Implementation of the 64-meter-diameter Antennas at the Deep Space Stations in Australia and Spain

The management and construction aspects of the Overseas 64-m Antenna Project in which two 64-m antennas were constructed at the Tidbinbilla Deep Space Communications Complex in Australia, and at the Madrid Deep Space Communications Complex in Spain are described. With the completion of these antennas the Deep Space Network is equipped with three 64-m antennas spaced around the world to maintain continuous coverage of spacecraft operations. These antennas provide approximately a 7-db gain over the capabilities of the existing 26-m antenna nets. The report outlines the project organization and management, resource utilization, fabrication, quality assurance, and construction methods by which the project was successfully completed. Major problems and their solutions are described as well as recommendations for future projects

Book Reviews

Reviews of the following books: The Letters of Thomas Gorges, Deputy Governor of the Province of Maine, 1640-1643, edited by Robert E. Moody; Maine Resources: Printed and Non-Printed compiled by Walter J. Taranko and Dorothy A. Gregory; Barrels and Daring by Patrick C. Dowling; The Landing: A Remembrance of Her People and Shipyards by Thomas W. Murphy, Jr

Coherent interaction of laser pulses in a resonant optically dense extended medium under the regime of strong field-matter coupling

Nonstationary pump-probe interaction between short laser pulses propagating in a resonant optically dense coherent medium is considered. A special attention is paid to the case, where the density of two-level particles is high enough that a considerable part of the energy of relatively weak external laser-fields can be coherently absorbed and reemitted by the medium. Thus, the field of medium reaction plays a key role in the interaction processes, which leads to the collective behavior of an atomic ensemble in the strongly coupled light-matter system. Such behavior results in the fast excitation interchanges between the field and a medium in the form of the optical ringing, which is analogous to polariton beating in the solid-state optics. This collective oscillating response, which can be treated as successive beats between light wave-packets of different group velocities, is shown to significantly affect propagation and amplification of the probe field under its nonlinear interaction with a nearly copropagating pump pulse. Depending on the probe-pump time delay, the probe transmission spectra show the appearance of either specific doublet or coherent dip. The widths of these features are determined by the density-dependent field-matter coupling coefficient and increase during the propagation. Besides that, the widths of the coherent features, which appear close to the resonance in the broadband probe-spectrum, exceed the absorption-line width, since, under the strong-coupling regime, the frequency of the optical ringing exceeds the rate of incoherent relaxation. Contrary to the stationary strong-field effects, the density- and coordinate-dependent transmission spectra of the probe manifest the importance of the collective oscillations and cannot be obtained in the framework of the single-atom model.Comment: 10 pages, 8 figures, to be published in Phys. Rev.

Novel Compound Heterozygous Mutations Expand the Recognized Phenotypes of \u3cem\u3eFARS2\u3c/em\u3e-linked Disease

Mutations in mitochondrial aminoacyl-tRNA synthetases are an increasingly recognized cause of human diseases, often arising in individuals with compound heterozygous mutations and presenting with system-specific phenotypes, frequently neurologic. FARS2 encodes mitochondrial phenylalanyl transfer ribonucleic acid (RNA) synthetase (mtPheRS), perturbations of which have been reported in 6 cases of an infantile, lethal disease with refractory epilepsy and progressive myoclonus. Here the authors report the case of juvenile onset refractory epilepsy and progressive myoclonus with compound heterozygous FARS2 mutations. The authors describe the clinical course over 6 years of care at their institution and diagnostic studies including electroencephalogram (EEG), brain magnetic resonance imaging (MRI), serum and cerebrospinal fluid analyses, skeletal muscle biopsy histology, and autopsy gross and histologic findings, which include features shared with Alpers-Huttenlocher syndrome, Leigh syndrome, and a previously published case of FARS2 mutation associated infantile onset disease. The authors also present structure-guided analysis of the relevant mutations based on published mitochondrial phenylalanyl transfer RNA synthetase and related protein crystal structures as well as biochemical analysis of the corresponding recombinant mutant proteins

Looking Towards 2030: Strengthening the Environmental Health in Childhood-Adolescent Cancer Survivor Programs

Childhood and adolescent cancer survivors (CACS) are a high-risk population for non-communicable diseases and secondary carcinogenesis. The Environmental and Community Health Program for Longitudinal Follow-up of CACS in the region of Murcia, Spain, is an ongoing pioneering program that constitutes a model for social innovation. This study aims to present the program tools and protocol as a whole, as well as a profile of the incidence, survival, and spatiotemporal distribution of childhood cancer in the region of Murcia, Spain, using 822 sample cases of cancer diagnosed in children under 15 years of age (1998-2020). While the crude incidence rate across that entire period was 149.6 per 1 million, there was an increase over that time in the incidence. The areas with a higher standardized incidence ratio have shifted from the northwest (1998-2003) to the southeast (2016-2020) region. Overall, the ten-year survival rate for all tumor types was 80.1% over the entire period, increasing the five-year survival rate from 76.1 (1998-2003) to 85.5 (2014-2018). CACS living in areas with very poor outdoor air quality had lower survival rates. Furthermore, integrating environmental health into clinical practice could improve knowledge of the etiology and prognosis, as well as the outcomes of CACS. Finally, monitoring individual carbon footprints and creating healthier lifestyles, alongside healthier environments for CACS, could promote wellbeing, environmental awareness, and empowerment in order to attain Sustainable Development Goals for non-communicable diseases in this population.This research was supported by the Environment, Survival and Childhood Cancer Project, Spanish Federation of Parents of Children with Cancer (FFIS-CCE-2019-11); Environmental Health Profile for Children Project funded by Sociedad Pediatria Sureste Esp. (FFIS-DF-2022-36); the International Network of Environment, Survival and Childhood Cancer (ENSUCHICA) in Europe and Latin America (FFIS EU17-01-01); Fundación Científica de la AECC (MACAPE-2004); Medio Ambiente Cáncer Pediátrica en la Región De Murcia (MACAPEMUR-2009 ~FFIS/EMER09/15); the Mount Sinai International Exchange Program for Minority Students funded by the National Institute of Minority Health and Health Disparities (T37 MD001452); and the International Training and Research Program in Environmental and Occupational Health funded by the Fogarty International Center, United States (TW00640). The funders had no role in the completion of the research project, the writing of the manuscript for publication, or the decision to publish the results.S

Short- and Long-Term Propagation of Spacecraft Orbits

The Planetary Observer Planning Software (POPS) comprises four computer programs for use in designing orbits of spacecraft about planets. These programs are the Planetary Observer High Precision Orbit Propagator (POHOP), the Planetary Observer Long-Term Orbit Predictor (POLOP), the Planetary Observer Post Processor (POPP), and the Planetary Observer Plotting (POPLOT) program. POHOP and POLOP integrate the equations of motion to propagate an initial set of classical orbit elements to a future epoch. POHOP models shortterm (one revolution) orbital motion; POLOP averages out the short-term behavior but requires far less processing time than do older programs that perform long-term orbit propagations. POPP postprocesses the spacecraft ephemeris created by POHOP or POLOP (or optionally can use a less accurate internal ephemeris) to search for trajectory-related geometric events including, for example, rising or setting of a spacecraft as observed from a ground site. For each such event, POPP puts out such user-specified data as the time, elevation, and azimuth. POPLOT is a graphics program that plots data generated by POPP. POPLOT can plot orbit ground tracks on a world map and can produce a variety of summaries and generic ordinate-vs.-abscissa plots of any POPP data

Scientific Exploration of Near-Earth Objects via the Crew Exploration Vehicle

The concept of a crewed mission to a Near-Earth Object (NEO) has been analyzed in depth in 1989 as part of the Space Exploration Initiative. Since that time two other studies have investigated the possibility of sending similar missions to NEOs. A more recent study has been sponsored by the Advanced Programs Office within NASA's Constellation Program. This study team has representatives from across NASA and is currently examining the feasibility of sending a Crew Exploration Vehicle (CEV) to a near-Earth object (NEO). The ideal mission profile would involve a crew of 2 or 3 astronauts on a 90 to 120 day flight, which would include a 7 to 14 day stay for proximity operations at the target NEO. One of the significant advantages of this type of mission is that it strengthens and validates the foundational infrastructure for the Vision for Space Exploration (VSE) and Exploration Systems Architecture Study (ESAS) in the run up to the lunar sorties at the end of the next decade (approx.2020). Sending a human expedition to a NEO, within the context of the VSE and ESAS, demonstrates the broad utility of the Constellation Program s Orion (CEV) crew capsule and Ares (CLV) launch systems. This mission would be the first human expedition to an interplanetary body outside of the cislunar system. Also, it will help NASA regain crucial operational experience conducting human exploration missions outside of low Earth orbit, which humanity has not attempted in nearly 40 years

Technology requirements of exploration beyond Neptune by solar sail propulsion

This paper provides a set of requirements for the technology development of a solar sail propelled Interstellar Heliopause Probe mission. The mission is placed in the context of other outer solar systems missions, ranging from a Kuiper Belt mission through to an Oort cloud mission. Mission requirements are defined and a detailed parametric trajectory analysis and launch date scan performed. Through analysis of the complete mission trade space a set of critical technology development requirements are identified which include an advanced lightweight composite High-Gain Antenna, a high-efficiency Ka-band travelling-wave tube amplifier and a radioisotope thermoelectric generator with power density of approximately 12 W/kg. It is also shown that the Interstellar Heliopause Probe mission necessitates the use of a spinning sail, limiting the direct application of current hardware development activities. A Kuiper Belt mission is then considered as a pre-curser to the Interstellar Heliopause Probe, while it is also shown through study of an Oort cloud mission that the Interstellar Heliopause Probe mission is the likely end-goal of any future solar sail technology development program. As such, the technology requirements identified to enable the Interstellar Heliopause Probe must be enabled through all prior missions, with each mission acting as an enabling facilitator towards the next