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On July 17, 2006 Dean Acosta (NASA Press Secretary), Mike Griffin (Administrator), Bill Gerstenmaier (Associate Administrator of Space Operations), and Mike Leinbach (NASA Launch Director) expressed how proud they were to be a part of the STS-121/ Discovery team. They also explained how flawlessly the mission performed and how it was the best mission ever flown. They proceeded to answer numerous questions from the press.
An accurate real-time operator functional state assessment makes it possible to perform task management, minimize risks, and improve mission performance. In this paper, we discuss the development of an individualized operator functional state assessment model that identifies states likely leading to operational errors. To address large individual variations, we use two different approaches to build a model for each individual using its data as well as data from subjects with similar responses. If a subject's response is similar to that of the individual of interest in a specific functional state, all the training data from this subject will be used to build the individual model. The individualization methods have been successfully verified and validated with a driving test data set provided by University of Iowa. With the individualized models, the mean squared error can be significantly decreased (by around 20%).
NASA s Evolutionary Xenon Thruster (NEXT) project is developing next generation ion propulsion technologies to provide future NASA science missions with enhanced mission performance benefit at a low total development cost. The objective of the NEXT project is to advance next generation ion propulsion technology by producing engineering model and prototype model system components, validating these through qualification-level and integrated system testing, and ensuring preparedness for transitioning to flight system development. This paper describes the NEXT ion propulsion system development status, characteristics and performance. A review of mission analyses results conducted to date using the NEXT system is also provided.
Current research on vertical- or short-takeoff-and-landing (V/STOL) aircraft is concentrating on developing a multirole-capable fighter. Several V/STOL concepts being studied show a capability performing for short-takeoff and vertical-landing (STOVL) missions. This paper is concerned with a propulsion concept which promises added flexibility in mission performance: the hybrid-tandem fan. This propulsion concept is combined with four aircraft planforms and the performance of each is evaluated on a representative mission. The four aircraft planforms used in the study are a conventional wing-tail, a forward-swept wing and canard, a delta-wing and canard, and an oblique wing and tail. The mission was chosen so that the four aircraft all had approximately the same gross takeoff weight. The four designs are compared at various phases of the mission.
Potential requirements for planetary missions in the 1980s, capabilities of the Interim Upper Stage (IUS) candidates to perform those missions, and Shuttle/IUS mission profile options for performance enhancement are examined. The most demanding planetary missions are the Pioneer Saturn/Uranus/Titan Probe and the Mariner-class orbiters of Mercury, Jupiter, and Saturn. Options available to designers of these missions will depend on the specific IUS selected for development and the programmatic phasing of the IUS and the NASA Tug. Use of Shuttle elliptic orbits as initial conditions for IUS ignition offers significant performance improvements; specific values are mission dependent.
With increased sensor data rates, and limited downlink capability, NASA missions have increased demands for onboard processing for applications ranging from synthetic aperture radar (SAR) data reduction to hyperspectral image processing and recognition, and even artificial intelligence (AI). Graphics Processor Units (GPUs) offer an attractive processing architecture for many of the applications due to their massive parallelism. As no radiation hardened GPU devices currently exist, any near term GPU-based onboard processors must use commercially available devices. To address this need NASA GSFC is collaborating with Cubic Aerospace Incorporated to, (a) characterize the capability of GPUs to meet the demands of a candidate onboard processing application, thereby demonstrating their ability to improve mission performance, reduce spacecraft SWaP, and potentially enable new missions, and (b) evaluate the radiation tolerance of capable COTS GPU devices to determine their suitability for spaceflight applications and understand any mitigations that are needed. A candidate onboard processing image has been prototyped and evaluated on a commercial GPU board and has demonstrated significantly increased processing throughput. Radiation tests for commercial GPU devices are planned for early fiscal year 2019.
An integrated system for the multidisciplinary analysis and optimization of airframe and propulsion design parameters is being developed. This system is known as IPAS, the Integrated Propulsion/Airframe Analysis System. The traditional method of analysis is one in which the propulsion system analysis is loosely coupled to the overall mission performance analysis. This results in a time consuming iterative process. First, the engine is designed and analyzed. Then, the results from this analysis are used in a mission analysis to determine the overall aircraft performance. The results from the mission analysis are used as a guide as the engine is redesigned and the entire process repeated. In IPAS, the propulsion system, airframe, and mission are closely coupled. The propulsion system analysis code is directly integrated into the mission analysis code. This allows the propulsion design parameters to be optimized along with the airframe and mission design parameters, significantly reducing the time required to obtain an optimized solution.
An integrated system for the multidisciplinary analysis and optimization of airframe and propulsion design parameters is being developed. This system is known as IPAS, the Integrated Propulsion/Airframe Analysis System. The traditional method of analysis is one in which the propulsion system analysis is loosely coupled to the overall mission performance analysis. This results in a time consuming iterative process. First, the engine is designed and analyzed. Then, the results from this analysis are used in a mission analysis to determine the overall aircraft performance. The results from the mission analysis are used as a guide as the engine redesigned and the entire process repeated. In IPAS, the propulsion system, airframe, and mission are closely coupled. The propulsion system analysis code is directly integrated into the mission analysis code. This allows the propulsion design parameters to be optimized along with the airframe and mission design parameters, significantly reducing the time required to obtain an optimized solution.
The Radiation and Technology Demonstration (RTD) Mission has the primary objective of demonstrating high-power (10 kilowatts) electric thruster technologies in Earth orbit. This paper discusses the conceptual design of the RTD spacecraft photovoltaic (PV) power system and mission performance analyses. These power system studies assessed multiple options for PV arrays, battery technologies and bus voltage levels. To quantify performance attributes of these power system options, a dedicated Fortran code was developed to predict power system performance and estimate system mass. The low-thrust mission trajectory was analyzed and important Earth orbital environments were modeled. Baseline power system design options are recommended on the basis of performance, mass and risk/complexity. Important findings from parametric studies are discussed and the resulting impacts to the spacecraft design and cost.
The Landsat Data Continuity Mission (LDCM) is scheduled for a December 2012 launch date. LDCM is being managed by an interagency partnership between NASA and the U.S. Geological Survey (USGS). In order to provide the necessary spectral coverage of the visible through shortwave-infrared (SWIR) and the thermal-infrared (TIR), the satellite will carry two sensors. The Operational Land Imager (OLI) will collect data for nine visible to shortwave spectral bands with a spatial resolution of 30 m (with a 15 m panchromatic band). The Thermal Infrared Sensor (TIRS) will collect coincident image data for two TIR bands with a spatial resolution of 100 m. The OLI is fully assembled and tested and has been shipped by it's manufacturer, Ball Aerospace and Technology Corporation, to the Orbital Sciences Corporation (Orbital) facility where it is being integrated onto the LDCM spacecraft. Pre-launch testing indicates that OLI will meet all performance specification with margin. TIRS is in development at the NASA Goddard Space F!ight Center (GSFC) and is in final testing before shipping to the Orbital facility in January, 2012. The presentation will describe the LDCM satellite instrument systems, present pre-launch performance data for OLI and TIRS, and present simulated images to highlight notable features and expected imaging performance.
Ingenuity may be the first of many Mars aerial vehicles. Rotorcraft increase the range and speed that can be traveled to locations of interest. This enables mission concepts previously considered not viable on Mars, such as missions performing science investigations in regions of high elevation, steep terrain, caves/lava tubes, and surveys of the lower atmosphere. Recent work done at NASA Ames Research Center and NASA’s Jet Propulsion Laboratory (JPL) show that significant science can be performed by rotorcraft either independently or as assistants to rovers and landers. Small rotorcraft of Ingenuity’s general size can be potentially integrated into missions already scheduled for launch. Additionally, larger rotorcraft can support standalone novel mission concepts but are still be able to be sized and configured for deployment from heritage entry, descent, and landing (EDL) systems. One such mission concept of interest is to determine if organics are associated with clay-bearing or silica-rich soil. For such a mission, a small rotorcraft “robotic assistant” to a lander or rover could help determine if ancient sediment contains biosignatures in regions such as Mawrth Vallis. Ingenuity has demonstrated that rotorcraft can be developed relatively quickly and inexpensively and increase the types and amount of science that can be performed on any given mission. Recent research has suggested that rotorcraft of Ingenuity’s general size can have their performance characteristics significantly enhanced – increasing their range, speed, and payload capacity – by using new generation rotor blade airfoils optimized for Mars operating conditions. Rotorcraft could potentially be a standard adjunct to all future lander and rover missions. This paper presents an advanced Mars helicopter design that leverages significantly the design heritage of the Ingenuity Mars Helicopter Technology Demonstrator (MHTD).
Data processing systems, thermal subsystems, design, and mission performance summary for Surveyor 1 spacecraft
Systems analysis and flight performance of Atlas Centaur launch vehicle with Surveyor 1 lunar probe
This paper presents a comparison of trajectory generation methodologies using acoustic source noise models of different fidelity for motion planning for an acoustically-aware aircraft subject to constraints on the vehicle dynamic performance, mission, and acoustic footprint of the vehicle at a set of (three-dimensional) observer locations. The performance of a pre-mission Bézier curve-based planner and a (near) real-time stochastic model predictive control planner are compared. Additionally, a comparison is made between the motion planning performance using a lower-fidelity acoustic model based on propeller tip Mach number and omni-directional sound power radiation, and a hemisphere-based higher-fidelity acoustic model. It is demonstrated that the asymmetry in hemisphere-based acoustic model can be exploited for improved flight path planning and trajectory-tracking performance in the presence of acoustic constraints.
The potential of Nuclear Electric Propulsion (NEP) to meet the increasing demands of our planetary space exploration program is examined and evaluated. Based on an assumption of a modest growth beyond current technology, an NEP system is described that provides performance advantage over all competitive technologies. Flight times and available payload mass - as indicators of mission performance - are compared for several mission opportunities of interest. NEP is shown to have a unique capacity for substantial reductions in mission flight times in terms of payloads consistent with the needs of planetary exploration.
Exploration Mission 1 (EM-1) will be the first mission to send an uncrewed Orion Multi-Purpose Crew Vehicle (MPCV) to cislunar space in the fall of 2019. EM-1 was originally conceived as a lunar free-return mission, but was later changed to a Distant Retrograde Orbit (DRO) mission as a precursor to the Asteroid Redirect Mission. To understand the required mission performance (i.e., propellant requirement), a series of trajectory optimization runs was conducted using JSC's Copernicus spacecraft trajectory optimization tool. In order for the runs to be done in a timely manner, it was necessary to employ a parallelization approach on a computing cluster using a new trajectory scan tool written in Python. Details of the scan tool are provided and how it is used to perform the scans and post-process the results. Initially, a scan of daily due east launched EM-1 DRO missions in 2018 was made. Valid mission opportunities are ones that do not exceed the useable propellant available to perform the required burns. The initial scan data showed the propellant and delta-V performance patterns for each launch period. As questions were raised from different subsystems (e.g., power, thermal, communications, flight operations, etc.), the mission parameters or data that were of interest to them were added to the scan output data file. The additional data includes: (1) local launch and landing times in relation to sunrise and sunset, (2) length of eclipse periods during the in-space portion of the mission, (3) Earth line of sight from cislunar space, (4) Deep Space Network field of view looking towards cislunar space, and (5) variation of the downrange distance from Earth entry interface to splashdown. Mission design trades can also be performed based on the information that the additional data shows. For example, if the landing is in darkness, but the recovery operations team desires a landing in daylight, then an analysis is performed to determine how to change the mission design to meet this request. Also, subsystems request feasibility of alternate or contingency mission designs, such as adding an Orion main engine checkout burn or Orion completing all of its burns using only its auxiliary thrusters. This paper examines and presents the evolving trade studies that incorporate subsystem feedback and demonstrate the feasibility of these constrained mission trajectory designs and contingencies.
During exploration-class missions, sensorimotor disturbances may lead to disruption in the ability to ambulate and perform functional tasks during the initial introduction to a novel gravitational environment following a landing on a planetary surface. The overall goal of our current project is to develop a sensorimotor adaptability training program to facilitate rapid adaptation to these environments. We have developed a unique training system comprised of a treadmill placed on a motion-base facing a virtual visual scene. It provides an unstable walking surface combined with incongruent visual flow designed to enhance sensorimotor adaptability. Greater metabolic cost incurred during balance instability means more physical work is required during adaptation to new environments possibly affecting crewmembers? ability to perform mission critical tasks during early surface operations on planetary expeditions. The goal of this study was to characterize adaptation to a discordant sensory challenge across a number of performance modalities including locomotor stability, multi-tasking ability and metabolic cost. METHODS: Subjects (n=15) walked (4.0 km/h) on a treadmill for an 8 -minute baseline walking period followed by 20-minutes of walking (4.0 km/h) with support surface motion (0.3 Hz, sinusoidal lateral motion, peak amplitude 25.4 cm) provided by the treadmill/motion-base system. Stride frequency and auditory reaction time were collected as measures of locomotor stability and multi-tasking ability, respectively. Metabolic data (VO2) were collected via a portable metabolic gas analysis system. RESULTS: At the onset of lateral support surface motion, subj ects walking on our treadmill showed an increase in stride frequency and auditory reaction time indicating initial balance and multi-tasking disturbances. During the 20-minute adaptation period, balance control and multi-tasking performance improved. Similarly, throughout the 20-minute adaptation period, VO2 gradually decreased following an initial increase after the onset of support surface motion. DISCUSSION: Resu lts confirmed that walking in discordant conditions not only compromises locomotor stability and the ability to multi-task, but comes at a quantifiable metabolic cost. Importantly, like locomotor stability and multi-tasking ability, metabolic expenditure while walking in discordant sensory conditions improved during adaptation. This confirms that sensorimotor adaptability training can benefit multiple performance parameters central to the successful completion of critical mission tasks.
The Synchronous Earth Observation Satellite (SEOS) is a geostationary system which provides unique possibilities for earth surveillance. Questions of SEOS applications are considered, taking into account the employment of the Large Earth Survey Telescope. Aspects of performance and costs are examined. The generation of a value function in connection with a quantitative ranking of the applications is discussed along with an analysis performed to determine those parameter values which will maximize mission performance capability at given levels of system cost.