This PDF file contains the front matter associated with SPIE Proceedings Volume 11505, including the Title Page, Copyright information, and Table of Contents.

The CYGNSS constellation of eight satellites was launched in December 2016 into a low inclination Earth orbit. Each satellite carries a four-channel bi-static radar receiver which measures signals transmitted by GPS satellites and scattered back into space by the Earth surface. Over the ocean, surface roughness, near-surface wind speed and air-sea latent heat flux are estimated from the direct measurements of surface scattering cross section. Over the land, estimates of soil moisture and flood inundation are also possible. An overview and the current status of the mission will be presented, together with highlights of recent scientific results.

The Temporal Experiment for Storms and Tropical Systems Demonstration (TEMPEST-D) mission is the first CubeSat-based multi-frequency microwave sounder to provide global data over a sustained period. The mission was designed to demonstrate on-orbit capabilities of a five-frequency millimeter-wave radiometer for a complete TEMPEST mission using a closely-spaced train of eight 6U CubeSats with identical low-mass, low-power millimeter-wave sensors to sample rapid changes in convection and surrounding water vapor every 3-4 minutes for up to 30 minutes. The TEMPEST-D satellite was launched on May 21, 2018 from NASA Wallops to the ISS and was successfully deployed on July 13, 2018, into a 400-km orbit at 51.6° inclination. The TEMPEST-D sensor has been operating nearly continuously since its first light data on September 5, 2018. On-orbit results indicate that TEMPEST-D is a very well-calibrated, highly stable radiometer, indistinguishable in performance from larger operational sensors.

The Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats (TROPICS) mission, selected by NASA as part of the Earth Venture–Instrument (EVI-3) program, will provide nearly all-weather observations of 3-D temperature and humidity, as well as cloud ice and precipitation horizontal structure, at high temporal resolution to conduct high-value science investigations of tropical cyclones. TROPICS will provide rapid-refresh microwave measurements (median refresh rate better than 60 minutes for the baseline mission) over the tropics that can be used to observe the thermodynamics of the troposphere and precipitation structure for storm systems at the mesoscale and synoptic scale over the entire storm lifecycle. TROPICS comprises a constellation of six CubeSats in three low-Earth orbital planes. All TROPICS flight hardware has been delivered in anticipation of launches occurring no earlier than 2021.

The requirements of the natural resources sector for remote sensing products are generally very demanding both in terms of data quality and coverage/revisit time. The MANTIS mission (Mission and Agile Nanosatellite for Terrestrial Imagery Services) is being developed to specifically fulfil those requirements using a compact and agile 12U Cubesat system. MANTIS will embark the iSIM90-12U (integrated Standard Imager for Microsatellites) an innovative high-resolution optical payload for Earth Observation missions developed by Satlantis Microsats SL. The payload consists of a compact binocular telescope specifically designed to fit within a volume of 8U, and thus ideal for 12U CubeSat standard platforms. The design relies on iSIM technology, comprised by the integration of four key technologies: a binocular diffraction-limited optical system working at visible and near-infrared wavelength; a high precision, robust and light structure; a set of innovative COTS detectors with 2D CMOS sensors; and a high-performance and reconfigurable on-board processing unit with super-resolution algorithms implemented. Open Cosmos Ltd. as Prime is responsible for the end-to-end space mission service, including the provision of a new generation 12U spacecraft platform, while Terrabotics Ltd. will analyse and provide data to the end users. The mission is funded by the European Space Agency’s InCubed (Investing in Industrial Innovation) program supporting innovative activities related to Earth Observation enabling European industry to compete commercially in the global marketplace. An overview of the development status of the mission will be presented focusing on the consolidation of the payload design and the mission end products.

The CubeSat Infrared Atmospheric Sounder (CIRAS) is a remote sensing instrument under development for the demonstration and technology maturation of hyperspectral infrared sounding in a 6U CubeSat. The CIRAS instrument utilizes a 2D Focal Plane Array (FPA) of High Operating Temperature-Barrier Infrared Detectors (HOT-BIRD). The HOT-BIRD material provides improved uniformity, higher allowable operating temperatures, and lower 1/f noise. The performance of the HOT-BIRD FPA was tested inside a Integrated Dewar and Cryocooler Assembly (IDCA). Testing involved using an external Blackbody Calibrator Target (BCT) to generate numerous images of the object at varying temperatures of the scene. The data acquired was compared to a radiometric model to characterize the responsivity of the detectors. In addition, a solid angle correction was developed to improve the accuracy of the modeling. Real and synthetic images are presented in the comparative analysis to validate the expected responsivity of the detectors through calculation of the quantum efficiency.

Anthropogenic emissions of reactive nitrogen species have significantly increased, largely because of discharges from livestock, agricultural intensification and fertilizer use. Reactive nitrogen affects air quality, sensitive natural ecosystems, and the carbon balance. The proposed mission aims at providing high spatial resolution measurements (<1 km) of NH3. These data will complement future hyperspectral sounding missions, monitoring emissions over industrial, domestic, and agricultural hotspots. The mission is based on a compact hyperspectral imager in the Thermal Infrared spectral range, deployed on a small satellite platform. We report on the mission design and objectives and address the technical feasibility of retrieving NH3 with a small satellite.

blair3sat is a student-run team based in Montgomery County, Maryland, developing a 3U CubeSat. The satellite will include the instrument suite SIRVLAS, which contains an optical instrument and a Radio Frequency (RF) instrument. The objective of the mission is to prove that a set of instruments like SIRVLAS in a CubeSatstyle satellite is able to generate a three-dimensional mapping of ionospheric electron density. The optical instrument will measure OI 777.4 nm emissions in the lower ionosphere in a limb view geometry. Since the 777.4 nm wavelength is emitted from the radiative recombination reaction of O⁺ and e^-, its intensity is proportional to the square of the electron density. Therefore, by measuring the intensity of the 777.4 nm emission, electron densities may be calculated. These electron densities will be used as a reference for the data processing of RF signals. Specifically, correlation between the two instruments is performed through constrained optimization of known ray-tracing PDEs. Mappings of electron density in the ionosphere will allow for a better understanding of radio applications including radar and missile tracking, while allowing for the verification of current atmospheric and climatological models.

In 1951, Birks and Black showed experimentally that the fluorescence efficiency of anthracene bombarded by alphas varies with total fluence. Since 1990, we have found that the Birks and Black relation describes the reduction in emission yield for every tested luminescent material except lead phosphate glass due to proton irradiation. A few years ago, the 3 MeV half brightness fluence for exotic materials like EuD4TEA was measured to be about 3 x 1010 mm-2. Conversely, ZnS:Mn compounds were found to have equivalent half brightness values that are about one thousand times larger. Based on these measurements, EuD4TEA might be a candidate sensor material to monitor large-scale solar events for astronauts in vehicles flying in near earth space. The purpose of this presentation is to show results from our research on exotic EuD4TEA and its use as a radiation sensor for the CAPE-3 1U CubeSat that will launch in the near future.

The Miniaturized Ultraviolet Imager, or MUVI for short is a compact wide field UV imager currently in development at UC Berkeley Space Sciences Laboratory and Cal Poly, San Luis Obispo. MUVI is designed to fit in a 2U CubeSat form factor and provide wide field, high resolution images of the ionosphere at far ultraviolet wavelengths. This paper details the design and analyses of MUVI’s primary structure and detector mounting flexure. The team has developed a novel approach for replicating the boundary conditions of a CubeSat dispenser for on-ground vibration testing. Design challenges, including accommodation of a deployable optic and meeting volume constraints of a 2U envelope, are discussed in detail. Existing prototype subassemblies and mass models were integrated and aligned to the structure prior to environmental testing.

The Arcsecond Space Telescope Enabling Research in Astrophysics (ASTERIA) was a 6-unit CubeSat technology demonstration mission that was built at NASA’s Jet Propulsion Laboratory (JPL) and deployed from the International Space Station (ISS) on November 20^th, 2017. After successfully completing its 90-day primary mission that demonstrated arcsecond-level line-of-sight pointing and focal plane thermal stability for exoplanet detection, it entered an extended mission performing onboard software demonstrations alongside science until end of mission in December 2019. At the end of its lifetime it was being used as a demonstration platform for several experiments, including low earth orbit (LEO) optical navigation operations. With its visible light astrometric camera and stable attitude control system, the ASTERIA spacecraft showed itself to be a capable platform for the imaging of geosynchronous satellites from LEO. This paper will describe the imagery attained in flight and also the image processing algorithms that were developed to render that imagery into navigation quality data. These algorithms dealt with hot pixel filtering, noise modeling, attitude registration, star signal rejection and satellite signal identification. Brightness prediction algorithms used for target selection will also be discussed.

Lunar Ice Cube, scheduled to be launched on ARTEMIS I in late 2021, is a deep space cubesat mission with the goals of demonstrating 1) a cubesat-scale instrument (BIRCHES) capable of addressing NASA HEOMD Strategic Knowledge Gaps related to lunar volatile distribution (abundance, location, and transportation physics of water ice), and 2) cubesat propulsion, via the Busek BIT 3 RF Ion engine. The mission will also demonstrate the AIM/IRIS microcryocooler for the first time in deep space. BIRCHES integration is nearly complete, with several changes made to the thermal design to improve detector performance. Final preflight instrument testing and calibration, our ongoing concern to be emphasized here, have been delayed due to the mandated closure rules of NASA facilities. Lunar Ice Cube, along with two other cubesats deployed from ARTEMIS I, Lunar Flashlight and LunaH-Map, will be the first deep cubesat missions to deliver science data to the Planetary Data System.

Increased opportunities to fly payloads on orbital, lander, and/or rover platforms will greatly facilitate the meeting of high priority goals for lunar exploration and lunar science, especially those requiring distributed measurements on multiple platforms to be fully realized. Compact, robust versions of instruments, designed to be integrated with a variety of platforms, or utilized in astronaut-deployed or handheld devices are already under development. These include cameras, spectrometers, particle analyzers, field instruments, and seismometers.

The current global ocean vector wind dataset is refreshed 2-3 times per day, making it difficult to observe the planetary boundary layer on hourly timescales across hundreds of kilometers. A constellation of many satellite scatterometers could measure global, hourly winds, but current scatterometers are too costly for high-quantity deployment. To rapidly search for low-cost designs, we have developed a full-system, parametric extrema model for satellite wind scatterometer constellations. The model predicts ranges of performance for metrics covering backscatter measurement, wind retrieval, spatial resolution, refresh rate, satellite power, temperature, data flow, and cost. We evaluate the model quality by comparing its predicted performance to the actual performance of several extant scatterometers. The model performs well on most performance metrics, but further work is required to refine the normalized standard deviation model to account for pulse compression.

In order to expand the versatile applications of CubeSat, which rely on autonomous cooperative rendezvous and docking instruments, multiple mother–daughter units are arranged together for on–orbit servicing. In the final approach phase, camera type rendezvous and docking sensors are ideal in designing trajectory with relative attitude measurement between the target and the chaser units for the final approach operations. In the development of space rendezvous and docking cameras for CubeSat, the docking lens must be customized according to the requirements of the appropriate specifications in order to install the small instruments for the final approach phase. Customized design of small space–docking lens should also fulfill the specification requirements of using radiation resistant glass materials and small enough in size. This paper introduces an optical design of the customized space–docking lens to be applied in CubeSat.

We have developed the PolCube payload, a polarimeter camera for 12U CubeSat mission, in order to demonstrate the performance feasibility technically since 2019. Main objectives of the PolCube camera are the dust detection around Korean peninsula and monitoring super-thin clouds distribution on global oceans. KASI and Korean consortium members maintain a good collaboration with NASA LaRC team in this project. PolCube is a compact payload under 5kg in mass and under 15W in power consumption. This payload has two optical heads, two detectors with 1280 x 1024 CMOS array format, and two filter sets with 4 wavelengths and 0, 60, 90, 120 polarization angles. Each optical head has a field of view of 10 degrees (Swath width ~ 98km) at the altitude of 567km Sun-synchronous orbit. 12U CubeSat spacecraft will be made by a CubeSat company managed by Busan city & KIOST in Korea. In this paper, we will describe the current design of the PolCube payload development.