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At least 703 records · Page 39

Autonomous Flight Safety System - Phase III

The Autonomous Flight Safety System (AFSS) is a joint KSC and Wallops Flight Facility project that uses tracking and attitude data from onboard Global Positioning System (GPS) and inertial measurement unit (IMU) sensors and configurable rule-based algorithms to make flight termination decisions. AFSS objectives are to increase launch capabilities by permitting launches from locations without range safety infrastructure, reduce costs by eliminating some downrange tracking and communication assets, and reduce the reaction time for flight termination decisions.

Source record↗

Using Lunar Module Shadows To Scale the Effects of Rocket Exhaust Plumes

Excavating granular materials beneath a vertical jet of gas involves several physical mechanisms. These occur, for example, beneath the exhaust plume of a rocket landing on the soil of the Moon or Mars. We performed a series of experiments and simulations (Figure 1) to provide a detailed view of the complex gas-soil interactions. Measurements taken from the Apollo lunar landing videos (Figure 2) and from photographs of the resulting terrain helped demonstrate how the interactions extrapolate into the lunar environment. It is important to understand these processes at a fundamental level to support the ongoing design of higher fidelity numerical simulations and larger-scale experiments. These are needed to enable future lunar exploration wherein multiple hardware assets will be placed on the Moon within short distances of one another. The high-velocity spray of soil from the landing spacecraft must be accurately predicted and controlled or it could erode the surfaces of nearby hardware. This analysis indicated that the lunar dust is ejected at an angle of less than 3 degrees above the surface, the results of which can be mitigated by a modest berm of lunar soil. These results assume that future lunar landers will use a single engine. The analysis would need to be adjusted for a multiengine lander. Figure 3 is a detailed schematic of the Lunar Module camera calibration math model. In this chart, formulas relating the known quantities, such as sun angle and Lunar Module dimensions, to the unknown quantities are depicted. The camera angle PSI is determined by measurement of the imaged aspect ratio of a crater, where the crater is assumed to be circular. The final solution is the determination of the camera calibration factor, alpha. Figure 4 is a detailed schematic of the dust angle math model, which again relates known to unknown parameters. The known parameters now include the camera calibration factor and Lunar Module dimensions. The final computation is the ejected dust angle, as a function of Lunar Module altitude.

Source record↗

Exploration of CIGAS Alloy System for Thin-Film Photovoltaics on Novel Lightweight and Flexible Substrates

Thin-film photovoltaics (TFPV) on lightweight and flexible substrates offer the potential for very high solar array specific power (W/kg). ITN Energy Systems, Inc. (ITN) is developing flexible TFPV blanket technology that has potential for specific power greater than 2000 W/kg (including space coatings) that could result in solar array specific power between 150 and 500 W/kg, depending on array size, when mated with mechanical support structures specifically designed to take advantage of the lightweight and flexible substrates.(1) This level of specific power would far exceed the current state of the art for spacecraft PV power generation, and meet the needs for future spacecraft missions.(2) Furthermore the high specific power would also enable unmanned aircraft applications and balloon or high-altitude airship (HAA) applications, in addition to modular and quick deploying tents for surface assets or lunar base power, as a result of the high power density (W/sq m) and ability to be integrated into the balloon, HAA or tent fabric. ITN plans to achieve the high specific power by developing single-junction and two-terminal monolithic tandem-junction PV cells using thin-films of high-efficiency and radiation resistant CuInSe2 (CIS) partnered with bandgap-tunable CIS-alloys with Ga (CIGS) or Al (CIAS) on novel lightweight and flexible substrates. Of the various thin-film technologies, single-junction and radiation resistant CIS and associated alloys with gallium, aluminum and sulfur have achieved the highest levels of TFPV device performance, with the best efficiency reaching 19.5% under AM1.5 illumination conditions and on thick glass substrates.(3) Thus, it is anticipated that single- and tandem-junction devices with flexible substrates and based on CIS and related alloys will achieve the highest levels of thin-film space and HAA solar array performance.

Woods, Lawrence M.↗

Ares V: New Opportunities for Scientific Payloads

What if scientists and payload planners had access to three to five times the volume and five to nine times the mass provided by today's launch vehicles? This simple question can lead to numerous exciting possibilities, all involving NASA's new Ares V cargo launch vehicle now on the drawing board. Multiple scientific fields and payload designers have that opportunity with the Ares V cargo launch vehicle, being developed at NASA as the heavy-lift component of the U.S. Space Exploration Policy. When the Ares V begins flying late next decade, its capabilities will significantly exceed the 1960s-era Saturn V or the current Space Shuttle, while it benefits from their engineering, manufacturing, and infrastructure heritage. It will send more crew and cargo to more places on the lunar surface than Apollo and provide ongoing support to a permanent lunar outpost. Moreover, it will restore a strategic heavy-lift U.S. asset, which can support human and robotic exploration and scientific ventures for decades to come. Assessment of astronomy payload requirements since Spring 2008 has indicated that Ares V has the potential to support a range of payloads and missions. Some of these missions were impossible in the absence of Ares V's capabilities. Collaborative design/architecture inputs, exchanges, and analyses have already begun between scientists and payload developers. A 2008 study by a National Research Council (NRC) panel, as well as analyses presented by astronomers and planetary scientists at two weekend conferences in 2008, support the position that Ares V has benefit to a broad range of planetary and astronomy missions. This early dialogue with Ares V engineers is permitting the greatest opportunity for payload/transportation/mission synergy and the least financial impact to Ares V development. In addition, independent analyses suggest that Ares V has the opportunity to enable more cost-effective mission design.

Creech, Steve↗

Dynamic Stability Testing of the Mars Science Laboratory Entry Capsule

Results from a 26 shot ballistic range test of the Mars Science Laboratory (MSL) entry capsule are presented. The supersonic pitch damping properties of the MSL capsule were characterized between Mach 1.35 and Mach 3.5 and total angles-of-attack from 0 to 30 degrees. In flight, the MSL entry capsule will utilize a radial center-of-gravity offset to produce a non-zero trim angle-of-attack. This offset trim angle will produce lift, enabling the capsule to fly a guided entry and reducing the landing footprint dimensions to within 10 km of the desired landing site. A lifting configuration could not be tested at the ballistic range used for this test as the models would swerve into the range walls, possibly damaging cameras, the coordinate reference system or other facility assets. Ballistic (non-lifting) data was extracted and will be implemented in a conservative fashion to ensure that the dynamic stability characteristics of the flight vehicle are bounded. A comparison between the MSL pitch damping results and the dynamic model of the Mars Exploration Rover capsule shows generally close agreement with no significant differences in damping characteristics due to the change in backshell geometry. Dynamic moments are also compared to the MSL reaction control system (RCS) control authority to show the controller has sufficient margin to easily damp any dynamic stability effects.

Schroenenberger, Mark↗

Implementing an Applied Science Program

The work implied in the NASA Applied Science Program requires a delicate balancing act for the those doing it. At the implementation level there are multiple tensions intrinsic to the program. For example each application of an existing product to a decision support process requires deep knowledge about the data and deep knowledge about the decision making process. It is highly probable no one person has this range of knowledge. Otherwise the decision making process would already be using the data. Therefore, a team is required. But building a team usually requires time, especially across agencies. Yet the program mandates efforts of relatively short duration. Further, those who know the data are scientists, which makes them essential to the program. But scientists are evaluated on their publication record. Anything which diverts a scientist from the research for his next publication is an anathema to him and potential death to their career. Trying to get another agency to use NASA data does not strike most scientists as material inherently suitable for publication. Also, NASA wishes to rapidly implement often substantial changes to another agency's process. For many reasons, such as budget and program constraints, speed is important. But the owner of a decision making process is tightly constrained, usually by law, regulation, organization and custom. Changes when made are slow, cautious, even hesitant, and always done according a process specific to the situation. To manage this work MSFC must balance these and other tensions. Some things we have relatively little control over, such as budget. These we try to handle by structural techniques. For example by insisting all of our people work on multiple projects simultaneously we inherently have diversification of funding for all of our people. In many cases we explicitly use some elements of tension to be productive. For example the need for the scientists to constantly publish is motivation to keep tasks short and to the immediate point. As another example, the DSS agency and it personnel are treated as integral to the effort at every step. Thus, their ways of doing things, their problems and their assets become part of the solution. MSFC also manages the Applied Science work' within a strategic framework.' First, the scientists are necessarily at the core of all of this work as well as all of the work within the larger' organization. We therefore strive to keep a roughly 50-50 balance between the work done on tasks funded directly by the research side of NASA's Science Mission Directorate and funding from the applied side. Done at both the organization level and the level of the individual, this keeps the scientist both happy and productive over the long term. We also try diligently to remove as much burden from the scientist as practical by employing people such as the authors and others to do tasks not requiring; scientific knowledge. We also have designed our effort to take full use of external partners. We actively seek and support, including fund, people from multiple organizations to join us as committed collaborators. In this we use today's money and today's problem to help us diversify and strengthen for tomorrow. MSFC also considers the Applied Science work holistically. Each element is viewed as a step in a larger process. At a management level we can chose to emphasize or encourage certain areas which service long term goals. Thus, if we think work in a particular area should be developed, we can start with the smaller, less costly elements and grow.

Rickman, Doug↗

The Ares Launch Vehicles: Critical Capabilities for America's Continued Leadership in Space

The Constellation Program renews the nation's commitment to human space exploration a) Access to ISS. b) Human explorers to the Moon and beyond. c) Large telescopes and other hardware to LEO . Hardware is being built today. Development made easier by applying lessons learned from 50 years of spaceflight experience. Ares V heavy-lift capability will be a strategic asset for the nation. Constellation provides a means for world leadership through inspiration and strategic capability.

Cook, Stephen A.↗

Wireless Network Communications Overview for Space Mission Operations

The mission of the On-Board Wireless Working Group (WWG) is to serve as a general CCSDS focus group for intra-vehicle wireless technologies. The WWG investigates and makes recommendations pursuant to standardization of applicable wireless network protocols, ensuring the interoperability of independently developed wireless communication assets. This document presents technical background information concerning uses and applicability of wireless networking technologies for space missions. Agency-relevant driving scenarios, for which wireless network communications will provide a significant return-on-investment benefiting the participating international agencies, are used to focus the scope of the enclosed technical information.

Fink, Patrick W.↗

Unified Communications for Space Inventory Management

To help assure mission success for long-duration exploration activities, NASA is actively pursuing wireless technologies that promote situational awareness and autonomy. Wireless technologies are typically extensible, offer freedom from wire tethers, readily support redundancy, offer potential for decreased wire weight, and can represent dissimilar implementation for increased reliability. In addition, wireless technologies can enable additional situational awareness that otherwise would be infeasible. For example, addition of wired sensors, the need for which might not have been apparent at the outset of a program, night be extremely costly due in part to the necessary routing of cables through the vehicle. RFID, or radio frequency identification, is a wireless technology with the potential for significant savings and increased reliability and safety in space operations. Perhaps the most obvious savings relate to the application of inventory management. A fully automated inventory management system is highly desirable for long-term sustaining operations in space environments. This assertion is evidenced by inventory activities on the International Space Station, which represents the most extensive inventory tracking experience base in the history of space operations. In the short tern, handheld RFID readers offer substantial savings owing to reduced crew time for inventory audits. Over the long term, a combination of improved RFID technology and operational concepts modified to fully utilize the technology should result in space based inventory management that is highly reliable and requires very little crew time. In addition to inventory management, RFID is likely to find space applications in real-time location and tracking systems. These could vary from coarse-resolution RFID portals to the high resolution afforded by ultra-wideband (UWB) RFID. Longer range RFID technologies that leverage passive surface acoustic wave (SAW) devices are being investigated to track assets on a lunar or planetary surface.

Gifford, Kevin K.↗

Mars Reconnaissance Orbiter In-flight Anomalies and Lessons Learned: An Update

The Mars Reconnaissance Orbiter mission has as its primary objectives: advance our understanding of the current Mars climate, the processes that have formed and modified the surface of the planet and the extent to which water has played a role in surface processes; identify sites of possible aqueous activity indicating environments that may have been or are conducive to biological activity; and thus identify and characterize sites for future landed missions; and provide forward and return relay services for current and future Mars landed assets. MRO's crucial role in the long term strategy for Mars exploration requires a high level of reliability during its 5.4 year mission. This requires an architecture which incorporates extensive redundancy and cross-strapping. Because of the distances and hence light-times involved, the spacecraft itself must be able to utilize this redundancy in responding to time-critical failures. For cases where fault protection is unable to recognize a potentially threatening condition, either due to known limitations or software flaws, intervention by ground operations is required. These aspects of MRO's design were discussed in a previous paper [Ref. 1]. This paper provides an update to the original paper, describing MRO's significant in-flight anomalies over the past year, with lessons learned for redundancy and fault protection architectures and for ground operations.

Mars Reconnaissance Orbiter↗

Port-O-Sim Object Simulation Application

Port-O-Sim is a software application that supports engineering modeling and simulation of launch-range systems and subsystems, as well as the vehicles that operate on them. It is flexible, distributed, object-oriented, and realtime. A scripting language is used to configure an array of simulation objects and link them together. The script is contained in a text file, but executed and controlled using a graphical user interface. A set of modules is defined, each with input variables, output variables, and settings. These engineering models can be either linked to each other or run as standalone. The settings can be modified during execution. Since 2001, this application has been used for pre-mission failure mode training for many Range Safety Scenarios. It contains range asset link analysis, develops look-angle data, supports sky-screen site selection, drives GPS (Global Positioning System) and IMU (Inertial Measurement Unit) simulators, and can support conceptual design efforts for multiple flight programs with its capacity for rapid six-degrees-of-freedom model development. Due to the assembly of various object types into one application, the application is applicable across a wide variety of launch range problem domains.

Lanzi, Raymond J.↗

Ares V: Game Changer for National Security Launch

NASA is designing the Ares V cargo launch vehicle to vastly expand exploration of the Moon begun in the Apollo program and enable the exploration of Mars and beyond. As the largest launcher in history, Ares V also represents a national asset offering unprecedented opportunities for new science, national security, and commercial missions of unmatched size and scope. The Ares V is the heavy-lift component of NASA's dual-launch architecture that will replace the current space shuttle fleet, complete the International Space Station, and establish a permanent human presence on the Moon as a stepping-stone to destinations beyond. During extensive independent and internal architecture and vehicle trade studies as part of the Exploration Systems Architecture Study (ESAS), NASA selected the Ares I crew launch vehicle and the Ares V to support future exploration. The smaller Ares I will launch the Orion crew exploration vehicle with four to six astronauts into orbit. The Ares V is designed to carry the Altair lunar lander into orbit, rendezvous with Orion, and send the mated spacecraft toward lunar orbit. The Ares V will be the largest and most powerful launch vehicle in history, providing unprecedented payload mass and volume to establish a permanent lunar outpost and explore significantly more of the lunar surface than was done during the Apollo missions. The Ares V consists of a Core Stage, two Reusable Solid Rocket Boosters (RSRBs), Earth Departure Stage (EDS), and a payload shroud. For lunar missions, the shroud would cover the Lunar Surface Access Module (LSAM). The Ares V Core Stage is 33 feet in diameter and 212 feet in length, making it the largest rocket stage ever built. It is the same diameter as the Saturn V first stage, the S-IC. However, its length is about the same as the combined length of the Saturn V first and second stages. The Core Stage uses a cluster of five Pratt & Whitney Rocketdyne RS-68B rocket engines, each supplying about 700,000 pounds of thrust. Its propellants are liquid hydrogen and liquid oxygen. The two solid rocket boosters provide about 3.5 million pounds of thrust at liftoff. These 5.5-segment boosters are derived from the 4-segment boosters now used on the Space Shuttle, and are similar to those used in the Ares I first stage. The EDS is powered by one J-2X engine. The J-2X, which has roughly 294,000 pounds of thrust, also powers the Ares I Upper Stage. It is derived from the J-2 that powered the Saturn V second and third stages. The EDS performs two functions. Its initial suborbital burns will place the lunar lander into a stable Earth orbit. After the Orion crew vehicle, launched separately on an Ares I, docks with the lander/EDS stack, EDS will ignite a second time to put the combined 65-metric ton vehicle into a lunar transfer orbit. When it stands on the launch pad at Kennedy Space Center late in the next decade, the Ares V stack will be approximately 381 feet tall and have a gross liftoff mass of 8.1 million pounds. The current point-of-departure design exceeds Saturn V s mass capability by approximately 40 percent. Using the current payload shroud design, Ares V can carry 315,000 pounds to 29-degree low Earth orbit (LEO) or 77,000 pounds to a geosynchronous orbit. Another unique aspect of the Ares V is the 33-foot-diameter payload shroud, which encloses approximately 30,400 cubic feet of usable volume. A larger hypothetical shroud for encapsulating larger payloads has been studied. While Ares V makes possible larger payload masses and volumes, it may alternately make possible more cost-effective mission design if the relevant payload communities are willing to consider an alternative to the existing approach that has driven them to employ complexity to solve current launch vehicle mass and volume constraints. By using Ares V s mass and volume capabilities as margin, payload designers stand to reduce development risk and cost. Significant progress has been made on the Ares V to support a plaed fiscal 2011 authority-to-proceed (ATP) milestone. The Ares V team is actively reaching out to external organizations during this early concept phase to ensure that the Ares V vehicle can be leveraged for national security, science, and commercial development needs. This presentation will discuss Ares V vehicle configuration, the path to the current concept, accomplishments to date, and potential payload utilization opportunities.

Sumrall, Phil↗

Heavy Lift for National Security: The Ares V

The NASA Ares Projects Office is developing the launch vehicles to move the United States and humanity beyond low earth orbit. Ares I is a crewed vehicle, and Ares V is a heavy lift vehicle being designed to launch cargo into LEO and transfer cargo and crews to the Moon. This is a snapshot of development and capabilities. Ares V is early in the requirements formulation stage of development pending the outcome of the Review of U.S. Human Space Flight Plans Committee and White House action. The Ares V vehicle will be considered a national asset, creating unmatched opportunities for human exploration, science, national security, and space business.

Sumrall, Phil↗

Detection, Identification, Location, and Remote Sensing Using SAW RFID Sensor Tags

The Electromagnetic Systems Branch (EV4) of the Avionic Systems Division at NASA Johnson Space Center in Houston, TX is studying the utility of surface acoustic wave (SAW) radiofrequency identification (RFID) tags for multiple wireless applications including detection, identification, tracking, and remote sensing of objects on the lunar surface, monitoring of environmental test facilities, structural shape and health monitoring, and nondestructive test and evaluation of assets. For all of these applications, it is anticipated that the system utilized to interrogate the SAW RFID tags may need to operate at fairly long range and in the presence of considerable multipath and multiple-access interference. Towards that end, EV4 is developing a prototype SAW RFID wireless interrogation system for use in such environments called the Passive Adaptive RFID Sensor Equipment (PARSED) system. The system utilizes a digitally beam-formed planar receiving antenna array to extend range and provide direction-of-arrival information coupled with an approximate maximum-likelihood signal processing algorithm to provide near-optimal estimation of both range and temperature. The system is capable of forming a large number of beams within the field of view and resolving the information from several tags within each beam. The combination of both spatial and waveform discrimination provides the capability to track and monitor telemetry from a large number of objects appearing simultaneously within the field of view of the receiving array. In this paper, we will consider the application of the PARSEQ system to the problem of simultaneous detection, identification, localization, and temperature estimation for multiple objects. We will summarize the overall design of the PARSEQ system and present a detailed description of the design and performance of the signal detection and estimation algorithms incorporated in the system. The system is currently configured only to measure temperature (jointly with range and tag ID), but future versions will be revised to measure parameters other than temperature as SAW tags capable of interfacing with external sensors become available. It is anticipated that the estimation of arbitrary parameters measured using SAW-based sensors will be based on techniques very similar to the joint range and temperature estimation techniques described in this paper.

Barton, Richard J.↗

Increasing the Cost-efficiency of the DSN

JPL has operated the Deep Space Network (DSN) on behalf of NASA since the 1960's. Over the last two decades, the DSN budget has generally declined in real-year dollars while the aging assets required more attention, and the missions became more complex. As a result, the budget has been increasingly consumed by Operations and Maintenance (O and M), significantly reducing the funding wedge available for technology investment and for enhancing the DSN capability and capacity. Responding to this budget squeeze, the DSN launched an effort to improve the cost-efficiency of the O and M. In this paper we: Analyze the components of O&M. We note for example that, for the DSN, less than 20% of the staff engage in the traditional human-in-front-a-console role, so any effort to increase the cost efficiency must go beyond reducing the number of "Real-time operators." Explain the underlying organizational and cultural structures. Any cost-efficiency activities changes either accept, or carefully modify these structures. For example, the DSN O&M is based on the concept that there are three nearly identical antenna complexes separated by approximately 1200 in latitude and that each antenna complex is operated by a different contractor (driven by international agreements). Explore planned changes in the customer interface, e.g. web-based automated scheduling, and the processes required for a transition. Changes have to be evaluated in the larger end-to-end context, e.g. do the changes provide a net cost-efficiency for the DSN and the missions, or do they merely shift cost from the DSN to the missions. Consider possible significant changes in real-time pass management, e.g. full-remoting of operations, and lights-dim operations, while maintaining (or improving) the performance metrics of the DSN. Investigate how procedural and administrative changes could increase cost-efficiency, in conjunction with changes in the customer interfaces and real-time pass management. Examples would be handling of inter-governmental agreements, improved sharing of resources with other agencies, and better use of commercial (rather than government) resources

Deep Space Network (DSN)↗

Using FLUKA to Calculate Spacecraft: Single Event Environments: A Practical Approach

The FLUKA nuclear transport and reaction code can be developed into a practical tool for calculation of spacecraft and planetary surface asset SEE and TID environments. Nuclear reactions and secondary particle shower effects can be estimated with acceptable accuracy both in-flight and in test. More detailed electronic device and/or spacecraft geometries than are reported here are possible using standard FLUKA geometry utilities. Spacecraft structure and shielding mass. Effects of high Z elements in microelectronic structure as reported previously. Median shielding mass in a generic slab or concentric sphere target geometry are at least approximately applicable to more complex spacecraft shapes. Need the spacecraft shielding mass distribution function applicable to the microelectronic system of interest. SEE environment effects can be calculated for a wide range of spacecraft and microelectronic materials with complete nuclear physics. Evaluate benefits of low Z shielding mass can be evaluated relative to aluminum. Evaluate effects of high Z elements as constituents of microelectronic devices. The principal limitation on the accuracy of the FLUKA based method reported here are found in the limited accuracy and incomplete character of affordable heavy ion test data. To support accurate rate estimates with any calculation method, the aspect ratio of the sensitive volume(s) and the dependence must be better characterized.

Koontz, Steve↗

Life Sciences Data Archive (LSDA) in the Post-Shuttle Era

Now, more than ever before, NASA is realizing the value and importance of their intellectual assets. Principles of knowledge management, the systematic use and reuse of information/experience/expertise to achieve a specific goal, are being applied throughout the agency. LSDA is also applying these solutions, which rely on a combination of content and collaboration technologies, to enable research teams to create, capture, share, and harness knowledge to do the things they do well, even better. In the early days of spaceflight, space life sciences data were been collected and stored in numerous databases, formats, media-types and geographical locations. These data were largely unknown/unavailable to the research community. The Biomedical Informatics and Health Care Systems Branch of the Space Life Sciences Directorate at JSC and the Data Archive Project at ARC, with funding from the Human Research Program through the Exploration Medical Capability Element, are fulfilling these requirements through the systematic population of the Life Sciences Data Archive. This project constitutes a formal system for the acquisition, archival and distribution of data for HRP-related experiments and investigations. The general goal of the archive is to acquire, preserve, and distribute these data and be responsive to inquiries from the science communities.

Fitts, Mary A.↗

Workshop on Sustainable Infrastructure with NASA Science Mission Directorate and NASA's Office of Infrastructure Representatives

NASA conducted a workshop in July 2009 to bring together their experts in the climate science and climate impacts domains with their institutional stewards. The workshop serves as a pilot for how a federal agency can start to: a) understand current and future climate change risks, b) develop a list of vulnerable institutional capabilities and assets, and c) develop next steps so flexible adaptation strategies can be developed and implemented. 63 attendees (26 scientists and over 30 institutional stewards) participated in the workshop, which extended across all or part of three days.

Rosenzweig, Cynthia↗