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The Interface Region Imaging Spectrograph (IRIS) Small Explorer's (SMEX) science investigation is centered on three themes of broad significance to solar and plasma physics, space weather, and astrophysics. Which types of non-thermal energy dominate in the chromosphere and beyond? How does the chromosphere regulate mass and energy supply to the corona and heliosphere? How do magnetic flux and matter...
Comparisons are shown between transport model calculations and secondary-neutron cross sections from 400 MeV/nucleon Kr + Pb interactions. Variations are made in the input files used for the calculations in order to take into account corrections applied to the data for background, flux attenuation, and other effects inherent with neutron measurements at accelerator facilities. Results show that the...
The US Supreme Court's holding in Bilski v Kappos limits software developers attempting to patent inventions using method claims. The Bilski holding limited the scope of business method patents to those that claim a method hosted on a machine or those that effect a transformation of a particular article into a different state or thing. While today's scope of method claims is more limited than before...
C-130 aircraft1 is considered to be one of the most reliable military cargo aircraft. Its popularity mainly rests with military users especially with the air forces around the world. It forms the backbone for tactical and transportation operations. It is equipped with four T-56 turboprop engines to keep the transport aircraft in air. During missions the aircraft might get exposed to short runway takeoffs...
A new class of Rodrigues-vectors-based strapdown attitude algorithms is developed in this paper. This class of algorithms uses Rodrigues vectors instead of the widely used rotation vector and applies the conception of least square technique. The multiple summations of gyro samples is used to obtain the least square estimation of Rodrigues vectors increment in an attitude update period. Such estimation...
In this paper, we detail the design, fabrication, and test of a set of architecturally related ASICs implemented using radiation hardened by design (RHBD) techniques. The ASICs are notable for their reuse of common components and interfaces, thereby dramatically reducing design time and cost. These chips perform relatively simple functions such as data conversion, multiplexing, and digital I/O under...
The analytical theory of the propagation of annular Gaussian beams through turbulence is briefly reviewed in this work. Wave (physical) optics simulations are implemented for various scenario parameters under weak to strong fluctuation conditions. Comparisons of the analytic and simulation beam intensity profiles show remarkable agreement. In weak turbulence, scintillation index results are also consistent...
In this paper, the advantages of UWB (Ultra-Wide Band) transmission for satellite communications are investigated together with the ones coming from the use of EHF (Extremely High Frequency) where there is the possibility of exploiting a huge spectrum availability. In particular, a comparison among UWB approaches is shown in terms of BER performance, considering hardware impairments.
The Lunar Reconnaissance Orbiter (LRO) was launched into lunar orbit in June 2009. Among its objectives are to find potential safe landing sites, locate potential resources, test new technologies, and characterize the lunar radiation environment. To accomplish the latter objective, the Cosmic Ray Telescope for the Effects of Radiation (CRaTER), a linear energy transfer (LET) spectrometer is mounted...
The Air Force Research Laboratory (AFRL) developed an initial plug-and-play capability for spacecraft to better define interfaces, similar to USB on personal computers, in order to simplify spacecraft development and reduce cost and schedule. Much of this improved definition involves standardizing software interfaces between spacecraft components and a spacecraft network. The Spacecraft Avionics Experiment...
Multitarget-Multisensor tracking metrics have been studied extensively in recent years. These tracking metrics require a unique assignment of tracks to truth objects at each scoring time. There are two typical approaches to address this track-to-truth assignment problem. The first approach involves developing content vectors for the measurements (i.e., vectors indicating the percentage of each truth...
The Mars Sample Return (MSR) campaign involves three complementary spacecraft missions, one of which will contain a Mars Ascent Vehicle (MAV) to deliver the Martian sample to orbit for subsequent retrieval and return to Earth. MAV must deliver a 5-kg sample container containing up to 500 g of surface material to a 520 ± 60-km orbit while satisfying all surface and mission requirements. Lockheed Martin...
Often in computer-based simulations, sensor models are used to generate realistic data to stimulate an algorithm under test. These algorithms might include, but are not limited to, guidance, navigation, control, tracking, and mission management algorithms. This paper builds on the authors' previous research to apply a systematic approach for comparing two separately developed models of the same sensor...
This paper presents a new on-line methodology for detecting intermittent disconnection failures. The detection principle operates on the fundamental Lorentz Law that states that sudden changes in flux create a large voltage, resulting in an arc. This arc propagates as a traveling wave through the circuit until all the energy associated with it is dissipated. It is possible to detect that traveling...
This paper provides an overview of the event-driven architecture that will be used onboard the James Webb Space Telescope (JWST) to carry out the series of exposures, maneuvers, and engineering activities that were selected beforehand by the JWST planning and scheduling subsystem. Each week during one of the ground communication intervals one observation plan segment that contains an ordered list...
This paper summarizes the results from the multi-year research program completed at U.C. Berkeley, Space Sciences Laboratory, Center for Extreme Ultra Violet Astrophysics (CEA) in collaboration with engineering personnel from the Advanced Analysis Department at Lockheed Martin Space Systems Company. The research used the NASA EUVE satellite subsystem and payload equipment analog telemetry from the...
The traditional software engineering approach at NASA uses a waterfall model. While this results in software that meets the requirements and is functionally correct, it may not result in the safest software, as verification and validation do not consider the software's usability. Since flight controllers need to make time-sensitive decisions based on telemetry, the flexibility and usability of the...
With the trend in spacecraft flight software systems toward the use of message-based architectures, flight software systems are being decomposed into several discrete applications each with a relatively narrow focus. These applications, however, share several common requirements for initialization, command processing, parameter management and telemetry generation. Even with a single common design,...
Simulation is a powerful tool for the study of complex systems, especially in the aerospace context, where systems are too expensive and too critical to allow real experimentation. Among simulation paradigms, a particularly well-suited approach in this context is distributed simulation, where each subsystem is simulated by its own simulation component, and the interactions between these components...
In 2010, Mars Exploration Rover (MER) Project became the first NASA mission to incorporate a public cloud into its daily mission-critical operations. Since then, the operators and scientists have experienced 100% availability on tactical plan saves, searches, and retrieval. MER has also pushed tactical data onto lower cost storage systems in the cloud environments, which continue to deliver cost savings,...
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