We present full-sky maps of the cosmic microwave background (CMB) and polarized synchrotron and t... more We present full-sky maps of the cosmic microwave background (CMB) and polarized synchrotron and thermal dust emission, derived from the third set ofPlanckfrequency maps. These products have significantly lower contamination from instrumental systematic effects than previous versions. The methodologies used to derive these maps follow closely those described in earlier papers, adopting four methods (Commander,NILC,SEVEM, andSMICA) to extract the CMB component, as well as three methods (Commander,GNILC, andSMICA) to extract astrophysical components. Our revised CMB temperature maps agree with corresponding products in thePlanck2015 delivery, whereas the polarization maps exhibit significantly lower large-scale power, reflecting the improved data processing described in companion papers; however, the noise properties of the resulting data products are complicated, and the best available end-to-end simulations exhibit relative biases with respect to the data at the few percent level. Us...
Planetary Defense and Space Environment Applications, 2016
Recently, there has been a dramatic change in the way space missions are viewed. Large spacecraft... more Recently, there has been a dramatic change in the way space missions are viewed. Large spacecraft with massive propellant-filled launch stages have dominated the space industry since the 1960’s, but low-mass CubeSats and low-cost rockets have enabled a new approach to space exploration. In recent work, we have built upon the idea of extremely low mass (sub 1 kg), propellant-less spacecraft that are accelerated by photon propulsion from dedicated directed-energy facilities. Advanced photonics on a chip with hybridized electronics can be used to implement a laser-based communication system on board a sub 1U spacecraft that we call a WaferSat. WaferSat spacecraft are equipped with reflective sails suitable for propulsion by directed-energy beams. This low-mass spacecraft design does not require onboard propellant, creating significant new opportunities for deep space exploration at a very low cost. In this paper, we describe the design of a prototype WaferSat spacecraft, constructed on a printed circuit board. The prototype is envisioned as a step toward a design that could be launched on an early mission into Low Earth Orbit (LEO), as a key milestone in the roadmap to interstellar flight. In addition to laser communication, the WaferSat prototype includes subsystems for power source, attitude control, digital image acquisition, and inter-system communications.
We discuss a hypothetical existential threat from a 10 km diameter comet discovered 6 months prio... more We discuss a hypothetical existential threat from a 10 km diameter comet discovered 6 months prior to impact. We show that an extension of our work on bolide fragmentation using an array of penetrators, but modified with small nuclear explosive devices (NED) in the penetrators, combined with soon-to-be-realized heavy lift launch assets with positive $C_3$ such as NASA SLS or SpaceX Starship (with in-orbit refueling) is sufficient to mitigate this existential threat. A threat of this magnitude hitting the Earth at a closing speed of 40 km/s would have an impact energy of roughly 300 Teratons TNT, or about 40 thousand times larger than the current combined nuclear arsenal of the entire world. This is similar in energy to the KT extinction event that killed the dinosaurs some 66 million years ago. Such an event, if not mitigated, would be an existential threat to humanity. We show that mitigation is conceivable using existing technology, even with the short time scale of 6 months warni...
Large scale directed energy offers the possibility of radical transformation in a variety of area... more Large scale directed energy offers the possibility of radical transformation in a variety of areas, including the ability to achieve relativistic flight that will enable the first interstellar missions, as well as rapid interplanetary transit. In addition, the same technology will allow for long-range beamed power for ion, ablation, and thermal engines, as well as long-range recharging of distant spacecraft, long-range and ultra high bandwidth laser communications, and many additional applications that include remote composition analysis, manipulation of asteroids, and full planetary defense. Directed energy relies on photonics which, like electronics, is an exponentially expanding growth area driven by diverse economic interests that allows transformational advances in space exploration and capability. We have made enormous technological progress in the last few years to enable this long-term vision. In addition to the technological challenges, we must face the economic challenges ...
In the nearly 60 years of spaceflight we have accomplished wonderful feats of exploration that ha... more In the nearly 60 years of spaceflight we have accomplished wonderful feats of exploration that have shown the incredible spirit of the human drive to explore and understand our universe. Yet in those 60 years we have barely left our solar system with the Voyager 1 spacecraft launched in 1977 finally leaving the solar system after 37 years of flight at a speed of 17 km/s or less than 0.006% the speed of light. As remarkable as this is we will never reach even the nearest stars with our current propulsion technology in even 10 millennium. We have to radically rethink our strategy or give up our dreams of reaching the stars, or wait for technology that does not currently exist. While we all dream of human spaceflight to the stars in a way romanticized in books and movies, it is not within our power to do so, nor it is clear that this is the path we should choose. We posit a technological path forward, that while not simple, it is within our technological reach. We propose a roadmap to ...
We study the fundamental limits of detection for astrophysical observations in the far infrared. ... more We study the fundamental limits of detection for astrophysical observations in the far infrared. Understanding these fundamental limits is critical to the planning and analysis of experiments in this region. We specifically characterize the difficulties associated with observing in the 0.1-10 THz (30-3000 \mu m) regime including extraterrestrial, atmospheric, and optical emission. We present signal, noise, and integration time models for selected terrestrial, aircraft, balloon, and space missions. While ground based telescopes offer the great advantage of aperture size, and hence angular resolution, they suffer from the relatively low transmission and high radiance of the atmosphere, particularly for wavelengths less than 500 \mu m. Space telescopes are the inverse; they are limited by a small aperture, while an airborne telescope is constrained by both. Balloon-borne telescopes provide an option over much of the band. A quantitative understanding of this is critical in comparing th...
Large scale directed energy offers the possibility of radical transformation in a variety of area... more Large scale directed energy offers the possibility of radical transformation in a variety of areas, including the ability to achieve relativistic flight that will enable the first interstellar missions as well as rapid interplanetary transit. In addition, the same technology opens a wide mission space that allows a diverse range of options from long range beamed power to remote spacecraft and outposts to planetary defense to remote composition analysis and manipulation of asteroids, among others. Directed energy relies on photonics, which like electronics is an exponentially expanding growth area driven by diverse economic interests that allows transformational advances in space exploration and capability. In order to begin to fully exploit this capability it is important to understand not only the possibilities enabled by it, but also the technological challenges involved and to have a logical roadmap to exploit this option. This capability is both synergistic with conventional pro...
The ARCADE II instrument was designed to compare the cosmic microwave background spectrum to a bl... more The ARCADE II instrument was designed to compare the cosmic microwave background spectrum to a blackbody spectrum at long (cm) wavelengths where the first stars are predicted to distort the ideal spectrum of the big bang. Reionization generates larger relative distortions at low frequencies. ARCADE II observed at 5 frequencies (3, 8, 10, 30 & 90 GHz). Each radiometer has
Destriping is a well-established technique for removing low-frequency correlated noise from Cosmi... more Destriping is a well-established technique for removing low-frequency correlated noise from Cosmic Microwave Background (CMB) survey data. In this paper we present a destriping algorithm tailored to data from a polarimeter, i.e. an instrument where each channel independently measures the polarization of the input signal. We also describe a fully parallel implementation in Python released as Free Software and analyze its results and performance on simulated datasets, both the design case of signal and correlated noise, and with additional systematic effects. Finally we apply the algorithm to 30 days of 37.5 GHz polarized microwave data gathered from the B-Machine experiment, developed at UCSB. The B-Machine data and destriped maps are made publicly available. The purpose is the development of a scalable software tool to be applied to the upcoming 12 months of temperature and polarization data from LATTE (Low frequency All sky TemperaTure Experiment) at 8 GHz and to even larger
We present full-sky maps of the cosmic microwave background (CMB) and polarized synchrotron and t... more We present full-sky maps of the cosmic microwave background (CMB) and polarized synchrotron and thermal dust emission, derived from the third set ofPlanckfrequency maps. These products have significantly lower contamination from instrumental systematic effects than previous versions. The methodologies used to derive these maps follow closely those described in earlier papers, adopting four methods (Commander,NILC,SEVEM, andSMICA) to extract the CMB component, as well as three methods (Commander,GNILC, andSMICA) to extract astrophysical components. Our revised CMB temperature maps agree with corresponding products in thePlanck2015 delivery, whereas the polarization maps exhibit significantly lower large-scale power, reflecting the improved data processing described in companion papers; however, the noise properties of the resulting data products are complicated, and the best available end-to-end simulations exhibit relative biases with respect to the data at the few percent level. Us...
Planetary Defense and Space Environment Applications, 2016
Recently, there has been a dramatic change in the way space missions are viewed. Large spacecraft... more Recently, there has been a dramatic change in the way space missions are viewed. Large spacecraft with massive propellant-filled launch stages have dominated the space industry since the 1960’s, but low-mass CubeSats and low-cost rockets have enabled a new approach to space exploration. In recent work, we have built upon the idea of extremely low mass (sub 1 kg), propellant-less spacecraft that are accelerated by photon propulsion from dedicated directed-energy facilities. Advanced photonics on a chip with hybridized electronics can be used to implement a laser-based communication system on board a sub 1U spacecraft that we call a WaferSat. WaferSat spacecraft are equipped with reflective sails suitable for propulsion by directed-energy beams. This low-mass spacecraft design does not require onboard propellant, creating significant new opportunities for deep space exploration at a very low cost. In this paper, we describe the design of a prototype WaferSat spacecraft, constructed on a printed circuit board. The prototype is envisioned as a step toward a design that could be launched on an early mission into Low Earth Orbit (LEO), as a key milestone in the roadmap to interstellar flight. In addition to laser communication, the WaferSat prototype includes subsystems for power source, attitude control, digital image acquisition, and inter-system communications.
We discuss a hypothetical existential threat from a 10 km diameter comet discovered 6 months prio... more We discuss a hypothetical existential threat from a 10 km diameter comet discovered 6 months prior to impact. We show that an extension of our work on bolide fragmentation using an array of penetrators, but modified with small nuclear explosive devices (NED) in the penetrators, combined with soon-to-be-realized heavy lift launch assets with positive $C_3$ such as NASA SLS or SpaceX Starship (with in-orbit refueling) is sufficient to mitigate this existential threat. A threat of this magnitude hitting the Earth at a closing speed of 40 km/s would have an impact energy of roughly 300 Teratons TNT, or about 40 thousand times larger than the current combined nuclear arsenal of the entire world. This is similar in energy to the KT extinction event that killed the dinosaurs some 66 million years ago. Such an event, if not mitigated, would be an existential threat to humanity. We show that mitigation is conceivable using existing technology, even with the short time scale of 6 months warni...
Large scale directed energy offers the possibility of radical transformation in a variety of area... more Large scale directed energy offers the possibility of radical transformation in a variety of areas, including the ability to achieve relativistic flight that will enable the first interstellar missions, as well as rapid interplanetary transit. In addition, the same technology will allow for long-range beamed power for ion, ablation, and thermal engines, as well as long-range recharging of distant spacecraft, long-range and ultra high bandwidth laser communications, and many additional applications that include remote composition analysis, manipulation of asteroids, and full planetary defense. Directed energy relies on photonics which, like electronics, is an exponentially expanding growth area driven by diverse economic interests that allows transformational advances in space exploration and capability. We have made enormous technological progress in the last few years to enable this long-term vision. In addition to the technological challenges, we must face the economic challenges ...
In the nearly 60 years of spaceflight we have accomplished wonderful feats of exploration that ha... more In the nearly 60 years of spaceflight we have accomplished wonderful feats of exploration that have shown the incredible spirit of the human drive to explore and understand our universe. Yet in those 60 years we have barely left our solar system with the Voyager 1 spacecraft launched in 1977 finally leaving the solar system after 37 years of flight at a speed of 17 km/s or less than 0.006% the speed of light. As remarkable as this is we will never reach even the nearest stars with our current propulsion technology in even 10 millennium. We have to radically rethink our strategy or give up our dreams of reaching the stars, or wait for technology that does not currently exist. While we all dream of human spaceflight to the stars in a way romanticized in books and movies, it is not within our power to do so, nor it is clear that this is the path we should choose. We posit a technological path forward, that while not simple, it is within our technological reach. We propose a roadmap to ...
We study the fundamental limits of detection for astrophysical observations in the far infrared. ... more We study the fundamental limits of detection for astrophysical observations in the far infrared. Understanding these fundamental limits is critical to the planning and analysis of experiments in this region. We specifically characterize the difficulties associated with observing in the 0.1-10 THz (30-3000 \mu m) regime including extraterrestrial, atmospheric, and optical emission. We present signal, noise, and integration time models for selected terrestrial, aircraft, balloon, and space missions. While ground based telescopes offer the great advantage of aperture size, and hence angular resolution, they suffer from the relatively low transmission and high radiance of the atmosphere, particularly for wavelengths less than 500 \mu m. Space telescopes are the inverse; they are limited by a small aperture, while an airborne telescope is constrained by both. Balloon-borne telescopes provide an option over much of the band. A quantitative understanding of this is critical in comparing th...
Large scale directed energy offers the possibility of radical transformation in a variety of area... more Large scale directed energy offers the possibility of radical transformation in a variety of areas, including the ability to achieve relativistic flight that will enable the first interstellar missions as well as rapid interplanetary transit. In addition, the same technology opens a wide mission space that allows a diverse range of options from long range beamed power to remote spacecraft and outposts to planetary defense to remote composition analysis and manipulation of asteroids, among others. Directed energy relies on photonics, which like electronics is an exponentially expanding growth area driven by diverse economic interests that allows transformational advances in space exploration and capability. In order to begin to fully exploit this capability it is important to understand not only the possibilities enabled by it, but also the technological challenges involved and to have a logical roadmap to exploit this option. This capability is both synergistic with conventional pro...
The ARCADE II instrument was designed to compare the cosmic microwave background spectrum to a bl... more The ARCADE II instrument was designed to compare the cosmic microwave background spectrum to a blackbody spectrum at long (cm) wavelengths where the first stars are predicted to distort the ideal spectrum of the big bang. Reionization generates larger relative distortions at low frequencies. ARCADE II observed at 5 frequencies (3, 8, 10, 30 & 90 GHz). Each radiometer has
Destriping is a well-established technique for removing low-frequency correlated noise from Cosmi... more Destriping is a well-established technique for removing low-frequency correlated noise from Cosmic Microwave Background (CMB) survey data. In this paper we present a destriping algorithm tailored to data from a polarimeter, i.e. an instrument where each channel independently measures the polarization of the input signal. We also describe a fully parallel implementation in Python released as Free Software and analyze its results and performance on simulated datasets, both the design case of signal and correlated noise, and with additional systematic effects. Finally we apply the algorithm to 30 days of 37.5 GHz polarized microwave data gathered from the B-Machine experiment, developed at UCSB. The B-Machine data and destriped maps are made publicly available. The purpose is the development of a scalable software tool to be applied to the upcoming 12 months of temperature and polarization data from LATTE (Low frequency All sky TemperaTure Experiment) at 8 GHz and to even larger
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