A Low Power Command and Control Module for Small Satellites

Utah State University/Space Dynamics Laboratory has developed a low power computer system for command and control, attitude determination, and telemetry for small spacecraft. The system has been developed for the 15-kilogram class Ionospheric Observation Nanosatellite Formation (ION-F) satellites. This constellation of three satellites is being built by Utah State University (USUSat), University of Washington/Cornell University (DawgStar), and Virginia Polytechnic Institute (HokieSat) and is part of the AFSOR/DARPA University Nanosatellite program with additional support from industry, NASA, the Air Force Research Labs, and the Air Force Space Test Program. The command and data handling (C&DH) system is based upon industrial-grade components, including a third generation Hitachi SuperH RISC processor and radiation tolerant ACTEL FPGAs. The memory subsystem is comprised of 256 Kbytes of EEPROM, 8 Mbytes of redundant flash memory, and 5 Mbytes of SRAM. The C&DH system also contains a 16 Mbyte telemetry buffer, digital and analog I/O interfaces, and a DMA-oriented CMOS camera system. The C&DH is radiation tolerant to approximately 5k Rad total dose. Single event upsets are dealt with at the hardware level by over current monitoring circuitry, redundant voting memory configurations, and multiple software watchdog timers. The entire computer system consumes less than 1.75 Watts peak, with an average of 1 Watt, and provides an 80-MIPS, 32-bit computation platform for a small spacecraft. An initial prototype satellite has successfully passed extensive environmental testing and demonstrated the advanced capabilities of the ION-F C&DH system

Coordinated investigation of summer time mid-latitude descending E layer (Es) perturbations using Na lidar, ionosonde, and meteor wind radar observations over Logan, Utah (41.7°N, 111.8°W)

It is well known that there is a strong correlation between the formation of a descending sporadic E layer (Es) and the occurrence of large upper atmospheric zonal wind shears, most likely driven by solar thermal tides and/or gravity waves. We present new results of Esperturbation events captured between 13 and 17 July 2011 (UT days 194–198) as part of a coordinated campaign using a wind/temperature Na lidar at Utah State University [41.7ºN, 111.8°W], and a Canadian Advanced Digital Ionosonde (CADI; Scientific Instrumentation Ltd., Saskatoon, Saskatchewan, Canada) and SkiYMet meteor wind radar, both located at nearby Bear Lake Observatory [41.9°N, 111.4°W]. During this period, the CADI detected strong descending Es on 2 days (195 and 197) when large modulations of the top-side mesospheric Na layer occurred in synchronism with strong oscillations in the ionosonde E region echoes. A weakening in the descending E layer echoes was observed on the other 2 days (196 and 198) coincident with a large reduction in the zonal diurnal and semidiurnal amplitudes above 95 km. Both tidal components were found to have comparable contributions to the total zonal wind shear that was critical for Es formation and its downward propagation. Further investigation indicates that the weakening tidal amplitudes and the occurrence of the Es events were also influenced by a strong quasi-two-day period modulation, suggesting significant quasi-two-day wave (QTDW) interactions with the tides. Indeed, a nonlinear, wave-wave interaction-induced 16-hour period child wave was also detected, with amplitude comparable to that of the prevailing tides. These interaction processes and their associated effects are consistent with earlier Thermosphere Ionosphere Mesosphere Electrodynamics General Circulation Model studies of nonlinear interactions between the migrating tidal waves and the QTDW and were probably responsible for the observed damping of the tidal amplitudes resulting in the disruption of the Es

Rayleigh Scatter Lidar Observations of the Midlatitude Mesosphere’s Response to Sudden Stratospheric Warmings

The original Rayleigh-scatter lidar that operated at the Atmospheric Lidar Observatory (ALO; 41.7°N, 111.8°W) in the Center for Atmospheric and Space Sciences (CASS) on the campus of Utah State University (USU) collected a very dense set of temperature data for 11 years, from 1993 through 2004. The temperatures derived from these data extended over the mesosphere, from 45 to 90 km. This work will focus on the extensive Rayleigh lidar observations made during the seven major SSW events that occurred between 1993 and 2004. In order to determine the characteristics of the midlatitude mesospheric temperatures during SSWs, comparisons were made between the temperature profile on an individual night during a SSW event and the climatological (11-year average) temperature profile for that night. An overall disturbance pattern was observed in the mesospheric temperatures during these SSWs. It included coolings (sometimes very significant) in the upper mesosphere and warmings in the lower mesosphere

The Mid-Latitude Mesosphere’s Response to Sudden Stratospheric Warmings as Determined from Rayleigh Lidar Temperatures

The original Rayleigh-scatter lidar that operated at the Atmospheric Lidar Observatory (ALO; 41.7°N, 111.8°W) in the Center for Atmospheric and Space Sciences (CASS) on the campus of Utah State University (USU), collected temperature data for 11 years, from 1993 through 2004. The temperatures derived from these data extended over the mesosphere, from 45 to 90 km. Recently, they were combined with other observations to examine the mid-latitude responses to Sudden Stratospheric Warmings (SSWs) in the polar regions. (The other observational instruments being an ionosonde, a meteor wind radar, a Na lidar, and a satellite.) Extensive Rayleigh lidar observations were made during a dozen SSW events. In order to look for effects of the SSWs, comparisons were made between the temperature profile on individual nights during an SSW event and the climatological temperature profile for that night of the year. An overall disturbance pattern was observed in the mesospheric temperatures during northern hemisphere SSWs. It included coolings (sometimes very significant) in the upper mesosphere and warmings in the lower mesosphere. Examples of the effects in the mesosphere from southern hemisphere SSWs are also given

Midlatitude Mesospheric Temperature Anomalies During Major SSW Events as Observed with Rayleigh-Scatter Lidar

While the mesospheric temperature anomalies associated with Sudden Stratospheric Warmings (SSWs) have been observed extensively in the polar regions, observations of these anomalies at midlatitudes are sparse. The original Rayleigh-scatter lidar that operated at the Atmospheric Lidar Observatory (ALO; 41.7°N, 111.8°W) in the Center for Atmospheric and Space Sciences (CASS) on the campus of Utah State University (USU) collected a very dense set of temperature data for 11 years, from 1993 through 2004. The temperatures derived from these data extended over the mesosphere, from 45 to 90 km. This work focuses on the extensive Rayleigh lidar observations made during seven major SSW events that occurred between 1993 and 2004, and aims to compile a climatological study of the midlatitude mesospheric temperatures during these SSW events. In order to determine the characteristics of the midlatitude mesospheric temperatures during SSWs, comparisons were made between the temperature profile on an individual night during a SSW event and the climatological (11-year average) temperature profile for that night. An overall disturbance pattern was observed in the mesospheric temperatures during these SSWs. It included coolings in the upper mesosphere, comparable to those seen in the polar regions, and warmings in the lower mesosphere

Connection between the midlatitude mesosphere and sudden stratospheric warmings as measured by Rayleigh-scatter lidar

While the mesospheric temperature anomalies associated with Sudden Stratospheric Warmings (SSWs) have been observed extensively in the polar regions, observations of these anomalies at midlatitudes are much more sparse. The Rayleigh-scatter lidar system, which operated at the Center for Atmospheric and Space Sciences on the campus of Utah State University (41.7°N, 111.8°W), collected a very dense set of observations, from 1993 to 2004, over a 45–90 km altitude range. This paper focuses on Rayleigh lidar temperatures derived during the six major SSW events that occurred during the 11 year period when the lidar was operating and aims to characterize the local response to these midlatitude SSW events. In order to determine the characteristics of these mesospheric temperature anomalies, comparisons were made between the temperatures from individual nights during a SSW event and a climatological temperature profile. An overall disturbance pattern was observed in the mesospheric temperatures associated with SSW events, including coolings in the upper mesosphere and warmings in the upper stratosphere and lower mesosphere, both comparable to those seen at polar latitudes

Active Thermal Control for the Multispectral Earth Sensors (ACMES) Mission

The Active Thermal Architecture (ATA) is a sub 1U active thermal control system providing payload thermal support and setpoint thermal control for the Active Cooling for Multispectral Earth Sensors (ACMES) mission. Based on a single-phase fluid loop heat exchanger, the ATA features a micro centrifugal pump, an innovative working fluid, and a two-axis flexible rotary fluid joint coupled to a deployable tracking radiator. The ATA system leverages advanced Ultrasonic Additive Manufacturing (UAM) techniques to directly integrate the ATA system within the payload and CubeSat structure. NASA\u27s Science Mission Directorate has selected the ATA system to fly on the ACMES mission. A 12U CubeSat technology demonstration funded by the In-space Validation of Earth Science Technologies (InVEST) program. The ATA will serve as payload support to the Hyperspectral Thermal Imaging instrument (HyTi). A high spectral/spatial density long-wave infrared (8-10.7 μm) instrument. HyTi also features advanced, onboard high-performance computing. The ATA will thermally support HyTi allowing for continuous operations. ACMES will also feature two student-led instrument development projects. A highly sensitive methane detector FINIS and a planar Langmuir/Impedance probe PLAID. ACMES will be a joint development effort between Orion Space, the University of Hawaii, and Utah State University

Effects of Major Sudden Stratospheric Warmings Identified in Midlatitude Mesospheric Rayleigh-Scatter Lidar Temperatures

Mesospheric temperature anomalies associated with Sudden Stratospheric Warmings (SSWs) have been observed extensively in the polar regions. However, observations of these anomalies at midlatitudes are sparse. The very dense 11-year data set, collected between 1993–2004, with the Rayleigh-scatter lidar at the Atmospheric Lidar Observatory (ALO; 41.7°N, 111.8°W) at the Center for Atmospheric and Space Sciences (CASS) on the campus of Utah State University (USU), has been carefully examined for such anomalies. The temperatures derived from these data extend over the mesosphere, from 45 to 90 km. During this period extensive data were acquired during seven major SSW events. In this work we aim to determine the characteristics of the midlatitude mesospheric temperatures during these seven major SSWs. To do this, comparisons were made between the temperature profiles on individual nights before, during, and after the SSW events and the corresponding derived climatological temperature profiles (31-day by 11-year average) for those nights. A consistent disturbance pattern was observed in the mesospheric temperatures during these SSWs. A distinct shift from the nominal winter temperature pattern to a pattern more characteristic of summer temperatures was seen in the midlatitude mesosphere close to when the zonal winds in the polar stratosphere (at 10 hPa, 60° N) reversed from eastward to westward. This shift lasted for several days. This change in pattern included coolings in the upper mesosphere, comparable to those seen in the polar regions, and warmings in the lower mesosphere