Search NASA⌕ Search

SEARCH · Search NASA

Results for “spacecraft systems”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records

helioLuna: Prospect for cislunar spacecraft and near-earth asteroid detection using heliostat fields at night

We experimentally and computationally investigate a proposed frequency-domain method for detecting and tracking cislunar spacecraft and near-earth asteroids using heliostat fields at night. Unlike imaging, which detects spacecraft and asteroids by their streak in sidereally-fixed long-exposure photographs, our proposed detection method oscillates the orientation of heliostats concentrating light from the stellar field and measures the light’s photocurrent power spectrum at sub-milliHertz resolution. If heliostat oscillation traces out an ellipse fixed in the galactic coordinate system, spacecraft or asteroids produce a peak in photocurrent power spectrum at a frequency slightly shifted from the starlight peak. The frequency shift is on the scale of milliHertz and proportional to apparent angular rate relative to sidereal. Relative phase corresponds to relative angular position, enabling tracking. A potential advantage of this frequency-domain method over imaging is that detectivity improves with apparent angular rate and number of heliostats. Since heliostats are inexpensive compared to an astronomical observatory and otherwise unused at night, the proposed method may cost-effectively augment observatory systems such as NASA’s Asteroid Terrestrial-impact Last Alert System (ATLAS).

79 ASTRONOMY AND ASTROPHYSICS↗

Resolve instrument onboard XRISM: design, integration, and instrument test results

The Resolve instrument onboard the X-Ray Imaging and Spectroscopy Mission (XRISM) consists of an array of 6 × 6 silicon-thermistor microcalorimeters cooled down to 50 mK and a high-throughput X-ray mirror assembly (XMA) with a focal length of 5.6 m. XRISM is a recovery mission of ASTRO-H/Hitomi, and the Resolve instrument is a rebuild of the ASTRO-H Soft X-ray spectrometer (SXS) and the Soft X-ray Telescope (SXT) that achieved energy resolution of ∼ 5 eV FWHM on orbit, with several important changes based on lessons learned from ASTRO-H. The flight models of the Dewar and the electronics boxes were fabricated, and the instrument test and calibration were conducted in 2021. By tuning the cryocooler frequencies, energy resolution better than 4.9 eV FWHM at 6 keV was demonstrated for all 36 pixels and high-resolution grade events, as well as energy-scale accuracy better than 2 eV up to 30 keV. The immunity of the detectors to microvibration, electrical conduction, and radiation was evaluated. The instrument was delivered to the spacecraft system in April 2022. The XMA was tested and calibrated separately. Its angular resolution is 1.27′, and the effective area of the mirror itself is 570 cm 2 at 1 keV and 424 cm 2 at 6 keV. We report the design and the major changes from the ASTRO-H SXS, the integration, and the results of the instrument test.

X-ray↗

Staging of ion propulsion thrusters

Spacecraft thruster systems are disclosed. In some instances, a spacecraft thruster system may include stacked ion thrusters and/or ion thruster layers. The ion thrusters and/or ion thruster layers may be sequentially activated and jettisoned from the thruster system after use.

33 ADVANCED PROPULSION SYSTEMS↗

Outer Radiation Belt Dynamics During the October 2012 Storm Revisited: Rapid Inward Radial Transport From a Dynamic Outer Boundary

Earth's outer radiation belt electron flux is highly variable and can be enhanced by over an order of magnitude over timescales less than one day, as observed during the October 2012 storm. Previous studies of this storm (e.g., Reeves et al., 2013, https://doi.org/10.1126/science.1237743) have invoked local acceleration to explain this. However, here, we argue that the observations can instead be explained by fast inward radial transport. One method often invoked to distinguish between these two acceleration processes is the existence of local peaks in electron phase space density (PSD) as a function of L* at fixed first, M, and second, K, adiabatic invariants. However, this method relies on the assumption that the evolution of the PSD as a function of L* occurs over timescales slower than the satellite orbital period. Here, high spatiotemporal resolution data from the Global Positioning System (GPS) spacecraft constellation is used to show that enhancements in the PSD occur during the October 2012 storm over short timescales not resolvable by the Van Allen Probes. In addition, Geostationary Operational Environmental Satellite spacecraft data also indicate that these enhancements are consistent with relativistic electron injections. A radial diffusion model is shown to reproduce the PSD dynamics observed by the Van Allen Probes, once rapid variations at the simulation outer boundary are included, consistent with GPS data. This verifies that apparently “locally growing” peaks in PSD along high apogee satellite orbits can be produced by fast inward radial transport without requiring the action of any local acceleration processes.

99 GENERAL AND MISCELLANEOUS↗

In-flight performance of the XRISM/Resolve detector system

The Resolve instrument was launched on board the XRISM observatory in early September 2023. The Resolve spectrometer is based on a high-sensitivity X-ray calorimeter detector system (DS) that has been successfully deployed in many ground and sub-orbital spectrometers. However, the Resolve instrument is the first long-term implementation in space. The instrument will provide essential diagnostics for nearly every class of X-ray emitting objects, from galactic supernova remnants to the outskirts of galaxy clusters, without degradation for spatially extended objects. The Resolve DS consists of a 36-pixel microcalorimeter array operated at a heat sink temperature of 50 mK. In pre-flight testing, the DS demonstrated a resolving power of better than 1300 at 6 keV with a simultaneous bandpass from below 0.3 keV to above 12 keV and a timing precision better than 100μs. An anti-coincidence detector placed directly behind the microcalorimeter array effectively suppresses background. The detector energy-resolution budget included terms for interference from the Resolve cooling system and the spacecraft. Additional terms for energy-scale stability, on-orbit effects, and use of mid-grade events were also included, predicting an end-of-life, on-orbit performance for high- and mid-resolution grade events that meet the requirement of 7 eV FWHM at 6 keV. Here, we discuss the actual on-orbit performance of the Resolve DS and compare this with the performance in pre-flight testing, on-orbit predictions, and the almost identical Hitomi/SXS instrument. We will also discuss the on-orbit gain stability, an assessment of on-orbit interference, and measurements of the on-orbit background.

Astronomy and AstroPhysics↗

Air Blast Mesh Sensitivity and Pressure Mapping Study

Nose cone structural and aerodynamic characteristics are essential for intelligent design of aircraft, spacecraft, and ballistic systems. Finite element analysis can be used to help understand the structural integrity and flight characteristics of different nose cones. A mesh sensitivity study was undertaken for a particular nose cone geometry that was used in tests at LANL facilities in order to confirm the integrity of the meshed geometry. A simple cone that best matched closed-form theoretical solutions was modeled, and received good correlation to the theory. Complexity was then added back to the nose cone. Parameters applied to the simple cone were then implemented in the nose cone geometry giving assurance of accuracy after the geometry was changed. Nose cone results averaged 6.3% error for radial displacement when compared with the theoretical. Hoop stress averaged 6.0% error and meridional stress averaged 5.7% error at the finest mesh level. Meshes showed signs of convergence when compared to all three theoretical solutions. Finally, pressure time-history data from LANL computational fluid dynamics simulations was applied to the surface of the final nose cone geometry. The pressure data was interpolated from pressure gauge locations onto nearby meshed elements, which allowed for FEA software to run simulations on the cone with the pressure data as a loading condition. The pressure mapping resulted in the ability to understand the nose cone’s rigid body motion that in turn can inform design of future nose cones.

42 ENGINEERING↗

Systematic analysis of melt pool dynamics in laser processing of mixed powder feedstocks

Functionally graded materials (FGMs) fabricated via additive manufacturing of blended powders offer the potential to spatially tailor properties for new technologies, such as fusion first-wall systems, turbine blades, and spacecraft. However, processing these materials is difficult due to the multiplicity of processing parameters to optimize, all of which must be changed as substrate material, powder feedstock compositions, and melt pool dynamics evolve. Here, this work systematically evaluates the qualitative and quantitative effects of these variables on the melt pool size, shape, composition, and particle distribution in an exemplar Ti-Ta system, and connects the experimental results to Marangoni flow behavior and phenomena observed in other systems. Increasing laser power linearly increases melt pool size and layer thickness, driving engineering considerations such as part/geometrical tolerances. Decreasing laser velocity changes the melt pool shape from lenticular to convex and reduces chemical homogeneity due to extreme thermal and compositional gradients between the melt pool center and boundaries. Thermophysical property differences between the powder feedstock and substrate material, as well as the directionality of the gradient, affect dilution and melt pool dynamics, which in turn affect the melt pool boundary characteristics, shape, and uniformity. Mixed powder feedstocks of intermediate compositions do not behave according to linear interpolations between single-material endpoints, instead building taller and wider melt pools. As such, it is recommended to quantify process maps for at least one intermediate composition in the FGM or multi-material system of interest to ensure optimized processing parameters, predictable melt pool sizes and shapes, and compositional and spatial precision.

Dissimilar↗

Probing cosmic inflation with the LiteBIRD cosmic microwave background polarization survey

LiteBIRD, the Lite (Light) satellite for the study of B-mode polarization and Inflation from cosmic background Radiation Detection, is a space mission for primordial cosmology and fundamental physics. The Japan Aerospace Exploration Agency (JAXA) selected LiteBIRD in May 2019 as a strategic large-class (L-class) mission, with an expected launch in the late 2020s using JAXA’s H3 rocket. LiteBIRD is planned to orbit the Sun–Earth Lagrangian point L2, where it will map the cosmic microwave background polarization over the entire sky for three years, with three telescopes in 15 frequency bands between 34 and 448 GHz, to achieve an unprecedented total sensitivity of $2.2\, \mu$K-arcmin, with a typical angular resolution of 0.5° at 100 GHz. The primary scientific objective of LiteBIRD is to search for the signal from cosmic inflation, either making a discovery or ruling out well-motivated inflationary models. The measurements of LiteBIRD will also provide us with insight into the quantum nature of gravity and other new physics beyond the standard models of particle physics and cosmology. We provide an overview of the LiteBIRD project, including scientific objectives, mission and system requirements, operation concept, spacecraft and payload module design, expected scientific outcomes, potential design extensions, and synergies with other projects.

59 BASIC BIOLOGICAL SCIENCES↗

High-speed Boulders and the Debris Field in DART Ejecta

On 2022 September 26 the Double Asteroid Redirection Test (DART) spacecraft collided with Dimorphos, the moon of the near-Earth asteroid 65803 Didymos, in a full-scale demonstration of a kinetic impactor concept. The companion Light Italian Cubesat for Imaging of Asteroids (LICIACube) spacecraft documented the aftermath, capturing images of the expansion and evolution of the ejecta from 29 to 243 s after the impact. We present results from our analyses of these observations, including an improved reduction of the data and new absolute calibration, an updated LICIACube trajectory, and a detailed description of the events and phenomena that were recorded throughout the flyby. One notable aspect of the ejecta was the existence of clusters of boulders, up to 3.6 m in radius, that were ejected at speeds of up to 52 m s −1 . Our analysis of the spatial distribution of 104 of these boulders suggests that they are likely the remnants of larger boulders shattered by the DART spacecraft in the first stages of the impact. The amount of momentum contained in these boulders is more than 3 times that of the DART spacecraft, and it is directed primarily to the south, almost perpendicular to the DART trajectory. Recoil of Dimorphos from the ejection of these boulders has the potential to change its orbital plane by up to a degree and to impart a non-principal-axis component to its rotation state. Damping timescales for these phenomena are such that the Hera spacecraft, arriving at the system in 2026, should be able to measure these effects.

asteroid dynamics↗

Nanoscale oxidation behavior of carbon fibers revealed with in situ gas cell STEM

Thermal protection systems are used to protect spacecraft payloads during the extreme conditions of atmospheric entry. The backbone of the composite material often used for NASA mission is carbon fiber, which oxidizes at these conditions. This study presents the direct observation of carbon oxidation using in situ Scanning Transmission Electron Microscopy (STEM). A thin section of a commercially-available carbon fiber material containing multiple structures was examined by STEM in a closed-environmental cell in which temperature was raised from 25 to 1050 °C under a steady flow of air. Results show that the random polycrystalline carbon structure oxidized more uniformly and rapidly than the single crystallite region, which oxidized more anisotropically. These findings are the first to directly observe the structural dependence of carbon oxidation rates at these length-scales while also giving important insight into the onset of pitting at various active surface sites, important pieces in fundamentally understanding of carbon oxidation.

36 MATERIALS SCIENCE↗

Energy Evolution from the Chromosphere to the Heliosphere in the 2021 October 28 Solar Eruption

We perform a detailed study of the energetics for a well-observed solar eruption and flare that occurred on 2021 October 28. This event included a GOES class X1.0 flare, a global extreme-UV (EUV) wave, and a coronal mass ejection (CME) that reached speeds of >2000 km s −1 . The event was observed from a variety of spacecraft in NASA’s Heliophysics System Observatory, including multiple missions near Earth, STEREO-A off the Sun-Earth line, and Solar Orbiter, near the Sun-Earth line at about 0.8 au. Using remote sensing, in situ observations, and in some cases scaling laws based on previous observations, we characterize the following quantities: free magnetic energy, energy in nonthermal electrons, energy in nonthermal ions, bolometric energy, energy deposited in the chromosphere, thermal energy radiated in the flare loops, energy dissipated by the EUV wave, CME kinetic and gravitational potential energy, CME energy flux in the heliosphere, and the energy partition in the CME shock. We find that the total energy released during the event is consistent with estimates of the pre-event stored magnetic energy, and the CME kinetic + potential energy dominates the energy partition.

solar coronal mass ejection shocks↗

The Need for a System Science Approach to Global Magnetospheric Models

This perspective advocates for the need of a combined system science approach to global magnetospheric models and to spacecraft magnetospheric data to answer the question “Do simulations behave in the same manner as the magnetosphere does?” (instead of the standard validation question “How well do simulations reproduce spacecraft data?”). This approach will 1) validate global magnetospheric models statistically, without the need for a direct comparison against spacecraft data, 2) expose the deficiencies of the models, and 3) provide physics support to the system analysis performed on the magnetospheric system.

79 ASTRONOMY AND ASTROPHYSICS↗

Enhanced flexibility and thermal conductivity of HfC decorated carbon nanofiber mats

Future-generation spacecraft components allude discovery of novel materials that can withstand extreme environments (>2000 °C). The combined effect of ultra-high temperature ceramics (UHTCs) and carbon fibers (C f ) can satisfy the demanding requirements of aerospace applications. A novel, hybrid, and flexible hafnium carbide (HfC)-decorated carbon nanofiber (C nf ) mat was fabricated via electrospinning. Enhanced thermal stability of the flexible HfC decorated C nf over C nf can be elucidated from the 20-fold increment in thermal conductivity and the onset of degradation at higher temperatures (840 °C). Successful integration of multi-layered sandwich lattice using in-housed fabricated HfC decorated C nf showed retention of the fibrous structure even after extreme spark plasma sintering (SPS) process at 1850 °C. Fabricating a similar multi-layered structure using procured C f was unsuccessful due to bundled agglomeration and micron-sized fibers. High-load indentation suggests that HfC decorated C nf interlayer is stronger (~2.3 times) than the parent UHTC with no cracking at the interface. Compared with the HfC matrix, the indentation-damaged area at the interface reduced up to ~56% due to toughening mechanisms such as C nf , fiber pull-out and bridging. The synthesized HfC decorated Cnf mat is proposed as an ultra-thin filler material for joining similar or dissimilar UHTCs while maintaining similar chemistry and better mechanical integrity at the interface. Furthermore, the findings insinuate a new paradigm in designing hybrid and flexible ceramic-containing materials for thermal protection systems (TPS) of future-generation spacecraft components that can mitigate failure in extreme environments (>2000 °C).

36 MATERIALS SCIENCE↗

Jupiter missions as probes of dark matter

Jupiter, the fascinating largest planet in the solar system, has been visited by nine spacecraft, which have collected a significant amount of data about Jovian properties. In this paper, we show that one type of the in situ measurements on the relativistic electron fluxes could be used to probe dark matter (DM) and dark mediator between the dark sector and our visible world. Jupiter, with its immense weight and cool core, could be an ideal capturer for DM with masses around the GeV scale. The captured DM particles could annihilate into long-lived dark mediators such as dark photons, which subsequently decay into electrons and positrons outside Jupiter. The charged particles, trapped by the Jovian magnetic field, have been measured in Jupiter missions such as the Galileo probe and the Juno orbiter. We use the data available to set upper bounds on the cross section of DM scattering off nucleons, σ χn , for dark mediators with lifetime of order $O$ (0.1–1) s. The results show that data from Jupiter missions already probe regions in the parameter space un- or under-explored by existing DM searches, e.g., constrain σχn of order (10 –41 –10 –39 ) cm 2 for 1 GeV DM dominantly annihilating into e + e – through dark mediators. This study serves as an example and an initial step to explore the full physics potential of the large planetary datasets from Jupiter missions. We also outline several other potential directions related to secondary products of electrons, positron signals and solar axions.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

MULTI-MISSION THERMOELECTRIC GENERATOR ASSEMBLY TESTING AND LAUNCH OPERATIONS FOR MARS 2020

The Space Nuclear Power and Isotope Technologies (SNPIT) division at Idaho National Laboratory (INL) fuels, performs acceptance testing, and provides spacecraft integration support of Radioisotope Power Systems (RPS) in support of National Aeronautics and Space Administration (NASA) missions. Recently the SNPIT team completed assembly, testing and launch support of the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) for the Mars 2020 Perseverance Rover mission.

07 ISOTOPE AND RADIATION SOURCES↗

MULTI-MISSION THERMOELECTRIC GENERATOR ASSEMBLY TESTING AND LAUNCH OPERATIONS FOR MARS 2020

The Space Nuclear Power and Isotope Technologies (SNPIT) division at Idaho National Laboratory (INL) fuels, performs acceptance testing, and provides spacecraft integration support of Radioisotope Power Systems (RPS) in support of National Aeronautics and Space Administration (NASA) missions. Recently the SNPIT team completed assembly, testing and launch support of the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) for the Mars 2020 Perseverance Rover mission.

07 ISOTOPE AND RADIATION SOURCES↗

The Solar System calcium isotopic composition inferred from Ryugu samples

The Hayabusa2 spacecraft has returned samples from the Cb-type asteroid (162173) Ryugu to Earth. Previous petrological and chemical analyses support a close link between Ryugu and CI chondrites that are presumed to be chemically the most primitive meteorites with a solar-like composition. However, Ryugu samples are highly enriched in Ca compared to typical CI chondrites. To identify the cause of this discrepancy, here we report stable Ca isotopic data (expressed as δ 44/40 Ca SRM915a ) for returned Ryugu samples collected from two sites. We found that samples from both sites have similar δ 44/40 Ca SRM915a (0.58 ± 0.03 ‰ and 0.55 ± 0.08 ‰, 2 s.d.) that fall within the range defined by CIs. This isotopic similarity suggests that the Ca budget of CIs and Ryugu samples is dominated by carbonates, and the variably higher Ca contents in Ryugu samples are due to the abundant carbonates. Precipitation of carbonates on Ryugu likely coincided with a major episode of aqueous activity dated to have occurred ~5 Myr after Solar System formation. Based on the pristine Ryugu samples, the average δ 44/40 Ca SRM915a of the Solar System is defined to be 0.57 ± 0.04 ‰ (2 s.d.).

79 ASTRONOMY AND ASTROPHYSICS↗

X-Ray Imaging and Spectroscopy Mission

The X-Ray Imaging and Spectroscopy Mission (XRISM) is a joint mission between the Japan Aerospace Exploration Agency (JAXA) and the National Aeronautics and Space Administration (NASA) in collaboration with the European Space Agency (ESA). In addition to the three space agencies, universities and research institutes from Japan, North America, and Europe have joined to contribute to developing satellite and onboard instruments, data-processing software, and the scientific observation program. XRISM is the successor to the ASTRO-H (Hitomi) mission, which ended prematurely in 2016. Its primary science goal is to examine astrophysical problems with precise, high-resolution X-ray spectroscopy. XRISM promises to discover new horizons in X-ray astronomy. It carries a 6 × 6 pixelized X-ray microcalorimeter on the focal plane of an X-ray mirror assembly (Resolve) and a co-aligned X-ray CCD camera (Xtend) that covers the same energy band over a large field of view. XRISM utilizes the Hitomi heritage, but all designs were reviewed. The attitude and orbit control system was improved in hardware and software. The spacecraft was launched from the JAXA Tanegashima Space Center on 2023 September 6 (UTC). During the in-orbit commissioning phase, the onboard components were activated. Although the gate valve protecting the Resolve sensor with a thin beryllium X-ray entrance window was not yet opened, scientific observation started in 2024 February with the planned performance verification observation program. The nominal observation program commenced with the following guest observation program beginning in 2024 September.

Astronomy and AstroPhysics↗