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Among the size, weight and power constraints imposed by the CubeSat specification, the limitation associated with power can be addressed through a distributed computing architecture. This paper describes such a distributed computing architecture and its operational design in the form of command and data handling system and telemetry formulation, adapted for a CubeSat whose power requirements for proving...
In miniaturized radars where power, real estate, speed and low cost are tight constraints and Doppler tolerance is not a major concern biphase codes are popular and FIR filter is used for digital pulse compression (DPC) implementation to achieve required range resolution. Disadvantage of low peak to sidelobe ratio (PSR) of biphase codes can be overcome by linear programming for either single stage...
The Orbiting Low Frequency Antenna for Radio Astronomy (OLFAR) project is a feasibility study investigating a low frequency radio telescope in space using a swarm of autonomous nano satellites. Due to ionospheric interference found at frequencies below 30 MHz, such an instrument is not feasible on earth. The effect of the non-symmetrical deployment of the antenna and the effect of the non-uniform...
This paper discusses recent advances in tip clearance measurement systems for turbine engines using through-the-case eddy current sensors (TTC-ECS). Improved performance has been achieved through a combination of new designs for the magnetic components as well as the signal processing electronics. A novel preamplifier circuit eliminates the band-limiting effects of interwinding capacitance and cable...
This paper discusses recent advances in tip clearance measurement systems for turbine engines using capacitive probes. Real time measurements of individual blade pulses are generated using wideband signal processing providing 3 dB bandwidths of typically 5 MHz. Subsequent mixed-signal processing circuitry provide real-time measurements of maximum, minimum, and average clearance with latencies of one...
With the exception of the CubeSat specification, CubeSat design and development approaches have been mostly ad hoc, which has questioned their reliability. A systems engineering approach, based on the guidelines of NASA's Systems Engineering Handbook has been developed for CubeSats to facilitate systematic design, development and address their reliability, traceability, and reusability. The CubeSat...
Organizations that ignore near-miss data may be inappropriately rewarding risky behavior. If managers engage in risky behavior and succeed, research shows that these managers are likely to be promoted without close scrutiny of their risky decisions, even if the success is because of good fortune [1]. Over time such risk taking compounds as similar near-misses are repeatedly observed and the ability...
The knowledge of the turbulence conditions and the ability to describe its properties are the key aspects to improve performance and extend the range of optical communication systems. The developed multi-channel, outdoor 3.2 km, partially over water, turbulence measurement and monitoring communication platform is directed to collect significant amount of the experimental data with the goal of statistically...
The goal of this work was to (1) define parameters to characterize a pointing mechanism, (2) design a setup to test these parameters and, (3) verify the test methods by comparing the results to the theoretically calculated or independently verified numbers. The verification of the test results was conducted with an in-house built Antenna Pointing Mechanism for on-orbit servicing applications.
In this paper we present a Universal and Interoperable Ground Control Station (UIGCS) simulator for fixed and rotary wing Unmanned Aerial Vehicles (UAVs), and all types of payloads. One of the major constraints is to operate and manage multiple legacy and future UAVs, taking into account the compliance with NATO Combined/Joint Services Operational Environment (STANAG 4586). Another purpose of the...
Recent developments in high altitude balloon platform capabilities, specifically long duration flights in excess of 50 days at over 100,000 ft and precision pointing with performance at the arc sec level or better have raised the question whether this platform can be utilized for high-value planetary science observations. In January of 2012 a workshop was held at NASA Glenn Research Center in Cleveland,...
A predictive medicine program allows disease and illness including mental illness to be predicted using tools created to identify the presence of accelerated aging (a.k.a. disease) in electrical and mechanical equipment. When illness and disease can be predicted, actions can be taken so that the illness and disease can be prevented and eliminated. A predictive medicine program uses the same tools...
Satellite mission control systems typically are operated by scheduling missions to the visibility between ground stations and satellites. The communication for the mission is achieved by interacting with satellite visibility and ground station support. Specifically, the satellite forms a cone-type visibility passing over a ground station, and the antennas of ground stations support the satellite....
The U.S. Air Force procures many launch vehicles and launch vehicle services to place their satellites at their desired location in space. The equipment on-board these satellite and launch vehicle often suffer from premature failures that result in the total loss of the satellite or a shortened mission life sometimes requiring the purchase of a replacement satellite and launch vehicle. The Air Force...
The “Variable Vector Countermeasure Suit (V2Suit) for Space Exploration” is an integrated countermeasure platform to mitigate the spaceflight-induced physiologic adaptation and de-conditioning that manifests during long-duration spaceflight and gravitational transitions. The V2Suit integrates flywheel gyroscopes and inertial measurement units within a wearable module that can be placed on the body...
The Radiation Belt Storm Probes (RBSP) mission is part of NASA's Living With a Star Program, and launched August 30, 2012. The fundamental goal of the mission is to provide an understanding, ideally to the point of predictability, of how populations of relativistic electrons and penetrating ions in space form or change in response to variable inputs of energy from the Sun. The mission consists of...
The self diagnostic accelerometer (SDA) developed by the NASA Glenn Research Center was tested for the first time in an aircraft engine environment as part of the Vehicle Integrated Propulsion Research (VIPR) program. The VIPR program includes testing multiple critical flight sensor technologies. One such sensor, the accelerometer, measures vibrations to detect faults in the engine. In order to rely...
This paper aims to develop IMU/Vision/Lidar integrated navigation system which can provide accurate relative navigation information in GNSS denied environments. The developed integrated navigation system consists of an IMU, a vision sensor and a Lidar sensor. In order to overcome limitation of low accuracy of MEMS inertial navigation solution when GNSS signal cannot be used, 2-dimensional optical...
This paper offers a useful application of Uniform Input Voltage Distribution (UIVD) control [6-9] for Distributed-Input Parallel-Output (DIPO) converter power systems. The primary control objective of UIVD for DIPO converters is to achieve grouped maximum power throughput from non-identical renewable power sources. Secondly, this paper features a revised Maximum Power Tracking (MPT) controller design...
Recently we suggested a dust-based active debris removal technique to selectively remove small untrackable debris that occupies a very large volume around the Earth. For designing a working system an accurate knowledge of the dynamics of the released dust in orbit is necessary. In this paper we numerically examine the dynamics of non-interacting spherical tungsten dust grains of diameter between 30-60...
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