Introduction
The idea of interstellar travel has interested humanity for many years. It has been a central theme of numerous science fiction novels and movies that subjected millions of people to the notion that ever-advancing technology will allow unlocking humanity’s potential to achieve interstellar travel. Even though the idea of traveling to the nearby stars was often discussed in literary circles, the first scientific article exploring the mathematical dimension of the issue was published only in 1952 by a fellow member of the British Interplanetary Society (BIS) Les Shepherd (“Interstellar Travel” par. 1). The publication marked the starting point of BIS’s long-standing interest in interstellar travel. Since then, BIS has circulated numerous articles related to the speculative topic. Humanity’s interest in the possibility of interstellar cosmic journey has been fueled by the recent advances in the fields of science and technology. The last 25 years are associated with a rapid wave of new planet discoveries that opened the door to potentially habitable planets (Siegel par. 1).
Even though the idea of interstellar travel has been discussed at length by numerous scholars interested in the issue, there is no scientific consensus on whether it is realizable in the foreseeable future, if at all. Moreover, the discussion and critical analysis of the feasibility of travel between stars is often hindered by “the giggle factor” (“The Physics of Interstellar Travel” par. 1). It has to do with the fact that gigantic distance separating the stars leads some scientists to instantly reject the idea. Nonetheless, many scholars believe that a case for interstellar cosmic journey is a solid one. This paper will explore the feasibility of interstellar travel and provide information about the current progress in the area of propulsion mechanisms that could become a key to a new era of space exploration. It will argue that interstellar journey is feasible and could be achieved in the not-so-distant future.
Distance and Speed
It is obvious that the biggest issue related to interstellar travel is distance. Taking into account that time of a cosmic journey is proportional to its distance, it could be argued that for this type of mission to become possible, it should address the problem of speed. Due to the fact that a distance separating the stars precludes reaching them within a span of human life, it is necessary to come up with a viable solution for achieving spacecraft velocity that would allow to significantly shorten the time of journey. However, it is extremely difficult to address this issue. The existing means of solving the problem of acceleration do not allow to overcome the distance barrier.
For instance, Saturn V rocket that was used by NASA in the late sixties and early seventies and Space Shuttle used liquid-fueled engines that are not suitable for a long distance space travel (“Interstellar Travel” par. 3). Taking into consideration the enormity of transit time, it is necessary to develop new means of spaceflight that would allow achieving exhaust velocity that is significantly higher than that of existing chemical propulsion systems. (“Interstellar Travel” par. 3). There are electric, nuclear, and nuclear thermal solutions offering the potential for propelling a spacecraft so far that it could potentially reach the Oort cloud (“Interstellar Travel” par. 3). However, in order to achieve a velocity high enough, a spacecraft would have to carry significant science payloads preventing it from engaging in an interstellar flight. Therefore, it is necessary to consider other alternatives for existing propulsion systems.
BIS developed the first concept of an interstellar probe as far back as in 1970 (Long, Obousy and Hein 1820). The study was called Project Daedalus and was aimed at addressing certain theoretical aspects of the Fermi paradox. It helped to prove that interstellar cosmic journey was possible in principle and opened a way for further research. In 2009, the collaboration between associates of BIS and the Tau Zero Foundation (TZF) brought into existence another mission called Project Icarus: son of Daedalus – flying closer to another star (Long, Obousy and Hein 1820).
The main objective of the project is to revisit Project Daedalus in order to further understanding of physics and engineering necessary for interstellar travel. Project Icarus has already helped to extend theoretical foundations of numerous fields of science necessary for the creation of engines needed for the high-velocity thrust generation (Long, Obousy and Hein 1821). Taking into consideration the fact that the project is still in the concept design phase and, most likely, will remain there for many years it is still too early to speculate about the date of the first interstellar travel.
It should be mentioned that numerous scientists still doubt the possibility of engaging in an interstellar mission for the reasons that will be discussed in the following sections of the paper. However, it would be unreasonable to discount humanity’s ability to overcome all imaginable barriers on its way to progress. Taking into consideration the fact that “faster than life travel is possible under certain rare conditions,” it could be argued that not only does the issue of interstellar travel deserves scientific analysis, but also that it is something that could be solved (The Physics of Interstellar Travel” par. 31).
It is important to realize that even though there are still numerous obstacles preventing the development of an interstellar spacecraft, there is no problem that cannot be solved through a concerted effort of the world’s most advanced societies. I strongly believe that if humanity is ever to engage in a journey to the nearest stars, it has to initiate worldwide research and development mission akin to the Manhattan Project. Moreover, it could be argued that a concerted effort of the most powerful world governments could help to develop potentially viable substitutes for existing liquid-fueled engines that are not suitable for a long distance space travel in the nearest future. The following section of the paper will explore the current concepts of propulsion solutions.
Propulsion Solutions
Photon propulsion is a concept that has a potential to open the door to interstellar travel within the next century. According to the article titled “Prospective of Photon Propulsion for Interstellar Flight” written by Bae, photon propulsion could potentially allow achieving approximately ten percent of the light speed, thereby making the idea of traveling to the nearest stars more feasible. It should be mentioned that photon propulsion is no longer just a concept— a recent laboratory success has proved that photon thruster is able to significantly amplify thrust (Bae 254).
Moreover, progress in optics that has led to the development of power lasers provided solid theoretical and practical foundations for the photon propulsion systems. Nonetheless, there are still some theoretical limits to the concept of the photon propulsion technology that have to be addressed if it is to be taken seriously. Specifically, the maximum velocity that could be achieved with the help of the photon thruster is “orders of magnitude less than required for interstellar flight” (Bae 254). Therefore, in order to achieve a velocity that would surpass 0.1 c, it is necessary to utilize multistage photon propulsion engines (Bae 254). It means that a spacecraft would have to be separated from a photon generator. Therefore, it poses a substantial limit on the use of the photon propulsion systems.
The concept of a Beamed-Laser Propulsion (BLM) was put forward by Forward in order to overcome the limits posed by the separation of a photon generator from a spacecraft (qtd. in Bae 255). Forward’s solution to the manned interstellar flight is based on the idea that BLM could allow placing the expellant and the energy source near the Sun and beaming photons to a spacecraft that is moved by a photon propulsion engine. However, the scientist concedes that at the current rate of scientific development the project could be implemented only by 2500 (Bae 254).
Taking into consideration the recent development of quantum computers, it is reasonable to assume that Forward is too pessimistic about the humanity’s potential to make rapid scientific leaps. A recent breakthrough research on quantum computing conducted by MIT and Google company suggests that humanity might be entering a new era of exponential growth of scientific knowledge (“Interstellar Travel” par. 1). Therefore, I believe that current knowledge barriers preventing the development of photon propulsion engines supplied by BLM systems could be overcome before 2500.
Risks
Just like every technological endeavor of substantial scale, interstellar travel is associated with numerous drawbacks and risks. Many scientists argue that even the enormity of possible payoffs does not justify such a journey, given the long list of risk factors and existential threats presented by travel to the nearest stars (Regis par. 1).
One of the most important threats to the successful space mission has to do with the fact that interstellar medium is filled with the enormous amount of different objects that could lead to dangerous collisions. According to Gingell, even the slightest impact of space debris on an interstellar spacecraft traveling at relativistic speeds would amount to the ruinous effect of an H-bomb explosion (gtd. in Regis par. 2). Another type of threat to the well-being of space travelers could arise from within a cosmic vessel. It has to do with the fact that environment of a spacecraft is not particularly conducive to the long-term habitation.
Cosmic travelers would be subjected to hardware malfunctions, prolonged periods of stress and depression, DNA mutations, and radiation among other existential threats (Regis par. 2). It could be argued that the first interstellar travel is most likely to be a multigenerational journey; therefore, it is safe to assume that the inhabitants of a spacecraft would be exposed to threats that go beyond immediate physical dangers of space. Long voyage could present a risk of tyranny, civil war, despotic religion and other forms of corruption potentially dangerous to crew members.
Conclusion
The idea of interstellar travel has been discussed at length by numerous scholars interested in the issue; however, there is no scientific consensus on whether it is realizable in the foreseeable future, if at all. Nonetheless, it could be argued that if the current trends in scientific progress continue, humanity will achieve interstellar travel in the not-so-distant future.
Works Cited
Bae, Young. “Prospective of Photon Propulsion for Interstellar Flight.” Physics Procedia, vol. 38, no. 2, 2012, pp. 253-279.
“Interstellar Travel.” BIS, Web.
Long, Kelvin, Richard Obousy, and Andreas Hein. “Project Icarus: Optimization of Nuclear Fusion Propulsion for Interstellar Missions.”Acta Astronautica, vol. 68, no.11, 2011, pp. 1820-1829.
Regis, Ed. “Interstellar Travel as Delusional Fantasy [Excerpt].”Scientific American, 2015, Web.
Siegel, Ethan. “Ask Ethan: Is Interstellar Travel Possible?”Forbs. 2016, Web.
“The Physics of Interstellar Travel.”Michio Kaku, n.d., Web.