The Rationale for Human and Robotic Space Exploration
Charles Walker, of the Boeing Company and a former astronaut (the first and only astronaut sponsored by industry), moderated the panel. Walker introduced the Panel on the Rationale for Human and Robotic Space Exploration by remarking that it is in our nature to explore. As we develop technologies, they are applied to create tools that assist us in the pursuit of space exploration. Over time, the instruments we create have become complex. One researcher in the field, he said, has suggested that our robotic instruments have three characteristics: programmability, mechanical capability, and flexibility.1 These, of course, mirror or attempt to imitate, even expand, human capabilities. So, cognizant of the great challenges of space exploration and development, the committee asked the following focusing questions of the panelists:
What are the compelling reasons for human or robotic presence in space?
What are the appropriate roles for robotic exploration and human exploration and development of space?
What technological barriers must be overcome?
What role should the U.S. government, industry, academia, and private citizens have in this exploration and development of space?
How best do we establish and sustain public support for such endeavors?
The panel included National Academy of Engineering member and former astronaut Neil Armstrong; staff director of the U.S. House of Representatives Committee on Science David Goldston; planetary scientist Wesley Huntress, director of the Carnegie Institution's Geophysical Laboratory and former NASA senior executive; executive director of the U.S. Chamber of Commerce Space Enterprise Council David Logsdon; NASA's Space Architect Gary Martin; and former Mars Exploration Program manager for the Jet Propulsion Laboratory, Donna Shirley, director of the Experience Science Fiction Museum.
Neil Armstrong opened his remarks with a quote from the 5th century B.C. Greek Antisthenes: "The beginning of wisdom is calling things by their correct names." He noted the lack of linguistic standards or enforcement in American English and suggested that the establishment of such standards for engineering terms would be a worthy pursuit. Engineering requires careful use of language since errors in communication can have devastating consequences. Armstrong noted that the term “robot” was created by Czech writer Josef Capek and his playwright brother, Karel Capek, for a 1920 play entitled Rossum's Universal Robots. Named after the Czech word robota, meaning forced work,
the robots in that play were defined by their autonomous behavior. Armstrong then observed that although spacecraft do not live up to that original definition of the term, their onboard programming and ability to be remotely controlled from Earth have made for valuable accomplishments.
Armstrong said that the Apollo program benefited from early probes sent by the United States to map the Moon and test the lunar surface. He also noted that these probes have accumulated 13 successes and 16 failures, not unlike the (almost) 1 in 3 Mars probe success rate. Increasing the success rate of future probes through increased autonomous capability, he thought, would depend on extended systems reliability and performance range. As their separation from Earth increases, spacecraft need more autonomy. Summarizing his view on the rationale for space exploration, Armstrong said it is to increase our knowledge of space and to develop the means to use it to our advantage.
Answering a question from moderator Charles Walker about the relative roles of government and industry, Armstrong observed that while industry is willing to engage in enterprises incurring very short-term financial losses, it does so only if it sees those losses leading to longer-term profitability,which limits the role it can perform. Perhaps not-for-profit corporations can exercise somewhat more business flexibility, he suggested, but the principle is similar.
Another question about Armstrong’s view on appropriate roles of humans and robotics in space exploration and development elicited the reply that NASA should have kept human spaceflight and robotics investments together, working toward common mission goals. Mission accomplishment is the overriding goal in Armstrong's view; achieve that, and safety will usually follow.
The final question, from Darrell Branscome, asked how public support can be increased. Armstrong's response was that publicly funded endeavors are proposed by the presidential administration and then approved and funded by the Congress, which is supposed to reflect the public will. But the public will is elusive. Because most people do not have the information at hand to make informed decisions, they rely on the Congress to make the best decision possible.
David Goldston began his remarks by noting that they were his own, not those of particular members of Congress or a congressional committee. He said the rationale for human spaceflight was less clear than the rationale for science-driven robotic missions. The latter missions are well defined by virtue of the peer review process. In Washington, D.C., he said, the rationale for human missions is fuzzy, and most explanations cannot survive rigorous scrutiny. He summarized the basic reasons for space exploration as follows:
Science. While science is often cited as a rationale for human missions, much science can be conducted robotically, and there are no clear criteria for determining when sending humans on science missions is worth the additional expense and risk. In proposing its space exploration vision for NASA, the White House has carefully stated that it is not science-driven but informed by science. Goldston thought that was an honest position, but NASA is not using the same language in its discussions of the new vision and should be doing so.
Education and public excitement. In Goldstein’s opinion, this is the most commonly stated rationale but the weakest one. He noted that U.S. education was
not likely to suddenly improve just from the excitement of a human space mission. He noted that the launch of the first Sputnik satellite prompted the federal government to put money not only into space programs, but also into education programs. The greatest excitement at this time is being generated by unmanned programs; examples he gave were the Mars rovers and the Hubble Space Telescope. He concluded that the ability of human spaceflight to stir up excitement is not really a valid rationale.
International security. Goldston reflected on this as a valid rationale for Project Apollo in the 1960s but not in the first decade of the new century. He suggested that some may hope that the newly inaugurated Chinese manned spaceflight capability will provide some momentum for the new space exploration vision. Goldston noted further that the administration has framed its vision in terms of international cooperation, not of security.
Commerce. He called this rationale for human exploration an intriguing one but one not well developed by the White House. It seemed to him that no actions had been proposed or taken to get the commercial sector involved.
Far reaching ideas. Goldston said that ideas such as beaming energy from the Moon to Earth were often cited in passing, but seemingly without real thought or effort behind them.
Human destiny and exploring the unknown. Goldston called this the most legitimate rationale but also a complicated one. There is a public will to explore, but expanding our understanding of the world can be done with unmanned space probes. He said that the Lewis and Clark analogy doesn't quite work, because expanded human understanding of the solar system can occur without human missions. While concluding that this rationale needs more thought, Goldston said that Congress and the public may find it difficult to prioritize a mission motivated primarily by “human destiny.”
Goldston continued by addressing the question of appropriate roles for human and robotic exploration. He supported the administration’s notion of dropping the walls between human and robotic programs, but cautioned that even if the programs are intertwined they will continue to compete for money, so it is important not to sacrifice unmanned for manned missions. Goldston said that unmanned missions must continue to be assessed as they are now, with open, competitive peer review. They also should not be slaves to manned missions. There are legitimate goals for unmanned space exploration. Manned space missions should not be justified by designing robotics that must be maintained and supported by humans; use humans only when necessary. Politics should not drive the design of space exploration.
Goldston then spoke of public support for spaceflight. It has always been iffy, he said. There needs to be open, public discussion without hype. Goldston felt that NASA should have such a dialogue, especially about cost, and that this could improve NASA's credibility. He encouraged the panel and the workshop to so inform NASA. He concluded his remarks by noting that in a recent hearing before the House of Representatives’ Committee on Science, NASA was unclear about how much the new space exploration vision would cost.
Charles Walker asked Goldston what was necessary for sustaining a program of exploration over the long term. Goldston replied that it begins with being upfront about costs and risks, both to humans and mission success. He said that NASA had been unwilling to do this for the International Space Station program, with life sciences research replacing the old mix of reasons for the station’s existence.. He added that we must understand the state of our knowledge, then learn as we go along and change as needed.
Wesley Huntress began his remarks by defining robots as tools. He referred to the Mars exploration rovers, Spirit and Opportunity, now operating on the surface of Mars, and suggested that they would be ten times more effective if there were a human operator controlling them from Mars orbit providing virtually instant feedback rather than from Earth, with delays of more than 10 minutes.
Huntress then went into his presentation, drawn from a study done under the auspices of the International Academy of Astronautics, beginning with a strategy for science-driven exploration. Guiding principles were presented: addressing broad public and scientific interest, starting with a goal, establishing the destination and a plan, then utilizing robots where possible and humans where necessary. Desired outcomes would follow, in his strategy, through a systematic plan with goals established first, then destinations. The strategy would be flexible, affordable, and sustainable. Huntress made the point that there are also cultural and political imperatives for space exploration. Science alone is not a sufficiently strong imperative. Further, he contended that scientific objectives or goals come from fundamental human questions—What is our origin? What is our future? Are we alone? To explore these objectives we have four destinations, he said: the Sun-Earth Lagrangian point (L2),2 the Moon, near-Earth objects, and Mars. Huntress then elaborated on the scientific activities and technical exploration architectures appropriate for each of those destinations. He summarized his remarks by saying that a successful architecture for exploration should use a stepping-stone approach extending outward from Earth.
In answer to a question about what technologies critically need advancing, Huntress replied that he believed almost all of these things could be done with technologies now in hand. He did note, however, a few technology advances that would be a great help. One is nuclear propulsion, especially nuclear-electric, for transporting cargo at reduced risk and in shorter times. Project Prometheus is therefore a critical program. Huntress continued, saying that optical communications technologies are needed to increase bandwidth, and added that the satellites on which the optical communications are installed could also carry systems to help with surface navigation. An Internet node at Mars might also be a good thing. Finally, he noted that heavy-lift launch to space and inspace construction technology also might be good investments. But he advised that these technological investments should not be made if we can get by without them.
David Logsdon provided the workshop with prepared remarks. The Space Enterprise Council of the U.S. Chamber of Commerce addresses space issues across the full
spectrum of American industry. Logsdon said his remarks, based on the Council’s views, were inspired by a common dedication on the part of member companies, despite their diversity, to the promotion of commerce on the ground and in space. These members support an integrated approach to human and robotic space exploration that takes advantage of the strengths of both and that will evolve as knowledge and technology advance.
Regarding the compelling reasons for space exploration, Logsdon reflected on the large-scale, government-backed expeditions of the past—for example, the Spanish-backed discovery of this continent and the Lewis and Clark exploration of the American West. He saw a lesson in those endeavors—namely, that while the impact might not be seen in the short run, in the longer run it is profound. He then spoke of drawing inspiration from human heroes and the exploration of new frontiers that created them. Our nation’s industries have been bolstered over the past several decades by a government and private sector workforce that, motivated by our nation having been first on the Moon, took up the science, mathematics, and engineering disciplines. Logsdon extended this point to international competition: As evidenced throughout the history of aviation technology and business, “if we don’t do it, they will.”
Regarding barriers to new programs of exploration, he spoke of the unknown effects of long-duration spaceflight, the need for a new launch vehicle, cost uncertainties, and, finally, political uncertainties. In the absence of a political imperative like we had in the 1960s, Logsdon made a clear call for the American public to support space exploration. To rally this support, the White House would have to be involved, perhaps through a body like a national space council. Another way to gain support would be to make space exploration a course of study during the middle school and high school years. Other ways of rallying public support for space exploration included coalitions of stakeholder industries that would campaign for space and efforts by American’s movie and video game entertainment industries. He concluded by saying that it is essential for the benefits of space exploration and development to be articulated in terms of everyday life.
Charles Walker asked Logsdon if there should be legislation to further encourage industry to participate and invest in space exploration. Logsdon replied that the Commercial Space Act legislation applied. Panelist David Goldston added that the House Science Committee added amendments in February 2004 to ensure that industry is not jeopardized. This bill may be voted on by the House of Representatives soon.
Gary Martin opened by referring to the public’s support of NASA while acknowledging that the agency cannot point to specifics to prove this support. To the public there is no single NASA strategy: the space shuttles, unmanned probes, Earth science, all these pieces exist without an overarching framework. NASA needed the President's vision for national space exploration, he said. It is the framework, the context, and the long-term picture. It will depend on sustained growth and will be accomplished through a sequence of steps, human and robotic missions, to the Moon, Mars, and beyond. The requisite characteristics of a national policy for space exploration were contained in the President's directive, which calls for a step-wise increase in capability but on no particular timetable. For this, a strategic and systematic process is necessary. Recently, the role of the International Space Station has come into question. Now it has a focused set of goals because it is an important stepping-stone in a larger
strategy. Martin elaborated, saying the ISS is not going to be everything to everybody but acknowledging that it had previously been promoted as such.
Martin said that exciting science, such as peering beneath the ice and into the oceans of the moons of Jupiter, requires a lot of power. NASA's Project Prometheus will provide that power, first for robotic missions. Nuclear reactor technology for surface power on planets needs research before it can be used in this application. Nuclear propulsion will be necessary as well. For instance, nuclear thermal propulsion can reduce the mass of a crewed vehicle to Mars to almost one-half that of a crewed vehicle using chemical propulsion. And, Martin continued, employing aerobraking technology at Mars will reduce the mass another 40 percent or so. He listed other important technologies such as bioastronautics and heavy-lift space transportation.
On the respective roles of government and industry, Martin said the government's is to make the large investments and take the big technology risks, thereby enabling science. Industry will bring creativity and innovation. He hoped that entrepreneurs will be able to get involved and expressed a need for industry to benefit from this participation. Academia will be the source of peer-review, science goals, and mission planning and will teach the next generation of workers and researchers. Martin closed his remarks by saying that private citizens should be the ultimate beneficiaries of this new exploration vision. They should be able to understand what their national space program has under way and be inspired. According to NASA-sponsored research, the public is supportive of NASA programs, he said, but the public would like to understand the larger context of those programs and desired more information about NASA missions.
Donna Shirley began her remarks by saying she intended to be terribly pragmatic. She echoed other panelists in saying that robotics should be used when they can do the job and humans used only when necessary. The Hubble Space Telescope was designed for servicing by astronauts, but a robotic servicer could probably be built and flown for about the cost of a shuttle launch. Shirley contended that we don't need to make arguments for people to go to space—they want to go! The popularity of science fiction about humans in space, including the mythic Star Wars movie series, shows that humans want to go into space. She thought that one fruitful technology area is to increase the autonomy of telerobotics, making the machines more capable of operating with less human supervision. On the matter of technology barriers, she mentioned the current state of robotics, saying we need smarter robotics and that the research is being done in universities today. Robots need not mimic humans but have been successful by imitating insect behavior. Shirley mentioned Rodney Brooks of the Massachusetts Institute of Technology’s Computer Science and Artificial Intelligence Laboratory as one of those university researchers. Shirley went on to say that launch costs must be reduced. Human survival and effectiveness of human work in space require more study, and the ISS is the place to do that, but she observed that astronauts do not like to be test subjects because they believe any weaknesses found will prevent them from flying again. Finally, on the topic of technology, Shirley stated that nuclear power and propulsion are necessary. Space exploration will not go far without them, and we don't want our missions to be slaves to the diurnal and seasonal variations on planetary surfaces, as they are when hardware is powered by photovoltaics.
Shirley, turning to the role of government, told the workshop that the government should do what cannot be done anywhere else. Industry needs to do what is profitable,
but incentives need to be put in place that will make companies eager to invest in particular areas. She added that more private enterprise needs to be introduced to the space business, noting that many wealthy individuals had become interested in space launch. Shirley specifically named Paul Allen of Scaled Composites, Elon Musk of SpaceX, Dennis Tito, and the investors in Armadillo Aerospace. She noted that Federal Aviation Administration licensing of human spaceflight is an enormous hurdle for private companies, and the regulations are arcane.
Returning to government space programs, Shirley said, that the truth must be told about costs. The new national space exploration vision should not be treated as a jobs program. Observing that this is the approach NASA has often used to sell its programs to Congress, she contended it is not the best way to develop an exploration program. She was also concerned that the problem of how cargo will be returned from orbit after the shuttle’s retirement is not being considered, but it should be.
Shirley opined that the congressional habit of earmarking programs is “killing us," taking needed program funding to pay for politically motivated local projects. She also commented on the NASA organization, pointing out that the Jet Propulsion Laboratory succeeds because it is a contractor, not a government entity. She thought that NASA should look into privatizing its centers in order to motivate them to be more efficient and competitive.
Shirley asked for the public to be made part of the process. The public must feel ownership before it can advocate space exploration. She referred to Mark Craig, of NASA Johnson Space Center, as having attempted to get feedback from the public on space exploration. NASA has not really worked at this, she said, calling its public affairs approach an attempt to sell the public on what NASA wants rather than engaging it in formulating the programs. Finally, she told the workshop that the Moon as a destination is a diversion from Mars, not a stepping-stone on the way. If it is to be a goal, it should be sold as one separate from the goal of reaching Mars.
The panel discussion began with Molly Macauley suggesting that the dividing line between humans and robotics is not as clear as the panel members had just made it out to be. She asked how one determines what the discrete role of each is—what are the trade-offs? Wes Huntress replied that first each case must be studied and that the answer will always be relative. David Goldston responded that this was the right question to be asking, and that from a policy perspective neither NASA nor the White House had been clear in answering it so far. The NASA budget request, he said, muddles things by merging human and robotic programs. According to Goldston, the question we need to be asking is, When are humans absolutely necessary, and for what? Gary Martin stated that NASA is looking at what goals the science enterprises are setting as their highest priorities and is then determining what technologies are needed to accomplish those goals. Once the technologies are determined, they will be developed.
In a follow-up question to panel members, Charles Trimble wanted to know what they thought of having a set ratio of human to robotics efforts in program budgets, with the human efforts including physiological studies. Donna Shirley did not think much of having such a ratio. Set a goal—where we want to go and what we want to do there—then decide on the costs and the allocation of budget, she said. Asked if robots could do everything, she responded no: there is science that can be done most cost effectively by robots, but robotics can't do it all. How, then, is a budget to be set for the human
imperative, asked Trimble? David Goldston responded that NASA had set aside a share of its budget for humans and a share for robot-conducted science. This established partitioning is good for robotic science and keeps it from being devoured by the human spaceflight programs, but he said he was nervous about setting an arbitrary dollar figure. A program should prove that human spaceflight content is necessary to its good. Goldston, observing that when Congress considers the budget, NASA competes with other federal science institutions like the National Science Foundation, asked for public input on the proposition that we need human spaceflight for its own sake and on the value that should be attached to such flight. Neil Armstrong then opined that had the space station program been allowed to proceed as originally planned, without congressional delays, the station would now be complete and at a fraction of the present cost.
Dava Newman then suggested that the question, Should we separate the human and robotic efforts? is the wrong question to ask, that we're confusing the issue. Are not humans and robotics part of a whole system needing integration? she asked, suggesting that systems analysis be used to study exploration opportunities and architectures be allowed to determine what the roles are and how they are best performed. Goldston responded that he believed Congress would like to see this done. There are enormous and artificial divisions within the NASA culture inhibiting this integration, said Shirley, who has written an article on the subject.3 Huntress believed that the Apollo program—which landed the first humans on the Moon—would never have succeeded had the human and robotic elements not been totally intertwined. When that program ended, robotics found a customer in the science community and did well. Now it has two customers: the same science community and the human support function. That division of labor needs to be made clearer. Goldston responded that, although such division is a good idea, it would not decouple the “what” from the “when.” Gary Martin interjected that in the Mars exploration program the robotic missions will look for water, the source of life as we know it. The human missions that ensue will do science that follows up those robotic explorers. Humans can recognize something out of the ordinary, something interesting, which is, he said, a unique ability. Donna Shirley disagreed with that statement, saying that robots merely extend human senses in distance and wavelength. Armstrong contended that, by Capek’s definition, we really have not had robots yet. Quoting from the plant manager in Capek’s play Rossum's Universal Robots, he joked that “Robots remember everything but think of nothing new. They would make very good university professors.” Eric Rice asked the final question of the session: How can implementation of the new exploration policy better engage the public? Donna Shirley responded that NASA had looked into that and that Mark Craig, at the Johnson Space Center, should be asked. Gary Martin concluded by saying that NASA was having surveys done—listening to what the public says on the subject to better understand what that public would like to see from its space program.