LightWorks (United States)

Operational space-to-ground free-space optical communication requires robust, rapidly deployable ground terminals that can perform in real-world environments. Archangel Lightworks has developed the TERRA-M: a compact, weatherproof optical ground station designed for quick deployment and autonomous operation in support of high-throughput, proliferated space networks. The current system is multi-mission capable, and software defined, supporting both CCSDS O3K and SDA OCT standards. This paper presents initial results from field trials of the system, including commissioning, pointing acquisition and tracking performance, and S2G link testing with a LEO LCT. These results validate the ground terminal's potential for scalable global optical ground networks and inform the next steps in operational readiness.

Thermodynamic modeling of metal oxide reduction is crucial for optimizing chemical processes and materials in systems dependent on off-stoichiometric reduction/re-oxidation cycling. Two prevalent methods for extracting reduction thermodynamics from thermogravimetric data are linearized van ‘t Hoff (VH) analysis and the compound energy formalism (CEF). This work evaluates the accuracy of these methods by constructing invertible ground truth thermodynamic models, generating hypothetical thermogravimetric data, and determining the reduction thermodynamic using both VH and CEF methods. Our findings reveal that the VH method produces absolute errors 3–5 times higher than the CEF in kJ/mol O or J/mol O K for enthalpy and entropy of reduction, respectively. In contrast, the CrossFit CEF (CF-CEF) method yields errors often less than 10 kJ/mol O or J/mol O K. Moreover, the CF-CEF method provides models based on mole fraction, temperature, and extent of reduction, while a typical VH analysis provides thermodynamics of only the specific compositions measured. Although simple to implement, the VH method suffers from significant, non-systematic errors due to entropy/enthalpy compensation and defect modeling. Consequently, we recommend the more complex but robust, CF-CEF method for extracting redox thermodynamics from thermogravimetric measurements.

Abstract A two‐step solar thermochemical looping cycle based on Co3Mo3N/Co6Mo6N reduction/nitridation reactions offers a pathway for green NH3 production that utilizes concentrated solar irradiation, H2O, and air as feedstocks. The NH3 production cycle steps both derive process heat from concentrated solar irradiation and encompass 1) the reduction of Co3Mo3N in H2 to Co6Mo6N and NH3; and 2) nitridation of Co6Mo6N to Co3Mo3N with N2. Co3Mo3N reduction/nitridation reactions are examined at different H2 and/or N2 partial pressures and temperatures. NH3 production is quantified in situ using liquid conductivity measurements coupled with mass spectrometry (MS). Solid‐state characterization is performed to identify a surface oxygen layer that necessitates the addition of H2 during cycling to prevent surface oxidation by trace amounts of O2. H2 concentrations of > 5% H2/Ar and temperatures >500 °C are required to reduce Co3Mo3N to Co6Mo6N and form NH3 at 1 bar. Complete regeneration of Co3Mo3N from Co6Mo6N is achieved at conditions of 700 °C under 25–75% H2/N2. H2 pressure‐swings are observed to increase NH3 production during Co3Mo3N reduction. The results represent the first comprehensive characterization of and definitive non‐catalytic production of NH3 via chemical looping with metal nitrides and provide insights for technology development.

Solar thermochemical hydrogen production is an attractive technology that stores intermittent solar energy in the form of chemical bonds. Efficient operation requires the identification of a redox‐active metal oxide (MOx) material that can achieve high conversion of water to hydrogen at minimal energy input. Water splitting occurs by consecutive reduction and reoxidation reactions of MOx. MOx is reduced to MOx−δ and, in the second step, is reoxidized by water recovering the initial MOx and generate H2. The material must reduce at temperatures achievable in concentrated solar receiver/reactors, while maintaining a thermodynamic driving force to split water. At equilibrium, extent of reduction depends on temperature and oxygen partial pressure, and in this analysis, a set of thermodynamic properties, namely, enthalpy and entropy of oxygen vacancy formation, is sufficient to represent MOx. Herein, a method to easily classify materials based on these thermodynamic properties under any condition of oxygen partial pressure and temperature is presented. This method is based on fundamental thermodynamic principles and is applicable for any redox material with known thermodynamic properties. Despite the simplicity of the method, it is believed that this analysis will support future research in targeting thermodynamic properties of redox‐active metal oxides.

CGH testing of off-axis aspheric segments is augmented using CMM point cloud measurement for highly off-axis aspheric mirrors.