That mission, agency officials argue, will develop a number of key technologies, like solar electric propulsion, needed for later missions to Mars.

“The FY [fiscal year] ’15 budget request keeps NASA on a steady path we’ve been following, a stepping-stone approach to meet the President’s challenge of sending humans to Mars in the 2030s,” Bolden said Wednesday in a meeting of the NASA Advisory Council (NAC) at NASA Headquarters. He suggested that some people had forgotten the goals laid out in the President’s 2010 speech, which also called for a human mission to a near Earth asteroid by 2025.

“Some of you may say the same thing that some of the committee members ask me when I go to the Hill: ‘When did you guys decide you were going to do all this new stuff?’ We’ve been on this path since 2010,” Bolden said, recounting the goals laid out in Obama’s speech. “For a variety of reasons, it just kind of went over people’s heads. But it didn’t go over our heads.”

The president’s speech originally suggested that humans would travel out beyond the Earth-Moon system to visit an asteroid. However, John Holdren, director of the Office of Science and Technology Policy (OSTP), told the NAC last week the ARM was still consistent with that 2010 goal.

“I think the current version of the NASA plan is consistent with the President’s vision,” Holdren said. “The President’s vision was laid out with very broad brushstrokes.” The ARM, he said, fulfills several objectives in preparing for future exploration as well as science and commercialization. “I think it is an incredibly valuable mission in terms of the number of purposes it serves, largely using technologies and components that are being developed with current budgets.”

What happens after the ARM—which may not be wrapped up until 2025, depending on when a suitable asteroid can be moved into cislunar space to be visited by astronauts—remains uncertain. The Global Exploration Roadmap (GER), developed by a dozen space agencies, including NASA, lays out a basic path to Mars that starts with continued utilization of the ISS and includes human missions to near Earth asteroids, the lunar surface, and locations in cislunar space. However, the GER doesn’t endorse a specific set of missions, or even a single path, that would lead to humans on the surface of Mars.

“I know that different members have their own personal favorite destinations and interim missions, but this amendment puts the job of deciding the pathway forward where it squarely belongs, by requiring NASA to develop an informed and realistic roadmap to get this nation to Mars,” said Rep. Edwards.

In recent weeks, NASA has been pushing a three-phase concept for the future of human space exploration. The initial step, “Earth Reliant”, involves utilization of the International Space Station (ISS), “mastering the fundamentals” of long-duration human spaceflight while still able to return home in hours. The “Proving Ground” features missions in cislunar space, like the ARM, lasting from a month to a year, while the “Earth Independent” phase involves human missions to “Mars, its moons, and other deep space destinations,” according to one NASA graphic. That plan, though, doesn’t define exactly what those missions would be, beyond the ARM and human missions to the Martian surface itself.

NASA has also been experimenting with the language it uses for its human exploration program. “I don’t even like the term ‘exploration’ any more. We’re ‘pioneering,’” Bolden said at an April 3 meeting of the Space Studies Board and Aeronautics and Space Engineering Board. “Exploration implies that you’re going out, but you’re coming back home. When we go to Mars, the intent is not to go back home. Crews will come back home, but the infrastructure there will get larger and larger.”

Despite those high-minded concepts, the lack of definition of specific missions has been frustrating to some in Congress. On April 9, the House Science Committee’s space subcommittee approved a new NASA authorization bill that addresses that issue among others. The bill would requite NASA to develop an “Exploration Roadmap” that would specify “the sets and sequences of missions required” to develop the technologies and capabilities needed to send humans to the surface of Mars. That report would be due to Congress 180 days after the bill’s enactment, with updates every two years thereafter.

“The agreement before us today makes absolutely clear that NASA’s goal for the human spaceflight program should be to send humans to Mars,” said Rep. Steven Palazzo (R-MS), chairman of the space subcommittee, referring to a bipartisan deal on an amended version of the bill. “Proposals that cannot be proven essential to a Mars mission should be removed from this portfolio.”

“The roadmap will allow NASA’s technical experts to analyze the merits of potential interim destinations towards achieving the goal of sending humans to Mars,” said Rep. Donna Edwards (D-MD), the subcommittee’s ranking member. “I know that different members have their own personal favorite destinations and interim missions, but this amendment puts the job of deciding the pathway forward where it squarely belongs, by requiring NASA to develop an informed and realistic roadmap to get this nation to Mars.”

Even without that Congressional impetus, NASA has started to define what at least next step beyond ARM would be. At last week’s NAC meeting, Bill Gerstenmaier, NASA associate administrator for human exploration and operations, said NASA was examining concepts for a crew-tended habitat in cislunar space that would make use of technologies developed and tested on ISS and the ARM, including solar electric propulsion to move the habitat through cislunar space.

“This habitation module would potentially be the same habitation module we would take to Mars with us,” he said. That module, he said, could be developed commercially, or by an international partner, based on interest the agency has received from both sectors. “We’re exploring all of those opportunities.”

Mars base illustration
A NASA chart shown at a meeting of the NASA Advisory Council last week illustrates NASA’s concepts from going from Earth to Mars, but offers few details on specific missions. (larger version) (credit: NASA)

The Moon and the critical path

Absent from even those vague plans, though, is any mention of NASA crewed missions to the surface of the Moon. While NASA has interest in operations in cislunar space, including lunar orbit, the agency and the administration aren’t planning on setting aside funding to develop the landers and other technologies needed for landing humans on the Moon.

“You will not be able to build an international partnership if you don’t include the Moon in your roadmap,” said Hufenbach.

At an international workshop about the GER held April 10–11 at the Applied Physics Laboratory (APL) in Laurel, Maryland, the role of the Moon in future exploration became a topic of debate. Early in the meeting, NASA’s Roland Martinez, chair of the International Architecture Working Group of the International Space Exploration Coordination Group, which developed the GER, noted that NASA was not planning any human missions to the lunar surface. “It’s not part of NASA’s critical path to Mars.”

Others at the meeting, though, reacted strongly to that comment. “I’m kind of surprised you reached that conclusion, because you guys are wrong,” argued Mark Robinson, a professor in the School of Earth and Space Exploration at Arizona State University and principal investigator of the main camera on NASA’s Lunar Reconnaissance Orbiter. “If you want to get to Mars with human beings, you’ve got to go to the Moon first so you can learn how to live and work on another planet.”

Human lunar missions may be important for attracting international partners who, unlike NASA, have not yet landed people on the Moon but are interested in doing so. “You will not be able to build an international partnership if you don’t include the Moon in your roadmap,” said Bernhard Hufenbach of ESA’s European Space Research and Technology Centre.

Lunar missions, he added, may also be important for maintaining public interest in a program that will take two decades or more before humans set foot on Mars. “I don’t think you can do missions to deep space, the lunar vicinity, or asteroids for a period of 20 years without sending humans to a planetary body like the lunar surface,” he said. “It will not be inspiring enough. You will not keep the public engaged.”

The administration, though, is unswayed by those who calling for the inclusion of human lunar landings in NASA’s exploration roadmap. “Those folks may never be persuaded that spending $60 to 80 billion to do that is not the best use of $60 to 80 billion in the environment that we now find ourselves,” Holdren said at last week’s NAC meeting. “People are just not realistic about the costs of these things.”

However, at a meeting of a NAC human exploration and operations committee earlier last week, Gersetenmaier said that NASA would be open to cooperating with on human lunar landings if other nations or even commercial entities decided to pursue such a mission on their own. “If the partners or commercial industries push that [lunar] surface activity, we would go evaluate and see if that makes sense for us,” he said. “The Asteroid Redirect Mission isn’t committing us to no lunar activity. It’s not either-or.”

Does NASA have an exploration strategy?

At last week’s NAC meeting, council members took in presentations by Bolden, Holdren, Gesternmaier, and others that touched upon NASA’s exploration plans. A major topic of discussion was whether those plans truly constituted a detailed strategy for exploration that NASA could carry out.

“You communicate that the United States has a human exploration strategy, but I think that many of your outside fan clubs and cheerleading sections are not convinced,” said new NAC member Tom Young, a retired aerospace industry executive. “I think the perception is that it’s more of a passion and a dream than a strategy.” He added that for NASA’s plan to be considered a strategy, “it has to be resourced in a manner that assures that it can be executed.”

“Humans to Mars is so utterly compelling as a goal that, push it out 50 years, I don’t care, it’s still what NASA ought to be striving for,” Squyres said.

Bolden acknowledged that the plan wasn’t as detailed as what some would like. “I think we have a rough plan in place that we’re trying to put some meat on because everyone’s asking” what the lifecycle costs of programs like the Space Launch System (SLS) will be, he said. “No, we don’t have what would really be a valid strategy that the common man would accept, but we’re working on a plan that at least identifies the milestones that are needed to get there.”

Bolden added that this situation isn’t necessarily new. “There has never been a time in this nation when a strategy has been appropriately resourced,” he said.

The question of resources—specifically, funding—appeared to be the NAC’s major concern about NASA’s exploration plans, be they considered a roadmap or a strategy. In his presentation, NASA’s Gerstenmaier said the agency’s exploration plans required “modest” increases in the agency’s exploration budget over the long term, although he didn’t define how much that would be.

“It’s the best thing I’ve seen yet,” said Charles Kennel, chairman of the Space Studies Board, of NASA’s plans. “The only weakness I could spot at the present time is the credibility of the funding.”

Young, in the NAC’s discussion last week, remained skeptical that NASA truly had a strategy because of the funding issues. “I think the disconnect between the dream and reality is so stark that—I’m trying to find a better word than alarming, but that’s what I end up with,” he said.

Many members appeared to think it inevitable that NASA’s plans to send humans to Mars in the mid-2030s would be delayed. “The free parameter is schedule,” said NAC chairman Steve Squyres, meaning that if budgets don’t increase sufficiently, programs will be delayed. “The question I would pose is, at what point does the strategy fall apart? At what point does the stretching become so great that things break, that thinks simply don’t work?”

Squyres suggested that point might come if timelines for Mars missions stretch out beyond the careers of anyone working on it. “If it’s so far out to the right that it’s not going to happen in the foreseeable future, you have to ask if it’s the best thing for us to do to spend money on things that are aimed at getting us to Mars, or should we change the goal completely.”

However, later in the meeting, Squyres concluded that issue wasn’t as big a risk as other concerns, like flying missions so infrequently that safety becomes jeopardized. “Humans to Mars is so utterly compelling as a goal that, push it out 50 years, I don’t care, it’s still what NASA ought to be striving for,” he said. “I don’t care how far out it gets pushed, that doesn’t break the program.”

That leaves NASA at risk if being trapped in a conundrum: pursuing a program of sending humans to Mars that is compelling enough for the agency to pursue no matter its budget situation, but not compelling enough, perhaps, to win adequate funding to carry it out in a reasonable manner and timeframe. A compelling plan (or roadmap, or strategy) of human exploration leading to Mars may be a necessary—but perhaps alone not sufficient—condition to winning that funding.


ISPCS 2015