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At least 19 records

Space science technology: In-situ science. Sample Acquisition, Analysis, and Preservation Project summary

The Sample Acquisition, Analysis, and Preservation Project is summarized in outline and graphic form. The objective of the project is to develop component and system level technology to enable the unmanned collection, analysis and preservation of physical, chemical and mineralogical data from the surface of planetary bodies. Technology needs and challenges are identified and specific objectives are described.

Aaron, Kim↗

Characterizing water/rock interaction in simulated comet nuclei via calorimetry: Tool for in-situ science, laboratory analysis, and sample preservation

Although results from the Giotto and Vega spacecraft flybys of comet P/Halley indicate a complex chemistry for both the ices and dust in the nucleus, carbonaceous chondrite meteorites are still regarded as useful analogs for the rocky components. Carbonaceous chondrites mixed with water enable simulation of water/rock interactions which may occur in cometary nuclei. Three general types of interactions can be expected between water and minerals at sub-freezing temperatures: heterogeneous nucleation of ice by insoluble minerals; adsorption of water vapor by hygroscopic phases; and freezing and melting point depression of liquid water sustained by soluble minerals. Two series of experiments were performed in a differential scanning calorimeter (DSC) with homogenized powders of the following whole-rock meteorites and comparison samples: Allende (CV3), Murchison (CM2), Orgueil (CI), Holbrook (L6), and Pasamonte (eucrite) meteorites as well as on peridotite (PCC-1, USGS), saponite (Sap-Ca-1, CMS), montmorillonite (STx-1, CMS), and serpentine (Franciscan Formation, California). Results are briefly discussed.

Allton, Judith H.↗

Next-generation in-situ science concepts and technology

This paper discusses the concepts of a next-generation in situ science program, named Sample Acquisition, Analysis, and Preservation (SAAP), established by NASA to develop critical technologies for remote identification, acquisition, processing, analysis, and preservation of materials for the in situ science, engineering characterization, and earth return. Special attention is given to the SAAP architecture, system design, remote sensing system, sample acquisition system, and methods for sample analysis. A diagram of the SAAP preliminary system conceptual design is included.

Muirhead, Brian↗

Voyager-Neptune telemetry - The DSN 70 meter antenna upgrade

The Deep Space Network (DSN) is responsible for the acquisition of in-situ science and engineering measurements and navigation data from spacecraft exploring the Solar System. Key characteristics of the DSN design approach, the costs to upgrade performance over the past several decades, and some fundamental constraints on performance are discussed. The specific 70-meter upgrade task and the resulting overall benefits to Voyager-Neptune and the mission set are addressed.

Hall, Justin R.↗

NASA/Ames Research Center's science and applications aircraft program

NASA-Ames Research Center operates a fleet of seven Science and Applications Aircraft, namely the C-141/Kuiper Airborne Observatory (KAO), DC-8, C-130, Lear Jet, and three ER-2s. These aircraft are used to satisfy two major objectives, each of equal importance. The first is to acquire remote and in-situ scientific data in astronomy, astrophysics, earth sciences, ocean processes, atmospheric physics, meteorology, materials processing and life sciences. The second major objective is to expedite the development of sensors and their attendant algorithms for ultimate use in space and to simulate from an aircraft, the data to be acquired from spaceborne sensors. NASA-Ames Science and Applications Aircraft are recognized as national and international facilities. They have performed and will continue to perform, operational missions from bases in the United States and worldwide. Historically, twice as many investigators have requested flight time than could be accommodated. This situation remains true today and is expected to increase in the years ahead. A major advantage of the existing fleet of aircraft is their ability to cover a large expanse of the earth's ecosystem from the surface to the lower stratosphere over large distances and time aloft. Their large payload capability allows a number of scientists to use multi-investigator sensor suites to permit simultaneous and complementary data gathering. In-flight changes to the sensors or data systems have greatly reduced the time required to optimize the development of new instruments. It is doubtful that spaceborne systems will ever totally replace the need for airborne science aircraft. The operations philosophy and capabilities exist at NASA-Ames Research Center.

Hall, G. Warren↗

Constraints on Titan's ionosphere

The near flyby of Saturn's moon Titan by Voyager 1 revealed a Venus-like interaction between the moon and Saturn's magnetospheric plasma. Although neither the radio science experiment occultation observation nor the in-situ measurements directly detected the ionosphere, plasma of ionospheric origin was observed as Voyager 1 passed through Titan's wake. Balancing the magnetic pressure in this low-beta region of Saturn's magnetosphere with ionospheric particle pressure yields an upper limit on the ionospheric density. Using an ionospheric temperature equal to the exospheric temperature of 200 K yields a charge density of about 3000/cu cm, which is consistent with the peak ionospheric electron density inferred from a balance of electron impact ionization of molecular nitrogen and recombination loss. Both of these quantities are consistent with limits derived from Voyager 1 observations. Good constraints on these quantities are important in planning the Cassini mission to orbit Saturn and probe Titan's ionosphere and atmosphere at the beginning of the next century.

Mcnutt, Ralph L., Jr.↗

Proposed methods for the reconstruction of the Pioneer/Venus probe entry trajectories

In connection with the Pioneer Venus Project, an orbiter and an array of atmospheric probes are sent to Venus in separate launches during 1978. The four probes, which are transported to the planet on an instrumented Bus are released approximately 20 days prior to encounters. There are three identical small probes and a large probe. Each is designed to make in-situ atmospheric measurements. One of the principal scientific objectives of the Pioneer Venus (P/V) multiprobe mission is the determination of the structure and composition of the Venusian atmosphere down to the planet surface. To enhance the science return it is of paramount importance to be able to accurately determine the spacecraft entry trajectories. In addition to the in-situ spacecraft measurements, earth-based Doppler data are available. The process felt to be most applicable for the P/V multiprobe entry trajectory reconstruction is considered, with emphasis placed on the highly dynamic upper entry segment of the trajectory.

Findlay, J. T.↗

Characterization of a graphite epoxy optical bench during thermal vacuum cycling

In-situ monitoring of the Wide-Field/Planetary Camera, a Hubble Space Telescope science instrument, was performed in a vacuum environment to better understand the formation of ice on cooled optical detectors. Several diagnostic instruments were mounted on an access plate to view the interior of the instrument housing and the graphite epoxy optical bench. The instrumentation chosen and the rationale for choosing the instrumentation are discussed. In addition, the performance of the instrumentation during monitoring operations is discussed.

Hansen, Patricia A.↗

Spacelab - A new tool for cooperative research

For work in earth orbit, the European Space Agency, ESA, in cooperation with NASA, has developed a flexible laboratory system called Spacelab, which will fit into the Space Shuttle. Spacelab will offer new possibilities for conducting research related to the behavior and properties of the neutral and ionized atmosphere. Up to 400 km altitude, the total payload weight will be in excess of 25,000 kg. The main advantages of Spacelab consist of high payload weight, power, the return of the instrumentation, and the availability of man for real-time operation of the equipment. Limitations are related to the local contamination, the restriction of mission duration to periods from one to four weeks, and limited altitudes and inclinations (for early missions). Spacelab is, therefore, not suited for many types of in-situ sensing, or for long-term monitoring. Attention is given to the proposed science program, passive observations, and chemical releases and active experiments.

Schmerling, E. R.↗

A coated-wire ion-selective electrode for ionic calcium measurements

A coated-wire ion-selective electrode for measuring ionic calcium was developed, in collaboration with Teknektron Sensor Development Corporation (TSDC). This coated wire electrode sensor makes use of advanced, ion-responsive polyvinyl chloride (PVC) membrane technology, whereby the electroactive agent is incorporated into a polymeric film. The technology greatly simplifies conventional ion-selective electrode measurement technology, and is envisioned to be used for real-time measurement of physiological and environment ionic constituents, initially calcium. A primary target biomedical application is the real-time measurement of urinary and blood calcium changes during extended exposure to microgravity, during prolonged hospital or fracture immobilization, and for osteoporosis research. Potential advanced life support applications include monitoring of calcium and other ions, heavy metals, and related parameters in closed-loop water processing and management systems. This technology provides a much simplified ionic calcium measurement capability, suitable for both automated in-vitro, in-vivo, and in-situ measurement applications, which should be of great interest to the medical, scientific, chemical, and space life sciences communities.

Hines, John W.↗

Moderate Resolution Imaging Spectrometer (MODIS) design evolution and associated development and verification of data product efforts

The Moderate Resolution Imaging Spectrometer (MODIS) is a key observing facility to be flown on the Earth Observing System (EOS). The facility is composed of two instruments called MODIS-N (nadir) and MODIS-T (tilt). The MODIS-N is being built under contract to NASA by the Santa Barbara Research Center. The MODIS-T is being fabricated by the Engineering Directorate at the Goddard Space Flight Center. The MODIS Science Team has defined nearly 40 biogeophysical data products for studies of the ocean and land surface and properties of the atmosphere including clouds that can be expected to be produced from the MODIS instruments shortly after the launch of EOS. The ocean, land, atmosphere, and calibration groups of the MODIS Science Team are now proceeding to plan and implement the operations and facilities involving the analysis of data from existing spaceborne, airborne, and in-situ sensors required to develop and validate the algorithms that will produce the geophysical data products. These algorithm development and validation efforts will be accomplished wherever possible within the context of existing or planned national and international experiments or programs such as those in the World Climate Research Program.

Salomonson, Vincent V.↗

A Jupiter Orbiter mother/daughter spacecraft concept

The feasibility of a tandem launch of a mother/daughter spacecraft pair with a single launch vehicle for a 1981 Mariner Jupiter Orbiter mission is described. The mother is a close derivative of the three-axis stabilized Mariner Jupiter Saturn 1977 spacecraft with the addition of a Viking-type propulsion module for orbit capture; it concentrates on the planetology and satellite science objectives. The daughter is a small, simple spin-stabilized spacecraft taking advantage of the mother's transit and delivery capabilities; it obtains in-situ measurements of the surrounding planetary environment. A conceptual design of the daughter spacecraft is presented.

Duxbury, J. H.↗

Applications of ISES for vegetation and land use

Remote sensing relative to applications involving vegetation cover and land use is reviewed to consider the potential benefits to the Earth Observing System (Eos) of a proposed Information Sciences Experiment System (ISES). The ISES concept has been proposed as an onboard experiment and computational resource to support advanced experiments and demonstrations in the information and earth sciences. Embedded in the concept is potential for relieving the data glut problem, enhancing capabilities to meet real-time needs of data users and in-situ researchers, and introducing emerging technology to Eos as the technology matures. These potential benefits are examined in the context of state-of-the-art research activities in image/data processing and management.

Wilson, R. Gale↗

Space Science in the Twenty-First Century: Imperatives for the Decades 1995 to 2015

A unified program is outlined for studying the Earth, from its deep interior to its fluid envelopes. A system is proposed for measuring devices involving both space-based and in-situ observations that can accommodate simultaneously a large range of scientific needs. The scientific objectices served by this integrated infrastructure are cased into a framework of four grand themes. In summary these are: to determine the composition, structure, dynamics, and evolution of the Earth's crust and deeper interior; to establish and understand the structure, dynamics, and chemistry of the oceans, atmosphere, and cryosphere, and their interaction with the solid Earth; to characterize the history and dynamics of living organisms and their interaction with the environment; and to monitor and understand the interaction of human activities with the natural environment. A focus on these grand themes will help to understand the origin and fate of the planet, and to place it in the context of the solar system.

Source record↗

In Situ Data

In-situ planetary data include all measurements made by a wide variety of instruments whose sensors are exposed directly to the planetry environment. Typical measurements include those of magnetic fields, energetic particle densities and energy distributions, plasma wave characteristics, ionospheric and neutral gas densities, temperatures, composition and motions. A large body of scientists in the United States, and the world, are involved in research using in-situ data. Many of these scientists are associated with Mission investigations groups which provide specific types of in-situ data. These groups, in the course of data analysis, use data provided by similar groups. The interdisciplinary nature of these investigations fosters exchange and reliance upon one another for data is heavy. To a lesser extent, correlative data sets are obtained from the National Space Science Data Center (NSSDC). However, the data entries often have limited temporal and spatial resolution, are of uncertain quality, and are usually available only for measurements that are several years old.

Source record↗

The Galileo dust detector

The Galileo Dust Detector is intended to provide direct observations of dust grains with masses between 10(sup -19) kg and 10(sup -9) kg in interplanetary space and in the Jovian system, to investigate their physical and dynamical properties as functions of the distances to the Sun, to Jupiter and to its satellites, to study its interaction with the Galilean satellites and the Jovian magnetosphere. Surface phenomena of the satellites (like albedo variations), which might be effects of meteoroid impacts will be compared with the dust environment. Electric charges of particulate matter in the magnetosphere and its consequences will be studied; e.g. the effects of the magnetic field on the trajectories of dust particles and fragmentation of particles due to electrostatic disruption. The investigation is performed with an instrument that measures the mass, speed, flight direction and electric charge of individual dust particles. It is a multi-coincidence detector with a mass sensitivity 10(sup 6) times higher than that of previous in-situ experiments which measured dust in the outer solar system. The instrument weighs 4.2 kg, consumes 2.4 W, and has a normal data transmission rate of 24 bits/s in nominal spacecraft tracking mode. On December 29, 1989 the instrument was switched-on. After the instrument had been configured to flight conditions cruise science data collection started immediately. In the period to May 18, 1990 at least 168 dust impacts have been recorded. For 81 of these dust grains, masses and impact speeds have been determined. First flux values are also given.

Gruen, E.↗

Trends in Planetary Data Analysis. Executive summary of the Planetary Data Workshop

Planetary data include non-imaging remote sensing data, which includes spectrometric, radiometric, and polarimetric remote sensing observations. Also included are in-situ, radio/radar data, and Earth based observation. Also discussed is development of a planetary data system. A catalog to identify observations will be the initial entry point for all levels of users into the data system. There are seven distinct data support services: encyclopedia, data index, data inventory, browse, search, sample, and acquire. Data systems for planetary science users must provide access to data, process, store, and display data. Two standards will be incorporated into the planetary data system: Standard communications protocol and Standard format data unit. The data system configuration must combine a distributed system with those of a centralized system. Fiscal constraints have made prioritization important. Activities include saving previous mission data, planning/cost analysis, and publishing of proceedings.

Evans, N.↗

The use of aircraft and satellite remote sensing of phytoplankton chlorophyll concentrations in case 2 estuarine waters of the Chesapeake Bay

Two projects using remote sensing of phytoplankton chlorophyll concentrations in the Chesapeake Bay estuary were proposed. The first project used aircraft remote sensing with a compact radiometer system developed at NASA's Goddard Space Flight Center (GSFC), the Ocean Data Acquisition System (ODAS). ODAS includes three radiometers at 460, 490, and 520 nm, an infrared temperature sensor (PRT-5), Loran-C for navigation, and a data acquisition system using a PC and mass storage device. This instrument package can be flown in light aircraft at relatively low expense, permitting regular and frequent flights. Sixteen flights with ODAS were completed using the Virginia Institute of Marine Science's De Havilland 'Beaver'. The goal was to increase spatial and temporal resolution in assaying phytoplankton pigment concentrations in the Chesapeake. At present, analysis is underway of flight data collected between March and July 1989. The second project focused on satellite data gathered with the Nimbus-7 Coastal Zone Color Scanner (CZSC) between late 1978 and mid 1986. The problem in using CZSC data for the Chesapeake Bay is that the optical characteristics of this (and many) coastal and estuarine waters are distinct from those of the open ocean for which algorithms for computing pigment concentrations were developed. The successful use of CZCS data for the estuary requires development of site-specific algorithms and analytical approaches. Of principal importance in developing site-specific procedures is the availability of in-situ data on pigment concentrations. A significant data set was acquired from EPA's Chesapeake Bay Program in Annapolis, Maryland, and clear satellite scenes are being analyzed for which same-day sea truth measurements of pigment were obtained. Both the University of Miami and GSFC Seapak systems are being used in this effort. The main finding to date is an expected one, i.e., the algorithms developed for oceanic waters are inadequate to compute pigment concentrations for the Case 2 waters of the Chesapeake Bay. One reason is the overestimation of aerosol radiances by assuming that water-leaving radiance in Band 4 of CZCS (670 nm) is zero, an assumption that is invalid for the Bay. This prompted any attempts to iterative procedures for estimating the proportion of the Band 4 radiance that is actually attributable to aerosol by estimating the water-leaving component using optical data. A cruise on the Chesapeake the week of 7 August 1989 was conducted to collect additional optical data necessary to this task.

Harding, Lawrence W., Jr.↗