Friday, November 18, 2016

The ROVER Missions


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            For thousands of years, standardization has been a defining characteristic of Chinese culture. From the Terracotta Army, produced in the 3rd century BCE by hand, to modern manufacturing methods that incorporate machine automation, modular design has allowed us to increase extensively our capacity to provide goods to a rising global population, all while retaining elements of individuality. The ability to use the same pieces for a variety of configurations means that elaborate, updateable, interchangeable goods can now be assembled piecemeal from smaller, more easily mass-produced parts. When Henry Ford popularized the concept of the assembly line in the early 1900s, it perhaps marked the beginning of the modern era of mass production. And in the century since, both our knowledgebase and technical capacity have grown exponentially, giving us unprecedented access to view and experience the wonders of the universe. At this very moment, there are astronauts orbiting roughly 250 miles above the Earth’s surface in the International Space Station! We have a view of the cosmos that is virtually unfathomable even by modern standards. But, with as much progress as we made in the 20th century, and with the ever-growing rate of progress made thus far in the 21st century, humankind is bound to explore much more of the universe as it becomes technologically accessible to us; namely, our own solar system. So, what should we be sending out into the solar system?
            The answer to this question depends upon what we are trying to find out. It presently costs around $10,000 per pound to send materials and people into space. Thus, it can be argued that the impetus for design already is that of carefully balancing efficiency and instrumentation so that cost can be minimized. With the advent of nanotech, 3D printing, smaller memory systems with much higher capacity, radioisotope power, and countless other technologies made possible by discoveries throughout the 20th century, the call to reduce size while increasing functionality has never been easier to respond to. (The cell phones we so nonchalantly carry around in our pockets have far more computing power than that of the computers used to land astronauts on the moon!) However, due to the nature of exponentially increasing technical capabilities, even the Mars rover Curiosity is only as sophisticated as technology developed long before its launch in 2011. So, we have a very important hurdle to jump over when designing for otherworldly exploration; that is, once a project is approved and funded, deviation from the approved plan is highly unlikely. Therefore, even if new technology is developed while the project is being built that might enhance functionality, the likelihood of that new technology making its way into the project is extremely low, if not non-existent. There might, however, be a way around this problem if we embrace the concept of standardized interchangeability.
            Now that practically all our instrumentation has been digitized and is much more compact, the idea of standardizing orbiters and rovers is more than feasible--it's inevitable. The idea is to build a single chassis that can have instrumentation easily and readily changed to fulfill objectives specific to each world the rig will be sent to. The Rapidly-interchangeable Orbiter/Vehicle Exploration Rig, or ROVER, is an ambitious project that represents the future of planetary body mapping. Incorporating everything from the Chinese-influenced standardization to Japanese origami, the goal of ROVER is to utilize the best of what we know works. For example, with the success of the Mariner, Viking, and Voyager missions in the 60s and 70s, and more recently with the Mars Exploration Rovers and Mars Science Laboratory in the 2000s, we have a pretty good idea of the instrumentation necessary to, say, search for life. Since we can’t go to most of the worlds that we are interested in exploring yet, it means we have to let robots be our remotely-accessed senses. Janet Vertesi of Princeton University spent several years studying the Mars Exploration Rover mission team gaining valuable insight into what it takes to plan for daily rover activities. Vertesi writes, “Skilled visualization and embodiment practices are part of adopting the robot’s sensitivities and mobilities relative to its environment on Mars” (p 399). In other words, we must become the robot to think and move like it. Once we understand how to think and act like the robots we send to other worlds, it becomes easier to plan their daily movements:

This skill is not only enacted through representational practices and talk, but is also physically performed through gestures and movements that write the Rover onto the human body. Eliding human and robotic experience begins at the level of talk about the robotic body. Although it lacks a humanoid shape, various parts of the Rover are verbally related to human body parts and actions… The Rovers ‘talk’ to Earth via communication antennas, ‘sleep’ at night, ‘wake up’ and ‘take a nap’, ‘stare’ or ‘look’ at targets on the surface regularly throughout the day. These active verbs describe technical activities, but also reinforce an experiential dimension of these activities consistent with human experience (p 399).

            Again, the sensors required for each mission depend upon what we’re looking for. Say we want to send ROVER to Europa to look for signs of life; what will we need? Starting with the orbiter, there must be a way to communicate with both the team on Earth and the rover on the surface so the use of high-gain and low-gain antennas as well as UHF have proven effective in several previous missions. A new technology that can be incorporated into an orbiter is a version of CubeSats. CubeSats are tiny satellites about the size of a cantaloupe that can be released en masse from the orbiter to assist in surface imaging. While the CubeSats can be used to image the surface in the visible spectrum (possibly other wavelengths), the orbiter itself will house the more sophisticated imaging systems for infrared, ultraviolet, and radio. Once in orbit, telemetry spikes can be released that fall and impact the surface, communicating the data to the orbiter. (Telemetry spikes are an idea I have that could come in handy on a mission to Europa. Since Europa has a tenuous atmosphere, we shouldn’t have to worry about these spikes burning up in it. They can be released, the fall and impact data collected and transmitted to Earth, and then we can take time to analyze the data to determine the most viable landing area.) The idea is to gain as much insight about the surface as possible before releasing the vehicle to land. Another important instrument the orbiter will have is a dust collector and (if available) a compact mass spectrometer to study the material released from plumes that are pulled from cracks in the surface by Jupiter’s magnetic field. The orbiter must have a long-lasting power source. The Curiosity rover presents a convincing case for why we should probably choose radioisotope power for both orbiters and rovers on missions to the outer solar system. (Another rather ambitious idea is to include a sort of “mini-LIGO” [if it’s even possible] to measure the gravitational distortion that occurs as a spacecraft orbits a moon around a massive planet such as Jupiter.) Finally, due to the huge magnetic fields produced by Jupiter, electronic shielding is a given here.
            The lander vehicle that will eventually be released will incorporate much more advanced versions of technologies that have been used before. Of course, if we want to see what we’re doing, we must have a variety of cameras recording data across the spectrum. Any material collected by the “arms” of the rover can be analyzed with onboard gas and liquid chromatographs that can detect chirality. The material can also be viewed through a microscope to search for microscopic signs of life. Europa is likely to have a large, sub-surface ocean of probably highly salty liquid water, indicated by the presence of a magnetic field. Therefore, we’re going to want to use ground-penetrating radar to understand the depth of the ocean. As well, we’re going to want to drill into the surface. Since it is currently unknown exactly how thick the crust is, a better option might be to bring along an apparatus that incorporates a chunk of sealed radioactive material that can be tethered, placed on the surface by the rover, and then allowed to melt through. Since the atmospheric pressure is so low, the melted water will sublime away, allowing the chunk to continue its descent into the unknown unabated by material that would normally slow the process by having to be continually removed. Even if we don’t reach the sub-surface ocean, some of the ice can be collected and melted for pH testing. If landing near one of the plumes created by tidal forces, the rover can drive close to it and collect some of the material being ejected for analysis. A wide range of spectrometers (visible, IR, gas, ion, etc.) will be housed in the rover giving it the greatest chance of finding evidence for biogenic materials. Essentially, ROVER will emulate the Mars Science Laboratory but will exceed its predecessor in the key areas of standardization and instrumentation. The objective of the ROVER missions is to cost-effectively explore every moon in the solar system by 2050.
The 20th century marked a turning point in the human condition. We discovered truths about the universe that were unfathomable just a century prior. In just the past few decades, we have amassed more knowledge than in all of humankind’s history combined. We’ve even landed astronauts on the moon! But, we’re at an important crossroads in society. In my humble opinion, we are living in the most pivotal point in humankind’s history. We have the technology to easily feed, clothe, and house the entire human population of Earth; to automate most repetitive jobs; and to ensure the required dynamic disequilibrium for life on this beautiful world. But, we don’t really do any of that. Instead, we seem content with working on more elaborate ways to kill each other over imaginary concepts such as religion and money. (As an aside, I think it’s fair for me to at least mention a particular aspect of my view of money. That is, knowing that money is simply a form of debt, which is itself a figment, it appears we have been (and continue) asking the wrong question. The question shouldn’t be, “Do we have the money?” If we are serious about innovation, serious about taking care of the planet, serious about learning, growing, and taking care of each other, then the question is, “Do we have the resources and the technical know-how?” Money is a nothing thing. We can’t build the launch vehicles, the orbiters, the rovers, the instruments or anything else out of cash. At least, if we did, they wouldn’t work. Sure, we can argue about motivation but if it takes a figment of our collective imagination to motivate us to do anything on this planet for the betterment of it or ourselves, we are a sorry lot indeed and probably deserve to wipe ourselves out sooner rather than later.) So, we must ask ourselves the question, “Do we deserve stewardship of this planet?” If we can’t be bothered to take care of our very own majestic world—to ensure that we do not compromise Earth’s habitability—how can we possibly be trusted to take care of other worlds we might one day explore and possibly inhabit? In the 20th century, we proved to ourselves that we can venture out into the universe. Now that we have swiftly moved into the 21st century, it’s time to prove that we should

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