Search

AeroCube-10 is a two-CubeSat mission built and operated by The Aerospace Corporation. Among several payloads is a space solar cell experiment designed to measure solar cell radiation damage as well as the space radiation environment believed to cause it. This paper describes first on-orbit results of the space solar cell experiment on AeroCube-10.

Several energetic particle sensors designed to make measurements in the current decade are described and their technology and capabilities discussed and demonstrated. Most of these instruments are already on orbit or approaching launch. These include the Magnetic Electron Ion Spectrometers (MagEIS) and the Relativistic Electron Proton Telescope (REPT) that are flying on the Van Allen Probes, the Fly's Eye Electron Proton Spectrometers (FEEPS) flying on the Magnetospheric Multiscale (MMS) mission, and Dosimeters flying on the AC6 Cubesat mission. We focus mostly on the electron measurement capability of these sensors while providing summary comments of their ion measurement capabilities if they have any.

The Aerospace Corporation’s AeroCube-6 nanosatellites collected simultaneous on-orbit micro-dosimeter and experimental solar cell data. Building on the results of this previous mission, we have developed new instrumentation and a new experiment to better characterize on-orbit degradation of space solar cells while measuring the charged particle radiation causing it. This paper discusses initial ground test results and instrument development efforts for a payload to be flown on a new mission, called AeroCube-10.

A 1064 nm, 1 mJ pulsed fiber MOPA module, housed in 16”x14”x2.5” package for application in a lunar and planetary in-situ surface dating instrument is demonstrated. The module is based on a three-stage MOPA with a 60 μm core tapered fiber terminal amplifier. The master oscillator and first two preamplifier stages, which generate 20 μJ pulses, are all contained on a 13”x11”x1” board. Several improvements to the electronic signal control were instrumental to the laser development, including bipolar drive of the phase modulator for SBS suppression, shaping of the seed pulse to compensate pulse steepening, and pulsed operation of the power amplifier pump to reduce spontaneous emission at low pulse repetition frequency. The packaged laser runs at a repetition rate of 10 kHz and generates 10 ns pulses at 1 mJ with a 40 GHz linewidth, an M 2 ~ 1.2 beam quality, and an 18 dB polarization extinction ratio. The modular design enables seven independent lasers to be stacked in a 20”x18”x16.25” enclosure, supporting a path towards a fiber laser based LARIMS for advanced materials characterization and chronological dating in harsh and remote environments.

The Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on the Lunar Reconnaissance Orbiter (LRO) characterizes the radiation environment to be experienced by humans during future lunar missions. CRaTER measures the effects of ionizing energy loss in matter due to penetrating solar energetic protons (SEP) and galactic cosmic rays (GCR), specifically in silicon solid-state detectors and after interactions with tissue-equivalent plastic (TEP), a synthetic analog of human tissue. The CRaTER investigation quantifies the linear energy transfer (LET) spectrum in these materials through direct measurements with the lunar space radiation environment, particularly the interactions of ions with energies above 10 MeV, which penetrate and are detected by CRaTER. Combined with models of radiation transport through materials, CRaTER LET measurements constrain models of the biological effects of ionizing radiation in the lunar environment as well as provide valuable information on radiation effects on electronic systems in deep space. In addition to these human exploration goals, CRaTER measurements also provide new insights on the spatial and temporal variability of the SEP and GCR populations and their interactions with the lunar surface. We present here an overview of the CRaTER science goals and investigation, including: an instrument description; observation strategies; instrument testing, characterization, and calibration; and data analysis, interpretation, and modeling plans., United States. National Aeronautics and Space Administration (contract NNG05EB92C)

[1] We report new measurements of solar minimum ionizing radiation dose at the Moon onboard the Lunar Reconnaissance Orbiter (LRO) from June 2009 through May 2010. The Cosmic Ray Telescope for the Effects of Radiation (CRaTER) instrument on LRO houses a compact and highly precise microdosimeter whose design allows measurements of dose rates below 1 micro-Rad per second in silicon achieved with minimal resources (20 g, ∼250 milliwatts, and ∼3 bits/second). We envision the use of such a small yet accurate dosimeter in many future spaceflight applications where volume, mass, and power are highly constrained. As this was the first operation of the microdosimeter in a space environment, the goal of this study is to verify its response by using simultaneous measurements of the galactic cosmic ray ionizing environment at LRO, at L1, and with other concurrent dosimeter measurements and model predictions. The microdosimeter measured the same short timescale modulations in the galactic cosmic rays as the other independent measurements, thus verifying its response to a known source of minimum-ionizing particles. The total dose for the LRO mission over the first 333 days was only 12.2 Rads behind ∼130 mils of aluminum because of the delayed rise of solar activity in solar cycle 24 and the corresponding lack of intense solar energetic particle events. The dose rate in a 50 km lunar orbit was about 30 percent lower than the interplanetary rate, as one would expect from lunar obstruction of the visible sky.

This report documents the critical design review for the High Linear Energy Transfer (HiLET) instrument subsystem of the Dose/Surface Charging and Plasma Monitor Flight Model 2. The design review took place on 15 January 2004 at The Aerospace Corporation, El Segundo, CA.

The Global UV imager (GUVI) is an imaging spectrometer on the NASA TIMED spacecraft. GUVI produces simultaneous monochromatic images at five 'colors' as its field of view is scanned from horizon to horizon. The instrument consists of a scan mirror feeding a parabolic telescope and Rowland circle spectrometer, with a wedge-and-strip detector at the focal plane. We describe the design, and give an overview of the environmental parameters that will be measured. GUVI is a modified version of the Special Sensor UV Spectrographic Imager (SSUSI), which will fly on the DMSP Block 5D3 satellites S-16 through S-20, We present some results from the optical calibration of the five SSUSI units.

The expression of three different actin genes in the sea urchin, Strongylocentrotus purpuratus, was monitored in embryos and adult tissues by using untranslated mRNA sequences as specific hybridization probes. Three distinct patterns of expression were found: muscle specific, embryo specific, and constitutive (i.e., present in all tissues examined). The actin genes encoding the muscle-specific and constitutively expressed genes were each found to be present once in the haploid genome. The embryo-specific probe could derive from either a single gene or a small subset of actin genes. These data demonstrate that at least three members of the sea urchin actin gene family are expressed in distinct ways and thus are probably associated with different regulatory programs of gene expression necessary for development of this metazoan.

RNA complementary to bulk humanplacental DNA was synthesized in vitro both in the presence and absence of 3 H-labeled ribonucleotides. The 3 H-labeled RNA was used directly for hybridization to the DNA of human metaphase chromosomes, whereas the unlabeled complementary RNA was labeled chemically with 125 I before hybridization. A comparison of autoradiographs produced by either isotope revealed no qualitative differences in the chromosomal annealing sites of the same population of RNA molecules. Since 125 I-labeled nucleic acids give similar, if not identical, results as do 3 H-labeled nucleic acids in in situ hybridization experiments, their use should make possible the localization of genetic elements for which tritium labeling methods are either inadequate or not possible.

The Energetic Particle Detector (EPD) Investigation is one of five particles and fields investigations on the Magnetospheric Multiscale (MMS) mission. This mission consists of four satellites operating in close proximity in elliptical, low-inclination orbits, and is focused upon the fundamental physics of magnetic reconnection. The Energetic Particle Detector (EPD) investigation aboard the four MMS spacecraft consists of two instrument designs, the EIS (Energetic Ion Spectrometer) and the FEEPS (Fly’s Eye Electron Proton Spectrometer). This present paper describes FEEPS from an instrument physics and engineering point of view, and provides some test and calibration data to facilitate effective analysis and use of the flight data for scientific purposes. A FEEPS consists of six Heads, each composed of two Eyes. Each eye is a particle telescope with a single silicon detector; there are nine electron eyes and three ion eyes per FEEPS. The energy coverage is from 25 keV to 650 keV for electrons and 45 keV to 650 keV for ions. Each eye has sixteen energy channels, the spacing of which can be modified by command. The fields of view and pointing of each eye are designed to provide a broad, instantaneous field of view for the twelve eyes per FEEPS. There are two FEEPS per MMS spacecraft mounted such that the pair along with the single EIS provide more than $3\pi$ -sr instantaneous solid-angle coverage and complete coverage in the equatorial region. A twenty-second spacecraft rotation period is divided into sixty-four sectors to provide detailed temporal and spatial sampling. Data are acquired in three modes: Burst Mode, the primary science mode; Fast Survey Mode; and Slow Survey Mode.

This paper describes the Magnetic Electron Ion Spectrometer (MagEIS) instruments aboard the RBSP spacecraft from an instrumentation and engineering point of view. There are four magnetic spectrometers aboard each of the two spacecraft, one low-energy unit (20–240 keV), two medium-energy units (80–1200 keV), and a high-energy unit (800–4800 keV). The high unit also contains a proton telescope (55 keV–20 MeV).

Quantitative electron microscopy can provide objective measurements of nuclear atypia in lymphoid cells in skin biopsies during early stages of infiltration of the skin as part of inflammatory or neoplastic processes. This potentially provides a method for establishing reproducible criteria for determining whether an individual skin biopsy represents mycosis fungoides or is unlikely to represent mycosis fungoides. To investigate such criteria, quantitative electron microscopic studies of skin biopsies from 109 patients were performed. Seventy-seven patients had benign disorders, 16 patients had early mycosis fungoides, and 16 patients had controversial lesions. Measurements were made of lymphocyte nuclear profile perimeter and areas in electron micrographs. A nuclear contour index was calculated. On the basis of the mean degree of nuclear convolution alone, mycosis fungoides was not adequately distinguished from benign disorders. Better discrimination was achieved when the proportion of cells with a anuclear contour index of 9.0 or more was considered as an additional actor. When statistical methods were used to select discriminating factors, the best electron microscopic discrimination between benign and mycosis fungoides groups occurred when the proportion of cells with a nuclear contour index of 7 or more and the proportion of cells with a nuclear profile area greater than 30 sq. micrometer. were used together. Nomograms are presented which demonstrate the use of these criteria for a given case.

The progress that has been made in the last several years toward an understanding of the expression of the actin genes of the sea urchin is impressive. It serves as an excellent example of how the application of modern molecular biological techniques to a classic experimental system (the sea urchin embryo) can begin to give us insight into the processes of embryological development. There is reason to hope that general principles will emerge from studies such as these, but many questions are unanswered. With specific regard to the actin genes and proteins, there are some obvious questions. Are the actins encoded by the different genes functionally distinct, and what roles do they play in differentiation and development? How is the expression of each of these genes regulated; i.e., what molecules participate, how do they work, where are they located in the embryo, and when do they appear? The more general question is: How are these (and other) genes and proteins affected by, or how do they contribute to, determination and induction in early development? We hope that answers to the specific questions posed will provide important steps toward answers to the general question.

A 46-year-old man presented with an unusual angiosarcoma of skin and urinary bladder, clinically suggestive of Kaposi's sarcoma (KS). Histologically, the pattern was that of an anaplastic angiosarcoma with only minimal regions considered characteristic of KS. It is suggested that this rare type of angiosarcoma may be closely related to, if not best classified as, an anaplastic variant of KS. The cutaneous lesions responded to intralesional vinblastine. The association of anaplastic angiosarcoma with homosexual sexual practices should be investigated along with those cases having the classical histologic characteristics of Kaposi's sarcoma.

Quantitative electron microscopy was used to measure lymphocyte nuclear contours in skin biopsies from 109 patients, 77 with benign disorders, 16 with early mycosis fungoides (MF), and 16 with controversial lesions. A nuclear contour index (NCI) was calculated on electron micrographs by dividing the nuclear profile circumference by the square root of the nuclear area. Significant differences were found between the group mean NCI for MF (NCI = 6.1 +/- 0.1) and for the benign group (NCI = 4.6 to 5.4 +/- 0.1; P less than 0.005). The group mean NCI for the controversial cases was significantly lower than that of the MF group (P less than 0.05). It is suggested that a definite electron microscopic diagnosis of MF requires first a patient mean NCI of 6.1 or more, and second, at least 6% of lymphocytes with an NCI of 9 or more. These criteria give a false positive rate of 3% in benign and controversial disorders and a 50% false negative rate for early MF. Only lymphocytes with an NCI of 16 or more appear specific for MF (or Sezary's syndrome), but are not found in all cases.

Seven patients with lymphomatoid papulosis were treated with solutions of topical carmustine, a nitrosourea compound. Recently used schedules have employed 10 mg of carmustine in dilute alcohol applied to the total skin surface daily for four to 17 weeks (total dosage, 280 to 1,180 mg). All patients experienced a rapid reduction in the number and size of lesions. Maintenance therapy consisted of local applications of carmustine (2 to 4 mg/mL of 95% ethanol) to individual new papules. This method was effective in suppressing disease activity and reduced by half the average life cycle of individual lesions. However, long-term lesion-free remissions were not seen. Bone marrow depression did not occur.