This PDF file contains the front matter associated with SPIE Proceedings Volume 10769, including the Title Page, Copyright information, Table of Contents, Author and Conference Committee lists

The Institute for Atmospheric and Environmental Research at the University of Wuppertal and the Institute of Energy and Climate Research Stratosphere (IEK-7) at the Research Center Juelich developed a novel CubeSat payload for atmospheric research. The payload consists of a small spectrometer for the observation of airglow at 762 nm. The line intensities of the oxygen A-band are used to derive temperatures in the mesosphere and lower thermosphere (MLT) region. The temperature data will be used to analyze dynamical wave structures in the atmosphere which have become increasingly important for the modeling of the climate system. Integrated in a 6U CubeSat, the instrument needs a highly accurate attitude determination and control system (ADCS) for limb sounding of the atmosphere. The agility of a CubeSat shall be used to sweep the line-of-sight through specific regions of interest to derive a three-dimensional image of an atmospheric volume using tomographic reconstruction techniques.

The spectrometer technology chosen to measure the ro-vibrational structure of the O2 atmospheric band at 762 nm is a Spatial Heterodyne Interferometer (SHI) originally proposed by Pierre Connes in 1958. The throughput of an SHI is orders of magnitude larger than of a conventional grating spectrometer of the same size. It can be designed to deliver extraordinary spectral resolution to resolve individual emission lines. The utilization of a two-dimensional imaging detector allows for recording interferograms at adjacent locations simultaneously. Since an SHI has no moving parts, it can be built as a monolithic block which makes it very attractive for remote sensing, especially from space.

Earth-observing satellite scatterometers are important instruments capable of measuring a variety of geophysical properties. Historically, the scatterometer design space has revolved around two main architectures: the fan beam and the scanning pencil beam. Since the implementation of these architectures, developments in satellite- relevant technology, spacecraft standards, and engineering practice have expanded the potential design space for Earth-observing scatterometer systems. This expanded design space is investigated and example designs are presented that utilize the expanded design space to improve performance and reduce cost.

A low cost, low power, and low mass GNSS receiver (called Cion) has been developed and is currently flying on the CICERO cubesats. The receiver was designed in less than a year by JPL for Tyvak and GeoOptics for use in the GeoOptics CICERO constellation and leverages 25 years of JPL GNSS receiver design experience. Cion uses a commercial off-the-shelf (COTS) computer along with existing space qualified RF down-converters, software, and firmware to produce atmospheric Radio Occultation (RO) data. By combining a FPGA with dual core ARM processor and an embedded system controller, the Xilinx Zynq processor is an enabling technology that provides a customizable digital signal processing platform integrated into the computer (System on a chip) and enables off-the-shelf hardware to become the main engine behind this software defined radio. Using Linux for the on-board computer allows for fast development times and liberal use of existing open source software libraries. The parts of the receiver that require real-time implementation are performed in the Field Programmable Gate Array (FPGA), which can also be reprogrammed in flight. While the Zynq is not rad hard, the silicon on insulator (SOI) technology is rad tolerant 'by accident', allowing for its use in many space-based applications. Early results show that the Cion is working as designed, has demonstrated the first known GLONASS occultations, and obtains high quality atmospheric profiles with excellent lower troposphere penetration (near Earth’s surface).

Hyperspectral infrared sounding in a CubeSat will provide a new dimension to the current suite of IR sounders by allowing measurements at multiple times of day and enabling formation flying of IR sounders for new data products such as Atmospheric Motion Vector (AMV) winds. This paper focuses on technology development during the CubeSat Infrared Atmospheric Sounder (CIRAS) project sponsored by the NASA Earth Science Technology Office (ESTO), and coincident studies by the NOAA Office of Projects, Planning, and Analysis (OPPA). The CIRAS approach incorporates key new instrument technologies developed at JPL’s Microdevices Lab (MDL) including a 2D array of High Operating Temperature Barrier Infrared Detector (HOT-BIRD) material, selected for its high uniformity, low cost, low noise and higher operating temperatures than traditional materials. The second key technology is an MWIR Grating Spectrometer (MGS) designed by Ball Aerospace with a JPL MDL slit and immersion grating to provide hyperspectral infrared imaging in a CubeSat volume. The third key technology is a blackbody calibration target fabricated with MDL’s black silicon to have very high emissivity in a flat plate construction. JPL has completed design and breadboard of the mechanical, electronic and thermal subsystems for CIRAS payload including a HOT-BIRD FPA, with filters in a dewar and a breadboard of the electronics and scan mirror assembly. Blue Canyon Technologies, developer of the CIRAS 6U CubeSat, completed the Final Design Review for the spacecraft.

The need for advanced cooled electro-optical instrumentation in remote observations of the atmosphere is well known and demonstrated by SABER on the TIMED mission. The relatively new use of small satellites in remote earth observing missions as, well as the challenges, are epitomized by the upcoming NOAA EON-IR 12U CubeSat missions. These advanced CubeSat missions, which hope to accomplish scientific objectives on the same scale as larger more traditional satellites, require advanced miniaturized cryocoolers and active methods for thermal management and power control. The active CryoCubeSat project (ACCS) is a demonstration of such a technology. Utilizing Ultrasonic Additive Manufacturing (UAM) techniques, a Mechanical Pumped Fluid Loop (MPFL), and miniature pumps and cryocoolers to create a closed loop fluid-based heat interchange system. The ACCS project creates a two-stage thermal control system targeting 6U CubeSat platforms. The first stage is composed of a miniature Ricor K508N cryocooler while the second is formed by a UAM fabricated heat exchanger MPFL system powered by a micro TCS M510 pump. The working fluid is exchanged between a built-in chassis heat exchanger and a deployable tracking radiator. This work details the theory design and testing of a relevant ground-based prototype and the analysis and modeling of the results as well as the development of a design tool to help in customized active thermal control designs for small satellites. Ultimately, the ACCS project hopes to enable a new generation of advanced CubeSat atmospheric observing missions.

Recent technology advances in miniature microwave radiometers that can be hosted on very small satellites has made possible a new class of affordable constellation missions that provide very high revisit rates of tropical cyclones and other severe weather. The Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats (TROPICS) mission was selected by NASA as part of the Earth Venture–Instrument (EVI-3) program and is now in development with planned launch readiness in late 2019. The overarching goal for TROPICS is to 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 (TCs). 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 will comprise a constellation of at least six CubeSats in three low-Earth orbital planes. Each CubeSat will host a high performance radiometer to provide temperature profiles using seven channels near the 118.75 GHz oxygen absorption line, water vapor profiles using three channels near the 183 GHz water vapor absorption line, imagery in a single channel near 90 GHz for precipitation measurements (when combined with higher resolution water vapor channels), and a single channel at 205 GHz that is more sensitive to precipitation-sized ice particles and low-level moisture. This observing system offers an unprecedented combination of horizontal and temporal resolution in the microwave spectrum to measure environmental and inner-core conditions for TCs on a nearly global scale and is a major leap forward in the temporal resolution of several key parameters needed for assimilation into advanced data assimilation systems capable of utilizing rapid-update radiance or retrieval data. Here, we provide an overview of the mission and an update on current status, with a focus on unique characteristics of the Cubesat system, recent performance simulations on a range of observables to be provided by the constellation, and a summary of science applications.

The objective of this research is to evaluate the potential for CubeSats and other small satellite constellations to mitigate a potential data gap and/or improve numerical weather forecasts. This is conducted as a collaborative project involving NOAA AOML and NESDIS/STAR, CIMSS, and the University of MD. To this end, a series of Observing System Simulation Experiments (OSSEs) is being conducted. These experiments utilize both global and regional OSSE systems. Specific instruments being evaluated include the CubeSat Infrared Atmospheric Sounder (CIRAS), the Micro-sized Microwave Atmospheric Sounder-2 (MicroMAS-2), the Cyclone Global Navigation Satellite System (CYGNSS), and the Time-Resolved Observations of Precipitation and storm Intensity with a Constellation of Smallsats (TROPICS) mission. The diverse set of OSSEs that have been performed to date show potential for each of these systems to mitigate a data gap and to contribute to improved prediction and begin to quantify their relative impacts.

The Snow and Water Imaging Spectrometer (SWIS) is a science-grade imaging spectrometer and telescope system suitable for CubeSat applications, spanning a 350-1700 nm spectral range with 5.7 nm sampling, a 10 degree field of view and 0.3 mrad spatial resolution. The system operates at F/1.8, providing high throughput for low-reflectivity water surfaces, while avoiding saturation over bright snow or clouds. The SWIS design utilizes heritage from previously demonstrated instruments on airborne platforms, while advancing the state of the art in compact sensors of this kind in terms of size and spectral coverage. We provide an overview of the preliminary spacecraft configuration design for accommodation in a 6U CubeSat platform.

Hawkeye is an ocean color instrument that is part of the SeaHawk satellite developed for SOCON, the Sustained Ocean Color Observations using Nanosatellites program funded by the Gordon and Betty Moore Foundation and managed by the University of North Carolina – Wilmington (UNC-W). HawkEye has spectral characteristics similar to SeaWiFS, but with 8 times finer resolution and a smaller field of view more appropriate for lakes, rivers, and near-shore terrestrial environments. With a volume of only 10 × 10 × 10 cm (a CubeSat 1U), it can produce 8 bands of image data in a single pass, each with 1800 × 6000 pixels, with a resolution of 120 meters per pixel. This paper will present a short summary of instrument design, the spacecraft interface, and "lessons learned" during this effort. Scientists considering using linear arrays in a pushbroom mode for remote sensing will find this useful. Much of the discussion will center on optical performance, such as flat field calibration, polarization effects, stray light, out-of-band response, and exposure linearity. Images from field tests will be shown.

Signals-of-Opportunity (SoOp) reflectometry is a concept for reutilizing existing microwave satellite transmissions, in bands allocated for space-to-Earth communications and navigation, for the purpose of Earth remote sensing. SoOp uses a bistatic radar geometry employing forward scatter, which views Earth differently from traditional monostatic (backscatter) radars and radiometers. Additionally, SoOp enables use of microwave frequencies outside the limited number of narrow and protected bands allocated for remote sensing. A powerful example of the science returns achievable using SoOp is currently being demonstrated on orbit by the NASA’s Cyclone Global Navigation Satellite System (CYGNSS) mission, which measures ocean surface wind speed using reflected Global Positioning System (GPS) signals. Over the past decade we have seen a growing number of communication and navigation signals coming into existence spanning the range of frequencies from Very High Frequency (VHF) to K Bands, which could be used to measure different variables using wavelengths optimally suited to specific interactions with the Earth system, including: Soil Moisture; Sea Surface Height; Ocean Vector Winds; Snow Water Equivalent; Root Zone Soil Moisture; and Vegetation Water Content. The use of SoOp for earth remote sensing could enable these measurements from small passive receivers in Low Earth Orbit (LEO) on CubeSat constellations to improve the temporal frequency of the observations. This paper describes different architectures of CubeSats constellations that could be used to measure different science measurements as well as identifying some of the challenges of the SoOp technique.

The Arkyd-6 (A6) satellite is a technology demonstration CubeSat designed and manufactured by Planetary Resources, the first of which was successfully launched on PSLV C-40 on January 12, 2018. Onboard the A6 satellite is a broadband midwave-infrared instrument sensitive from 3.4 - 5.1 microns. The instrument was designed around upselected COTS components, then modified and qualified in-house for operation in low-Earth orbit. From a 505-km orbit, the instrument will achieve a 38-meter GSD and includes a diffraction-limited F/4 lens assembly. The instrument was radiometrically calibrated on the ground for at-lens brightness temperature over this band. This presentation will focus on ground qualification and performance testing, on-orbit instrument commissioning, and instrument performance assessment going into nominal operations.

Cubesats operating in deep space face challenges Earth-orbiting cubesats do not. 15 deep space cubesat 'prototypes' will be launched over the next two years including the two MarCO cubesats, the 2018 demonstration of dual communication system at Mars, and the 13 diverse cubesats being deployed from the SLS EM1 mission within the next two years. Three of the EM1 cubesat missions, including the first deep space cubesat 'cluster', will be lunar orbiters with remote sensing instruments for lunar surface/regolith measurements. These include: Lunar Ice Cube, with its 1-4 micron broadband IR spectrometer, BIRCHES, to determine volatile distribution as a function of time of day; Lunar Flashlight, to confirm the presence of surface ice at the lunar poles, utilizing an active source (laser), and looking for absorption features in the returning signal; and LunaH-Map to characterize ice at or below the surface at the poles with a compact neutron spectrometer. In addition, the BIRCHES instrument on Lunar Ice Cube will provide the first demonstration of a microcryocooler (AIM/IRIS) in deep space. Although not originally required to do so, all will be delivering science data to the Planetary Data System, the first formal archiving effort for cubesats. 4 of the 20 recently NASA-sponsored (PSDS3) study groups for deep space cubesat/smallsat mission concepts were lunar mission concepts, most involving 12U cubesats. NASA SIMPLEX 2/SALMON 3 AO will create ongoing opportunities for low-cost missions as 'rides' on government space program or private sector vehicles as these become available.

The Lunar Flashlight (LF) mission will send a CubeSat to lunar orbit via NASA’s Space Launch System (SLS) test flight. The LF spacecraft will carry a novel instrument to quantify and map water ice harbored in the permanently shadowed craters of the lunar South Pole. The LF instrument, an active multi-band reflectometer which employs four high power diode lasers in the 1-2 μm infrared band, will measure the reflectance of the lunar surface near water ice absorption peaks. We present the detailed instrument design and system engineering required to deploy this instrument within very demanding CubeSat resource allocations.

Far more definitive information on composition is required to resolve the question of origin for the Martian moons Phobos and Deimos. Current infrared spectra of the objects are inconclusive due to the lack of strong diagnostic features. Definitive compositional measurements of Phobos could be obtained using in-situ X-ray, gamma-ray, or neutron spectroscopy or collecting and returning samples to Earth for analysis. We have proposed, in lieu of those methods, to derive Phobos and Deimos compositional data from secondary ion mass spectrometry (SIMS) measurements by calibrating the instrument to elemental abundance measurements made for known samples in the laboratory. We describe the Phobos/Deimos Regolith Ion Sample Mission (PRISM) concept here. PRISM utilizes a high-resolution TOF plasma composition analyzer to make SIMS measurements by observing the sputtered species from various locations of the moons' surfaces. In general, the SIMS technique and ion mass spectrometers complement and expand quadrupole mass spectrometer measurements by collecting ions that have been energized to higher energies, 50-100 eV, and making measurements at very low densities and pressures. Furthermore, because the TOF technique accepts all masses all the time, it obtains continuous measurements and does not require stepping through masses. The instrument would draw less than 10 W and weigh less than 5 kg. The spacecraft, nominally a radiation-hardened 12U CubeSat, would use a low-thrust Solar Electric Propulsion system to send it on a two-year journey to Mars, where it would co-orbit with Deimos and then Phobos at distances as low as 27 km.

Here we describe the Primitive Object Volatile Explorer (PrOVE), a smallsat mission concept to study the surface structure and volatile inventory of comets in their perihelion passage phase when volatile activity is near peak. CubeSat infrastructure imposes limits on propulsion systems, which are compounded by sensitivity to the spacecraft disposal state from the launch platform and potential launch delays. We propose circumventing launch platform complications by using waypoints in space to park a deep space SmallSat or CubeSat while awaiting the opportunity to enter a trajectory to flyby a suitable target. In our Planetary Science Deep Space SmallSat Studies (PSDS3) project, we investigated scientific goals, waypoint options, potential concept of operations (ConOps) for periodic and new comets, spacecraft bus infrastructure requirements, launch platforms, and mission operations and phases. Our payload would include two low-risk instruments: a visible image (VisCAM) for 5-10 m resolution surface maps; and a highly versatile multispectral Comet CAMera (ComCAM) will measure 1) H2O, CO2, CO, and organics non-thermal fluorescence signatures in the 2-5 μm MWIR, and 2) 7-10 and 8-14 μm thermal (LWIR) emission. This payload would return unique data not obtainable from ground-based telescopes and complement data from Earth-orbiting observatories. Thus, the PrOVE mission would (1) acquire visible surface maps, (2) investigate chemical heterogeneity of a comet nucleus by quantifying volatile species abundance and changes with solar insolation, (3) map the spatial distribution of volatiles and determine any variations, and (4) determine the frequency and distribution of outbursts.

Large or even medium sized asteroids impacting the Earth can cause damage on a global scale. Existing and planned concepts for finding near-Earth objects (NEOs) with diameter of 140 m or larger would take ~15-20 years of observation to find ~90% of them. This includes both ground and space based projects. For smaller NEOs (~50-70 m in diameter), the time scale is many decades. The reason it takes so long to detect these objects is because most of the NEOs have highly elliptical orbits that bring them into the inner solar system once per orbit. If these objects cross the Earth's orbit when the Earth is on the other side of the Sun, they will not be detected by facilities on or around the Erath. A constellation of MicroSats in orbit around the Sun can dramatically reduce the time needed to find 90% of NEOs ~100-140 m in diameter.

We are developing an inter-satellite omnidirectional optical communicator (ISOC) that will enable gigabit per second data rates over distances up to 1000 km in free space. Key features of the ISOC include its high data rates and its ability to maintain multiple simultaneous links with other spacecraft. In this paper we present design considerations for the ISOC, including selection of the mission-appropriate geometry, telescope design, receiver design, as well as beam pointing considerations. We also present experimental results obtained with the ISOC prototype. In addition, we present design considerations for a low-Earth-Orbit mission where four ISOC-furnished CubeSats form a swarm suitable for remote sensing. We believe the ISOC could be a technology enabler for future constellation and formation flying CubeSat missions for Remote Sensing.

Remote Laser-Evaporative Molecular Absorption (R-LEMA) spectroscopy is a NASA Innovative Advanced Concepts (NIAC) initiative to develop a sensor capable of remotely probing the molecular composition (as opposed to atomic composition) of cold solar system targets such as asteroids, comets and moons without significant atmospheres from a distant vantage. A continuous-wave laser heats a spot on the distant target; the heated spot forms a “backlighted” source through which the ejected plume is illuminated and target composition is determined from infrared molecular absorption lines. Theory and ongoing laboratory experiments indicate that the sensor concept is valid. To advance the system Technology Readiness Level (TRL), the concept must be demonstrated in the space environment. A formation-flying CubeSat experiment is proposed to demonstrate R-LEMA spectroscopy in the space environment. The main craft is equipped with a high-power laser, spectrometer and auxiliary subsystems necessary for executing the experiment. A second craft serves as target material, flying in formation at a specified distance from the main craft. This paper describes experimental objectives for a CubeSat experiment, including a 6U main craft and 3U target. In-orbit experiments are specified, and a supporting system architecture is derived from experimental objectives. A mechanical design is presented for both crafts, including all subsystem components required for the experiments. An execution sequence for in-orbit experiments is described.

To probe the molecular composition of a remote target, a laser is directed at a spot on the target, where melting and evaporation occur. The heated spot serves as a high-temperature blackbody source, and the ejected substance creates a plume of surface materials in front of the spot. Bulk molecular composition of the surface material is investigated by using a spectrometer to view the heated spot through the ejected plume. The proposed method is distinct from current stand-off approaches to composition analysis, such as Laser-Induced Breakdown Spectroscopy (LIBS), which atomizes and ionizes target material and observes emission spectra to determine bulk atomic composition. Initial simulations of absorption profiles based on theoretical models show great promise for the proposed method. This paper compares simulated spectral profiles with results of preliminary laboratory experiments. A sample is placed in an evacuated space, which is situated within the beam line of a Fourier Transform Infrared (FTIR) spectrometer. A laser beam is directed at the sample through an optical window in the front of the vacuum space. As the sample is heated, and evaporation begins, the FTIR beam passes through the molecular plume, via IR windows in the sidewalls of the evacuated space. Sample targets, such as basalt, are tested and compared to the theoretically predicted spectra.

Surface material on a remote target can be characterized by using a spectrometer to view a laser-heated spot on the target surface through the plume of ejected material. The concept is described as Remote Laser Evaporative Molecular Absorption (R-LEMA) spectroscopy.^1,2 The proposed method is distinct from current stand-off approaches to composition analysis, such as Laser-Induced Breakdown Spectroscopy (LIBS), which atomizes and ionizes target material and observes emission spectra to determine bulk atomic composition. Initial simulations of R-LEMA absorption profiles based on theoretical models show great promise for the proposed method. This paper describes an experimental setup being developed to acquire R-LEMA spectra in the laboratory under controlled conditions that will allow comparison to theoretically predicted spectral profiles. A sample is placed in a vacuum space; a laser beam is directed at the sample, through an optical window. As the sample is heated, and evaporation begins, thermal emission from the heated spot passes through the molecular plume, then out of the vacuum space via infrared windows. The thermal emission is directed into a FT-IR spectrometer, which is equipped with a source-brightness comparator to correct for changes in source intensity during a scan. Targets of known composition are tested and laboratory measurements are compared to the theoretically predicted spectra. Laboratory spectra for composite targets are also presented, including terrestrial rocks and asteroid regolith simulant.

This paper presents the general concepts related the control system design for a formation- ight cubesat experiment. The mission purpose is to analyze the mineral composition of asteroids, as well as to study the dynamic disturbance of a laser shot at the surface of such target. The present state-of-art of the system development, some results, future steps and challenges are discussed. The main idea is to give a general overview about the control demands and their links to the experiment requirements.

A NASA Innovative Advanced Concepts (NIAC) study aims to develop a technique for interrogating the molecular composition of asteroids from an orbiting spacecraft. The measurement concept relies on a high-power laser aboard the spacecraft whose objective is to melt and evaporate a spot on the surface of the target; the heated spot is then viewed by a spectrometer through the plume of ejected material. A CubeSat mission is envisioned as a test of the concept in the space environment, with a laser and spectrometer aboard a main craft, and a target craft flying in formation. A systems analysis is presented to define operational and mechanical characteristics of a laser and optical subsystem for the envisioned CubeSat experiment. Target materials drive the target flux requirement; common compounds found in celestial bodies were evaluated for spectral absorption and thermal properties. Suitable lasers are identified to provide the required flux, taking into account their technical specifications of size, power, intensity, wavelength, laser aperture angle, and analysis of Gaussian beam propagation. Respecting the technical specifications that should be taken into consideration in order to obtain the desired outcome (from the action of the laser), optical components suitable for use in a CubeSat were considered. An optical analysis is presented, based on models of the energy dissipation of the laser beam through optical components and along its path and through the space environment. Results of simulations are presented, including selected scenarios for distance between the laser source and the target.

Remote Laser-Evaporative Molecular Absorption (R-LEMA) spectroscopy is a sensor concept for probing molecular composition of asteroids from an orbiting spacecraft. R-LEMA uses a high-power laser aboard the spacecraft which is used to melt and evaporate a spot on the surface of the target; the heated spot is then viewed by a spectrometer through the plume of ejected material. Research supported by the NASA Innovative Advanced Concepts (NIAC) program aims to adapt a laboratory R-LEMA system for operational tests in the space environment. A CubeSat mission is envisioned as a test of the R-LEMA concept in the space environment, with a laser and spectrometer aboard a main craft, and a target craft flying in formation. A systems analysis is presented for the spectrometer and optical subsystem. For typical targets, selected molecular species are deemed to be important resources, e.g. water, hydrocarbons, economic minerals, etc. Infrared spectra of important resources are reviewed for general characteristics, and operational specifications for the spectrometer and optical subsystem are derived from the spectra. Operational and engineering tradeoffs for grating and FT-IR spectrometers are compared. Speed, resolution and wavenumber accuracy of FTIR designs are preferable, but long-motion interferometers become unwieldy in a CubeSat design. Bruker’s patented two-beam interferometer with double pivot scanning mechanism provides a compact FT-IR compatible with CubeSat geometry. Simulation results are presented for detection of important resources under various operational scenarios using the CubeSat design. Even at low concentrations, detectability of water and hydrocarbons is expected.

A NASA Innovative Advanced Concepts (NIAC) initiative is studying a sensor system for probing the molecular composition of asteroids from an orbiting spacecraft. The measurement concept uses a high-power laser directed at the target; the heated spot is then viewed by a spectrometer through the plume of ejected material. To test the measurement concept in the space environment, an experiment relying on two CubeSats flying in formation is proposed. One spacecraft, the target, carries a sample material; the other is envisioned as a 6U CubeSat carrying the laser and the spectrometer along with all other subsystems necessary for formation flying. A 200 W diode laser is considered, requiring sufficient space, energy supply, and thermal control. The high-power laser cannot run continuously due to limited energy storage availability in CubeSat systems. One alternative is to optimize power usage by running successive short-duration experiments in each orbit. Energy is supplied by a battery bank, which drains during laser operation, and re-charges from a solar photovoltaic array during latent periods. A systems analysis of the energy infrastructure is presented, based on the power rate at the battery input and output throughout a simulated orbit. Solar array and battery pack configurations are simulated to optimize the experiment cycle without depleting the battery. Simulations are run in MATLAB, and results of different hardware and orbital scenarios are discussed. The 200 W laser, powered by off-the-shelf battery and solar array components, will meet all mission requirements.

A satellite in orbit is exposed to external radiation from space, including: solar radiation, reflected light and earth emission. Heat is also generated through its internal components. Thermal design considerations are necessary to prevent any component from being damaged by excessive heating and to guarantee its performance. This paper explores options for thermal control mechanisms onboard a 6U CubeSat that includes a high-power laser. The CubeSat mission represents a space environment demonstration of a NASA Innovative Advanced Concepts (NIAC) project for determining asteroid composition. A Low Earth Orbit (LEO) CubeSat mission is simulated at 650 km altitude, and the sensor system will determine through spectrometric detection the composition of a cold target heated by an on-board laser. An intuitive interface was created using MATLAB’s tool GUIDE, where orbit, altitude and satellite position are input parameters that result in the average temperature at each orbit point, presented on a globe. The challenge is to find devices capable of controlling the temperature on the surfaces of the nanosatellite, and to be efficient enough to handle the heat generated by the laser when it is activated, requiring dissipation and expulsion of approximately 200 W. Mechanical designs tested include thermal straps, heat pipes, passive radiative surfaces and active schemes such as thermal louvres. Based on thermal gradients from analytical simulations and state-of-the-art in CubeSat thermal control, some of the tested thermal control schemes maintain the equipment within its working temperature range. The viability of selected thermal control schemes is discussed in this article.

Numerical simulation of heat transfer on a 6U CubeSat is performed. The spacecraft's primary mission is a space environment demonstration of a NASA Innovative Advanced Concepts (NIAC) project for the measurement of asteroid composition using a high-power laser. The laser works on cycles of 10 seconds on and 10 minutes off. Approximately 200 W is dissipated as heat when the laser is on. Attitude control mechanisms maintain the laser pointing towards the target, and also keep the spacecraft between the sun and the target. Simulations are performed using ANSYS CFX; boundary conditions are inserted as User Defined Functions. Mechanical design includes a network of heat pipes and passive radiative surfaces for heat distribution and expulsion. Four cases are addressed, all with orbit inclination of 90° and 650 km altitude. Two simulations have ascending node equal to 90°, named as hot cases. The remaining two cases have ascending node equal to 0, referred to as cold cases. For the hot case and laser turned off, the maximum and minimum temperatures obtained are 344 K and 282 K, respectively. Temperatures of 352 K and 287 K are found for this same orbit, but with the laser on. For the cold case and laser always off, extreme onboard temperatures are 334 K and 263 K, and with laser working, extremes are 342 K and 268 K. In all simulations the highest temperatures are on surfaces facing the sun while the lowest are on the opposite side. For the operating mode of the laser, its results for range of temperature on orbit are outside the suggested from manufacturer.

In a dual CubeSat system, to send data from the main satellite to the secondary one, and from the main satellite to earth or contrariwise, the transceivers must be chosen in order to achieve high transmission speeds and an optimal balance between efficiency and cost. A proposed experiment goes as follows: the primary satellite uses a spectrometer to gather data from the thermal infrared signal emitted by the target while hit by a laser beam originated from the main satellite; the data is then kept on hold in the main satellite until the next transmission window to the ground station opens and is later stored in-site and prepared for study and research. The proposed spacecraft to ground communication is based on the use of a low-cost UHF/VHF transceiver in the main satellite, used widely in CubeSat communication systems, and a hybrid antenna in the ground station facility and in the CubeSat as well, that is compatible with both frequencies and thus able to receive information sent from the main satellite. The main satellite must also have a receiver to be capable of commands to, and receiving telemetry data from the secondary satellite, which will send this information through the ZigBee (IEEE 802.15.4 RF) standard. This paper compares different transceivers for both satellites and ground station in order to guarantee the fastest and cheapest data transmission for the mission, and also calculates the data volume that will be sent during the entire mission in order to determine which communication equipment will maximize this mission's efficiency.

We have developed the Triple Tiny Ionospheric Photometer (Tri-TIP) as a CubeSat-compatible 1U sensor to obtain high-sensitivity measurements of the far-ultraviolet (FUV) OI 1356 Å airglow for remote sensing of ionospheric density. The Tri-TIP concept evolved from heritage sensors flown on the COSMIC/FORMOSAT-3 (CF3) constellation, and more recently as part of the GPS and Radio Occultation and UV Photometry – Colocated (GROUP-C) experiment on the International Space Station. The concept for all of these sensors is to isolate this emission using heated strontium-fluoride filters to eliminate shorter wavelength emissions such as O I 1304 Å and H I 1216 Å and cesium iodide photocathodes to reduce sensitivity longward of ~1800 Å. There are no other spectral features in this FUV portion of the airglow spectrum at night. However, the nadir-viewing sensors on CF3 observed significant long-wavelength emissions from city lights and moonlit clouds that contaminated the data. The GROUP-C instrument included a sapphire filter that could be alternated with the strontium fluoride to measure and remove this spectral “red leak” from the observations. The Tri-TIP design pairs a heated strontium fluoride filter in line with a sapphire beam splitter that feeds the UV (with spectral leak) and long-wavelength (spectral leak only) signals to two matched photomultiplier tubes (PMTs). A third PMT monitors the signal contribution from high-energy particles and dark current. We present the results from laboratory tests of these components that ensure the high-sensitivity performance of this new optical configuration for ionospheric remote sensing and imaging from a CubeSat platform.

We present on a concept study of the Goddard Miniature Coronagraph (GMC) mission for measuring the plasma flow in the solar corona in the form of solar wind and coronal mass ejections (CMEs). These mass flows can dramatically alter the near-Earth space environment to hazardous conditions posing danger to human technology in space. The primary science objective of the mission is to measure the properties of CMEs, coronal structures, and the solar wind near the Sun. The miniaturization of the coronagraph involves using a single-stage optics and a polarization camera, both of which reduce the size of the coronagraph. GMC will be accommodated in a small satellite that can be built with cubesat material to minimize cost. The development of the Dellingr mission at NASA/GSFC has provided expertise and a clear pathway to build the GMC mission. The hardware and software used for the Dellingr mission are technically sound, so the GMC mission can be fully defined. Software, pointing, control and communications systems developed for GSFC CubeSats can be readily adapted to cut costs. We present orbit options such as an ISS orbit or a Sun synchronous dawndusk polar orbit with the aim of maximizing solar observations.

LetSat is a 20-person undergraduate capstone design team at LeTourneau University. LetSat-1 is currently nearing the end of its preliminary design phase. The primary mission of LetSat-1 will be as a technology demonstrator for GPU-based artificial intelligence hardware. The primary component is a NVIDIA Tegra K1 general purpose GPU, with its associated peripherals. To utilize and demonstrate the capabilities of such a GPU, a novel navigation system is being developed. Using machine vision, the AI will analyze downward-looking photographs taken by an onboard camera to determine instantaneous orbital parameters. It is noted that such a scheme will work above any orbital body with permanent terrain, and it could easily be integrated into interplanetary spacecraft.

Blue Canyon Technologies (BCT) has developed a family of high-performance, turn-key CubeSat platforms (3U, 6U, and 12U) that provide all the necessary features to support remote sensing. The spacecraft core is BCT’s powerful XB1 avionics. The XB1 provides all C&DH, ADCS, EPS, and Software functionality in approximately 1U, which maximizes available volume for the payload and propulsion. This common avionics suite is used throughout the BCT CubeSat product line, which is currently baselined for over 20 missions, totaling over 45 CubeSats for various NASA, University, and commercial programs, such as TEMPEST-D, TROPICS, and PlanetiQ. The XB1 ADCS utilizes dual star trackers, which provide the highest-precision pointing available for CubeSats. On-orbit results from multiple missions have demonstrated less than 5 arcsecond pointing accuracy. BCT is also providing the precision payload scan mechanisms (and the corresponding momentum compensation) for programs such as TEMPEST-D and TROPICS. BCT’s highly-configurable solar panel deployment system (and optional solar array drive) can provide up to 120W of spacecraft power for some CubeSat configurations. The XB1 EPS performs all charge control, and provides selectable switched, regulated voltages to the payload. Battery capacity can be as much as nearly 200 Watt-hours. The C&DH/Comm can support >200Mbps downlink rates, with data storage up to 128GB, and a dedicated payload processor. Various XB spacecraft are also supporting multiple propulsion systems, including cold gas, electric propulsion, and green propellant. This paper will discuss these platform capabilities in more detail, as well as highlight some of the remote sensing missions currently being supported.

Deep space exploration will require laser communication systems optimized for cost, size, weight, and power. To improve these parameters, our group has been developing a photonic integrated circuit (PIC) based on indium phosphide for optical pulse position modulation (PPM). A field-programmable gate array (FPGA) was programmed to serve as a dedicated driver for the PIC. The FPGA is capable of generating 2-ary to 4096-ary PPM with a slot clock rate up to 700 MHz.

Instrument and small satellite missions often lack the budget, engineers, or experience to develop their own ground data and mission operations systems. The Advanced Multi-Mission Operations System (AMMOS) Instrument Toolkit (AIT) is an open source toolkit developed in support of International Space Station and small satellite missions at NASA with the intention of providing critical capabilities for mission development and operations in a light-weight and easily configured suite of tools.

AIT provides capabilities for commanding and sequencing, telemetry processing, scripting via a Python API, Deep Space Network SLE interfaces, and a web-based API and user interface for near real time operations monitoring. AIT aims for installation and configuration simplicity and keeps dependency requirements to a minimum, allowing for the toolkit to be installed and setup in only a few simple steps. Additionally, AIT is licensed under the permissive MIT license and available via public source control systems for ease of adoption and interagency collaboration.

High speed (≥1Ghz) and long distance (≥100km) data communication among CubeSats and NanoSats can accelerate the technology advancement and paves the way for critical applications such as formation flying and remote sensing. Design of a simple, lightweight optical transceiver with full duplex capability, fast-tracking speed and 360° field of regard for CubeSat is crucial due to extreme SWaP-C limitations. In this paper, we describe the design tradeoff between the field of view and collection efficiency in receiver design using Commercial off the Shelf (COTS) optics and detectors. We also briefly discussed the design tradeoffs in transmitter design for optimum performance. We show that to achieve maximum SNR at long distance(≥100km), the laser beam diameter needs to be 80%-90% of the scanning mirror diameter. In addition to that, we show that the intrinsic Field of View (FOV) of high speed(≥600MHz) Avalanche Photodiodes (APD) can be increased to ≥3° by incorporating optimized optics considering form factor of the CubeSat system. In addition, we present a scalable detector array design method using COTS components to achieve a wide full FOV(≥12°) with a uniform collection efficiency around 30%-60%. Furthermore, we demonstrated a multi-wavelength full duplex communication system based on dichroic filters as duplexer that shows significantly low crosstalk. The system also exhibits low transmission power loss(≤4%) as opposed to around 40% that of the conventional beam splitter based system.