Kelvin Long - Academia.edu (original) (raw)

Papers by Kelvin Long

Cornell University - arXiv, Jan 11, 2019

The Search for Extraterrestrial Intelligence (SETI) makes certain assumptions which guide all cur... more The Search for Extraterrestrial Intelligence (SETI) makes certain assumptions which guide all current search programs. To illustrate some, this includes (1) that interstellar flight is not possible (2) that the motivations of interstellar cultures are based largely on anthropomorphic understandings of homo sapiens (3) that the Fermi Paradox and the Drake equation are the starting point (axioms) of all reasoning (4) that definitions of 'life' are based largely on our understanding of homeostasis (5) that radio waves are the most likely method of interstellar communications (6) that unknown single event source signatures detected in space are not amenable to scrutiny due to the demands of the scientific method to be reproducible (7) that such anomalous signatures are either astronomical or communications based in type, with no consideration for emissions from advanced industrialisation or propulsion and power technology. These assumptions, and others, have guided the SETI community towards a constrained level of thinking that is equivalent to philosophical dogma. In this paper, we unpack these assumptions, and others, and argue that the potential for life and intelligent life in the Cosmos may be much greater than the SETI community currently appears to conclude. It is also argued that more progress in our understanding of our place in the Cosmos, can be made, if the separate disciplines of astronomy, interstellar spacecraft design, SETI, biology and philosophy can work together in a complimentary way. Presented at the 47 th IAA Symposium on the Search for Extraterrestrial Intelligence, SETI and Society.

Universe

To transport a spacecraft to distances far beyond the solar heliosphere and around the planets of... more To transport a spacecraft to distances far beyond the solar heliosphere and around the planets of other stars will require advanced space propulsion systems that go beyond the existing technological state of the art. The release of fusion energy from the interaction of two low mass atomic nuclei that are able to overcome the Coulomb barrier offers the potential for ∼1011J/g specific energy release and implies that robotic missions to the nearby stars to distances of ∼5–10 ly may be possible in trip durations of the order of ∼50–100 years, travelling at cruise speeds of the order of ∼0.05–0.15 c. Such missions would be characterised with ∼kN-MN thrust levels, ∼GW-TW jet powers, ∼kW/kg-MW/kg specific powers. One of the innovative methods by which fusion reactions can be ignited is via the impingement of laser beams onto an inertial confinement fusion capsule, imploding it to a thermonuclear state. This paper gives an overview of the physics of inertial confinement fusion and the inter...

arXiv: Instrumentation and Methods for Astrophysics, 2017

This paper discusses the physics, engineering and mission architecture relating to a gram-sized i... more This paper discusses the physics, engineering and mission architecture relating to a gram-sized interstellar probe propelled by a laser beam. The objectives are to design a fly-by mission to Alpha Centauri with a total mission duration of 50 years travelling at a cruise speed of 0.1c. Furthermore, optical data from the target star system is to be obtained and sent back to the Solar system. The main challenges of such a mission are presented and possible solutions proposed. The results show that by extrapolating from currently existing technology, such a mission would be feasible. The total mass of the proposed spacecraft is 23g and the space-based laser infrastructure has a beam power output of 15GW. Rurther exploration of the laser - spacecraft tradespace and associated technologies are necessary.

Journal of the British Interplanetary Society, Dec 1, 2011

At the outset of the project a Terms of Reference (ToR) document was created, stipulating that th... more At the outset of the project a Terms of Reference (ToR) document was created, stipulating that the mission duration be no more than 100 years, including acceleration and deceleration. In addition to this requirement, the mission should allow for some deceleration at the target solar system to increase encounter time. Another requirement is that the engine must be based upon mainly fusion propulsion, which means that fusion reactions must be responsible for 80-90% of the thust generation during the boost phase. ... Project Icarus is built upon the ...

Journal of Spacecraft and Rockets

The Sunvoyager is a concept mission for a space probe that can be sent outside of the solar helio... more The Sunvoyager is a concept mission for a space probe that can be sent outside of the solar heliosphere to a distance of 1000 AU in a trip time of only 3.4 years traveling at speeds of 1500 km/s or 325 AU/year. It is an advanced Voyager flyby probe, but the concept design is unique in that it would utilize an inertial confinement fusion propulsion engine driving a gram-scale capsule mass at 10 Hz pulse frequency using 5 MJ laser driver energy reaching the capsule. Such a design may be possible in the latter part of the 21st century. The probe would carry a 100-ton scientific payload for the purpose of observations from the location of gravitational focal point, a dwarf planet flypast, and imaging of interstellar asteroids. Secondary science objectives would include measurements of the interstellar medium, measurements of astrometry, and the search for extraterrestrial power and propulsion emission signatures. The propulsion engine is characterized by 23 kN thrust, 54 GW jet power, a...

arXiv: Popular Physics, 2019

Long range observations in the field of astronomy have opened up our understanding of the Solar S... more Long range observations in the field of astronomy have opened up our understanding of the Solar System, the Galaxy and the wider Universe. In this paper we discuss the idea of direct in-situ reconnaissance of nearby stellar systems, using robotic probes. In particular, we consider what additional knowledge can be learned that can only be obtained by such close encounters. This may include calibration of existing measurements, detailed observations of stellar winds, astrometry measurements of stellar parallax, refinement of our understanding of physics through the use of long baseline interferometers. In addition, getting close to an exoplanet will enable detailed knowledge of planetary interiors, surface processes, geological evolution, atmospheric composition and climate, internal seismology, detailed surface morphology and even the speculative possibility of detecting the presence of microbial life, detailed palaeontology or even indigenous life-forms. We argue that astronomical r...

Space-based manufacturing is considered a crucial next step for the further development of human ... more Space-based manufacturing is considered a crucial next step for the further development of human settlement in space. There are vast quantities of building resources distributed throughout space, with asteroids among the most apparent candidates for large-scale mining and resource provision. In this presentation, we present a hybrid simulation model in which building materials extracted from asteroids are used in a differential 3D manufacturing process to create expanding modular space architecture. This work is part of the larger research programme E|A|S (Evolving Asteroid Starships) in which concepts for self-developing and evolvable interstellar spacecraft are being created by the DSTART team at Delft University of Technology. A high-level 'factory model' has been created that simulates the different steps of an entire production chain. The functions of the core disjunct components of the model range from mining, processing, storage, and 3D printing to biological life sup...

Cornell University - arXiv, Jan 11, 2019

The Search for Extraterrestrial Intelligence (SETI) makes certain assumptions which guide all cur... more The Search for Extraterrestrial Intelligence (SETI) makes certain assumptions which guide all current search programs. To illustrate some, this includes (1) that interstellar flight is not possible (2) that the motivations of interstellar cultures are based largely on anthropomorphic understandings of homo sapiens (3) that the Fermi Paradox and the Drake equation are the starting point (axioms) of all reasoning (4) that definitions of 'life' are based largely on our understanding of homeostasis (5) that radio waves are the most likely method of interstellar communications (6) that unknown single event source signatures detected in space are not amenable to scrutiny due to the demands of the scientific method to be reproducible (7) that such anomalous signatures are either astronomical or communications based in type, with no consideration for emissions from advanced industrialisation or propulsion and power technology. These assumptions, and others, have guided the SETI community towards a constrained level of thinking that is equivalent to philosophical dogma. In this paper, we unpack these assumptions, and others, and argue that the potential for life and intelligent life in the Cosmos may be much greater than the SETI community currently appears to conclude. It is also argued that more progress in our understanding of our place in the Cosmos, can be made, if the separate disciplines of astronomy, interstellar spacecraft design, SETI, biology and philosophy can work together in a complimentary way. Presented at the 47 th IAA Symposium on the Search for Extraterrestrial Intelligence, SETI and Society.

Universe

To transport a spacecraft to distances far beyond the solar heliosphere and around the planets of... more To transport a spacecraft to distances far beyond the solar heliosphere and around the planets of other stars will require advanced space propulsion systems that go beyond the existing technological state of the art. The release of fusion energy from the interaction of two low mass atomic nuclei that are able to overcome the Coulomb barrier offers the potential for ∼1011J/g specific energy release and implies that robotic missions to the nearby stars to distances of ∼5–10 ly may be possible in trip durations of the order of ∼50–100 years, travelling at cruise speeds of the order of ∼0.05–0.15 c. Such missions would be characterised with ∼kN-MN thrust levels, ∼GW-TW jet powers, ∼kW/kg-MW/kg specific powers. One of the innovative methods by which fusion reactions can be ignited is via the impingement of laser beams onto an inertial confinement fusion capsule, imploding it to a thermonuclear state. This paper gives an overview of the physics of inertial confinement fusion and the inter...

arXiv: Instrumentation and Methods for Astrophysics, 2017

This paper discusses the physics, engineering and mission architecture relating to a gram-sized i... more This paper discusses the physics, engineering and mission architecture relating to a gram-sized interstellar probe propelled by a laser beam. The objectives are to design a fly-by mission to Alpha Centauri with a total mission duration of 50 years travelling at a cruise speed of 0.1c. Furthermore, optical data from the target star system is to be obtained and sent back to the Solar system. The main challenges of such a mission are presented and possible solutions proposed. The results show that by extrapolating from currently existing technology, such a mission would be feasible. The total mass of the proposed spacecraft is 23g and the space-based laser infrastructure has a beam power output of 15GW. Rurther exploration of the laser - spacecraft tradespace and associated technologies are necessary.

Journal of the British Interplanetary Society, Dec 1, 2011

At the outset of the project a Terms of Reference (ToR) document was created, stipulating that th... more At the outset of the project a Terms of Reference (ToR) document was created, stipulating that the mission duration be no more than 100 years, including acceleration and deceleration. In addition to this requirement, the mission should allow for some deceleration at the target solar system to increase encounter time. Another requirement is that the engine must be based upon mainly fusion propulsion, which means that fusion reactions must be responsible for 80-90% of the thust generation during the boost phase. ... Project Icarus is built upon the ...

Journal of Spacecraft and Rockets

The Sunvoyager is a concept mission for a space probe that can be sent outside of the solar helio... more The Sunvoyager is a concept mission for a space probe that can be sent outside of the solar heliosphere to a distance of 1000 AU in a trip time of only 3.4 years traveling at speeds of 1500 km/s or 325 AU/year. It is an advanced Voyager flyby probe, but the concept design is unique in that it would utilize an inertial confinement fusion propulsion engine driving a gram-scale capsule mass at 10 Hz pulse frequency using 5 MJ laser driver energy reaching the capsule. Such a design may be possible in the latter part of the 21st century. The probe would carry a 100-ton scientific payload for the purpose of observations from the location of gravitational focal point, a dwarf planet flypast, and imaging of interstellar asteroids. Secondary science objectives would include measurements of the interstellar medium, measurements of astrometry, and the search for extraterrestrial power and propulsion emission signatures. The propulsion engine is characterized by 23 kN thrust, 54 GW jet power, a...

arXiv: Popular Physics, 2019

Long range observations in the field of astronomy have opened up our understanding of the Solar S... more Long range observations in the field of astronomy have opened up our understanding of the Solar System, the Galaxy and the wider Universe. In this paper we discuss the idea of direct in-situ reconnaissance of nearby stellar systems, using robotic probes. In particular, we consider what additional knowledge can be learned that can only be obtained by such close encounters. This may include calibration of existing measurements, detailed observations of stellar winds, astrometry measurements of stellar parallax, refinement of our understanding of physics through the use of long baseline interferometers. In addition, getting close to an exoplanet will enable detailed knowledge of planetary interiors, surface processes, geological evolution, atmospheric composition and climate, internal seismology, detailed surface morphology and even the speculative possibility of detecting the presence of microbial life, detailed palaeontology or even indigenous life-forms. We argue that astronomical r...

Space-based manufacturing is considered a crucial next step for the further development of human ... more Space-based manufacturing is considered a crucial next step for the further development of human settlement in space. There are vast quantities of building resources distributed throughout space, with asteroids among the most apparent candidates for large-scale mining and resource provision. In this presentation, we present a hybrid simulation model in which building materials extracted from asteroids are used in a differential 3D manufacturing process to create expanding modular space architecture. This work is part of the larger research programme E|A|S (Evolving Asteroid Starships) in which concepts for self-developing and evolvable interstellar spacecraft are being created by the DSTART team at Delft University of Technology. A high-level 'factory model' has been created that simulates the different steps of an entire production chain. The functions of the core disjunct components of the model range from mining, processing, storage, and 3D printing to biological life sup...