Interstellar Space Flight: Social and Economic Considerations
by Richard Obousy
Arguably one of the key factors in the decision to begin construction of an interstellar spacecraft will be the economics. Any interstellar space vehicle is likely to be astronomically expensive to build, and in all likelihood will cost tens, hundreds and possibly thousands of times more than even the International Space Station (ISS). Of course, this potentially multi-trillion dollar burden on today’s suffocated economy is incredibly unlikely. However, we can perform a simple exercise to calculate approximately when such a project becomes fiscally feasible. Before we do consider the economics let us first contemplate some of the motives that might drive us to partake in such a project. Arguably one of the most convincing arguments, although least urgent, is the long-term stability of the sun. Clearly on billion year timescales, continued life on earth cannot be guaranteed. While Earth’s fate is not entirely sealed, the belief that the death of the sun is an event looming in the distant future is widely accepted. Although a civilization of some deep future may engineer ingenious methods to perpetuate life on Earth as long as possible, the Earth and ultimately the solar system itself will become increasingly inhospitable, and more appealing climes will manifest themselves compelling us to visit and maybe colonize other star systems. Another persuasive argument for the exploration and possible migration of at least a cross section of the human species is to hedge against natural or even manmade disasters thus adding security to our ultimate survival. Earth’s history is marked by profound and species destroying events including, but not limited to, asteroid impact, supervolcanic eruptions, and climate change. It appears that the human race is existing within a very human-friendly ‘pocket’ of geological history, but such favorable conditions are by no means guaranteed to last indefinitely. An alternative and somewhat convincing reason to explore beyond our own solar system is that such a mission could be considered an end in itself, the undertaking of which serves no deep survival purpose. Interstellar exploration could merely be an expression of a curious and energetic species looking to expand our grasp of the universe that we inhabit, much as today’s exploration of the solar system serves no ends other than to expand our knowledge of our direct neighbors in space. A future civilization with more abundant wealth and resources at her command may naturally become inclined to interstellar exploration. Underlying all of these assumptions is the belief that the solar system will in time, become the domain of an all encompassing, profoundly well organized commonwealth, with a vast economic and productive capability . Perhaps the enterprise of starship building, gargantuan by today’s standards, may be one of the few that is demanding enough to keep the community engaged. If history is to serve as a reliable yardstick, evidence indicates that new technological innovations tend to catalyze productivity, which is further used in the creation of armies, empires and opulent masterpieces of stone, steel and canvas. Starship construction may serve as a welcome alternative to these historic follies. Indeed – with a vast civilization comes a vast population and the lack of employment is known to be a factor in the destabilization of practical governments. At its zenith, the Apollo program employed 400,000 people and needed the support of more than 20,000 industrial firms and universities . The enterprise of constructing a starship would very likely be abundantly more challenging and quite possibly be 100 to 1000 times more demanding than the Apollo moon program. Thus, an admittedly simple, yet instructive linear extrapolation indicates that construction of an interstellar spacecraft might employ as many as 400 million people – more than the current population of the United States. Although these figures are very rough estimates, they do serve as an instructive guide to the possible scale of the project. What seems immediately apparent is that an interstellar vehicle would be a massive source of employment thus representing a huge public service. So what might the total cost be? According to Freeman Dyson in his 1968 paper titled ‘Interstellar Transport’ the cost could be as little as $100 Billion  which, adjusted for inflation, is about $650 billion US today. Contrast this with the estimates provided in the Daedalus papers  of as much as $100 trillion. For the purpose of this article, we will examine three different starship scenarios and attempt to estimate when the economical conditions would be in place to entertain such an endeavor. The first scenario is the ‘Thrifty Dyson Starship’ costing only $1 trillion. The second is a ‘Budget Daedalus’ with a price tag of $20 trillion. Finally we’ll have the full ‘Daedalus Class Starship’ with a price tag of $100 trillion. Let us assume that it will be economically feasible (and politically viable) to engage in the construction of an interstellar vehicle when the total cost represents just 1% Gross Domestic Product (GDP) for the constructing nation. As justification for this figure, some estimates place the price tag for the ISS at $100 billion for NASA (excluding costs shared by other partners), which represents about .6% of the GDP of the United States, and so 1% of the constructing nation’s GDP is a reasonable figure to work with. Assuming a conservative baseline growth of the economy of 2% per annum, we can extrapolate from current GDP to estimate when the project might begin. Next we must decide which nation(s) GDP we will examine. For the sake of argument we will select two possibilities. The first will be the GDP of the United States of America ($14.6 Trillion ), a country with a rich history of space exploration and a willingness to commit resources to the space program. The second will be a somewhat more optimistic GDP – that of the entire planet Earth ($61.1 Trillion ). It is not inconceivable that the current trend for governments to work closer will converge on a global scale. Challenging as this may be for us to imagine, we already see examples of this trend at work with the merging of the European economies into the Euro and the existence of the European Space Agency. It is with only a very small leap of the imagination that we may one day see a fully globalized economy with all nations of the Earth integrated and mutually benefiting from the arrangement. From this baseline setup we will next generate predictions for the date when it will become economically feasible to build each of the three starship scenarios, for the two selected economies assuming a 2% growth per year (Table 1).
Table 1. Predicted year that the construction of an interstellar spacecraft becomes economically feasible based on a 2% growth rate of the US and the global economy for three classes of vehicle
From Table 1 we see a range of predictions for the date when construction of an interstellar spacecraft becomes economically feasible. These estimates lie between 2013 as the earliest date, and 2340 as the latest date that construction could begin. The best-case scenario of 2013 is clearly ovelry optimistic in the sense that it would only give our planet 3 years to become economically and politically integrated and governed by a unified political entity. The estimate is, however, encouraging in the sense that, with enough will, we could construct an interstellar spacecraft in the not-too-distant future. All of this may seem like an incredible undertaking, but if we are to tackle a problem on the astronomical scale, then we must visualize solutions to suit. As a final exercise we will explore a lavishly optimistic scenario where we assume our ‘unified planetary government’ grows at 4% per annum and calculate the date it would become possible to build the ‘Budget Daedalus’ craft whose costs lie between our thrifty Dyson Starship and the full Daedalus Class starship. Compounding the Global GDP at 4% returns a date of 2099 for when construction of the ‘Budget Daedalus’ represents only 1% of the planets GDP. Thus it is, in some sense of the word, possible that our transition from the 21st century into the 22nd century will be celebrated with the construction of Earth’s first interstellar explorer. An exciting and delightful end to this century, one has to admit.  A. Martin, ‘World Ships – Concept, Cause, Cost, Construction and Colonisation’ JBIS, Vol 37, pp243-254, 1984.  NASA Langley Research Center’s Contributions to the Apollo Program. NASA Langley Research Center.  F. Dyson, ‘Interstellar Transport’, Physics Today, pp41-45, October 1968.  A. Martin, ‘Project Daedalus – The Final Report on the BIS Starship Study’, JBIS Supplement, 1978.  World Bank.