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NASA NTRS2009

The James Webb Space Telescope

The scientific capabilities of the James Webb Space Telescope (JWST) fall into four themes. The End of the Dark Ages: First Light and Reionization theme seeks to identify the first luminous sources to form and to determine the ionization history of the universe. The Assembly of Galaxies theme seeks to determine how galaxies and the dark matter, gas, stars, metals, morphological structures, and active nuclei within them evolved from the epoch of reionization to the present. The Birth of Stars and Protoplanetary Systems theme seeks to determine the physical and chemical properties of planetary systems around nearby stars and of our own, and investigate the potential for life in those systems. To enable these for science themes, JWST will be a large (6.6m) cold (50K) telescope launched to the second Earth-Sun Lagrange point early in the next decade. It is the successor to the Hubble Space Telescope, and is a partnership of NASA, ESA and CSA. JWST will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. I review the status and capabilities of the observatory and instruments in the context of the major scientific goals.

Gardner, Jonathan P.↗
NASA NTRS2006

Testing the TPF Interferometry Approach before Launch

One way to directly detect nearby extra-solar planets is via their thermal infrared emission, and with this goal in mind, both NASA and ESA are investigating cryogenic infrared interferometers. Common to both agencies' approaches to faint off-axis source detection near bright stars is the use of a rotating nulling interferometer, such as the Terrestrial Planet Finder interferometer (TPF-I), or Darwin. In this approach, the central star is nulled, while the emission from off-axis sources is transmitted and modulated by the rotation of the off-axis fringes. Because of the high contrasts involved, and the novelty of the measurement technique, it is essential to gain experience with this technique before launch. Here we describe a simple ground-based experiment that can test the essential aspects of the TPF signal measurement and image reconstruction approaches by generating a rotating interferometric baseline within the pupil of a large singleaperture telescope. This approach can mimic potential space-based interferometric configurations, and allow the extraction of signals from off-axis sources using the same algorithms proposed for the space-based missions. This approach should thus allow for testing of the applicability of proposed signal extraction algorithms for the detection of single and multiple near-neighbor companions...

interferometry↗
NASA NTRS2008

Liquid Oxygen/Liquid Methane Ascent Main Engine Technology Development

The National Aeronautics & Space Administration (NASA) has identified Liquid Oxygen (LO2)/Liquid Methane (LCH4) as a potential propellant combination for future space vehicles based upon the Exploration Systems Architecture Study (ESAS). The technology is estimated to have higher performance and lower overall systems mass compared to existing hypergolic propulsion systems. The current application considering this technology is the lunar ascent main engine (AME). AME is anticipated to be an expendable, pressure-fed engine to provide ascent from the moon at the completion of a 210 day lunar stay. The engine is expected to produce 5,500 lbf (24,465 N) thrust with variable inlet temperatures due to the cryogenic nature of the fuel and oxidizer. The primary technology risks include establishing reliable and robust ignition in vacuum conditions, maximizing specific impulse, developing rapid start capability for the descent abort, providing the capability for two starts and producing a total engine bum time over 500 seconds. This paper will highlight the efforts of the Marshall Space Flight Center (MSFC) in addressing risk reduction activities for this technology.

Robinson, Joel W.↗
NASA NTRS2008

The J-2X Upper Stage Engine: From Heritage to Hardware

NASA's Global Exploration Strategy requires safe, reliable, robust, efficient transportation to support sustainable operations from Earth to orbit and into the far reaches of the solar system. NASA selected the Ares I crew launch vehicle and the Ares V cargo launch vehicle to provide that transportation. Guiding principles in creating the architecture represented by the Ares vehicles were the maximum use of heritage hardware and legacy knowledge, particularly Space Shuttle assets, and commonality between the Ares vehicles where possible to streamline the hardware development approach and reduce programmatic, technical, and budget risks. The J-2X exemplifies those goals. It was selected by the Exploration Systems Architecture Study (ESAS) as the upper stage propulsion for the Ares I Upper Stage and the Ares V Earth Departure Stage (EDS). The J-2X is an evolved version ofthe historic J-2 engine that successfully powered the second stage of the Saturn I launch vehicle and the second and third stages of the Saturn V launch vehicle. The Constellation architecture, however, requires performance greater than its predecessor. The new architecture calls for larger payloads delivered to the Moon and demands greater loss of mission reliability and numerous other requirements associated with human rating that were not applied to the original J-2. As a result, the J-2X must operate at much higher temperatures, pressures, and flow rates than the heritage J-2, making it one of the highest performing gas generator cycle engines ever built, approaching the efficiency of more complex stage combustion engines. Development is focused on early risk mitigation, component and subassembly test, and engine system test. The development plans include testing engine components, including the subscale injector, main igniter, powerpack assembly (turbopumps, gas generator and associated ducting and structural mounts), full-scale gas generator, valves, and control software with hardware-in-the-loop. Testing expanded in 2007, accompanied by the refinement of the design through several key milestones. This paper discusses those 2007 tests and milestones, as well as updates key developments in 2008.

Byrd, THomas↗
NASA NTRS2009

Research on the International Space Station - An Overview

The International Space Station (ISS) celebrates ten years of operations in 2008. While the station did not support permanent human crews during the first two years of operations November 1998 to November 2000 it hosted a few early science experiments months before the first international crew took up residence. Since that time and simultaneous with the complicated task of ISS construction and overcoming impacts from the tragic Columbia accident science returns from the ISS have been growing at a steady pace. As of this writing, over 162 experiments have been operated on the ISS, supporting research for hundreds of ground-based investigators from the U.S. and international partners. This report summarizes the experimental results collected to date. Today, NASA's priorities for research aboard the ISS center on understanding human health during long-duration missions, researching effective countermeasures for long-duration crewmembers, and researching and testing new technologies that can be used for future exploration crews and spacecraft. Through the U.S. National Laboratory designation, the ISS is also a platform available to other government agencies. Research on ISS supports new understandings, methods or applications relevant to life on Earth, such as understanding effective protocols to protect against loss of bone density or better methods for producing stronger metal alloys. Experiment results have already been used in applications as diverse as the manufacture of solar cell and insulation materials for new spacecraft and the verification of complex numerical models for behavior of fluids in fuel tanks. A synoptic publication of these results will be forthcoming in 2009. At the 10-year point, the scientific returns from ISS should increase at a rapid pace. During the 2008 calendar year, the laboratory space and research facilities were tripled with the addition of ESA's Columbus and JAXA's Kibo scientific modules joining NASA's Destiny Laboratory. All three laboratories, together with external payload accommodations, support a wide variety of research racks and science and technology experiments. In 2009, the number of crewmembers will increase from three to six, greatly increasing the time available for research. The realization of the international scientific partnership provides new opportunities for scientific collaboration and broadens the research potential on the ISS. Engineers and scientists from around the world are working together to refine their operational relationships and build from their experiences conducting early science to ensure maximum utilization of the expanded capabilities aboard ISS. This paper will summarize science results and accomplishments, and discuss how the early science utilization provides the foundation for continuing research campaigns aboard the ISS that will benefit future exploration programs.

Evans, Cynthia A.↗
NASA NTRS2009

Hyperbolic Orbits and the Planetary Flylby Anomaly

Space probes in the Solar System have experienced unexpected changes in velocity known as the flyby anomaly [1], as well as shifts in acceleration referred to as the Pioneer anomaly [2-4]. In the case of Earth flybys, ESA s Rosetta spacecraft experienced the flyby effect and NASA s Galileo and NEAR satellites did the same, although MESSENGER did not possibly due to a latitudinal property of gravity assists. Measurements indicate that both anomalies exist, and explanations have varied from the unconventional to suggestions that new physics in the form of dark matter might be the cause of both [5]. Although dark matter has been studied for over 30 years, there is as yet no strong experimental evidence supporting it [6]. The existence of dark matter will certainly have a significant impact upon ideas regarding the origin of the Solar System. Hence, the subject is very relevant to planetary science. We will point out here that one of the fundamental problems in science, including planetary physics, is consistency. Using the well-known virial theorem in astrophysics, it will be shown that present-day concepts of orbital mechanics and cosmology are not consistent for reasons having to do with the flyby anomaly. Therefore, the basic solution regarding the anomalies should begin with addressing the inconsistencies first before introducing new physics.

Wilson, T.L.↗
NASA NTRS2008

Optics Requirements For The Generation-X X-Ray Telescope

US, European, and Japanese space agencies each now operate successful X-ray missions -- NASA s Chandra, ESA s XMM-Newton, and JAXA s Suzaku observatories. Recently these agencies began a collaboration to develop the next major X-ray astrophysics facility -- the International X-ray Observatory (IXO) -- for launch around 2020. IXO will provide an order-of-magnitude increase in effective area, while maintaining good (but not sub-arcsecond) angular resolution. X-ray astronomy beyond IXO will require optics with even larger aperture areas and much better angular resolution. We are currently conducting a NASA strategic mission concept study to identify technology issues and to formulate a technology roadmap for a mission -- Generation-X (Gen-X) -- to provide these capabilities. Achieving large X-ray collecting areas in a space observatory requires extremely lightweight mirrors.

O'Dell, S. .↗
NASA NTRS2008

Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions

The Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MSL-CETSOL and MICAST) are two investigations which supports research into metallurgical solidification, semiconductor crystal growth (Bridgman and zone melting), and measurement of thermo-physical properties of materials. This is a cooperative investigation with the European Space Agency (ESA) and National Aeronautics and Space Administration (NASA) for accommodation and operation aboard the International Space Station (ISS). Research Summary: Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing (CETSOL) and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MICAST) are two complementary investigations which will examine different growth patterns and evolution of microstructures during crystallization of metallic alloys in microgravity. The aim of these experiments is to deepen the quantitative understanding of the physical principles that govern solidification processes in cast alloys by directional solidification.

Gandin, Charles-Andre↗
NASA NTRS2008

25th Space Simulation Conference. Environmental Testing: The Earth-Space Connection

Topics covered include: Methods of Helium Injection and Removal for Heat Transfer Augmentation; The ESA Large Space Simulator Mechanical Ground Support Equipment for Spacecraft Testing; Temperature Stability and Control Requirements for Thermal Vacuum/Thermal Balance Testing of the Aquarius Radiometer; The Liquid Nitrogen System for Chamber A: A Change from Original Forced Flow Design to a Natural Flow (Thermo Siphon) System; Return to Mercury: A Comparison of Solar Simulation and Flight Data for the MESSENGER Spacecraft; Floating Pressure Conversion and Equipment Upgrades of Two 3.5kw, 20k, Helium Refrigerators; Affect of Air Leakage into a Thermal-Vacuum Chamber on Helium Refrigeration Heat Load; Special ISO Class 6 Cleanroom for the Lunar Reconnaissance Orbiter (LRO) Project; A State-of-the-Art Contamination Effects Research and Test Facility Martian Dust Simulator; Cleanroom Design Practices and Their Influence on Particle Counts; Extra Terrestrial Environmental Chamber Design; Contamination Sources Effects Analysis (CSEA) - A Tool to Balance Cost/Schedule While Managing Facility Availability; SES and Acoustics at GSFC; HST Super Lightweight Interchangeable Carrier (SLIC) Static Test; Virtual Shaker Testing: Simulation Technology Improves Vibration Test Performance; Estimating Shock Spectra: Extensions beyond GEVS; Structural Dynamic Analysis of a Spacecraft Multi-DOF Shaker Table; Direct Field Acoustic Testing; Manufacture of Cryoshroud Surfaces for Space Simulation Chambers; The New LOTIS Test Facility; Thermal Vacuum Control Systems Options for Test Facilities; Extremely High Vacuum Chamber for Low Outgassing Processing at NASA Goddard; Precision Cleaning - Path to Premier; The New Anechoic Shielded Chambers Designed for Space and Commercial Applications at LIT; Extraction of Thermal Performance Values from Samples in the Lunar Dust Adhesion Bell Jar; Thermal (Silicon Diode) Data Acquisition System; Aquarius's Instrument Science Data System (ISDS) Automated to Acquire, Process, Trend Data and Produce Radiometric System Assessment Reports; Exhaustive Thresholds and Resistance Checkpoints; Reconfigurable HIL Testing of Earth Satellites; FPGA Control System for the Automated Test of MicroShutters; Ongoing Capabilities and Developments of Re-Entry Plasma Ground Tests at EADS-ASTRIUM; Operationally Responsive Space Standard Bus Battery Thermal Balance Testing and Heat Dissipation Analysis; Galileo - The Serial-Production AIT Challenge; The Space Systems Environmental Test Facility Database (SSETFD), Website Development Status; Simulated Reentry Heating by Torching; Micro-Vibration Measurements on Thermally Loaded Multi-Layer Insulation Samples in Vacuum; High Temperature Life Testing of 80Ni-20Cr Wire in a Simulated Mars Atmosphere for the Sample Analysis at Mars (SAM) Instrument Suit Gas Processing System (GPS) Carbon Dioxide Scrubber; The Planning and Implementation of Test Facility Improvements; and Development of a Silicon Carbide Molecular Beam Nozzle for Simulation Planetary Flybys and Low-Earth Orbit.

Packard, Edward↗
NASA NTRS2008

Galileo - The Serial-Production AIT Challenge

The Galileo Project is one of the most demanding projects of ESA, being Europe's autarkic navigation system and a constellation composed of 30 satellites. This presentation points out the different phases of the project up to the full operational capability and the corresponding launch options with respect to launch vehicles as well as launch configurations. One of the biggest challenges is to set up a small serial 'production line' for the overall integration and test campaign of satellites. This production line demands an optimization of all relevant tasks, taking into account also backup and recovery actions. A comprehensive AIT concept is required, reflecting a tightly merged facility layout and work flow design. In addition a common data management system is needed to handle all spacecraft related documentation and to have a direct input-out flow for all activities, phases and positions at the same time. Process optimization is a well known field of engineering in all small high tech production lines, nevertheless serial production of satellites are still not the daily task in space business and therefore new concepts have to be put in place. Therefore, and in order to meet the satellites overall system optimization, a thorough interface between unit/subsystem manufacturing and satellite AIT must be realized to ensure a smooth flow and to avoid any process interruption, which would directly lead to a schedule impact.

Ragnit, Ulrike↗
NASA NTRS2009

Rightsizing LISA

The LISA science requirements and conceptual design have been fairly stable for over a decade. In the interest of reducing costs, the LISA Project at NASA has looked for simplifications of the architecture, at downsizing of subsystems, and at descopes of the entire mission. This is a natural activity of the formulation phase, and one that is particularly timely in the current NASA budgetary context. There is, and will continue to be, enormous pressure for cost reduction from both ESA and NASA, reviewers and the broader research community. Here, the rationale for the baseline architecture is reviewed, and recent efforts to find simplifications and other reductions that might lead to savings are reported. A few possible simplifications have been found in the LISA baseline architecture. In the interest of exploring cost sensitivity, one moderate and one aggressive descope have been evaluated; the cost savings are modest and the loss of science is not.

Stebbins, Robin T.↗
NASA NTRS2008

Embossed Teflon AF Laminate Membrane Microfluidic Diaphragm Valves

A microfluidic system has been designed to survive spaceflight and to function autonomously on the Martian surface. It manipulates microscopic quantities of liquid water and performs chemical analyses on these samples to assay for the presence of molecules associated with past or present living processes. This technology lies at the core of the Urey Instrument, which is scheduled for inclusion on the Pasteur Payload of the ESA ExoMars rover mission in 2013. Fabrication processes have been developed to make the microfabricated Teflon-AF microfluidic diaphragm pumps capable of surviving extreme temperature excursions before and after exposure to liquid water. Two glass wafers are etched with features and a continuous Teflon membrane is sandwiched between them (see figure). Single valves are constructed using this geometry. The microfabricated devices are then post processed by heating the assembled device while applying pneumatic pressure to force the Teflon diaphragm against the valve seat while it is softened. After cooling the device, the embossed membrane retains this new shape. This solves previous problems with bubble introduction into the fluid flow where deformations of the membrane at the valve seat occurred during device bonding at elevated temperatures (100-150 C). The use of laminated membranes containing commercial Teflon AF 2400 sheet sandwiched between spun Teflon AF 1600 layers performed best, and were less gas permeable than Teflon AF 1600 membranes on their own. Spinning Teflon AF 1600 solution (6 percent in FLOURINERT(Registered TradeMark) FC40 solvent, 3M Company) at 500 rpm for 1.5 seconds, followed by 1,000 rpm for 3 seconds onto Borofloat glass wafers, results in a 10-micron-thick film of extremely smooth Teflon AF. This spinning process is repeated several times on flat, blank, glass wafers in order to gradually build a thick, smooth membrane. After running this process at least five times, the wafer and Teflon coating are heated under vacuum at 220 C for one hour in order to drive off any residual solvent present in the composite film. After this, a second blank, glass wafer is brought down from above and the stack is held under vacuum at 3 atm mechanical pressure for ten 10 hours.

Willis, Peter↗
NASA NTRS2009

The International X-ray Observatory

The International X-Ray Observatory, a joint NASA-ESA-JAXA effort, is a next generation X-ray telescope that will answer many fundamental questions in contemporary astrophysics such as how do supermassive black holes influence galaxy evolution and how do galaxy clusters evolve (and how does this constrain dark energy and dark matter)? As a powerful astronomical observatory, IXO will also address questions ranging from the neutron star equation of state to the distribution and dynamical state of intergalactic material. X-ray spectroscopy, polarimetry, and timing studies provided by IXO's instruments will give detailed measures of abundances, temperatures, densities, magnetic fields and gravitational potentials. These measurements will be complementary to the next generation of observatories such as ALMA, JWST, and future ground-based optical-NIR telescopes. This mission will be ready for launch in the 2020-2021 timeframe and will launch on an Atlas V or Ariane V launch vehicle to L2. It employs a deployable optical bench to achieve the 20 meter focal length and a suite of five instruments. This talk will describe the motivating science for this mission as well as the spacecraft, instruments and optics

Hornschemeier, A.↗
NASA NTRS2009

Cassini/Huygens Probe Entry, Descent, and Landing (EDL) at Titan Independent Technical Assessment

Starting in January 2004, the NESC has received several communications from knowledgeable technical experts at NASA expressing shared concerns (mainly at the Langley Research Center (LaRC) and Ames Research Center (ARC)) about Huygens mission success. It was suggested that NASA become more technically involved directly in the analysis of Huygens' entry, descent and landing (EDL) focusing on the parachute deployment trigger performance and the resultant effects on the operation of the parachute system, and the determination of the radiative heating environment at Titan by ESA and the corresponding thermal protection system (TPS) response. A NESC Team was formed and tasked to provide an independent assessment of these concerns. The results of that assessment are documented in this report.

Powell, Richard W.↗
NASA NTRS2007

SPENVIS Implementation of End-of-Life Solar Cell Calculations Using the Displacement Damage Dose Methodology

This paper presents a method for using the SPENVIS on-line computational suite to implement the displacement damage dose (D(sub d)) methodology for calculating end-of-life (EOL) solar cell performance for a specific space mission. This paper builds on our previous work that has validated the D(sub d) methodology against both measured space data [1,2] and calculations performed using the equivalent fluence methodology developed by NASA JPL [3]. For several years, the space solar community has considered general implementation of the D(sub d) method, but no computer program exists to enable this implementation. In a collaborative effort, NRL, NASA and OAI have produced the Solar Array Verification and Analysis Tool (SAVANT) under NASA funding, but this program has not progressed beyond the beta-stage [4]. The SPENVIS suite with the Multi Layered Shielding Simulation Software (MULASSIS) contains all of the necessary components to implement the Dd methodology in a format complementary to that of SAVANT [5]. NRL is currently working with ESA and BIRA to include the Dd method of solar cell EOL calculations as an integral part of SPENVIS. This paper describes how this can be accomplished.

Walters, Robert↗
NASA NTRS2009

Area V: A National Launch Asset for the 21st Century

The goal of this presentation is to present an update on status and development of the Ares V launch vehicle. The Ares V is a heavy lift vehicle that is being designed to launch cargo into Low Earth Orbit and transfer Cargo and crews to the Moon. Slides show the commonalities between the Ares V, and the Ares I, and the Delta IV. The launch profile for a typical Lunar mission is reviewed. A timeline showing the progress from the Exploration Systems Architecture Study (ESAS) to the Lunar Capability Concept Review (LCCR) is presented. Other slides review the payload shroud, the payload vs altitude and inclination, the payload mass vs C3 Energy, projections of the performance for selected trajectories, and the planning calendar.

Sumrall, Phil↗
NASA NTRS2009

From LEO, to the Moon and then Mars: Developing a Global Strategy for Exploration Risk Reduction

Most nations currently involved in human spaceflight, or with such ambitions, believe that space exploration will capture the imagination of our youth resulting in future engineers and scientists, advance technologies which will improve life on earth, increase the knowledge of our solar system, and strengthen bonds and relationships across the globe. The Global Exploration Strategy, published in 2007 by 14 space agencies, eloquently makes this case and presents a vision for space exploration. It argues that in order for space exploration to be sustainable, nations must work together to address the challenges and share the burden of costs. This paper will examine Mars mission scenarios developed by NASA, ESA and other agencies and show resulting conclusions regarding key challenges, needed technologies and associated mission risks. It will discuss the importance of using the International Space Station as a platform for exploration risk reduction and how the global exploration community will develop lunar exploration elements and architectures that enable the long term goal of human missions to Mars. The International Space Station (ISS) is a critical first step both from a technology and capability demonstration point of view, but also from a partnership point of view. There is much work that can be done in low earth orbit for exploration risk reduction. As the current "outpost at the edge of the frontier", the ISS is a place where we can demonstrate certain technologies and capabilities that will substantially reduce the risk of deploying an outpost on the lunar surface and Mars mission scenarios. The ISS partnership is strong and has fulfilled mission needs. Likewise, the partnerships we build on the moon will provide a strong foundation for establishing partnerships for the human Mars missions. On the moon, we build a permanently manned outpost and deploy technologies and capabilities to allow humans to stay for long periods of time. The moon is interesting from a scientific point of view, but it is extremely important for development and demonstration the technologies and capabilities needed for human missions to Mars. This paper will show the logic and strategy for addressing technological, operational and programmatic challenges by using low earth orbit and lunar missions to enable the long term goal of exploration of our solar system.

Laurini, Kathleen C.↗
NASA NTRS2009

The 50 Constellation Priority Sites

The Constellation program (CxP) has developed a list of 50 sites of interest on the Moon which will be targeted by the LRO narrow angle camera. The list has also been provided to the M~ team to supplement their targeting list. This list does not represent a "site selection" process; rather the goal was to find "representative" sites and terrains to understand the range of possible surface conditions for human lunar exploration to aid engineering design and operational planning. The list compilers leveraged heavily on past site selection work (e.g. Geoscience and a Lunar Base Workshop - 1988, Site Selection Strategy for a Lunar Outpost - 1990, Exploration Systems Architecture Study (ESAS) - 2005). Considerations included scientific, resource utilization, and operational merits, and a desire to span lunar terrain types. The targets have been organized into two "tiers" of 25 sites each to provide a relative priority ranking in the event of mutual interference. A LEAG SAT (special action team) was established to validate and recommend modifications to the list. This SAT was chaired by Dr. Paul Lucey. They provided their final results to CxP in May. Dr. Wendell Mendell will organize an on-going analysis of the data as they come down to ensure data quality and determine if and when a site has sufficient data to be retired from the list. The list was compiled using the best available data, however, it is understood that with the flood of new lunar data, minor modifications or adjustments may be required.

Noble, S.↗