Scientific Return Research Articles

Characterization of the DART Impact Ejecta Plume on Dimorphos from LICIACube Observations

We modeled the geometry and the three-dimensional orientation of the ejecta cone triggered by the impact of the DART spacecraft on the asteroid Dimorphos. We used eight LUKE images of the impact acquired by the CubeSat LICIACube that flew by the Didymos system shortly after the impact. These images, which show the ejecta cone in both face-on and side-on profiles, enabled us to reconstruct the ejecta cone in inertial space. We started our model as a simple cone with a circular base and developed it to a rotated cone with an elliptical base that best fit the data. The cone axis points to R.A., decl. (in J2000): , +. The cone is characterized by two perpendicular half-angles of and a rotation of ω = 12° around its axis. The apex of the cone is located near the center of Dimorphos within 15 m. The intersection of the cone and the surface of Dimorphos (surface enclosed by the cone) would correspond to a crater with a maximum radius of about 65 m. The characterization of the cone axis is directly related to the computation of the momentum enhancement factor (β) of the impact, and it hence proves the crucial need of studying impacts in the context of planetary defence scenarios. The results of this work could potentially be used to constrain whether the impact took place in a strength-dominated or a gravity-dominated regime. This work shows the important scientific return of the LICIACube CubeSat in the context of planetary defence.

Analysis, Design, and Optimization of Robust Trajectories in Cislunar Environment for Limited-Capability Spacecraft

Nowadays, the space exploration is going in the direction of exploiting small platforms to get high scientific return at significantly lower costs. However, miniaturized spacecraft pose different challenges both from the technological and mission analysis point of view. While the former is in constant evolution due to the manufacturers, the latter is an open point, since it is still based on a traditional approach, not able to cope with the new platforms’ peculiarities. In this work, a revised preliminary mission analysis approach, merging the nominal trajectory optimization with a complete navigation assessment, is formulated in a general form and three main blocks composing it are identified. Then, the integrated approach is specialized for a cislunar test case scenario, represented by the transfer trajectory from a low lunar orbit to an halo orbit of the CubeSat LUMIO, and each block is modeled with mathematical means. Eventually, optimal solutions, minimizing the total costs, are sought, showing the benefits of an integrated approach.

Photogrammetric 3D reconstruction of Apollo 17 Station 6: From boulders to lunar rock samples integrated into virtual reality

Apollo 17 astronauts spent three days exploring the Taurus Littrow Valley on the Moon in 1972. During their third Extravehicular Activity, they spent more than 1 h at Station 6, a geologic waypoint consisting of three big and two small fragments of a boulder that rolled down the North massif. We have used all the available scanned digital Apollo photos taken by the astronauts at this Station 6 to compute a comprehensive 3D model of the explored area. We used Structure From Motion photogrammetry to automatically derive the position of each of the 154 available images using their overlap. All images were aligned in a single photogrammetric project, which allows on one hand to automatically visualize the astronaut positions during their investigations, and on the other hand to reconstruct in 3D the three main pieces of boulders, therefore constraining their respective size and orientation. In addition to the boulders, we show that the 3D reconstruction by photogrammetry can also be applied to the rock samples taken from the boulders themselves. These samples were systematically photographed from multiple angles at the LPI during the 70s when brought back to Earth. For the reconstruction, we used scanned archived images representing 16 stereoscopic pairs, to compute 3D models of samples 76015, 76215, 76315 and 76275. These models might play a role in preservation as some of the samples, latter sawed for analysis, do not exist anymore in their pristine form. 3D models of the boulders and rock samples can then be manipulated and visualized on a web-based platform. 3D models have also been integrated into a virtual reality scene in order to provide the possibility to investigate their properties at full scale in an immersive and collaborative way. The knowledge of the samples position and orientation directly in their context might for example provide additional constrains to better understand processes such as the space weathering alteration due to micrometeorite impacts and solar wind particle. 3D photogrammetric reconstructions using images taken by rovers and/or astronauts might be one of the basic techniques to consider in forthcoming lunar missions in order to maximize their scientific, educational and outreach return.

PulsarX: A new pulsar searching package

Context. Pulsar surveys with modern radio telescopes are becoming increasingly computationally demanding. This is particularly true for wide field-of-view pulsar surveys with radio interferometers and those conducted in real or quasi-real time. These demands result in data analysis bottlenecks that can limit the parameter space covered by the surveys and diminish their scientific return. Aims. In this paper we address the computational challenge of ‘candidate folding’ in pulsar searching, presenting a novel, efficient approach designed to optimise the simultaneous folding of large numbers of pulsar candidates. We provide a complete folding pipeline appropriate for large-scale pulsar surveys that includes radio frequency interference mitigation, de-dispersion, folding, and parameter optimisation. Methods. By leveraging the fast discrete dispersion measure transform (FDMT) algorithm, we have developed an optimised and cache-friendly implementation that we term the pruned FDMT (pFDMT). This implementation is specifically designed for candidate folding scenarios where the candidates are broadly distributed in dispersion measure space. The pFDMT approach efficiently reuses intermediate processing results and prunes the unused computation paths, resulting in a significant reduction in arithmetic operations. In addition, we propose a novel folding algorithm based on the Tikhonov-regularised least squares method that can improve the time resolution of the pulsar profile. Results. We present the performance of its real-world application as an integral part of two major pulsar search projects conducted with the MeerKAT telescope: the MPIfR-MeerKAT Galactic Plane Survey (MMGPS) and the Transients and Pulsars with MeerKAT (TRAPUM) project. In our processing of approximately 500 candidates, the theoretical number of de-dispersion operations can be reduced by a factor of around 50 when compared to brute-force de-dispersion, which scales with the number of candidates.

Comparative Raman spectroscopy of astrobiology relevant bio‐samples and planetary surface analogs under UV–VIS–IR excitation

AbstractWe investigated the potential of a laser selection in the broad optical range, from ultraviolet through visible to infrared (excitation wavelengths of 325, 532, 785, and 1064 nm) for combined analysis of Earth‐relevant extremophiles (Xanthoria elegans, Buellia frigida, and green alga of Circinaria gyrosa), carbohydrate molecules, as well as Mars and Moon surface regolith simulants as analog mineral mixtures (P‐MRS, S‐MRS, LRS, and JSC‐1). We show that the optimization of the laser photon energy provides (for at least one of the chosen excitation wavelengths) high‐end quality Raman spectra for each examined sample. In most cases, the infrared spectral range is advanced for biological samples, while an excitation in the visible and ultraviolet spectral range is often favorable or at least sufficient for accurate identification/resolution of mineral phases under the illuminated laser spot on the planetary surface simulants. Ultraviolet excitation does not always deliver significant contrast of the Raman Stokes responses to the induced photoluminescence in the studied biomolecules. Most prominent features in the Raman spectra of the biological samples are assigned to their specific pigments, also considered as biomolecular signatures of the extremophiles. The critical issue of specific advantages and limitations of each particular excitation source implies study for gaining scientific return from Raman spectroscopy for exobiological prospecting, for instance, the best trade between a single or dual excitation wavelength(s) for both biological and geological spectral data.

Roman with Rubin

Abstract Steven Gough-Kelly and Rachel Street argue in favour of maximising the science return of major facilities

Dynamic Targeting to Improve Earth Science Missions

Dynamic targeting (DT) is an emerging concept in which data from a lookahead instrument are used to intelligently reconfigure and point a primary instrument to enhance science return. For example, in the smart ice hunting radar (Smart Ice Cloud Sensing project), a forward-looking radiometer is used to detect deep convective ice storms, which are then targeted using a radar. In other concepts, forward-looking sensors are used to detect clouds so that a primary sensor can avoid them. To this end, we have developed several algorithms from operations research and an artificial intelligence/heuristic search to point/reconfigure the dynamic instrument. We present simulation studies of DT for these concepts and benchmark these algorithms to show that DT is a powerful tool with the potential to significantly improve instrument science yield.

Demonstrating Autonomy for Complex Space Missions: A Europa Lander Mission Autonomy Prototype

There is a desire for robotic spacecraft to perform exploration in unknown, dynamic environments. The Europa Lander Mission Concept is one such mission that needs to deal with an extremely limited lifetime and energy supply, manage intermittent communications with long blackouts, face numerous environmental dangers, and ultimately take place too far from Earth to rely on human control. No missions to date have operated with the required level of autonomy and under the same level of communication constraints, uncertainty, and mission concept complexity as this mission. As a result, the viability of the autonomy must be demonstrated before it will be trusted with mission-critical planning. In this paper, we present an autonomous software prototype that can demonstrate and test the ability of different planners and executives to carry out complex, science-centric missions with limited interventions from humans. The prototype uses a hierarchical utility model that is used to maximize both the amount of expected science return as well as the number of mission objectives imposed by the ground. We demonstrate how this system handles some of the autonomous tasks expected of complex space missions such as decision making, in-situ data acquisition and analysis, data prioritization, resource management, and failure response handling in both simulation and on actual hardware. Through several scenario-based experiments we show how different planners and executives can meet the challenges of the Europa Lander Mission Concept. We also demonstrate that this system can be used in concert with a hardware prototype for autonomy field tests.

Photo-zSNthesis: Converting Type Ia Supernova Lightcurves to Redshift Estimates via Deep Learning

Upcoming photometric surveys will discover tens of thousands of Type Ia supernovae (SNe Ia), vastly outpacing the capacity of our spectroscopic resources. In order to maximize the scientific return of these observations in the absence of spectroscopic information, we must accurately extract key parameters, such as SN redshifts, with photometric information alone. We present Photo-zSNthesis, a convolutional neural network-based method for predicting full redshift probability distributions from multi-band supernova lightcurves, tested on both simulated Sloan Digital Sky Survey (SDSS) and Vera C. Rubin Legacy Survey of Space and Time data as well as observed SDSS SNe. We show major improvements over predictions from existing methods on both simulations and real observations as well as minimal redshift-dependent bias, which is a challenge due to selection effects, e.g., Malmquist bias. Specifically, we show a 61× improvement in prediction bias 〈Δz〉 on PLAsTiCC simulations and 5× improvement on real SDSS data compared to results from a widely used photometric redshift estimator, LCFIT+Z. The PDFs produced by this method are well constrained and will maximize the cosmological constraining power of photometric SNe Ia samples.

A multitracer empirically driven approach to line-intensity mapping light cones

ABSTRACT Line-intensity mapping (LIM) is an emerging technique to probe the large-scale structure of the Universe. By targeting the integrated intensity of specific spectral lines, it captures the emission from all sources and is sensitive to the astrophysical processes that drive galaxy evolution. Relating these processes to the underlying distribution of matter introduces observational and theoretical challenges, such as observational contamination and highly non-Gaussian fields, which motivate the use of simulations to better characterize the signal. In this work we present skyline , a computational framework to generate realistic mock LIM observations that include observational features and foreground contamination, as well as a variety of self-consistent tracer catalogues. We apply our framework to generate realizations of LIM maps from the multidark planck 2 simulations coupled to the universemachine galaxy formation model. We showcase the potential of our scheme by exploring the voxel intensity distribution and the power spectrum of emission lines such as 21 cm, CO, [C ii], and Lyman-α, their mutual cross-correlations, and cross-correlations with galaxy clustering. We additionally present cross-correlations between LIM and submillimetre extragalactic tracers of large-scale structure such as the cosmic infrared background and the thermal Sunyaev-Zel’dovich effect, as well as quantify the impact of galactic foregrounds, line interlopers, and instrument noise on LIM observations. These simulated products will be crucial in quantifying the true information content of LIM surveys and their cross-correlations in the coming decade, and to develop strategies to overcome the impact of contaminants and maximize the scientific return from LIM experiments.

Statistical Prediction of [CII] Observations by Constructing Probability Density Functions Using SOFIA, Herschel, and Spitzer Observations

We present a statistical algorithm for predicting the [CII] emission from Herschel and Spitzer continuum images using probability density functions (PDFs) between the [CII] emission and continuum emission. The [CII] emission at 158[Formula: see text][Formula: see text]m is a critical tracer in studying the life cycle of interstellar medium and galaxy evolution. Unfortunately, its frequency is in the far-infrared (FIR), which is opaque through the troposphere and cannot be observed from the ground except for highly red-shifted sources ([Formula: see text]). Typically [CII] observations of closer regions have been carried out using suborbital or space observatories. Given the high cost of these facilities and limited time availability, it is important to have highly efficient observations/operations in terms of maximizing science returns. This requires accurate prediction of the strength of emission lines and, therefore, the time required for their observation. However, [CII] emission has been hard to predict due to a lack of strong correlations with other observables. Here we adopt a new approach to making accurate predictions of [CII] emission by relating this emission simultaneously to several tracers of dust emission in the same region. This is done using a statistical methodology utilizing PDFs among [CII] emission and Spitzer IRAC and Herschel PACS/SPIRE images. Our test result toward a star-forming region, RCW 120, demonstrates that our methodology delivers high-quality predictions with less than 30% uncertainties over 80% of the entire observation area, which is more than sufficient to test observation feasibility and maximize science return. The pickle dump files storing the PDFs and trained neural network module are accessible upon request and will support future FIR missions, for example, GUSTO and FIR Probe.

Spacecraft VLBI tracking to enhance stellar occultations astrometry of planetary satellites

Context. Stellar occultations currently provide the most accurate ground-based measurements of the positions of natural satellites (down to a few kilometres for the Galilean moons). However, when using these observations in the calculation of satellite ephemerides, the uncertainty in the planetary ephemerides dominates the error budget of the occultation. Aims. We quantify the local refinement in the central planet’s position achievable by performing Very Long Baseline Interferometry (VLBI) tracking of an in-system spacecraft temporally close to an occultation. We demonstrate the potential of using VLBI to enhance the science return of stellar occultations for satellite ephemerides. Methods. We identified the most promising observation and tracking opportunities offered by the Juno spacecraft around Jupiter as perfect test cases, for which we ran simulations of our VLBI experiment. Results. VLBI tracking at Juno’s perijove close to a stellar occultation locally (in time) reduces the uncertainty in Jupiter’s angular position in the sky to 250–400 m. This represents up to an order of magnitude improvement with respect to current solutions and is lower than the stellar occultation error, thus allowing the moon ephemeris solution to fully benefit from the observation. Conclusions. Our simulations showed that the proposed tracking and observation experiment can efficiently use synergies between ground- and space-based observations to enhance the science return on both ends. The reduced error budget for stellar occultations indeed helps to improve the moons’ ephemerides, which in turn benefit planetary missions and their science products, such as the recently launched JUICE and upcoming Europa Clipper missions.

Community Education to Foster Facility Engagement: Schools and Data Workshops to Enhance the Scientific Return of DKIST

Community Education to Foster Facility Engagement: Schools and Data Workshops to Enhance the Scientific Return of DKIST

Science Return of Probing Magnetospheric Systems of Ice Giants

Science Return of Probing Magnetospheric Systems of Ice Giants

Increased Science Return of Long Duration Missions Exploring Distant Environments through Autonomous Spacecraft Design

Increased Science Return of Long Duration Missions Exploring Distant Environments through Autonomous Spacecraft Design

Leveraging Artificial Intelligence to Enhance the Science Return of 4π Solar Constellations

Leveraging Artificial Intelligence to Enhance the Science Return of 4π Solar Constellations

Relative Impact of Spacecraft Payload Mass Fraction on Spacecraft Operations and Lifespan

Spacecraft payloads are the sensing components that remain active over time and ensure Spacecraft's capability to perform multiple operations. It determines the rate of mission extension and the amount of scientific return based on extended performance. But it degrades over time due to the continuous process of operation and several space environmental factors. This paper has estimated payload mass fraction using the Spacecraft's data to relate it to the lifetime of orbital Spacecraft. Our prime intent is to check whether the spacecraft payload mass fraction affects the Spacecraft's lifetime concerning the initial hypothesis that the spacecraft mass greatly influences spacecraft lifetime. We derive some mathematical relation and establish a relationship between spacecraft payload mass fraction and lifetime. Finally, to verify our relation, we employ spacecraft data to investigate and interpret reliability behavior based on payload fraction and lifetime relation.

Project Lyra: Another possible trajectory to 1I/’Oumuamua

The first interstellar object to be discovered, 1I/’Oumuamua, exhibited various unusual properties as it was tracked on its passage through the inner solar system in 2017/2018. In terms of the potential scientific return, a spacecraft mission to intercept and study it in situ would be invaluable. As an extension to previous Project Lyra studies, this paper elaborates an alternative mission to 1I/’Oumuamua, this time also requiring a Jupiter Oberth Manoeuvre (JOM) to accelerate the spacecraft towards its destination. The difference is in the combination of planetary flybys exploited to get to Jupiter, which includes a Mars encounter before proceeding to Jupiter. The trajectory identified is inferior to previous finds in terms of higher ΔV requirement (15.6 kms−1), longer flight duration (29 years) and less mission preparation time (launch 2026), however it benefits from a feature absent from previous JOM candidates, in that there is little or no ΔV en route to Jupiter (i.e. a free ride) which means the spacecraft need not carry a liquid propellant stage. This is marginally offset by the higher ΔV needed at Jupiter, requiring either 2 or 3 staged solid rocket motors. As an example, a Falcon Heavy Expendable with a CASTOR 30B booster followed by a STAR 48B can deliver 102kg to 1I/’Oumuamua by the year 2059. Other scenarios with shorter flight durations and higher payload masses are possible.

Phase ratio in single-scattering dust particles: Implication to future DESTINY+ study of asteroid (3200) Phaethon

The phase ratio is defined as a ratio of reflectivity of object at two different phase angles α. This light-scattering characteristic has revealed high sensitivity to physical parameters of a planetary regolith. We investigate the phase ratio of single-scattering irregularly shaped particles with different morphology by means of the discrete dipole approximation. The phase ratio defined at α = 0° and 30° appears to be highly sensitive to the imaginary part of refractive index and less sensitive to the size distribution of target particles; whereas, it is not sensitive to their real part of refractive index and irregular morphology when it attains a high level of disorder. Further, the phase ratio defined at α = 30° and 60° is almost fully insensitive to microphysics of target particles. This feature might help to enhance the scientific return from the future DESTINY+ mission to asteroid (3200) Phaethon.

Informing Volunteer Water Quality Monitoring Program Design and Watershed Planning: Case Study of StreamSmart Data Analysis in the Upper White River Basin, Arkansas

AbstractThe watershed group H2Ozarks founded the StreamSmart Citizen Science Program to establish baseline and long‐term water quality data for the Upper White River Basin, Arkansas. StreamSmart volunteers collect water samples and conduct habitat and macroinvertebrate community assessments at >20 sites across a land use‐land cover (LULC) gradient. Since 2020, H2Ozarks has adaptively assessed the program to ensure that the investment in water quality data meets core goals, with particular interest in planning tools and aligning expectations of volunteer effort with the level of training and support. Study objectives were to use StreamSmart data to 1) facilitate understanding of water quality response to stressors in the basin using a range of methods (Spearman rank correlation, non‐parametric changepoint analysis, and categorical and regression tree analysis) and 2) explore implications for program design and watershed planning. Water chemistry‐LULC relationships were in‐line with prior regional studies, as well as global patterns. Detected thresholds and hierarchy provide potential targets for managing LULC change to protect water quality, but further analysis is warranted to refine these relationships. Macroinvertebrate stressor‐response was most detectable for sensitive and less sensitive taxa and for habitat index components, suggesting potential to streamline these programmatic elements. Study findings for StreamSmart should also be informative for other small‐scale volunteer monitoring programs with limited resources, but which actively evaluate the types of data and program activities that yield a maximum scientific return on investment.