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Home , 2005 in spaceflight, Fred Singer, Human presence in space, Human spaceflight, Spaceflight, Space exploration

FORUM Achieving Presence in

Abstract about putting jobs in congressional districts as about putting feet on otherworldly rocks. One of the primary goals of human spaceflight has been put- But our telerobotic have evolved ting human cognition on other worlds. This is at the heart of dramatically since then, and this historically based pre- the premise of what we call . But -con- mise is no longer binding. We send rovers to that, trolled telerobotic facilities can now bring human senses to controlled by on Earth, and investigate other worlds and, in that respect, the historical premise of ex- much as a human would do in situ, with mobility, ploration, of boots on the ground, no longer clearly applies. vision, and some measure of dexterity. Of course, we We have ways of achieving remote presence that we never send across the that bring our used to have. But the distances over which this must be eyes, as well as some senses humans do not even have, achieved, by humans based on the Earth, is such that the to faraway venues. speed of light seriously handicaps their awareness and cogni- The contemporary of space exploration is tion. The highest quality telepresence can be achieved not therefore no longer entirely clear (Lester Robinson, only by having people on site, but also by having people close, 2009). NASA nevertheless chooses to use the word ex- and it is that requirement that truly mandates human space- ploration explicitly for human space flight. Interestingly, flight. In terms of cost, safety, and survival, getting people congressional authorizing legislation for the agency close is easier than getting people all the way there. It is sug- never refers to the importance of boots on otherworldly gested here that to the extent that space exploration is best rocks, but repeatedly refers instead to the importance of accomplished by achieving a sense of real human off-Earth ‘‘human presence’’ in space. The last NASA presence, that presence can be best achieved by optimally authorization act (P.L. 111-267; NASA, 2010), pro- combining human spaceflight to mitigate latency, with telero- nounces that ‘‘The long term goal of the human space botics, to keep those humans secure. This is culturally a new flight and exploration efforts of NASA shall be to expand perspective on exploration. permanent human presence beyond low-Earth and to do so, where practical, in a manner involving interna- tional partners.’’ Authorization bills now wending their 1 Introduction: Exploration and Presence way through Congress say much the same thing. While it is likely that congressional intent is to put humans in The popular premise of space exploration has been boots at exploration sites, those words are not the ones strongly based on historical templates. These templates that appear in federal legislation. The congressional figure space explorers as humans who put their boots on emphasis on ‘‘human presence’’ instead of human boots celestial rocks, ideally planting flags as they do so. This on the ground cuts to the heart of the premise of how premise was manifested by the , who space exploration might be viewed. That is a premise not brought human and awareness to the surface of necessarily consistent with the historical template for the , reaping huge geopolitical gain in the process. exploration, and is one that human spaceflight advocates Forty years ago, our lack of technical sophistication was are therefore not entirely comfortable with. such that bringing human insight and awareness to the Moon had to be done in exactly that way. Of course, the congressional premise for space exploration is as much Dan Lester Presence, Vol. 22, No. 4, Fall 2013, 345–349 Department of doi:10.1162/PRES_a_00160 University of Texas at Austin ª 2013 by the Massachusetts Institute of Austin, Texas 78712

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The ‘‘presence’’ community should be paying some the point that we now routinely do telerobotic surgery attention to this, because when Congress starts using the and remote control of deep undersea construction and phrase ‘‘human presence’’ to authorize a $17B agency, maintenance. In fact, the telerobotic dexterity and mo- the phrase takes on some importance. The attainment of bility we now have in many respects exceeds that of a has two important dimensions. space-suited human. You would not want to be operated One is technical, likely involving putting humans on on by a surgeon wearing a . , and the other is cultural, involving the historical It should be understood that space is routinely template for exploration that we are culturally wedded done telerobotically, although the tasks are done largely to. The purpose of this brief Forum article is to refresh autonomously, with supervision by controllers on the the issue in this community whose perceptions of tele- Earth. In the case of planetary , such as the presence and second-order mediated experience are Mars rovers, the latencies in such supervision are limited more sophisticated than that of the space exploration by the speed of light to 4–10 min, and by operational pro- community. tocols to many hours. Scientists do not have what we could call hands-on, real-time access to planetary venues 2 The Promise of Telepresence for Space that would constitute telepresence at those sites. Why is Exploration such access of value? A thought experiment might be to consider a field geologist on the Earth, handicapped by Human spaceflight is hard, expensive, and danger- such control latency. Every rock that he or she picks up or ous, and to the extent that our species needs to explore, moves aside, every turn to view it from different angles, such challenges on emplacing human presence are every surface scratch, every core sample, every step across understandable. But we have reached a level of techno- the surface, is the result of a series of perceptions and indi- logical refinement that putting boots on the ground may vidual controlled motions that each is delayed. The price not be the only way to explore. If and set- of latency for such complex work is enormous, and a real tlement were the goals of space exploration, boots on sense of presence on site is therefore scientifically ena- the ground would be of primary interest. But coloniza- bling. The Principal Investigator, tion and settlement of is in no way, right Steve Squyres, has said that a human on Mars could do in now, considered an established need of our nation by a minute what those rovers could do in a day (Squyres, our legislative bodies. 2005). That operational discrepancy is in many respects Thirty years ago, Marvin Minsky mused about the im- the result of communication latency to those rovers from portance of telepresence for space exploration (Minsky, the Earth. We can say that we have a measure of telepre- 1980). Somewhat later, Minsky formally proposed to sence on these rovers, but with the large latency, the qual- NASA that a could be entirely remotely con- ity of that telepresence is very poor. trolled from the Earth (Minsky, 1990). These ideas were In view of the tasks that a telepresent human would do exciting and innovative, but in addition to being techno- on another , the architecture of that needed telepre- logically handicapped at the time, were considered threat- sence can be defined. The human would want high- ening to the deeply ingrained premise that true explora- definition imaging to view the situation there, with a tion was something heroic that looked like Columbus or camera that could be moved as a human head could be Lewis and Clark. Those threats remain even today. moved. We have such imagers right now. A human would Of course, at that time, our telepresence capabilities want mobility, to explore different places. Wheeled were just in their infancy. But we now find ourselves with vehicles offer that capability, although perhaps not for vastly improved communication systems, and sensor climbing. A human would want dexterity with a fidelity packages that offer imaging at least as good as human comparable to a human hand and arm. That is more diffi- vision. Our robotic dexterous manipulation capabilities, cult, but the technological status of that capability is well- even offering some measure of haptics, have advanced to represented by contemporary telerobotic surgery, in

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which a remote surgeon can have dexterity that is far bet- latency. Space is a big place, and the communication ter, at least, than a human in a space suit would have. delays from the Earth to where presence is emplaced can Modern telerobotic dexterity, also represented by pros- be large. The operational price of latency has been well thetic limb teleoperation, and even explosive ordnance studied—see, for example, Sheridan and Ferrell (1963), disposal robots (EODs), demonstrates the dexterity that Held and Durlach (1991), and Sheridan (1993). For can now be achieved by a human in a space suit. This is Mars, the speed of light limits the two-way latency to 8– what at least scientific telepresence would look like. 40 min, depending on the orbital location of that planet. In fact, because of availability and plan- 3 Humans Versus Robots, or Humans ning overhead, commands and data are exchanged with Through Robots? the Mars rovers , , and on a timescale of more like a day. Even for the Moon, the In the last decade or two, the space exploration light-time limited latency is 2.6 s. For the Moon, the community has seen a humans-versus-robots argument sense of presence that is achievable is limited, and for develop, where mainly scientists point to the accomplish- Mars, it is downright poor. ments of robots, and question the need for human The recipe for the highest quality presence requires spaceflight at all. The counterargument by human space two-way latencies that are smaller than the human reac- flight advocates is that of course humans are more tion time, in order for the interaction to be considered insightful than robots and, besides, who fixes the robots? real time. The relevant human reaction time can be This argument has engendered fierce tirades between taken to be an eye-hand reaction time, on the order of these camps, but has come to the point that the argu- 200 ms. ment is tired and stale, and can be considered a false di- This recipe then dictates a limiting distance, which is chotomy (Launius McCurdy, 2007). It is now generally 200 ms times the speed of light (and divided by two to accepted, perhaps just in the interest of making peace account for bidirectionality). That distance, of about between these camps, that some combination of humans 30,000 km, is what we call the cognitive horizon, and robots is in the greater interest of advancing our because at distances closer than this we can, in principle, understanding of outer space. What an optimal partner- have a highly cognitive sense of presence, but at distan- ship or combination actually looks like is not well ces farther away, cognition is necessarily handicapped defined, however. (Lester Thronson, 2011). This is not a hard limit, of While fully autonomous robots are still far from being course, but just a distance at which cognitive awareness able to duplicate the cognitive performance of a human, starts to change. Of course, the Moon is a factor of six it is evident that the rapid advances in telerobotic tech- beyond the cognitive horizon, and Mars is factors of nology have made remote human surrogates far more ca- thousands beyond it. The International Space Station, pable than they used to be. Those advances will only about 400 km over the surface of the Earth, is well continue. It can be assumed that eventually such human within that distance. But low-latency telerobotics on the surrogates will match the senses, dexterousness, and mo- surface of the Earth controlled from Station (or on the bility of a human body. This would allow a human to Station controlled from Earth) are achievable mainly just embed his or her presence, avatar-like, at a site that may during relatively brief and infrequent ISS overpasses of be inhospitable to his or her human body. ground stations, rather than with the high bandwidth, but relatively large latency, TDRSS system that 4 The Price of Latency, and Cognitive is used for ISS data communication. More to the point, Horizons we already know how to put people up there in low- Earth orbit. We do it all the time. Space exploration has a caveat that makes it poorly The Earth is physically small enough that the chal- matched to terrestrial telerobotic pursuits. That caveat is lenge of latency in telerobotics is largely borne by space

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exploration. In fact, NASA and other leading space agen- 48). Minsky claimed inspiration from the science fiction cies have outstanding expertise at high-latency telero- short story ‘‘Waldo’’ by Robert Heinlein, whose title char- botics. But they have rather little expertise, compared acter rested comfortably in zero-g while he operated tele- with the multitude of applications in the commercial and robots down in the oppressive on the surface of the defense world, in low-latency telerobotics and high- Earth. The strategy was advanced more formally in the quality telepresence. NASA science, for example, has vir- Stafford Report, ‘‘America at the Threshold,’’ whose draft- tually no such expertise. One would like to believe that ing committee was convened by Vice President Dan those considering low-latency teleoperation for space ex- Quayle in 1991 to assess the Space Exploration Initiative ploration would acknowledge this fact, and with regard (Stafford Commission, 1991). Here the idea was called to at least human factors and task planning, would reach telescience. But in spite of these creative viewpoints, and out to those with some real operational, if not technical, in spite of rapidly developing telerobotic capabilities, the experience to offer. idea of space accomplishment by boots on rocks remained sacred and unchallengeable. Such telerobots would, after 5 On-Orbit Telerobotics and Surface all, change the practical definition of an Telepresence (Mindell, 2009). Several efforts involving the Interna- tional Space Station have since exercised on-orbit telepre- For distant worlds, the challenge of latency in tele- sence for lunar and planetary exploration in some detail. robotic control from the Earth is inviolable. But new What would humans do with their telepresence on thinking has refreshed the potential of telerobotic control planetary surfaces? Pretty much everything they would on planetary surfaces with high-quality human presence. do if they were down there themselves (Lester, 2012). For while human spaceflight is hard, expensive, and dan- Except they could spread that presence over large areas, gerous, human spaceflight down onto planetary surfaces is and exercise their presence on time scales that would be more so. Safe descent into a ‘‘gravity well’’ is critically de- vastly longer than a space suit could support an astronaut pendent on perfect control of propulsion, perhaps aerody- going for a walk. Their avatars would carry with them a namics. Operations in such a gravity well are likely to be sense of sight that would far outperform human eyes, in compromised by day–night cycles and airborne or levi- both resolution and spectral discrimination, and have tated dust. The prospect of ‘‘on-orbit telerobotics,’’ dexterity, at least in manipulative precision, that could where astronauts in orbit over a control outperform gloved human hands. With a properly cho- telerobots down below, is therefore exciting. With a well- sen orbit, their could remain in continual - chosen orbit, those astronauts can have such control for light, simplifying power and thermal constraints. extended periods of time, can operate telerobots stationed The potential of on-orbit telerobotics to put human at multiple sites all over the hemisphere below, staying presence in places where we would never want to put within the cognitive horizon as they do. This would be humans is nothing short of stunning. We can a done using life support and orbit control strategies already human presence on the 8008F surface of , turning worked out on the International Space Station. this way and that, stepping to the edge of outcrops and The strategy is not exactly new. , in the reaching out to pick up and inspect samples. We can 1970s, considered sending humans to the Martian moon envision human presence diving in the frigid methane where, among other things, they could control a lakes of the Saturnian moon . Telepresence applied dozen telerobots across the surface of Mars, about 20,000 to space exploration can vastly increase the number of km below (Singer, 1984, 2000). Soon after that, Marvin potential destinations for human presence, as opposed to Minsky, in insightful musings about telepresence noted human bodies, in space. above, concluded more generally, ‘‘I think the best way to This is not to say that we should not send humans to explore the is to have people in orbiting spacecraft the surfaces of the Moon and planets. The idea of coloni- to operate telerobots on the surface’’ (Minsky, 1980, p. zation and settlement is still attractive to many, and the

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soft power that comes with such an accomplishment has number of colleagues. I want to thank in particular Kip Hodges, geopolitical value. But to the extent that putting humans Cameron Ower, Kurt Klaus, Harley Thronson, Mark Craig, on planetary surfaces is presently unaffordable, on-orbit David Portree, Jim Garvin, George Schmidt, and Leonard David. telerobotics and telepresence could be a near-term approach to putting human bodies in these places. References The remarkable logical conclusion here, in view of dramatic developments in telerobotics and opportunities Held, R., Durlach, N. (1991). Telepresence, time delay, and for telepresence, is nothing short of a two-word rationale adaptation. In S. Ellis (Ed.)., Pictoral communication in vir- for human spaceflight—getting close. For with these tual and real environments (pp. 215–223). : Taylor developments, what separates us from high-quality Francis. human cognition and a real sense of presence in space is Launius, R. D., McCurdy, H. E. (2007) Robots and humans latency. Human spaceflight is how we remove that la- in space flight: Technology, , and interplanetary travel. Technology in Society, 29(3), 271–282. tency. To the extent that colonization and settlement Lester, D. (2012). Putting human awareness and cognition on become established goals, it really requires that humans other worlds. Space Times, 51(5), 4–7. go all the way there. But as noted above, those are goals Lester, D., Robinson, M. (2009). Visions of exploration. Space that have not yet been recognized as national priorities. Policy, 25(4), 236–243. Lester, D., Thronson, H. (2011). Human space exploration 6 Moving Human Cognition and human spaceflight: Latency and the cognitive scale of the . , 27(2), 89–93. The goal of ‘‘human presence,’’ with the extraordi- Mindell, D. (2009). The end of the cult of the astronaut. IEEE nary developments in teleoperation, shows space explo- Spectrum, 46(6), 58–61. ration in a new light. Those who research and develop Minsky, M. (1980). Telepresence. OMNI, 6, 46–51. theory about the concept of presence should be aware of Minsky, M. (1990). Proposal for a remotely manned space sta- what appears to the human spaceflight community as an tion. In G. Landis (Ed.), Vision-21: Space travel for the next inconvenient truth about exploration. This is that explo- millennium, NASA Conference Publication 10059, pp. ration derived from human presence may well not need 58–67. humans in situ, although it probably needs humans close National and Space Administration Authorization Act by. To humans exploring space by telepresence, there is of 2010, Pub. L. No. 111–267, 92 U.S.C. §18312 (2010). nothing simulated or virtual about the task. It is simply Sheridan, T. (1993). Space teleoperation through time delay: about relaying human cognition from one venue, which Review and prognosis. IEEE Transactions on and may be relatively inhospitable, to another nearby, which Automation, 9(5), 592–606. is more hospitable. Historical explorers had no such abil- Sheridan, T., Ferrell, W. (1963). Remote manipulative control with transmission delay. IEEE Transactions on Human Fac- ity, and our newfound capability offers a completely new tors in Electronics, 4(1), 25–29. cultural perspective on exploration. In order to take Singer, S. F. (1984). The PH-D proposal: A manned mission advantage of the opportunities that telepresence offers, to and Deimos. In P. Boston (Ed.), The case for we have to look beyond historical definitions of explora- Mars (pp. 39–65). San Diego, CA: Univelt. tion. Telepresence in space exploration is about much Singer, S. F. (2000). To Mars by way of its . Scientific more than technology, but about overcoming dated pre- American, 282(3), 56–57. conceptions of what exploration actually entails. Squyres, S. (2005). Roving Mars: Spirit, Opportunity, and the exploration of the red planet. New York: Books. Acknowledgments Stafford Commission. (1991). America at the threshold— Report of the synthesis group on America’s space exploration The potential importance of telepresence to space exploration has initiative. http://history.nasa.gov/stafford/rep/main_toc. been recently refreshed in collaboration and conversation with a PDF.

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