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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.

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At least 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS2011

Technical Tension Between Achieving Particulate and Molecular Organic Environmental Cleanliness: Data from Astromaterial Curation Laboratories

NASA Johnson Space Center operates clean curation facilities for Apollo lunar, Antarctic meteorite, stratospheric cosmic dust, Stardust comet and Genesis solar wind samples. Each of these collections is curated separately due unique requirements. The purpose of this abstract is to highlight the technical tensions between providing particulate cleanliness and molecular cleanliness, illustrated using data from curation laboratories. Strict control of three components are required for curating samples cleanly: a clean environment; clean containers and tools that touch samples; and use of non-shedding materials of cleanable chemistry and smooth surface finish. This abstract focuses on environmental cleanliness and the technical tension between achieving particulate and molecular cleanliness. An environment in which a sample is manipulated or stored can be a room, an enclosed glovebox (or robotic isolation chamber) or an individual sample container.

Allton, J. H.↗
NASA NTRS2012

Cleaning Genesis Mission Payload for Flight with Ultra-Pure Water and Assembly in ISO Class 4 Environment

Genesis mission to capture and return to Earth solar wind samples had very stringent contamination control requirements in order to distinguish the solar atoms from terrestrial ones. Genesis mission goals were to measure solar composition for most of the periodic table, so great care was taken to avoid particulate contamination. Since the number 1 and 2 science goals were to determine the oxygen and nitrogen isotopic composition, organic contamination was minimized by tightly controlling offgassing. The total amount of solar material captured in two years is about 400 micrograms spread across one sq m. The contamination limit requirement for each of C, N, and O was <1015 atoms/sq cm. For carbon, this is equivalent to 10 ng/cm2. Extreme vigilance was used in pre-paring Genesis collectors and cleaning hardware for flight. Surface contamination on polished silicon wafers, measured in Genesis laboratory is approximately 10 ng/sq cm.

Allton, Judith H.↗
NASA NTRS2013

Genesis Ultrapure Water Megasonic Wafer Spin Cleaner

A device removes, with high precision, the majority of surface particle contamination greater than 1-micron-diameter in size from ultrapure semiconductor wafer materials containing implanted solar wind samples returned by NASA's Genesis mission. This cleaning device uses a 1.5-liter/minute flowing stream of heated ultrapure water (UPW) with 1- MHz oscillating megasonic pulse energy focused at 3 to 5 mm away from the wafer surface spinning at 1,000 to 10,000 RPM, depending on sample size. The surface particle contamination is removed by three processes: flowing UPW, megasonic cavitations, and centripetal force from the spinning wafer. The device can also dry the wafer fragment after UPW/megasonic cleaning by continuing to spin the wafer in the cleaning chamber, which is purged with flowing ultrapure nitrogen gas at 65 psi (.448 kPa). The cleaner also uses three types of vacuum chucks that can accommodate all Genesis-flown array fragments in any dimensional shape between 3 and 100 mm in diameter. A sample vacuum chuck, and the manufactured UPW/megasonic nozzle holder, replace the human deficiencies by maintaining a consistent distance between the nozzle and wafer surface as well as allowing for longer cleaning time. The 3- to 5-mm critical distance is important for the ability to remove particles by megasonic cavitations. The increased UPW sonication time and exposure to heated UPW improve the removal of 1- to 5-micron-sized particles.

Allton, Judith H.↗
NASA NTRSDate not supplied

The Genesis Mission: A Unique Opportunity for Scientific Collaboration

The Genesis Solar Wind Sample Return was flown with the goal of creating a baseline of elemental and isotopic solar photospheric composition from solar matter (not rocks!) for use in cosmochemical modeling. No uses for the samples outside of Cosmochemistry were advertised, and for good reason. In these days of limited funding, there is an overwhelming tendency to look inward instead of recognizing that the best outcomes of science tend to be interdisciplinary. So, below, we suggest two radical acts of collaboration that we believe will accelerate the advancement of science.

A. J. G. Jurewicz↗
NASA NTRS2004

Genesis failure investigation report

On January 7, 2001, the Genesis spacecraft lifted off from Cape Canaveral. Its mission was to collect solar wind samples and return those samples to Earth for detailed analysis by scientists. The mission proceeded successfully for three-and-a-half years. On September 8, 2004, the spacecraft approached Earth, pointed the Sample Return Capsule (SRC) at its entry target, and then fired pyros that jettisoned the SRC. The SRC carried the valuable samples collected over the prior 29 months. The SRC also contained the requisite hardware (mechanisms, parachutes, and electronics) to manage the process of entry, descent, and landing (EDL). After entering Earth’s atmosphere, the SRC was expected to open a drogue parachute. This should have been followed by a pyro event to release the drogue chute, and then by a pyro event to deploy the main parachute at an approximate elevation of 6.7 kilometers. As the SRC descended to the Utah landing site, helicopters were in position to capture the SRC before the capsule touched down. On September 8, 2004, observers of the SRC’s triumphant return became concerned as the NASA announcer fell silent, and then became even more alarmed as they watched the spacecraft tumble as it streaked across the sky. Long-distance cameras clearly showed that the drogue parachute had not deployed properly.

UNKNOWN↗
NASA NTRS2004

Trajectory design for the Genesis backup orbit and proposed extended mission

In September 2004, the Genesis spacecraft will return to Earth with its collection of solar wind samples. If for some reason there are any difficulties with returning the samples to Earth during the nominal entry sequence, a contingency plan is in place for a second chance at a successful recovery. This paper will detail the processes used to generate possible backup trajectories, and provide a comparison of the contingency options examined through the course of the study.

Chung, Min-Kun J.↗
NASA NTRS1999

Genesis Trajectory Design

The Genesis mission will launch in 2001, sending a spacecraft into an L1 halo orbit in the Sun-Earth system to collect solar wind samples.

Genesis↗
NASA NTRS1993

A wind model for launch vehicle design

A new vector wind profile model is described based on the properties of the quadrivariate normal distribution which will help establish preliminary design ranges for angle of attack, angle of sideslip, aerodynamic pressure, and other launch vehicle flight variables. The model produces wind profiles that are a reasonable substitute for measured wind profile samples. The model wind profiles produce dispersion in aerodynamic load indicators that cover the dispersion range calculated from an extensive sample of Jimsphere wind profiles. This is accomplished with only 12 model wind profiles compared to 1800 Jimsphere profiles for a selected reference altitude. This represents an opportunity for a considerable reduction of computational effort during design phases that require many iterations to establish the merit of various design philosophies.

Adelfang, S. I.↗
NASA NTRS1989

LAWS simulation: Sampling strategies and wind computation algorithms

In general, work has continued on developing and evaluating algorithms designed to manage the Laser Atmospheric Wind Sounder (LAWS) lidar pulses and to compute the horizontal wind vectors from the line-of-sight (LOS) measurements. These efforts fall into three categories: Improvements to the shot management and multi-pair algorithms (SMA/MPA); observing system simulation experiments; and ground-based simulations of LAWS.

Emmitt, G. D. A.↗
NASA NTRS2022

Analysis of Solar Wind Damage in Genesis Sapphire Sample 61527

The Genesis mission collected samples of the solar wind (SW) by passive implantation into a variety of semiconductor (and other) materials and re-turned them to Earth in 2004. Subsets of these col-lector materials were exposed to either bulk solar wind, high-speed (coronal hole) solar wind, low speed (inter-stream) solar wind, or coronal mass ejections (CMEs). Although of short duration relative to naturally space-weathered materials, these exposures to SW caused structural damage (and related chemical changes) in silicon. Here we explore the structural consequences of bulk SW collection into Genesis single crystal sapphire.

L P Keller↗
NASA NTRS1986

Distribution of solar wind implanted noble gases in lunar samples

The distribution of solar wind implanted noble gases in lunar samples depends on implantation energy, fluence, diffusion, radiation damage and erosion. It is known that at least the lighter rare gases are fractionated after implantation, but the redistribution processes, which mainly drive the losses, are not well understood. Some information about this one can get by looking at the concentration profiles of solar wind implanted He-4 measured by the Gas Ion Probe in single lunar grains. The observed profiles were divided in three groups. These groups are illustrated and briefly discussed.

Kiko, J.↗
NASA NTRS2021

Hydroxylation of Apollo 17 Soil Sample 78421 by Solar Wind Protons

Hydroxylation by solar wind protons has been simulated in our laboratory on Apollo 17 lunar sample 78421, a very mature regolith sample that is rich with agglutinates (68%). The goal of this study was to determine the rate of hydroxyl formation and their thermal stability by monitoring changes in the SiOH (hydroxyl) stretching band near 3 μm using diffuse reflectance FTIR spectroscopy (DRIFTS). A 2 keV H2+ ion beam was used to simulate proton implantation on 78421 and on a crushed fused silica sample. We find that the OH band does not change unless the samples have been annealed in vacuum prior to irradiation. Qualitatively, the OH bands for the fused silica and 78421 are very different. The OH band for fused silica is centered at 2.74 μm and is relatively sharp ranging from 2.67 - 3.1 μm at full-width-at-half-maximum (FWHM), while the OH band for 78421 is centered at 3.0 μm and ranges from 2.74 - 3.37 μm at FWHM. The increase in wavelength and broadened nature of the OH band in 78421 may be associated with the OH’s proximity to surface defects and/or lattice vacancies. The lack of the H2O bending mode at 6.1 μm indicates that any adsorbed terrestrial H2O is below our detection limit, and therefore the H2O stretching mode at 2.9 μm is not significantly contributing to the broad 3 μm OH band and implies that proton implantation by itself does not lead to water formation. To simulate the maximum dayside temperature on the lunar surface, the lunar sample was heated after proton irradiation. The proton induced OH concentration was reduced by as much as 25% after heating to 400 K (127 °C).

Apollo 17↗
NASA NTRSDate not supplied

Extensibility of PICA TPS for Future Sample Return Missions

Stardust was the first successful robotic sample return mission delivering samples of the Comet Wild 2 to Earth in 2006. Genesis followed Stardust, in the era of “faster, better, cheaper,” collecting samples of solar wind. The Genesis sample return capsule (SRC) was larger and the program did not have the time nor funding to scale up the Stardust PICA heatshield and so, utilized an alternate heatshield. The successful Stardust mission led to future mission concepts baselining Stardust EDL, especially the entry heatshield. OSIRIS REx, was one such concept and the mission was designed to include build-to-print elements of the Stardust design. The primary scale-up limitation beyond Stardust and OSIRIS REx is the single-piece net cast PICA heatshield. In the past three years, FMI working with NASA Ames, expanded the manufacturing capability of PICA and demonstrated a 1.3 m PICA single piece TPS. This was done in anticipation of the Mars Sample Return mission as well as future Sample Return missions requiring larger-scale SRCs. This effort also identified a sustainable domestic replacement precursor for the PICA preform as the heritage precursor was discontinued in 2016 and FMI has gone through multiple rayon replacements since Stardust. As part of the effort, PICA was also tested at conditions higher than the Stardust or OSIRIS REx entry envelope to establish an expanded performance envelope and enable future sample return missions at higher entry speeds. The poster will highlight PICA sustainability and extensibility as part of the Sample Return to Earth session.

PICA thermal protection↗
NASA NTRS1991

Errors of five-day mean surface wind and temperature conditions due to inadequate sampling

Surface meteorological reports of wind components, wind speed, air temperature, and sea-surface temperature from buoys located in equatorial and midlatitude regions are used in a simulation of random sampling to determine errors of the calculated means due to inadequate sampling. Subsampling the data with several different sample sizes leads to estimates of the accuracy of the subsampled means. The number N of random observations needed to compute mean winds with chosen accuracies of 0.5 (N sub 0.5) and 1.0 (N sub 1,0) m/s and mean air and sea surface temperatures with chosen accuracies of 0.1 (N sub 0.1) and 0.2 (N sub 0.2) C were calculated for each 5-day and 30-day period in the buoy datasets. Mean values of N for the various accuracies and datasets are given. A second-order polynomial relation is established between N and the variability of the data record. This relationship demonstrates that for the same accuracy, N increases as the variability of the data record increases. The relationship is also independent of the data source. Volunteer-observing ship data do not satisfy the recommended minimum number of observations for obtaining 0.5 m/s and 0.2 C accuracy for most locations. The effect of having remotely sensed data is discussed.

Legler, David M.↗
NASA NTRS2004

The Genesis Mission Solar Wind Collection: Solar-Wind Statistics over the Period of Collection

The NASA Genesis spacecraft was launched August 8, 2001 on a mission to collect samples of solar wind for 2 years and return them to earth September 8, 2004. Detailed analyses of the solar wind ions implanted into high-purity collection substrates will be carried out using various mass spectrometry techniques. These analyses are expected to determine key isotopic ratios and elemental abundances in the solar wind, and by extension, in the solar photosphere. Further, the photospheric composition is thought to be representative of the solar nebula with a few exceptions, so that the Genesis mission will provide a baseline for the average solar nebula composition with which to compare present-day compositions of planets, meteorites, and asteroids. The collection of solar wind samples is almost complete. Collection began for most substrates in early December, 2001, and is scheduled to be complete on April 2 of this year. It is critical to understand the solar-wind conditions during the collection phase of the mission. For this reason, plasma ion and electron spectrometers are continuously monitoring the solar wind proton density, velocity, temperature, the alpha/proton ratio, and angular distribution of suprathermal electrons. Here we report on the solar-wind conditions as observed by these in-situ instruments during the first half of the collection phase of the mission, from December, 2001 to present.

Barraclough, B. L.↗
NASA NTRS2023

Space Weathering of Genesis Mission Solar-wind Collectors with Inferences for Weathering on Airless Bodies

Samples from the Genesis Solar Wind Sample Return (NASA Discovery 5) are a unique opportunity to study the initial stages of space weathering, i.e., the physical and chemical effects of solar-wind irradiation. Arrays of collectors containing multiple materials were each exposed to a different solar-wind regime (fast, slow, bulk, or coronal mass ejection) at the L1 point for long durations (years). Materials exposed to the solar wind included metals, semiconductors, and insulators. Although the time of exposure was obviously short relative to samples having extraterrestrial origins, optical properties, surface chemical properties, and matrix structure have changed in many collectors due to exposure to solar wind. The thickness of amorphous zones, where present, appears to correspond with the depth of the peak of the solar-wind H distribution in each regime. Damage from high-energy particles was negligible because the collectors were 700 μm or less in thickness and shielded from the back by the spacecraft. Micrometeorite impacts and sputtering were also negligible because of the short exposure times. Our current results are preliminary: We hope future workers will extend this study both to support Genesis characterization efforts and to further understand space-weathering processes on a geologic timescale.

space weathering↗