The Far- and Lyman-ultraviolet imaging demonstrator (FLUID) is a rocket-borne arcsecond-level ultraviolet (UV) imaging instrument covering four bands between 92 and 193 nm. FLUID will observe nearby galaxies to find and characterize the most massive stars that are the primary drivers of the chemical and dynamical evolution of galaxies and the co-evolution of the surrounding galactic environment. The FLUID short wave channel is designed to suppress efficiency at Lyman-α (121.6 nm) while enhancing the reflectivity of shorter wavelengths. Utilizing this technology, FLUID will take the first ever images of local galaxies isolated in the Lyman UV (90–120 nm). As a pathfinder instrument, FLUID will employ and increase the technology readiness level of band-selecting UV coatings and solar-blind UV detector technologies, including microchannel plate and solid-state detectors; technologies that are prioritized in the 2022 NASA Astrophysical Biennial Technology Report. These technologies enable high throughput and high sensitivity observations in the four co-aligned UV imaging bands that make up the FLUID instrument. We present the design of FLUID, status on the technology development, and results from initial assembly and calibration of the FLUID instrument.

Flat-fabrication technology may enable the next generation of gigantic deployable architectures devoted to the detection of faint cosmological signals. We assess the applicability of a multifunctional roll-out structure based on shape memory polymer technology for the realization of a large space observatory to measure the cosmological Dark Ages radio signal. Roll-out solutions offer advantageous properties for probe class missions, such as the capability to morph the shape to achieve sufficient structural performance while ensuring high packaging efficiency. We characterize the feasibility of a roll-out observatory in the context of a 5 years-long heliocentric mission scenario. Our preliminary study demonstrates how a four-250 m-long arms architecture with 150 evenly spaced short dipole antennas potentially meets the basic mission requirements dictated by the Dark Ages science case. We conduct a quasi-static structural analysis considering axial and bending loads acting on the arms to assess the structural properties of the proposed architecture, identifying geometric ranges which enable the structure to withstand expected loads while satisfying mass and size constraints. Printable electronics are considered in the design due to the ease of integration with the polymer substrate. In this regard, we explore two distinct electronics configuration options—centralized and decentralized—discussing their benefits in terms of power demand and data management. If successful, such a design may set the stage for future technological development aiming to realize tomographic measurements of the cosmological Dark Ages.

Photonic lantern nulling (PLN) is a method for enabling the detection and characterization of close-in exoplanets by exploiting the symmetries of the ports of a mode-selective photonic lantern (MSPL) to cancel out starlight. A six-port MSPL provides four ports where on-axis starlight is suppressed, while off-axis planet light is coupled with efficiencies that vary as a function of the planet’s spatial position. We characterize the properties of a six-port MSPL in the laboratory and perform the first testbed demonstration of the PLN in monochromatic light (1569 nm) and in broadband light (1450 to 1625 nm), each using two orthogonal polarizations. We compare the measured spatial throughput maps with those predicted by simulations using the lantern’s modes. We find that the morphologies of the measured throughput maps are reproduced by the simulations, though the real lantern is lossy and has lower throughputs overall. The measured ratios of on-axis stellar leakage to peak off-axis throughput are around 10−2, likely limited by testbed wavefront errors. These null-depths are already sufficient for observing young gas giants at the diffraction limit using ground-based observatories. Future work includes using wavefront control to further improve the nulls, as well as testing and validating the PLN on-sky.

The atmospheric dispersion corrector (ADC) of the Gemini Planet Imager (GPI) corrects the chromatic dispersion caused by differential atmospheric refraction (DAR), making it an important optic for exoplanet observation. Despite requiring <5 mas of residual DAR to avoid potentially affecting the coronagraph, the GPI ADC averages ∼7 and ∼11 mas of residual DAR in H and J band, respectively. We analyzed GPI data in those bands to find explanations for the underperformance. We found the model GPI uses to predict DAR underestimates humidity’s impact on incident DAR, causing on average a 0.54 mas increase in H band residual DAR. Additionally, the GPI ADC consistently undercorrects in H band by about 7 mas, causing almost all the H band residual DAR. J band does not have such an offset. Perpendicular dispersion induced by the GPI ADC, potentially from a misalignment in the prisms’ relative orientation, causes 86% of the residual DAR in J band. Correcting these issues could reduce residual DAR, thereby improving exoplanet detection. We also made an approximation for the index of refraction of air from 0.7 to 1.36 microns that more accurately accounts for the effects of humidity.

Large-field telescopes play a significant role in cutting-edge astronomical research fields, such as time-domain astronomy and cosmology. For such telescopes, ensuring symmetrical and uniform imaging across the entire field-of-view (FoV) is pivotal, particularly for areas such as astronomical photometry and astrometry. However, conventional image quality evaluation methods for telescope optical systems have mainly focused on imaging spot size. Other alternative methods, such as ellipticity based methods, also face the challenges of high computational requirements and limited assessment parameters. In addition, establishing a coherent link between the telescope structure and research domains such as photometry has remained a challenge. In response to these challenges, we introduce an assessment approach termed the ray tracing, spot-vector index, and angle (RSVA) approach. This approach offers a fresh perspective on optical systems, prioritizing the depiction of imaging spot shapes. It acts as a valuable supplement to traditional methods and has been effectively employed to analyze four 1-m aperture telescopes with an f-ratio of 3 for a 3 deg FoV. Building on this foundation, the RSVA can be further expanded to explore other research avenues, including exploring the interplay between photometry and telescope systems and guiding large FoV optical design.

Complementary metal-oxide-semiconductor (CMOS) detectors are a competitive choice for current and upcoming astronomical missions. To understand the performance variations of CMOS detectors in the space environment, we investigate the total ionizing dose effects on custom-made large-format X-ray CMOS detectors. Three CMOS detector samples were irradiated with a Co60 source with a total dose of 70 and 105 krad. We test and compare the performance of these detectors before and after irradiation. After irradiation, the dark current increases by roughly 20∼100 times, and the readout noise increases from 3 e− to 6 e−. The bias level at 50 ms integration time decreases by 13 to 18 digital number (DN) at −30°C. The energy resolution increases from ∼150 to ∼170 eV at 4.5 keV at −30°C. The conversion gain of the detectors varies for <2% after the irradiation. Furthermore, there are about 50 pixels in which bias at 50 ms has changed by more than 20 DN after the exposure to the radiation and about 30 to 140 pixels in which the readout noise has increased by over 20 e− at −30°C at 50 ms integration time. These results demonstrate that the performances of large-format CMOS detectors do not suffer significant degeneration in space environment.

We present moes, a ray tracing software package that computes the path of rays through echelle spectrographs. Our algorithm is based on sequential direct tracing with Seidel aberration corrections applied at the detector plane. As a test case, we model the CARMENES VIS spectrograph. After subtracting the best model from the data, the residuals yield an rms of 0.024 pix, setting a new standard for the precision of the wavelength solution of state-of-the-art radial velocity (RV) instruments. By including the influence of the changes of the environment in ray propagation, we are able to predict instrumental RV systematics at the 1 m/s level.