This PDF file contains the front matter associated with SPIE Proceedings Volume 11832, including the Title Page, Copyright information, and Table of Contents.

This Conference Presentation, “Millimeter-wave sounder/imager on a CubeSat providing global atmospheric science observations for more than two years on orbit: Temporal Experiment for Storms and Tropical Systems-Demonstration (TEMPEST-D) Mission,” was recorded at SPIE Optics + Photonics 2021 held in San Diego, California, United States.

The Active Thermal Architecture (ATA) is an advanced sub-1U Active Thermal Control technology (ATC) for high power payload support in 6U CubeSat form factors and above. The design utilizes a two-stage, single-phase mechanically pumped fluid loop coupled through a two-axis flexible rotary fluid hinge, to reject thermal power to a deployable tracking radiator. A COTS Ricor K508N cryocooler forms the second stage and provides cryogenic cooling to a custom Kevlar detector mount through a TMT pyrolytic graphene thermal strap. Passive vibration isolation and damping technologies prevent the transfer of jitter to the satellite systems. The ATA design utilizes state-of-the-art 3D fabrication techniques such as Ultrasonic Additive Manufacturing (UAM) to directly embed the working fluid channels into the HX, radiator, and CubeSat chassis allowing for the miniaturization and simplification of the ATA system into an integrated thermal control solution. This paper will focus on the design and ground-based characterization and qualification of the ATA system and provide performance metrics for its use as a thermal support subsystem for advanced infrared electro-optical CubeSat payloads. The ATA project is funded through a NASA Small Satellite Technology Program (SSTP) and is a partnership between the Center for Space Engineering at Utah State University and the Jet Propulsions Laboratory. The ATA active thermal control system has been raised to a TRL of 6 and hopes to provide payload support to advanced missions such as the SABER-Lite and JPL CIRAS projects.

Hydrosat's VanZyl-1 demonstration payload is representative of an emerging class of small satellite payloads, with a goal to enable infrared measurements relevant to Earth science applications in a small size, weight, and power (SWaP) footprint. In order to optimize the performance of an infrared instrument within the confines of a hosted payload allocation or other SmallSat form factor, careful attention must be paid to the radiometric calibration sources that will be available on orbit. This paper explores the state of the art in compact blackbody sources and alternative on-board calibration sources, as well as established practices for vicarious calibration such as oceans or the lunar surface. These options will be summarized in terms of high-level calibration goals including relative detector calibration, absolute response calibration, and reference target radiometric knowledge over time.

In this paper, we report a novel design of Ku band microstrip patch antenna for satellite interchange application. The antenna design consists of RT/Duroid 5880 (dielectric constant 2.2) substrate and PEC (Perfect Electric Conductor) ground and patch. Various antenna parameters such as far-field radiation pattern, return Loss, gain, directivity, impedance, and VSWR have been obtained and analyzed. The designed antenna has been thoroughly analyzed by varying geometrical parameters of the patch to study their impact on return loss, gain, and directivity enhancement, which helps to optimize the design as per our application. The proposed antenna is excited by a 50 Ω microstrip transmission line, and the antenna has achieved good impedance matching. The reported antenna design has been optimized to operate in the Ku band at resonant frequency 12.745 GHz for a wide range of applications in satellite communications, direct transmission satellites or satellite television, etc.

NASA’s New Observing Strategies (NOS) thrust provides a framework for identifying technology advances needed to exploit newly available observational capabilities, including high-quality instruments on constellations of SmallSats and CubeSats, that enable measurement of phenomena that could not be studied using previously available techniques. Satellite developers and operators require software tools to simulate new technologies and validate new mission concepts that can incorporate a dynamic set of observing assets with various instruments located at different vantage points. These new mission concepts include many more design variables than traditional missions, requiring tools to facilitate trade analysis and concept validation in an iterative fashion, similar to an Observing System Simulation Experiment (OSSE) framework. Several recent projects address design and operational trades by designing software packages such as the Trade-space Analysis Tools for Constellations (TAT-C) co-developed by Stevens Institute of Technology, the Simulation Toolset for Adaptive Remote Sensing (STARS) developed by The Ohio State University, and the Virtual Constellation Engine (VCE) developed by the University of Southern California. Each tool has different but complementary capabilities and can be run independently. However, linking capabilities using modern web-based service application programming interfaces (APIs) contributes to a powerful modeling ecosystem for the Earth Science community with well-defined interfaces that facilitate interoperability with existing mission planning tools. This presentation will describe the capabilities of each individual software tool as well as recent efforts to integrate their capabilities to evaluate and mature constellation mission concepts as part of the NOS thrust.

The feasibility of a novel lidar-based sensor for space debris detection is tested in a laboratory setting using a low-power transmitter and simplified receiver. The transmitter employs a Powell lens to spread transmitted laser light into an evenly distributed fan shape which detects particles or objects moving through the beam and measures their approximate size. Link budget calculations based on a theoretical model are validated. Additionally, several important considerations for future deployment on a satellite are identified.

Metal atoms and ions are deposited into the Earth’s Upper Atmosphere and Ionosphere via meteor ablation. The neutral atoms can undergo charge exchange with extant O⁺, O₂⁺, and N₂⁺ ions to become metallic ions. Metallic ions have lifetimes of several days in the ionosphere, allowing vertical wind shear to compress them into thin, dense layers that subsequently produce Sporadic-E propagation of HF radio signals. The Triple Magnesium Ionospheric Photometer (Tri-MIP) instrument was developed by the US Naval Research Laboratory (NRL) to observe airglow emissions from magnesium ions (Mg⁺) in the Earth’s atmosphere and measure global-scale Mg⁺ density from orbit as a proxy for the metallic ion population. This CubeSat compatible Space Weather sensor is a 1U ionospheric photometer that observes the ultraviolet 280 nm fluorescent emission of Mg⁺ on the sunlit portion of the orbit. The primary objective is to characterize the Mg⁺ distribution in the Earth’s atmosphere. We present the Tri-MIP instrument concept, laboratory measurements, and upcoming mission concepts.

In this work, we designed a 12U CubeSat Platform for a Multi-Tone Continuous Wave Lidar system, utilizing coherent detection, which is used as an optical altimetry and velocimetry measurement device. The spacecraft is designed to be operational for a period of 6 to 12 months, and the primary goals are to develop a standalone small spacecraft technology that enables an optical remote sensing. Here, we describe the mechanical design and the thermal analysis of the spacecraft. Due to the random vibration and shock response during launching, a vibration isolation was designed to protect the optical components and alignments. The necessity of high optical power creates thermally localized hot spots that need to be dissipated while remaining in the operational temperature range. We designed thermal dissipation systems, including radiators, heat pipes, thermo-electric coolers, and used space-grade exterior paint to sustain the operation of the MTCW Lidar in the 12U CS.

Hyperspectral infrared measurements of Earth’s atmosphere from space have proven their value for weather forecasting, climate science and atmospheric composition. The CubeSat Infrared Atmospheric Sounder (CIRAS) instrument will demonstrate a fully functional infrared temperature, water vapor and carbon monoxide sounder in a CubeSat sized volume for at least an order of magnitude lower cost than legacy systems. Design for a CubeSat significantly reduces cost of access to space and enables flight in a constellation to reduce revisit time and enable new measurements including 3D winds. A technology demonstration of CIRAS is currently under development at JPL. The effort has completed integration and ambient testing of a high fidelity brassboard, complete with the flight configured optics assembly developed by Ball Aerospace with a JPL Immersion Grating and Black Silicon Entrance Slit. The brassboard includes a flight-configured High Operating Temperature Barrier Infrared Detector (HOT-BIRD) mounted in an Integrated Dewar Cryocooler Assembly (IDCA), enabling testing in the ambient environment. Ambient testing included radiometric testing of the system to characterize the instrument operability and NEdT. Spatial testing was performed to characterize the system line spread function (LSF) in two axes and report FWHM of the LSF. Spectral testing involved an air path test to characterize the spectral/spatial transformation matrix, and an etalon was used to measure the Spectral Response Functions (SRFs). Results of the testing show the CIRAS performs exceptionally well and meets the key performance required of the system. The end result of testing is the CIRAS instrument now meets TRL 4 with confidence in a brassboard configuration ready for thermal vacuum (TVac) testing necessary to achieve TRL 5 for the system.

The Nano-satellite Atmospheric Chemistry Hyperspectral Observation System (NACHOS) is a high-throughput (f/2.9), high spectral resolution (~1.3 nm optical resolution, 0.6 nm sampling) Offner-design hyperspectral imager operating in the 300-500 nm spectral region. The 1.5U instrument payload (1U optical system, 0.5U electronics module) is hosted by a 1.5U LANL-designed CubeSat bus to comprise a 3U complete satellite. Spectroscopically similar to NASA’s Ozone Monitoring Instrument (OMI), which provides wide-field global mapping of ozone and other gases at coarse spatial resolution, NACHOS fills the complementary niche of targeted measurements at much higher spatial resolution. With 350 across-track spatial pixels and a 15-degree across-track field of view, NACHOS will provide spectral imaging at roughly 0.4 km per pixel from 500 km altitude. NACHOS incorporates highly streamlined gas-retrieval algorithms for rapid onboard processing, alleviating the need to routinely downlink massive hyperspectral data cubes. We will discuss the instrument design, challenges in achieving mechanical robustness to launch vibration in such a compact instrument, the onboard calibration system, and gas-retrieval data downlink strategy. We will also discuss potential science missions, including monitoring of NO₂ as an easily detected proxy for anthropogenic fossil-fuel greenhouse gases, monitoring lowlevel SO₂ degassing at pre-eruptive volcanoes, H₂CO from wildfires, and characterization of aerosols. The long-term vision is for a many-satellite constellation that could provide both high spatial resolution and frequent revisits for selected targets of interest. As an initial technology demonstration of this vision, the NACHOS project is currently slated to launch two CubeSats in early 2022.

Hyperspectral imaging with sufficient resolution and sensitivity for scientifically useful space-based mapping of trace gases has long required large and expensive satellite instruments. Miniaturizing this capability to a CubeSat configuration is a major challenge, but opens up more agile and far less expensive observing strategies. A major step in this direction is our development of NACHOS, an ultra-compact (1.5U instrument, 3U complete CubeSat) hyperspectral imager covering the 300-500nm spectral range in 400 channels. Here we describe laboratory and field performance characterization of this new instrument. Laboratory tests demonstrate spatial and spectral resolutions of <0.8 mrad and 1.3 nm, respectively, with good resolution of the spectral lines of our SO₂ and NO₂ target gases. Outdoor field tests under realistic illumination conditions provide real-world signal-to-noise benchmarks, and yield hyperspectral images displaying high quality solar and atmospheric spectra. To estimate on-orbit gas retrieval sensitivities, we computationally implanted plumes of varying concentrations into acquired hyperspectral datacubes. Applying our adaptive matched filter gas-retrieval algorithms to the generated scene, we predict NACHOS will be able to distinguish 35 and 7 ppm⋅m plumes of SO₂ and NO₂ (respectively) with high sensitivity; a capability well-suited to address scientific goals related to monitoring both passive SO₂ degassing from volcanoes and NO₂ emissions from anthropogenic sources. Lastly, we will show findings from thermal and vibrational environmental tests, performed in preparation for a scheduled early-2022 launch, demonstrating the extremely robust spectrometer design is well-suited for satellite-based deployment.

This Conference Presentation, “The CubeSat Lightning Imaging and Detection Experiment (CLIDE),” was recorded for Optics + Photonics 2021 held in San Diego, California, United States.