Launched on SpaceX Dragon vehicle on June 29, 2018, JPL's ECOSystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) instrument has successfully completed over five years in space and captured a number of important lessons learned. ECOSTRESS is a cryogenic instrument developed by the Jet Propulsion Laboratory for NASA. The mission lifetime for the instrument was 1-year, but because of its success and important science of high value, it has been granted several extensions to continue with on-orbit operations. ECOSTRESS is manifested to remain on-board the International Space Station (ISS) through Fiscal Year 2028. ECOSTRESS is a multispectral thermal infrared scanner with five spectral bands at 8-12.5 ?m for science and a band at 1.6 ?m for hot targets and cloud detection. ECOSTRESS provides data with 38m in-track by 69m cross-track spatial resolution and radiometric accuracy of 1 K and nominal precision of ? 0.3 K. A double-sided scan mirror, rotating at 25.4 rpm, allows the telescope to view a 53°wide nadir cross-track swath width of 402km and two internal blackbody calibration targets every 1.29 seconds. The thermal control subsystem maintains the instrument components within the allowable flight temperature limits. Its 13.2 ?m-cutoff Mercury Cadmium Telluride focal plane detector is cooled to 65 K by a pair of pulse tube cryocooolers and a third identical cryocooler cools an intermediate cold shield to 135 K. Waste heat generated by the cryocoolers and electronics is removed via heat exchangers cooled by a circulating pumped fluid loop provided by JAXA's JEM-EF module. Soon after the cold shield and focal plane cooled to their operating temperatures, ice contamination on focal plane and cold shield was detected. This paper provides a general overview of the cryogenic system and presents its on-orbit performance including impacts from ice contamination buildup and coolant fluid loop temperature changes.

As we look forward to the next generation of hyperspectral infrared (IR) atmospheric sounders, grating spectrometers hold promise for improved performance (e.g., horizontal and spectral resolutions) and more rapid revisit while reducing the size and complexity of the instrument. We briefly revisit the technology used in the Atmospheric Infrared Sounder (AIRS), recognizing that it was developed in the 1990’s and has matured key technologies in the areas of IR detectors, optical coatings, gratings, and cryocoolers. AIRS has been an unqualified success not only as a science and operational mission but also as a technology demonstration of the reliability and simplicity of grating spectrometer IR sounding instruments. Advancements in focal plane arrays (FPAs) have enabled a new class of grating spectrometer IR sounders that offer more spectral channels on a single FPA, mitigating some of the issues seen in AIRS that used linear arrays. These improvements have been manifested in the CubeSat Infrared Atmospheric Sounder (CIRAS) brassboard instrument, developed at the California Institute of Technology Jet Propulsion Laboratory with industry partner Ball Aerospace. Further enhancements beyond those used in CIRAS enable the development of a new class of instruments with a very long-wavelength infrared response and a very high spatial resolution (<2 km) that can be used for the next generation of IR sounders. Grating spectrometers provide advantages over other methods, including smaller apertures due to the ability to use larger FPAs, having no moving parts or laser metrology systems to produce spectra, lower internal FPA readout rates, and lower overall system data rates.

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.

Abstract. 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 winds. We focus 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 National Oceanic and Atmospheric Administration (NOAA) Office of Projects, Planning, and Analysis (OPPA). The CIRAS approach incorporates key instrument technologies, developed at the Microdevices Lab (MDL) at Jet Propulsion Laboratory (JPL), including a two-dimensional 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 a mid-wavelength infrared grating spectrometer 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 the CIRAS payload including a HOT-BIRD focal plane assembly, 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. NOAA is sponsoring the continued development of the CIRAS Proto-Flight Model (PFM) instrument at JPL using many of the existing subsystems. Completion of the PFM is expected in mid 2021, with launch no earlier than 2022.

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 CubeSat Infrared Atmospheric Sounder (CIRAS) is a NASA Earth Science Technology Office (ESTO) sponsored mission to demonstrate key technologies used in very high spectral resolution infrared remote sensing of Earth's atmosphere from space. CIRAS was awarded under the ESTO In-flight Validation of Earth Science Technologies (InVEST) program in 2015 and is currently under development at NASA JPL with key subsystems being developed by industry. CIRAS incorporates key new instrument technologies 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 to provide imaging spectroscopy for atmospheric sounding in a CubeSat volume. The MGS is under development by Ball Aerospace with the grating and slit developed by JPL. The third key technology is a blackbody fabricated with JPL's black silicon to have very high emissivity in a flat plate construction. JPL will also develop the mechanical, electronic and thermal subsystems for CIRAS, while the spacecraft will be a 6U CubeSat developed by Blue Canyon Technologies. This paper provides an overview of the design and acquisition approach, and provides a status of the current development.

The CubeSat Infrared Atmospheric Sounder (CIRAS) will measure upwelling infrared radiation of the Earth in the MWIR region of the spectrum from space on a CubeSat. CIRAS will demonstrate two new infrared sounding technologies. The first is 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 detectors are hybridized to a commercial ROIC and commercial camera electronics. The second technology is an MWIR Grating Spectrometer (MGS) to be designed and developed by Ball Aerospace to provide imaging spectroscopy for atmospheric sounding in a CubeSat volume. The MGS has no moving parts and is based on heritage spectrometers including the Ball Aerospace Spaceborne Infrared Atmospheric Sounder for GEO (SIRAS-G) IIP of 2007. JPL will develop the mechanical, electronic and thermal subsystems for CIRAS. The spacecraft will be a commercially available CubeSat. The integrated system will be a complete 6U CubeSat capable of measuring temperature and water vapor profiles with good lower tropospheric sensitivity. The CIRAS is the first step towards the development of an Earth Observing Nanosatellite Infrared (EON-IR) for potential use in a future operational forecasting system.

The CubeSat Infrared Atmospheric Sounder (CIRAS) will measure upwelling infrared radiation of the Earth in the Midwave Infrared (MWIR) region of the spectrum from space on a CubeSat. CIRAS will demonstrate two new infrared sounding technologies. The first is 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 detectors are hybridized to a commercial Readout Integrated Circuit (ROIC) and commercial camera electronics. The second technology is an MWIR Grating Spectrometer (MGS) to be designed and developed by Ball Aerospace to provide imaging spectroscopy for atmospheric sounding in a CubeSat volume. The MGS has no moving parts and is based on heritage spectrometers including the Ball Aerospace Spaceborne Infrared Atmospheric Sounder for GEO (SIRAS-G) IIP of 2007. JPL will develop the mechanical, electronic and thermal subsystems for CIRAS. The spacecraft will be a commercially available CubeSat. The integrated system will be a complete 6U CubeSat capable of measuring temperature and water vapor profiles with good lower tropospheric sensitivity. The CIRAS is the first step towards the development of an Earth Observing Nanosatellite Infrared (EON-IR) for potential use in a future operational forecasting system.

The Panchromatic Fourier Transform Spectrometer Engineering Model (PanFTS-EM) instrument is an imaging FTS to meet the requirements of the NASA GEO-CAPE Decadal Survey mission, as well as other missions for atmospheric composition and carbon cycle studies from geostationary orbit. PanFTS-EM is a flight-like engineering model which emulates the critical functions of the PanFTS flight instrument under realistic flight conditions.

The Jet Propulsion Laboratory (JPL) has identified the Thales LPT9510 pulse tube cryocooler as a candidate low cost cryocooler to provide active cooling on future cost-capped scientific missions. The commercially available cooler can provide refrigeration in excess of 2 W at 100K for 60W of power. JPL purchased the LPT9510 cooler for thermal and dynamic performance characterization, and has initiated the flight qualification of the existing cooler design to satisfy near-term JPL needs for this cooler. The LPT9510 has been thermally tested over the heat reject temperature range of 0C to +40C during characterization testing. The cooler was placed on a force dynamometer to measure the selfgenerated vibration of the cooler. Iris Technology has provided JPL with a brass board version of the Low Cost Cryocooler Electronics (LCCE) to drive the Thales cooler during characterization testing. The LCCE provides precision closed-loop temperature control and embodies extensive protection circuitry for handling and operational robustness; other features such as exported vibration mitigation and low frequency input current filtering are envisioned as options that future flight versions may or may not include based upon the mission requirements. JPL has also chosen to partner with Iris Technology for the development of electronics suitable for future flight applications. Iris Technology is building a set of radiation-hard, flight-design electronics to deliver to the Air Force Research Laboratory (AFRL). Test results of the thermal, dynamic and EMC testing of the integrated Thales LPT9510 cooler and Iris LCCE electronics is presented here.

The Mars Science Laboratory (Curiosity) landed successfully on Mars on August 5, 2012, eight months after launch. The chosen landing site of Gale Crater, located at 4.5 degrees south latitude, 137.4 degrees east longitude, has provided a much more benign environment than was originally planned for during the critical design and integration phases of the MSL Project when all possible landing sites were still being considered. The expected near-surface atmospheric temperatures at the Gale Crater landing site during Curiosity's primary mission (1 Martian year or 687 Earth days) are from −90°C to 0°C. However, enclosed within Curiosity's thermal control fluid loops the Chemistry and Mineralogy (CheMin) instrument is maintained at approximately +20°C. The CheMin instrument uses X-ray diffraction spectroscopy to make precise measurements of mineral constituents of Mars rocks and soil. The instrument incorporated the commercially available Ricor K508 Stirling cycle cryocooler to cool the CCD detector. After several months of brushing itself off, stretching and testing out its subsystems, Curiosity began the exploration of the Mars surface in October 2012. The CheMin instrument on the Mars Science Laboratory (MSL) received its first soil sample from Curiosity on October 24, and successfully analyzed its first soil sample. After a brief review of the rigorous Ricor K508 cooler qualification tests and life tests based on the original MSL environmental requirements this paper presents final pre-launch instrument integration and testing results, and details the operational data of the CheMin cryocooler, providing a snapshot of the resulting CheMin instrument analytical data.

NASA's Orbiting Carbon Observatory (OCO) was designed to make measurements of carbon dioxide concentrations from space with the precision and accuracy required to identify sources and sinks on regions scales (~1,000 km). Unfortunately, OCO was lost due to a failure of the launch vehicle. Since then, work has started on OCO-2, planned for launch in early 2013. This paper will document the OCO instrument performance and discuss the changes planned for the OCO-2 instrument.

The Orbiting Carbon Observatory (OCO) will carry a single science instrument scheduled for launch on an Orbital Sciences Corporation LeoStar-2 architecture spacecraft bus in December 2008. The science objective of the OCO instrument is to collect spaced based measurements of atmospheric CO2 with the precision, resolution, and coverage needed to identify CO2 sources and sinks and quantify their seasonal variability. The instrument will permit the collection of spatially resolved, high resolution spectroscopic observations of CO2 and O-2 absorption in reflected sunlight over both continents and oceans. These measurements will improve our ability to forecast CO2 induced climate change. The instrument consists of three bore-sighted, high resolution grating spectrometers sharing a common telescope with similar optics and electronics. One spectrometer is used for O-2 observations with a 0.765 pm channel, while the weak and strong CO2 bands are observed with 1.61 pm and 2.06 pm channels, respectively. The high-resolution spectrometers will measure reflected sunlight to retrieve the column-averaged CO2 dry air mole fraction, X-CO2. An extensive validation and correlation measurement program was developed for this mission to ensure that X-CO2 can be retrieved with precisions of 0.3% (1 ppm) on regional scales (8 degrees x 10 degrees). The nominal mission lifetime for the instrument is 2 years. The OCO spacecraft will be placed in a sun-synchronous near-circular polar orbit with an inclination of 98.2 degrees, mean altitude of 705 km, 98.9 minute orbit period and 1:26 pm ascending node.The thermal control system consists of passive and active elements to maintain the instrument within allowable flight temperature (AFT) limits. Passive thermal control includes multilayer insulation (MLI) blankets, thermal straps, and surface coatings to manage the transfer of waste energy from sources through structures and ultimately to radiators. Two detectors are cooled to 120 K and the third to 180 K by means of a mechanical pulse tube cryocooler. The optical bench is cooled to -5 degrees C with an outboard radiator. The instrument was fully integrated in December 2007 and has undergone EMI/EMC, vibration and two thermal vacuum (TV) tests. A general overview of the thermal control system with an emphasis on the two-phase heat rejection system (HRS) as well as the cryogenic subsystem is presented. The paper describes the instrument thermal requirements, thermal control and analysis approach, key design drivers and analysis results.

We present progress on developing a mechanical and thermal isolation package for maintaining multi-stage temperature control for various parts of a dewar package. Our long-wave QWIP focal plane is maintained at 40K while our optics package, which is at close proximity (~2mm) to the FPA, is maintained at 80K. Radiative baffling is controlled at acceptable levels using high conductance heat sinks, while conductance loads are minimized using proper insulating materials (polyimide synthetics) in combination with materials to preserve high structural stiffness (titanium, invar). Furthermore, the optics package is held at low cryogenic temperatures only ~ 6mm from the ZnSe dewar window. An effort is made to keep the complete electro-optical system at these low temperatures independently using only a single 10W low EM-noise closed cycle cryocooler. Proper geometry is defined which takes into account thermal symmetries and mechanical structural stability, while maintaining the necessary external 300K heat sinks. Both conductance and radiative loading on the opto-mechanical structure are examined using finite element analysis and proper heat sinking is established to thermally isolate the optics within the dewar jacket while maintaining proper structural stability. A custom LCC is designed which maximizes the thermal expansion budget between the FPA and optics package, while necessary structural mounting of the electronics boards are coupled with the dewar coldfinger.