2015 IEEE Aerospace Conference

This paper reports on the results of attempts to reduce the positioning error of strap down inertial navigation system using attitude information obtained by star tracker. In this regard, the position error equations of different channel in inertial navigation are modeled and error share of each sensor in position and attitude determination drifts are investigated. In continue celestial navigation... View full abstract»

Space communications architecture concepts, comprising the elements of the system, the interactions among them, and the principles that govern their development, are essential factors in developing National Aeronautics and Space Administration (NASA) future exploration and science missions. Accordingly, vital architectural attributes encompass flexibility, the extensibility to insert future capabi... View full abstract»

Flight simulators with a physical mock-up are dependent on the aircraft type and have high costs. In order to overcome high cost issues, a generic virtual reality flight simulator is designed. Virtual buttons are used without a physical mock-up to make the virtual reality flight simulator independent of the aircraft type. The classic virtual hand metaphor is employed to interact with the virtual o... View full abstract»

The Space Launch System (SLS) Program is making progress toward delivering a new capability for Beyond Earth Orbit (BEO) exploration. Developed with the goals of safety, affordability and sustainability, SLS will start with 10% more thrust than the Saturn V that launched astronauts to the Moon 40 years ago. From there it will evolve into the most powerful launch vehicle ever flown, via an evolutio... View full abstract»

Wireless Power Transfer (WPT) systems are considered as sophisticated alternatives for modern day wired power transmission. Resonance based wireless power delivery is an efficient technique to transfer power over a relatively long distance. This paper presents a summary of a two-coil wireless power transfer system with the design theory, detailed formulations and simulation results using the coupl... View full abstract»

Although NASA has an established process for documenting lessons learned from development and operation of its complex and challenging missions, a recent audit of the NASA lessons learned program found that most NASA Centers have made few contributions to the NASA lessons learned repository in recent years. Among the NASA Centers, the NASA/Caltech Jet Propulsion Laboratory (JPL) has a relatively m... View full abstract»

This paper describes a Multiple Hypothesis Prediction (MHP) method that is used to improve aircraft state (energy and attitude) and automation mode awareness. The paper specifically focuses on its application for mode awareness during the use of the Vertical Navigation (VNAV) function. VNAV is used during the majority of the flight phases to govern vertical motion of aircraft and it is essential f... View full abstract»

Several past studies have analyzed the topic of blunt body aerodynamics, and have gone in depth, detailing the reduction in drag caused by the effect of aero-spike structures that are attached to blunt shaped bodies in hypersonic flow, like re-entry capsules and missiles. The results have showed the formation of a bow shock in front of the spike, which creates a re-circulation region in front of t... View full abstract»

OSIRIS-REx is an acronym that captures the scientific objectives: Origins, Spectral Interpretation, Resource Identification, and Security□Regolith Explorer. OSIRIS-REx will thoroughly characterize near-Earth asteroid Bennu (previously known as 1019551999 RQ36). The OSIRIS-REx Asteroid Sample Return Mission delivers its science using five instruments and radio science along with the Touch-and-Go Sa... View full abstract»

The application of 2-dimensional periodic arrays of sub-wavelength structures as anti-reflection surfaces at the interface between a vacuum and commercial solar cell coverglass is investigated. It is determined that compared to commercial anti-reflective coatings a single anti-reflective sub-wavelength grating will yield 3.7 to 7.1% total increase in power production during a 24 hour orbital perio... View full abstract»

NASA is planning to launch the next generation of a space based Earth relay in 2025 to join the current Space Network, consisting of Tracking and Data Relay Satellites in space and the corresponding infrastructure on Earth. While the requirements and architecture for that relay satellite are unknown at this time, NASA is investing in communications technologies that could be deployed to provide ne... View full abstract»

The bathtub curve (BTC) can be viewed as an experimental reliability “passport” of a population of mass produced devices. This curve considers and reflects the combined effect of two irreversible processes: statistics-related mass-production process and reliability-physics-related degradation (aging) process. The statistics-related process results in a decreasing failure rate with time. The reliab... View full abstract»

The potential for space mission operations and the supporting ground infrastructure is growing dramatically, fueled by new technologies, but with that growth comes increased complexity, and daunting reliability and security challenges. And like most complex endeavors, space operations are being asked to do more with less. In order to deliver cost-effective space operations services, researchers mu... View full abstract»

Multidisciplinary system design optimization is performed to determine an optimal on-orbit satellite assembly mission architecture. Modern satellite assembly and launch systems rely on monolithic launches of complete satellites. There are many benefits, however, that may be attained through deviating from the status quo. Launching robotic, on-orbit assemble-able satellite modules increases the num... View full abstract»

Electronic assemblies lie at the heart of virtually every aerospace system and mission and have resided there since the earliest days of NASA. Presently electronic assemblies are arguably the most mission-critical aspect of every aerospace mission. Currently and for the past more than half-century traditional organic epoxy resin laminates have served at the substrate of first choice for printed ci... View full abstract»

Nowadays, Direct Sequence Code Division Multiple Access (DS/CDMA) still represents the core technology for the physical layer of several commercially-remunerative applications and standards, ranging from cellular networking, radiolocalization, satellite communications, automotive radar, etc. A very critical issue of Spread Spectrum and CDMA is still represented by the necessity of keeping the prob... View full abstract»

Long-Term Evolution Advanced (LTE-A) will rely on the concept of “small cell”, i.e. low-power and low-cost radio base station, whose target is to provide broadband and energy-efficient coverage in residential sites and hot spot outdoor environment. Small cells will be characterized by some peculiar features that will make easier the coordination among base stations in order to improve link capacit... View full abstract»

A three-stage systemic early failure analysis (SEFA) methodology is proposed. It addresses prevalent failures occurring during development using diverse experimental and theoretical techniques and structures. SEFA provides a flexible yet consistent effective and efficient approach leading to a rare combination of unified high quality, reliability, safety, improvement and profitability (QIP). The S... View full abstract»

Propulsion technology development efforts at the NASA Johnson Space Center continue to advance the understanding of the quantum vacuum plasma thruster (Q-Thruster), a form of electric propulsion. Through the use of electric and magnetic fields, a Q-thruster pushes quantum particles (electrons/positrons) in one direction, while the Q-thruster recoils to conserve momentum. This principle is similar ... View full abstract»

A Spacecraft Mission Software System (SMSS) consists of both ground and flight software working cohesively to perform failure-free and reliable spacecraft operations in order to meet critical NASA or Department of Defense mission objectives. Visualization of all interdependencies of system components provides a means for assessment and detection of problems that can lead to a potential failure of ... View full abstract»

In this paper, a relay-based energy-efficient cooperative communication strategy is proposed, under the hypothesis that the relay transmits with power drawn from energy-harvesting (EH) sources. Assuming a deterministic EH model under which the harvested amount of energy is known prior to transmission, a spectrally efficient adaptive Bit-Interleaved Coded (BIC) OFDM modulation scheme has been inves... View full abstract»

In the aerospace domain, defects in mitigating failures can have very high costs. This makes it imperative to have systematic testing approaches for making sure that failure mitigations work properly. This paper describes a model-based testing approach that targets mitigations of system failures. It includes models of the system, of possible failures, and required mitigations. It uses all three to... View full abstract»

Continuum robots, which have continuous mechanical structures comparable to the flexibility in elephant trunks and octopus arms, have been primarily geared toward the medical and defense communities. In space, however, NASA projects these robots to have a place in irregular inspection routines. The inherent compliance and bending of these continuum arms are especially suitable for inspection in ob... View full abstract»

As we approach the thirtieth anniversary of the Challenger Disaster (January 28, 2016), how do we continue to educate current and future leaders on how to make decisions that involve significant risk and uncertainty with the lessons of Challenger in mind? To address this challenge we have created a case that places decision makers in a situation of risky choice. The case uses but masks the facts o... View full abstract»

We present a method for predicting the failure rate, and thus the reliability of an electronic system by summing the failure rate of each known failure mechanism. We use a competing acceleration factor methodology by combining the physics of failure for each mechanism with their effects as observed by High/Low temperature and High/Low voltage stresses. Our method assumes that lifetime of each of i... View full abstract»