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This paper presents the concept of operations and preliminary design of a multi-satellite mission for the active removal of large pieces of debris from low Earth orbit. The mission consists of a mothership minisatellite, that carries six nanosatellites. The mothership acquires a relative orbit of a few kilometers with respect to the piece of orbital debris of interest and determines the attitude state...
Cold Atom Laboratory (CAL) is a facility that will enable scientists to study ultra-cold quantum gases in a microgravity environment on the International Space Station (ISS) beginning in 2016. The primary science data for each experiment consists of two images taken in quick succession. The first image is of the trapped cold atoms and the second image is of the background. The two images are subtracted...
NASA is developing a long-term strategy for achieving extended human missions to Mars in support of the policies outlined in the 2010 NASA Authorization Act and National Space Policy. The Authorization Act states that “A long term objective for human exploration of space should be the eventual international exploration of Mars.” Echoing this is the National Space Policy, which directs that NASA should,...
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 probability...
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...
To ensure safe unmanned aircraft (UA) operations in the US National Airspace System, Ground Based Sense and Avoid (GBSAA) capabilities have been added to the Standard Terminal Automation Replacement System (STARS) for the United States Air Force (USAF) at Cannon Air Force Base (AFB) to support Predator and Reaper UA operations. 1 2
The Asteroid Redirect Crewed Mission (ARCM) requires a Launch/Entry/Abort (LEA) suit capability and short duration Extra Vehicular Activity (EVA) capability from the Orion spacecraft. For this mission, the pressure garment selected for both functions is the Modified Advanced Crew Escape Suit (MACES) with EVA enhancements and the life support option that was selected is the Exploration Portable Life...
Gas-pressurized space suits are incredibly well engineered tools allowing astronauts to perform critical duties. However, current gas pressurized space suits have an inherent stiffness, causing fatigue, unnecessary energy expenditure, and in some instances injury. Prior to this research effort there was no technology allowing the human-space suit interface to be measured internally. We quantify and...
Small singularity size is critical for achieving low light loss and high contrast for vector vortex waveplate (VVW) based coronagraph. In the opto-mechanical system for recording VVW with photoalignment, reshaping the center light intensity distribution and precision alignment can effectively decrease singularity size. We have developed methods for redistributing the light intensity near the singularity...
Adjoint equations have been used for some time in optimal control theory. The adjoint method has played a prominent role in aerodynamic design due to the flexibility it offers in terms of choosing the flow physics model and cost functions. However, most of the applications in the literature are limited to simple geometries. This paper presents a methodology to deal with complex geometries when using...
In 2011, the National Space Organization (NSPO) of the National Applied Research Laboratories (NARL) in Taiwan, Republic of China (ROC), initiated a latest space program, called the FORMOSAT-7 (FS-7), whose mission consists of a new constellation of 12 satellites (to be built by Surrey Satellite Technology LTD) plus one additional NSPOBuilt satellite for an operational mission to replace the previous...
This paper describes the designing, detailed motion and frequency analysis and brief control approach of nano reaction wheels that has to be used as an actuator for STUDSAT-2. The designing part comprises of designing a flywheel, tetrahedral configuration explanation and the motor selection. The worst case disturbance modeling is done to design the flywheel considering the four primary environmental...
In this research, a technique is developed to separate an additive fault from a multiplicative fault of a system which is disturbed by integrated white noise. First, Predictor-based System Identification (PBSID) is formulated in a differenced form (DPBSID) in order to filter out the integrated white noise. Second, the differenced PBSID is reformulated in a recursive form (DRPBSID) which is for separating...
The Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft was launched on September 7, 2013 UTC, and completed its mission on April 17, 2014 UTC with a directed impact to the Lunar Surface. Its primary goals were to examine the lunar atmosphere, measure lunar dust, and to demonstrate high rate laser communications. The LADEE mission was a resounding success, achieving all mission objectives,...
Structural changes due to ice accretion are common causes for unmanned aerial vehicle incidents in Arctic regions. For fixed wing unmanned aerial vehicles (UAVs) the leading edge of airfoil surfaces is one of the primary surfaces exposed to these changes, causing a significant reduction in aerodynamic ability, i.e. decreasing lift and manoeuvrability, and increasing drag, weight, and consequently...
Research and development organizations frequently encounter challenges when attempting to identify an investment strategy and to accurately forecast the cost and schedule performance of selected projects. Fast moving and complex environments require managers to analyze quickly and to diagnose the value of returns on innovation investments versus allocated resources. Our Project Assessment Framework...
The main contribution of this paper is the design, development and evaluation of a light-weight Air Supply Unit (ASU) and its associated speed controller, suitable for use in Circulation Control Wings (CCW) of small-scale Unmanned Aerial Vehicles (UAVs). An iterative process, presented here, is used to optimize the design of the centrifugal compressor for the ASU through extensive simulation. The...
Precise predictions of the radiation environment inside space vehicles, and inside the human body, are essential when planning for long term deep space missions. Since these predictions include complex geometries, as well as the contributions from many different types of radiation, including neutrons, 3-D Monte Carlo codes with precise physics models are needed. In this paper, we present improvements...
The similarity of the plume radiation of solid rocket engines in different reduced-scale sizes is important for studying the radiation of regular-sized engines with small-scale tests. To determine the similarity of plume radiation between reduced-scale rockets and regular-sized rockets in ground-test conditions, the flow and radiation of rocket engines in the geometric reduced-scale ratios of 0.1...
A system for autonomous precision recovery of fixedwing unmanned aerial vehicles (UAVs) using low-cost GPS L1 C/A based RTK (Real-Time Kinematic) solution utilizing locally generated corrections is described and field tested. We present a system architecture which includes the setup of the hardware and software for the onboard GPS receiver, base-station, differential link, computers running open-source...
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