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...instead of having a ubiquitous presence throughout the solar system, humans haven’t set foot on the Moon in 35 years, and even our robotic explorations in that time have been throttled because we deliberately reduced our access to deep space. NASA
GOES DEEP [2.27.07] CAROLYN PORCO is a planetary scientist, the leader of the Imaging Science Team on the Cassini mission and director of the Cassini Imaging Central Laboratory for Operations.
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NASA GOES DEEP Boulder, Colo. — AFTER years of spending our nation’s space budget building an orbiting space station of questionable utility, serviced by an operationally expensive space shuttle of unsafe design, NASA has set a new direction for the future of human spaceflight. Once again, we have our sights on the Moon ... and beyond. We are finally, bodily, going to make our way into space, this time to stay. It is an opinion long and widely held within the space-exploration community that the Nixon administration’s termination of the program that built the Saturn V Moon rocket was a gargantuan mistake. One of the biggest challenges in exploring space is propulsion — that is, getting from point A to B efficiently, safely and quickly. And when the cargo is human, the challenges are even greater. One of our crowning technological achievements during the 1960s was the Apollo program and, in particular, the development of the Saturn V rocket. The Saturn V was the largest, most powerful vehicle the United States had ever built. It had a launching capacity more than five times greater, a developmental cost 25 percent lower and a build-and-operate cost less than half of that of today’s space shuttle. In those early days, the possibilities for human space travel were intoxicating. Back then, NASA plans called for an aggressive integrated human flight program that would expand on the developments of Apollo: the establishment of a 50-person lunar base, a 100-person Earth-orbiting space station and human landfall on Mars, all by the mid-1980s. Those plans also included a 50-person semi-permanent Martian base by the end of the 20th century. Instead, we went nowhere. Why? Because, largely for political reasons, we renounced the Moon, abandoned Apollo and the Saturn V and retreated to low Earth orbit, where we’ve spent the last 25 years going around in circles. The cost to the nation of this misstep was enormous. For starters, we lost an investment, adjusted for inflation to 2007 dollars, of $160 billion. That was the cost to get to, land on, walk on, drive on and otherwise explore the Moon. (Of that amount, $29 billion, in inflation-adjusted dollars, was the approximate cost of the Saturn V.) What’s more, the production facilities for the Saturn V and the other lunar exploration components, like the command and lunar modules, were all closed. At that point, we lost both the technological means for human deep space exploration and the collective knowledge of tens of thousands of engineers and scientists trained in human spaceflight. Equally troubling is what we put in place of Apollo. The $38 billion developmental cost of the shuttle has gotten us nowhere in the solar system fast. And the International Space Station could have been built with only half a dozen Saturn V launchings instead of the more than two dozen shuttle trips that will be required to finish it. The bottom line: a colossal misuse of funds and a disheartening lack of progress and loss of time. The termination of the Saturn V program also had a stifling effect on the robotic exploration of other planets. In essence, we lost the ability to deliver larger, and in some cases faster, payloads elsewhere in the solar system. Take, as an example, the 5,600-kilogram Cassini spacecraft, which was launched in 1997 and is now in orbit around Saturn. Its launching was timed so that after spending two years looping around the inner solar system to pick up speed, it could rendezvous with massive Jupiter for an additional boost that would send it to Saturn. All told, its flight time took seven years. Had the Saturn V, modified with an appropriate fourth upper stage, been used to launch Cassini directly to Jupiter first, its flight time to Saturn could have been cut by more than half. In space, as on Earth, time is money, and the money saved could have been spent elsewhere. Alternatively, for the same flight time, a vehicle of greater launching capacity can deliver a heavier payload. Take as an example the 480-kilogram New Horizons spacecraft, launched over a year ago to fly by Pluto in 2015 and eventually to explore the Kuiper Belt of icy debris that lies beyond it. Had it been launched on a modified Saturn V rocket, New Horizons could have carried a payload that was 15 times heavier and far more scientifically capable. In the end, instead of having a ubiquitous presence throughout the solar system, humans haven’t set foot on the Moon in 35 years, and even our robotic explorations in that time have been throttled because we deliberately reduced our access to deep space. Today, however, NASA is again looking up and out. Vigorous efforts are under way to complete the space station in order to fulfill international commitments that would be unwise to violate. When that is done, the plan is to retire the space shuttle in 2010 in favor of a new program to return to the Moon, with a party of humans, by 2020. A mainstay of this program is the Ares launching system, capable of sending 65 metric tons to the Moon — exceeding the capacity of the Saturn V by more than 40 percent. The official plans call not for flag-planting and grab-a-few-rocks-and-go but, by 2025, a solar-powered, human-tended, continuously inhabited research outpost rising from either the north or south pole of the Moon, where sunlight is persistent and water ice may be present. Sustainability, made possible in part by the use of lunar resources, is one goal. Another is on-site preparations for a push to the next outpost, Mars. And human spaceflight is not the only enterprise to benefit. Robotic reconnaissance, which by necessity must precede the dispatch of humans, has been ongoing for nearly 50 years. In that time, all the simple things have been done. Future missions to the planets and their moons will be more ambitious than anything yet tried. As one example, imagine what our future robotic travels around Saturn might be like. The Saturn planetary system includes Titan, a cold Mercury-sized moon with a dense, organic-laden, hazy atmosphere and a strangely Earth-like, variegated surface sculptured by winds and hydrocarbon rains. It also includes Enceladus, a moon one-tenth the size of Titan, whose jets of water vapor and fine icy particles extend thousands of miles into space and may very likely erupt from organic-rich liquid water reservoirs just below its surface — making this satellite arguably the most promising target we have available to us for astrobiological investigation. A scientifically comprehensive mission to this part of the solar system, using Ares and a Cassini-like trajectory to Saturn, could easily include several exploratory vehicles. One would be a Saturn orbiter far more capable than Cassini. This vehicle, in turn, would be large enough to carry and deliver a fully equipped balloon-borne scientific payload to float through the atmosphere of Titan and study its surface up close, and an Enceladus lander with equipment that could determine the moon’s physical properties and ascertain whether or not pre-biotic chemistry, and perhaps life, has arisen there. In other words, robotic exploration, and the insights that will be gained from it into the character, development and evolution of planetary bodies and even life itself, will be taken to new heights and, in turn, pave the way for the eventual arrival of humans throughout the solar system. Anyone up for an extreme excursion to the Enceladus Interplanetary Geyser Park? All told, the subtext is invigorating and unmistakable: Humanity’s future need not be confined to mere survival on our home planet. Other worlds beckon, we know how to reach them and we will once more be outward bound. And we will not be alone. China, India and Russia, all eager to be or remain prominent players on the world stage, have independent plans to stride the lunar surface. And Australia, Canada, Japan and the member nations of the European Space Agency will be pooling their resources with us in the return to the Moon — a circumstance that will bring the cost of the effort to any one nation within reason. THIS won’t be a space race so much as a global exodus undertaken by an international community. And peaceful cooperation among nations, as a tangible means to build strong lasting international partnerships and defuse tensions and conflicts in the future, will be a welcome result. In hindsight, maybe the pace of progress was predictable. Humans first explored Antarctica in the early 20th century. Decades passed before we had the technology that would allow us to establish a permanent presence. History will indicate the same for our interplanetary forays. Our initial “small step for a man” on the Moon took place in 1969. A half-century later, we will be there anew, to live and work. To reach that future will require two critical ingredients: adequate financing and a long-term cross-administration commitment that supports steady, uninterrupted progress. Our first reach for the Moon took us from President Kennedy’s spoken words to the lunar surface in little over eight years under a budget profile that saw peaks in annual NASA budget of more than $30 billion in current dollars — a shocking number by today’s standards and a good measure of how important we then considered the endeavor. While sustained budgets of that magnitude are out of the question today, what is not out of the question is our ability to pay to keep the goal front and center. We are now spending in Iraq, in a single month, $9 billion — more than half the annual budget NASA needs to stay on course. Forty-five years ago today, John Glenn Jr. became the first American to venture into orbit around the Earth. Just 9 years old, I knew at that moment that the future would be big and wide, and that I might go places no one had ever been before. There could be no better way today to encourage an equally optimistic belief in the future than to embark on an odyssey that presents tremendous challenges, demands discipline and rigor, requires decades-long focus, inspires international cooperation, promotes lasting peace, improves life for all and paints a stirring vision of an expanded human presence beyond the Earth. There could be no better way to say: the future is boundless, and it belongs to us.
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John Brockman, Editor and Publisher |
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