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NASA NTRS2018

Robust, Radiation Tolerant Command and Data Handling and Power System Electronics for SmallSats

In today's budgetary environment, there is significant interest within the National Aeronautics and Space Administration (NASA) to enable small robotic science missions that can be executed faster and cheaper than previous larger missions. To help achieve this, focus has shifted from using exclusively radiation-tolerant or radiation-hardened parts to using more commercial-off-the-shelf (COTS) components for NASA small satellite missions that can last at least one year in orbit. However, there are some portions of a spacecraft's avionics, such as the Command and Data Handling (C&DH) subsystem and the Power System Electronics (PSE) that need to have a higher level of reliability that goes beyond what is attainable with currently available COTS parts. While there are a number of COTS components that can withstand a total ionizing dose (TID) of tens or hundreds of kilorads, there is still a great deal of concern about tolerance to and mitigation of single-event effects (SEE).

6U satellite↗

NASA NTRS2019

Goddard Modular SmallSat Architecture (GMSA) Hardware Presentation

In today's rapidly advancing technology roadmap for space applications there is an emphasis on completing missions faster and cheaper than previous large-scale missions at the National Aeronautics and Space Administration (NASA) such as the Magnetospheric Multiscale (MMS) mission. As part of this effort, focus has shifted from using mostly radiation-tolerant or radiation-hardened parts to more commercial-off-the-shelf (COTS) components for missions that can last at least one year in orbit. However, there are some portions of a spacecraft's avionics, such as the command and data handling (C&DH) system and the Electrical Power Systems (EPS) that need to have some level of predictable reliability that goes beyond the capabilities of currently available COTS parts. While there are a number of COTS components that can withstand a total ionizing dose (TID) of tens or hundreds of kilorads, there is still a great deal of concern about tolerance to and mitigation of single-event effects (SEE).

Fraction, James↗

NASA NTRS1986

Space radiation effects on the thermo-mechanical behavior of graphite-epoxy composites

This investigation of composite material properties utilized T300/934 graphite-epoxy that was subjected to 1.0 MeV electron radiation for a total dose of 1.0 x 10 to the 10th rads at a rate of 5.0 x 10 to the 7th rads/hour, simulating a worst-case exposure equivalent to 30 years in space. Mechanical testing was performed on 4-ply unidirectional laminates over the temperature range of -250 F (116 K) to +250 F (394 K). In-plane elastic tensile and shear properties as well as strength were obtained. The results show that electron radiation degrades the epoxy matrix and produces products that volatilize at the temperatures considered. These degradation products plasticize the epoxy at elevated temperatures and embrittle it at low temperatures, thereby altering the mechanical properties of the composite.

Milkovich, Scott M.↗

NASA NTRS1998

Space Environment Effects: Low-Altitude Trapped Radiation Model

Accurate models of the Earth's trapped energetic proton environment are required for both piloted and robotic space missions. For piloted missions, the concern is mainly total dose to the astronauts, particularly in long-duration missions and during extravehicular activity (EVA). As astronomical and remote-sensing detectors become more sensitive, the proton flux can induce unwanted backgrounds in these instruments. Due to this unwanted background, the following description details the development of a new model for the low-trapped proton environment. The model is based on nearly 20 years of data from the TIRO/NOAA weather satellites. The model, which has been designated NOAAPRO (for NOAA protons), predicts the integral omnidirectional proton flux in three energy ranges: >16, >36, and >80 MeV. It contains a true solar cycle variation and accounts for the secular variation in the Earth's magnetic field. It also extends to lower values of the magnetic L parameter than does AP8. Thus, the model addresses the major shortcomings of AP8.

Huston, S. L.↗

NASA NTRS2015

Shields-1, A SmallSat Radiation Shielding Technology Demonstration

The NASA Langley Research Center Shields CubeSat initiative is to develop a configurable platform that would allow lower cost access to Space for materials durability experiments, and to foster a pathway for both emerging and commercial-off-the-shelf (COTS) radiation shielding technologies to gain spaceflight heritage in a relevant environment. The Shields-1 will be Langleys' first CubeSat platform to carry out this mission. Radiation shielding tests on Shields-1 are planned for the expected severe radiation environment in a geotransfer orbit (GTO), where advertised commercial rideshare opportunities and CubeSat missions exist, such as Exploration Mission 1 (EM-1). To meet this objective, atomic number (Z) graded radiation shields (Zshields) have been developed. The Z-shield properties have been estimated, using the Space Environment Information System (SPENVIS) radiation shielding computational modeling, to have ~30% increased shielding effectiveness of electrons, at half the thickness of a corresponding single layer of aluminum. The Shields-1 research payload will be made with the Z-graded radiation shields of varying thicknesses to create dose-depth curves to be compared with baseline materials. Additionally, Shields-1 demonstrates an engineered Z-grade radiation shielding vault protecting the systems' electronic boards. The radiation shielding materials' performances will be characterized using total ionizing dose sensors. Completion of these experiments is expected to raise the technology readiness levels (TRLs) of the tested atomic number (Z) graded materials. The most significant contribution of the Z-shields for the SmallSat community will be that it enables cost effective shielding for small satellite systems, with significant volume constraints, while increasing the operational lifetime of ionizing radiation sensitive components. These results are anticipated to increase the development of CubeSat hardware design for increased mission lifetimes, and enable out of low earth orbit (LEO) missions by using these tested material concepts as shielding for sensitive components and new spaceflight hardware

Thomsen, D. Laurence, III↗

NASA NTRS2010

The Biological Effectiveness of Different Radiation Qualities for the Induction of Chromosome Damage in Human Lymphocytes

Chromosome aberrations were measured in human peripheral blood lymphocytes after in vitro exposure to 28Si- ions with energies ranging from 90 to 600 MeV/u, or to 56Fe-ions with energies ranging from 200 to 5,000 MeV/u. The LET of the various Fe beams in this study ranged from 145 to 440 keV/micron and the LET of the Si ions ranged from 48 to 158 keV/ m. Doses delivered were in the 10- to 200-cGy range. Dose-response curves for chromosome exchanges in cells at first division after exposure, measured using fluorescence in situ hybridization (FISH) with whole-chromosome probes, were fitted with linear or linear-quadratic functions. The relative biological effectiveness (RBE) was estimated from the initial slope of the dose-response curve for chromosome damage with respect to -rays. The estimates of RBE(sub max) values for total chromosome exchanges ranged from 4.4+/-0.4 to 31.5+/-2.6 for Fe ions, and 11.8+/-1.0 to 42.2+/-3.3 for Si ions. The highest RBE(sub max) value for Fe ions was obtained with the 600-Mev/u beam, and the highest RBE(sub max) value for Si ions was obtained with the 170 MeV/u beam. For both ions the RBEmax values increased with LET, reaching a maximum at about 180 keV/micron for Fe and about 100 keV/ m for Si, and decreasing with further increase in LET. Additional studies for low doses 28Si-ions down to 0.02 Gy will be discussed.

Hada, M.↗

NASA NTRS2011

The Biological Effectiveness of Different Radiation Qualities for the Induction of Chromosome Damage in Human Lymphocytes

Chromosome aberrations were measured in human peripheral blood lymphocytes after in vitro exposure to Si-28-ions with energies ranging from 90 to 600 MeV/u, Ti-48-ions with energies ranging from 240 to 1000 MeV/u, or to Fe-56-ions with energies ranging from 200 to 5,000 MeV/u. The LET of the various Si beams in this study ranged from 48 to 158 keV/ m, the LET of the Ti ions ranged from 107 to 240 keV/micron, and the LET of the Fe-ions ranged from 145 to 440 keV/ m. Doses delivered were in the 10- to 200-cGy range. Dose-response curves for chromosome exchanges in cells at first division after exposure, measured using fluorescence in situ hybridization (FISH) with whole-chromosome probes, were fitted with linear or linear-quadratic functions. The relative biological effectiveness (RBE) was estimated from the initial slope of the dose-response curve for chromosome damage with respect to gamma-rays. The estimates of RBEmax values for total chromosome exchanges ranged from 4.4+/-0.4 to 31.5+/-2.6 for Fe ions, 21.4+/-1.7 to 28.3+/-2.4 for Ti ions, and 11.8+/-1.0 to 42.2+/-3.3 for Si ions. The highest RBEmax value for Fe ions was obtained with the 600 MeV/u beam, the highest RBEmax value for Ti ions was obtained 1000 MeV/u beam, and the highest RBEmax value for Si ions was obtained with the 170 MeV/u beam. For Si and Fe ions the RBEmax values increased with LET, reaching a maximum at about 180 keV/micron for Fe and about 100 keV/micron for Si, and decreasing with further increase in LET. Additional studies for low doses Si-28-ions down to 0.02 Gy will be discussed.

Hada, M.↗

NASA NTRS1997

Fusion Crust and the Measurement of Surface Ages of Antarctic Ordinary Chondrites

Natural thermoluminescence (TL) reflects radiation exposure and storage temperature. Meteorites generally exhibit thermoluminescence acquired during their long exposure to galactic cosmic rays in space. During atmospheric passage, temperatures are high enough to completely drain the TL, in the first mm of material under the fusion crust. We therefore refer to this surface layer as "fusion crust" although it does include some unmelted material just below the crust. When the meteorite lands on earth this drained layer will begin to build up natural TL once again due to radiation from cosmic rays and internal radionuclides. Cosmic ray annual dose is estimated to be between 0.04 and 0.06 rad/yr on the earth's surface in Antarctica while the internal radionuclides contribute only about 0.01 rad/yr. Therefore the total annual dose received by the meteorite while it is on the surface is between 0.05 and 0.07 rad/yr. If the meteorite is buried deeply in the ice it is effectively shielded from most cosmic rays and thus only internal radioactivity contributes to the annual dose.

Akridge, Jannette M. C.↗

NASA NTRS2010

The Biological Effectiveness of Silicon Ions is Significantly Higher than Iron Ions for the Induction of Chromosome Damage in Human Lymphocytes

Chromosome aberrations were measured in human peripheral blood lymphocytes after in vitro exposure to Si-28-ions with energies ranging from 90 to 600 MeV/u, or Fe-56-ions with energies ranging from 200 to 5,000 MeV/u. The LET of the various Fe beams in this study ranged from 145 to 440 keV/micron and the LET Si ions ranged from 48 to 158 keV/micron. Doses delivered were in the 10 to 200 cGy range. Dose response curves for chromosome exchanges in cells at first division after exposure, measured using fluorescence in situ hybridization (FISH) with whole chromosome probes, were fitted with linear or linear-quadratic functions. The relative biological effectiveness (RBE) was estimated from the initial slope of the dose response curve for chromosome damage with respect to gamma-rays. The estimates of RBE(sub max) values for total chromosome exchanges ranged from 4.4+/-0.4 to 31.5+/-2.6 for Fe ions, and 11.8+/-1.0 to 42.2+/-3.3 for Si ions. The highest RBE(sub max) value for Fe ions was obtained with the 600 Mev/u beam and 170 MeV/u beam produced the highest RBE(sub max) value for Si ions. For both ions the RBE(sub max) values increased with LET, reaching a maximum at about 180 keV/micron for Fe and about 100 keV/micron for Si, and decreased with further increase in LET.

George, Kerry↗

NASA NTRS1993

The effect of high-energy electron radiation on poly(arylene ether)s

Thin films of four experimental poly(arylene ether)s of similar chemical structure were exposed to 1 MeV electrons while under high vacuum. The films received total exposures of 5 x 10 exp 7 and 1 x 10 exp 9 rads at a dose rate of 5 x 10 exp 7 rads/h and a pressure of 2 x 10 exp -7 torr. Films exposed to 5 x 10 exp 7 rads showed dramatic changes in molecular weight distribution. After exposures of 1 x 10 exp 9 rads the films were only partially soluble in chloroform and exhibited no detectable changes in the glass transition temperatures. Thin-film tensile properties were also altered by the exposure to electron radiation. The effect of the exposures as determined by various analyses is discussed.

Connell, J. W.↗

NASA NTRS1984

Space Radiation Effects on Graphite-Epoxy Composite Materials

Radiation effects on engineering properties, dimensional stability, and chemistry on state of the art composite systems were characterized. T300/934 graphite-epoxy composite was subjected to 1.0 MeV electron radiation for a total dose of 1.0 x 10(10) rads at a rate of 5.0 x 10(7) rads/hour. This simulates a worst case exposure equivalent to 30 years in space. Mechanical testing was performed on he 4-ply unidirectional laminates over the temperature range of -250 F (116K) to +250 F (394K). A complete set of in-plane tensile elastic and strength properties were obtained (E sub 1, E sub 2, nu sub 12, G sub 12, X sub T, Y sub T, and S). In addition electron microscopy was used to study and analyze the fracture surfaces of all specimens tested. Results indicate that little difference in properties is noted at room temperature, but significant differences are observed at both low and elevated temperatures.

Milkovich, S. M.↗

NASA NTRS2017

A CubeSat-Payload Radiation-Reliability Assurance Case using Goal Structuring Notation

CubeSats have become an attractive platform for universities, industry, and government space missions because they are cheaper and quicker to develop than full-scale satellites. One way CubeSats keep costs low is by using commercial off-the-shelf parts (COTS) instead of space-qualified parts. Space-qualified parts are often costlier, larger, and consume more power than their commercial counterparts precluding their use within the CubeSat form-factor. Given typical power budgets, monetary budgets, and timelines for CubeSat missions, conventional radiation hardness assurance, like the use of space-qualified parts and radiation testing campaigns of COTS parts, is not practical. Instead, a system-level approach to radiation effects mitigation is needed. In this paper an assurance case for a system-level approach to mitigate radiation effects of a CubeSat science experiment is expressed using Goal Structuring Notation (GSN), a graphical argument standard. The case specifically looks at three main mitigation strategies for the radiation environment: total ionizing dose (TID) screening of parts, detection and recovery from single-event latch-ups (SEL) and single-event functional interrupts (SEFI). The graphical assurance case presented makes a qualitative argument for the radiation reliability of the CubeSat experiment using part and system-level mitigation strategies.

COTS↗

NASA NTRS2022

Single-Event Effect Testing of the PNI RM3100 Magnetometer for Space Applications

The results of a destructive single-event effect susceptibility radiation test of the PNI RM3100 magnetometer sensor, specifically the MagI 2 C ASIC (application-specific integrated circuit) on the sensor board are presented. The sensor is a low-resource commercial off-the-shelf (COTS) magneto-inductive magnetometer. The device was monitored for destructive events and functional interruptions during exposure to a heavy ion beam at the Lawrence Berkeley National Laboratory's 88′′ Cyclotron. The RM3100 did not experience any destructive single-event effects when irradiated to a total fluence of 1.4 × 10 7 cm −2 at an effective linear energy transfer (LET) of 76.7 MeV cm 2 mg −1 while operated at nominal voltage (3.3 V) and elevated temperature (85 ∘C). When these results are combined with previous total ionizing dose tests showing no failures up to 150 kRad (Si), we conclude that the PNI RM3100 is extremely radiation tolerant and can be used in a variety of space environments.

Mark B. Moldwin↗

NASA NTRS1984

Electron radiation effects on the thermal expansion of graphite/resin composites

The effects of 1 MeV electron radiation on the thermal expansion characteristics of two graphite reinforced resin matrix composite systems were studied. Specimens of both graphite/epoxy (T300/5208) and graphite/polyimide (C6000/PMR15) were irradiated to a total dose of 6 x 10 to the 9th rads at two different rates. Dynamic mechanical analyses (DMA) were performed to study changes in resin chemistry. Thermal expansion results indicate that radiation did produce permanent residual strains of up to -70 x 10 to the -6th for the graphite/epoxy when exposed to temperatures up to +280 F. However, no permaanent changes in the coefficient of thermal expansion (CTE) were observed. No permanent residual strains or changes in the CTE attributable to radiation were observed for the graphite/polyimide specimens. DMA results indicate that electron radiation caused chemical changes in the epoxy matrix. These changes resulted in a lower glass transition temperature and broader 'rubbery region' which extended into the temperature range of the thermal expansion tests.

Bowles, D. E.↗

NASA NTRS2005

Effects of Incident Electron Fluence and Energy on the Election Yield Curves and Emission Spectra of Dielectrics

We present an experimental study of evolution of electron emission yields and spectra as a result of internal charge build up due to electron dose. Reliable total, backscattered and secondary yield curves and electron emission spectra for un-charged insulators using a low fluence, pulsed electron beam (= or < 5 microsec at = or < 3 nA/sq mm or = or < 10(exp 5) e/sq mm per pulse) with low energy electron and UV flooding to neutralize the charging between pulses. Quantifiable changes in yield curves are observed due to < 100 fC/sq mm fluences for several excellent dielectric thin film materials. We find good agreement with a phenomenological argument based on insulator charging predicted by the yield curve; this includes an approximately linear decrease in the magnitude of the yield as incident energies approach the crossover energies and an exponential decrease in yield as accumulated internal charge reduces the landing energy to asymptotically approach a steady state surface charge and unity yield. We also find that the exponential decay of yield curves with fluence exhibit an energy dependent decay constant, alpha(E), over a broad range of incident energies below, between and above the crossover energies. Finally, we present some preliminary physics-based models for this energy dependence and attempt to relate our charging measurements to knowledge of how charge is deposited within the insulator, the mechanisms for charge trapping and transport, and how the profile of trapped charge affects the transport and emission of charges from insulators.

Sim, Alec↗

NASA NTRSDate not supplied

Impact of Space Radiation with Other Combined Space Environmental Factors on Plant Seeds and Plant Development: from Arabidopsis thaliana to Crops

One of the major concerns for long-term exploration missions beyond Earth’s magnetosphere is radiation risk, primarily from solar particle events (SPE) and galactic cosmic rays (GCR). With the goal of manned Mars exploration, the production of fresh food during long-duration space missions provides critical nutritional supplementation and may also benefit astronauts’ behavioral health. However, the effects of space radiation on plants and plant propagules have not been sufficiently investigated and characterized. To evaluate the effects of space radiation on plant seeds and development, we explored several platforms, including ground-based radiation facilities, the MISSE platform outside the ISS, and other Low Earth Obit (LEO) opportunities. Radiation particle types ranged from neutrons, single charged particles, simulated galactic cosmic rays, simulated solar particle events, the radiation field outside the ISS (total 10 months on the ISS), and the field inside a LEO vehicle (over 3 years). Radiation doses ranged from around 10 cGy to 80 cGy with acute or chronic exposures. In these studies up to 15 types of model plant and crop seeds were evaluated. In addition, tests were conducted to determine whether the combination of radiation exposure and simulated microgravity could have synergetic effects. Exposure to space radiation at the levels tested had no significant impact on the germination rate in Arabidopsis and the seeds from multiple crop plants; however, radiation exposure alone or with other combined factors reduced the viability of some seed types. Overall, the changes within plants grown from irradiated seeds were dose- and ion quality- dependent, with heavier ions causing more severe damage. These changes ranged from cotyledon deformation, shortened root length, smaller seedling size, and other signs of stress, depending on the seed types. Radiation exposure also significantly altered transcriptomic profiles in seedlings grown from irradiated seeds. The impact of space radiation on seeds and plants potentially affects the ability of plants to adapt to other environmental stresses (e.g. microgravity, water stress, and hardware constraints) as well as susceptibility to plant diseases, which need to be furtherly investigated.

Y Zhang↗

NASA NTRS1991

First biological and dosimetric results of the free flyer biostack experiment AO015 on LDEF

The main objectives of the Biostack Experiment are to study the effectiveness of the structured components of the cosmic radiation to bacterial spores, plant seeds, and animal cysts for a long duration spaceflight and to get dosimetric data such as particle fluences and spectra and total doses for the Long Duration Exposure Facility orbit. The configuration of the experiment packages allows the localization of the trajectory of the particles in each biological layer and to correlate the potential biological impairment or injury with the physical characteristics of the responsible particle. Although the Biostack Experiment was designed for a long duration flight of only nine months, most of the biological systems show a high hatching or germination rate. Some of the first observations are an increase of the mutation rate of embryonic lethals in the second generation of Arabidopsis seeds, somatic mutations, and a reduction of growth rates of corn plants and a reduction of life span of Artemia salina shrimps. The different passive detector systems are also in a good shape and give access to a proper dosimetric analysis. The results are summarized, and some aspects of future analysis are shown.

Reitz, G.↗

NASA NTRS2019

NASA GeneLab Platform Utilized for Space Radiation Dosimetry Biological Response Compared to Radiation Ground Studies

Ionizing radiation from Galactic Cosmic Rays (GCR) is one of the major risk factors factor that will impact health of astronauts on extended missions outside the protective effects of the Earth's magnetic field. Currently there are gaps in our knowledge of the health risks associated with chronic low dose, low dose rate ionizing radiation, specifically ions associated with high (H) atomic number (Z) and energy (E). The NASA GeneLab project (genelab.nasa.gov) aims to provide a detailed library of Omics datasets associated with biological samples exposed to HZE. The GeneLab Data System (GLDS) includes datasets from both spaceflight and ground-based studies, a majority of which involved exposure to ionizing radiation. Recently GeneLab has also assessed radiation dosimetry data with omics datasets associated with samples flown to the International Space Station (ISS). The combination of the detailed information on radiation exposure for ground-based studies and curated dosimetry information for spaceflight experiments allows GeneLab to be the first comprehensive Omics database for space related research from which an investigator can generate hypotheses to direct future experiments utilizing both ground and space biological radiation data. We demonstrate the usefulness of these datasets by analyzing multiple GeneLab datasets associated with both radiation ground-based studies and spaceflight studies. The radiation ground based studies we analyzed includes both in vivo and in vitro work with a range ions from protons to iron particles with doses from 0.1Gy to 2Gy. These datasets were compared to both in vivo and in vitro datasets from samples flown to the ISS and on shorter shuttle missions with total doses of 0.1 mGy to 30 mGys. From this analysis we were able to associate distinct biological signatures associating specific ions to specific biological response to radiation exposure in space. For example, we discovered radiation biological response related to cardiovascular effects from proton ground studies are the dominating response for samples related to cardiovascular effects on the ISS. With this work we will provide a summary of how different ions will impact different biological response in space and how this can be used in future studies to assess optimal ground experiments to simulate space radiation.

Beheshti, Afshin↗