The Global Impact of ITAR on the For-Profit and Non-Profit Space Communities

Under the United States Arms Export Control Act, the International Traffic in Arms Regulations (ITAR) control the export of technologies that are specified as defense articles on the United States Munitions List (USML). The Directorate of Defense Trade Controls (DDTC) within the Department of State (DoS) interprets and enforces these regulations in an effort to safeguard national security by denying advanced military technology to potential competitors

Assessment of Radiometer Calibration With GPS Radio Occultation for the MiRaTA CubeSat Mission

The microwave radiometer technology acceleration (MiRaTA) is a 3U CubeSat mission sponsored by the NASA Earth Science Technology Office. The science payload on MiRaTA consists of a triband microwave radiometer and global positioning system (GPS) radio occultation (GPSRO) sensor. The microwave radiometer takes measurements of all-weather temperature (V-band, 50-57 GHz), water vapor (G-band, 175-191 GHz), and cloud ice (G-band, 205 GHz) to provide observations used to improve weather forecasting. The Aerospace Corporation's GPSRO experiment, called the compact total electron content and atmospheric GPS sensor (CTAGS), measures profiles of temperature and pressure in the upper troposphere/lower stratosphere (~20 km) and electron density in the ionosphere (over 100 km). The MiRaTA mission will validate new technologies in both passive microwave radiometry and GPSRO: 1) new ultracompact and low-power technology for multichannel and multiband passive microwave radiometers, 2) the application of a commercial off-the-shelf GPS receiver and custom patch antenna array technology to obtain neutral atmospheric GPSRO retrieval from a nanosatellite, and 3) a new approach to space-borne microwave radiometer calibration using adjacent GPSRO measurements. In this paper, we focus on objective 3, developing operational models to meet a mission goal of 100 concurrent radiometer and GPSRO measurements, and estimating the temperature measurement precision for the CTAGS instrument based on thermal noise Based on an analysis of thermal noise of the CTAGS instrument, the expected temperature retrieval precision is between 0.17 and 1.4 K, which supports the improvement of radiometric calibration to 0.25 K

The low-order wavefront sensor for the PICTURE-C mission

The PICTURE-C mission will fly a 60 cm off-axis unobscured telescope and two high-contrast coronagraphs in successive high-altitude balloon flights with the goal of directly imaging and spectrally characterizing visible scattered light from exozodiacal dust in the interior 1-10 AU of nearby exoplanetary systems. The first flight in 2017 will use a 10^(-4) visible nulling coronagraph (previously flown on the PICTURE sounding rocket) and the second flight in 2019 will use a 10^(-7) vector vortex coronagraph. A low-order wavefront corrector (LOWC) will be used in both flights to remove time-varying aberrations from the coronagraph wavefront. The LOWC actuator is a 76-channel high-stroke deformable mirror packaged on top of a tip-tilt stage. This paper will detail the selection of a complementary high-speed, low-order wavefront sensor (LOWFS) for the mission. The relative performance and feasibility of several LOWFS designs will be compared including the Shack-Hartmann, Lyot LOWFS, and the curvature sensor. To test the different sensors, a model of the time-varying wavefront is constructed using measured pointing data and inertial dynamics models to simulate optical alignment perturbations and surface deformation in the balloon environment

Assessment of Radiometer Calibration With GPS Radio Occultation for the MiRaTA CubeSat Mission

The microwave radiometer technology acceleration (MiRaTA) is a 3U CubeSat mission sponsored by the NASA Earth Science Technology Office. The science payload on MiRaTA consists of a triband microwave radiometer and global positioning system (GPS) radio occultation (GPSRO) sensor. The microwave radiometer takes measurements of all-weather temperature (V-band, 50-57 GHz), water vapor (G-band, 175-191 GHz), and cloud ice (G-band, 205 GHz) to provide observations used to improve weather forecasting. The Aerospace Corporation's GPSRO experiment, called the compact total electron content and atmospheric GPS sensor (CTAGS), measures profiles of temperature and pressure in the upper troposphere/lower stratosphere (~20 km) and electron density in the ionosphere (over 100 km). The MiRaTA mission will validate new technologies in both passive microwave radiometry and GPSRO: 1) new ultracompact and low-power technology for multichannel and multiband passive microwave radiometers, 2) the application of a commercial off-the-shelf GPS receiver and custom patch antenna array technology to obtain neutral atmospheric GPSRO retrieval from a nanosatellite, and 3) a new approach to space-borne microwave radiometer calibration using adjacent GPSRO measurements. In this paper, we focus on objective 3, developing operational models to meet a mission goal of 100 concurrent radiometer and GPSRO measurements, and estimating the temperature measurement precision for the CTAGS instrument based on thermal noise Based on an analysis of thermal noise of the CTAGS instrument, the expected temperature retrieval precision is between 0.17 and 1.4 K, which supports the improvement of radiometric calibration to 0.25 K

Assessment of Radiometer Calibration With GPS Radio Occultation for the MiRaTA CubeSat Mission

© 2016 IEEE. The microwave radiometer technology acceleration (MiRaTA) is a 3U CubeSat mission sponsored by the NASA Earth Science Technology Office. The science payload on MiRaTA consists of a triband microwave radiometer and global positioning system (GPS) radio occultation (GPSRO) sensor. The microwave radiometer takes measurements of all-weather temperature (V-band, 50-57 GHz), water vapor (G-band, 175-191 GHz), and cloud ice (G-band, 205 GHz) to provide observations used to improve weather forecasting. The Aerospace Corporation's GPSRO experiment, called the compact total electron content and atmospheric GPS sensor (CTAGS), measures profiles of temperature and pressure in the upper troposphere/lower stratosphere (∼20 km) and electron density in the ionosphere (over 100 km). The MiRaTA mission will validate new technologies in both passive microwave radiometry and GPSRO: 1) new ultracompact and low-power technology for multichannel and multiband passive microwave radiometers, 2) the application of a commercial off-the-shelf GPS receiver and custom patch antenna array technology to obtain neutral atmospheric GPSRO retrieval from a nanosatellite, and 3) a new approach to space-borne microwave radiometer calibration using adjacent GPSRO measurements. In this paper, we focus on objective 3, developing operational models to meet a mission goal of 100 concurrent radiometer and GPSRO measurements, and estimating the temperature measurement precision for the CTAGS instrument based on thermal noise Based on an analysis of thermal noise of the CTAGS instrument, the expected temperature retrieval precision is between 0.17 and 1.4 K, which supports the improvement of radiometric calibration to 0.25 K

Nanosatellites for Earth Environmental Monitoring: The MicroMAS Project

The Micro-sized Microwave Atmospheric Satellite (MicroMAS) is a dual-spinning 3U CubeSat equipped with a passive microwave spectrometer that observes nine channels near the 118.75-GHz oxygen absorption line. The focus of this MicroMAS mission (hereafter, MicroMAS-1) is to observe convective thunderstorms, tropical cyclones, and hurricanes from a near-equatorial orbit. The MicroMAS-1 flight unit is currently being developed by MIT Lincoln Laboratory, the MIT Space Systems Laboratory, and the MIT Department of Earth and Planetary Sciences for a 2014 launch to be provided by the NASA CubeSat Launch Initiative program. As a low cost platform, MicroMAS offers the potential to deploy multiple satellites than can provide near-continuous views of severe weather. The existing architecture of few, high-cost platforms, infrequently view the same earth area which can miss rapid changes in the strength and direction of evolving storms thus degrading forecast accuracy. The 3U CubeSat has dimensions of 10 x 10 x 34.05 cm3 and a mass of approximately 4 kg. The payload is housed in the “lower” 1U of the dualspinning 3U CubeSat, and is mechanically rotated approximately once per second as the spacecraft orbits the Earth. The resulting cross-track scanned beam has a FWHM beam width of 2.4º, and has an approximately 20-km diameter footprint at nadir incidence from a nominal altitude of 500 km. Radiometric calibration is carried out using observations of cold space, the Earth\u27s limb, and an internal noise diode that is weakly coupled through the RF front-end electronics. In addition to the dual-spinning CubeSat, a key technology development is the ultra-compact intermediate frequency processor (IFP) module for channelization, detection, and analog-to-digital conversion. The payload antenna system and RF front-end electronics are highly integrated, miniaturized, and optimized for low-power operation. To support the spinning radiometer payload, the structures subsystem incorporates a brushless DC zerocogging motor, an optical encoder and disk, a slip ring, and a motor controller. The attitude determination and control system (ADCS) utilizes reaction wheels, magnetorquers, Earth horizon sensors, peak power tracking, a magnetometer, and a gyroscope. The communications system operates at S-band using the Open System of Agile Ground Stations (OSAGS) with a 2.025—2.120 GHz uplink and 2.200—2.300 GHz downlink at 230 kbps. MicroMAS-1 uses a Pumpkin CubeSat Motherboard with a Microchip PIC24 microcontroller as the flight computer running Pumpkin’s Salvo Real Time Operating System. Thermal management includes monitoring with thermistors, heating, and passive cooling. Power is generated using four double-sided deployable 3U solar panels and one 2U bodymounted panel with UTJ cells and an electrical power system (EPS) with 30 W-hr lithium polymer batteries from Clyde Space. Tests with the MicroMAS-1 Engineering Design Model (EDM) have resulted in modifications to the spinning assembly, stack and ADCS system and have informed the development of the flight model subsystems

Delirium and Clusters of Older Patients Affected by Multimorbidity in Acute Hospitals.

Objectives: Delirium is commonly seen in older adults with multimorbidity, during a hospitalization, resulting from the interplay between predisposing factors such as advanced age, frailty, and dementia, and a series of precipitating factors. The association between delirium and specific multimorbidity is largely unexplored so far although of potential key relevance for targeted interventions. The aim of the study was to check for a potential association of multimorbidity with delirium in a large cohort of older patients hospitalized for an acute medical or surgical condition. Design: This is a cross-sectional study nested in the 2017 Delirium Day project. Setting and participants: The study includes 1829 hospitalized patients (age: 81.8, SD: 5.5). Of them, 419 (22.9%) had delirium. Methods: Sociodemographic and medical history were collected. The 4AT was used to assess the presence of delirium. The Charlson Comorbidity index was used to assess multimorbidity. Results: The results identified neurosensorial multimorbidity as the most prevalent, including patients with dementia, cerebrovascular diseases, and sensory impairments. In light of the highest co-occurrence of 3 neurosensorial chronic conditions, we could hypothesize that a baseline altered brain functional and neural connectivity might determine the vulnerability signature for incipient overall system disruption in presence of acute insults. Conclusions and implications: Eventually, our findings moved a step forward in supporting the key importance of routine screening for sensory impairments and cognitive status of older patients for the highest risk of in-hospital delirium. In fact, preventive interventions could be particularly relevant and effective in preventing delirium in such vulnerable populations and might help refining this early diagnosis