Daytime adaptive optics for deep space optical communications
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laser communications↗
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Daytime adaptive optics for deep space optical communications
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Mars↗
Bio-stasis: A Strategy for Survivability and Payload Cost Reduction in Long-duration Space Missions
As humans proceed with long-term space voyages, involving flights with lasting duration of months or years, “adaptation to space” will eventually lead to hard realities resultant physiological and psychological conditions must be realistically estimated and considered before it occurs. It is obvious that humans in their lifespan cannot adopt to spaceflight environment by reversible modification of their complex biochemical reactions and physiological functions without jeopardizing sustainable homeostasis shaped by multiple generations during evolution. In this case Nature offers an evolutionary proven alternative strategy- a coordinative adjustment of metabolism in order to survive. Incorporation of this metabolic adjustment strategy along with the relevant life support system into space flight architecture would protect humans during long term space flight from many irreversible physiological alterations and may dramatically reduce overall cost of space missions. In addition to the harmful space radiation and prolonged weightlessness, incorporation of this strategy may also benefit by solving other major medical unknowns in interplanetary flight such as isolation and psychological stress which still remains a risk. It is one of the priorities of NASA and other space agencies to figure out not only how to keep long-distance travelers alive and in good cognitive health but also how to return them to normal life on Earth with a minimum rehabilitation period after prolonged exposure to space. Presently re-adaptation of astronauts to Earth conditions and recovery from spaceflight exposure may take many months and years and, in some cases, require medical intervention. Therefore, recognizing physiological adjustment of the energy-regulating system as a viable life support strategy for human space exploration beyond LEO is essential.
Bio-stasis;↗
Stable adaptive neurocontrollers for spacecraft and space robots
This paper reviews recently developed techniques of adaptive nonlinear control using neural networks, and demonstrates their application to two important practical problems in orbital operations. An adaptive neurocontroller is first developed for spacecraft attitude control applications, and then the same design, slightly modified, is shown to be effective in the control of free-floating orbital manipulators. The algorithms discussed have guaranteed stability and convergence properties, and thus constitute viable alternatives to existing control methodologies. Simulation results are presented demonstrating the performance of each algorithm with representative dynamic models.
Sanner, Robert M.↗
Solid modelling for the manipulative robot arm (power) and adaptive vision control for space station missions
The structure of a flexible arm derived from concatenation of the Stewart-Table-based links were studied. Solid modeling provides not only a realistic simulation, but is also essential for studying vision algorithms. These algorithms could be used for the adaptive control of the arm, using the well-known algorithms such as shape from shading, edge detection, orientation, etc. Details of solid modeling and its relation to vision based adaptive control are discussed.
Harrand, V.↗
Preflight Adaptation Training for Spatial Orientation and Space Motion Sickness
Two part-task preflight adaptation trainers (PATs) are being developed at the NASA Johnson Space Center to preadapt astronauts to novel sensory stimulus conditions similar to those present in microgravity to facilitate adaptation to microgravity and readaptation to Earth. This activity is a major component of a general effort to develop countermeasures aimed at minimizing sensory and sensorimotor disturbances and Space Motion Sickness (SMS) associated with adaptation to microgravity and readaptation to Earth. Design principles for the development of the two trainers are discussed, along with a detailed description of both devices. In addition, a summary of four ground-based investigations using one of the trainers to determine the extent to which various novel sensory stimulus conditions produce changes in compensatory eye movement responses, postural equilibrium, motion sickness symptoms, and electrogastric responses are presented. Finally, a brief description of the general concept of dual-adopted states that underly the development of the PATs, and ongoing and future operational and basic research activities are presented.
Harm, Deborah L.↗
The relationship between preflight underwater training and space motion sickness
SMS (Space Motion Sickness) severity was compared to WETF - (Weightless Environment Training Facility) trained and non-trained astronauts. Based on postflight medical debriefings, SMS severity was categorized as none, mild, moderate, and severe. The results showed 63% of all crewmembers on their first shuttle flight experienced some level of SMS. Of those, 55% had symptoms ranked moderate to severe. From the non-trained group, 35% had no SMS, 18% had mild, 29% had moderate, and 18% had severe. From the trained group, 41% had no SMS, 41% had mild, 19% had moderate, and 3% had severe SMS. These results indicate an inverse relationship (p <0.01) between WETF training and SMS severity. Preflight WETF training may have operations significance as a viable countermeasure to SMS.
Space Adaptation Syndrome (SAS)↗
Which Way is Up? Lessons Learned from Space Shuttle Sensorimotor Research
The Space Shuttle Program provided the opportunity to examine sensorimotor adaptation to space flight in unprecedented numbers of astronauts, including many over multiple missions. Space motion sickness (SMS) severity was highly variable across crewmembers. SMS generally lasted 2-3 days in-flight with approximately 1/3 of crewmembers experiencing moderate to severe symptoms, and decreased incidence in repeat flyers. While SMS has proven difficult to predict from susceptibility to terrestrial analogs, symptoms were alleviated by medications, restriction of early activities, maintaining familiar orientation with respect to the visual environment and maintaining contact cues. Adaptive changes were also reflected by the oculomotor and perceptual disturbances experienced early inflight and by the perceptual and motor coordination problems experienced during re-entry and landing. According to crew self-reports, systematic head movements performed during reentry, as long as paced within one's threshold for motion tolerance, facilitated the early readaptation process. The Shuttle provided early postflight crew access to document the initial performance decrements and time course of recovery. These early postflight measurements were critical to inform the program of risks associated with extending the duration of Shuttle missions. Neurological postflight deficits were documented using a standardized subjective rating by flight surgeons. Computerized dynamic posturography was also implemented as a quantitative means of assessing sensorimotor function to support crew return-to-duty assessments. Towards the end of the Shuttle Program, more emphasis has been placed on mapping physiological changes to functional performance. Future commercial flights will benefit from pre-mission training including exposures to launch and entry G transitions and sensorimotor adaptability assessments. While SMS medication usage will continue to be refined, non-pharmacological countermeasures (e.g., sensory aids) will have both space and Earth-based applications. Early postflight field tests are recommended to provide the evidence base for best practices for future commercial flight programs. Learning Objective: Overview of the Space Shuttle Program regarding adaptive changes in sensorimotor function, including what was learned from research, what was implemented for medical operations, and what is recommended for commercial flights.
Wood, S. J.↗
Enhanced Feasibility Assessment of Payload Adapters for NASA’s Space Launch System
The first flight of NASA’s new exploration-classlaunch vehicle, the Space Launch System (SLS), will test amyriad of systems designed to enable the next generation of deepspace human spaceflight, and launch from Kennedy SpaceCenter no earlier than December 2019. The initial Block 1configuration for EM-1 will be capable of lofting at least 70metric tons (t) of payload and send the Orion crew vehicle intoa distant retrograde lunar orbit, paving the way for future crewmissions to cislunar space and eventually Mars. A Block 1Bversion of SLS will lift at least 34 t to trans-lunar injection (TLI)in its crew configuration and at least 37 t to TLI in its cargoconfiguration no earlier than 2024. For Mars-class payloads,larger fairings and payload adapters for the Block 2 cargovehicle are under consideration. For missions beyond the Earth-Moon system, SLS offers greater characteristic energy (C3)than any other launch vehicle, enabling shorter transit times orheavier payloads with more robust science packages formissions to the outer solar system. Indeed, the unmatchedcombination of thrust, payload volume and departure energythat SLS provides opens new opportunities for human androbotic exploration of deep space.
Holladay, Jon B.↗
Adaptive optics for daytime deep space laser communications to Mars
This paper describes JPL research in adaptive optics (AO) to reduce the daytime background noise on a Mars-to-Earth optical communications link. AO can reduce atmosphere-induced wavefront aberrations, and enable single mode receiver operation thereby buying back margin in the deep space optical communications link.
adaptive optics↗
The Development of Real-Time Physiological Monitoring and Training Software for Remote Applications
Autogenic Feedback Training Exercise (AFTE) is an protocol and technology developed by Dr. Patricia Cowings and her associates at NASA Ames Research Center as a means to facilitate astronaut adaptation to space and exposure to the microgravity. AFTE is a training method which involves teaching subjects to voluntarily control several of their own physiological responses to environmental stressors. As the procedures matured, the training program was expanded to determine if technology developed to facilitate astronaut adaptation to space would be valuable in treating patients suffering from autonomic and vestibular pathologies and symptomatic relief from nausea and/or blood pressure control anomalies such as hypo- or hypertension. The present study, performed in conjunction with Morehouse School of Medicine, Biomedical Engineering at The University of Akron and NASA Ames Research Center has demonstrated that this technology can be successfully applied over vast distances. The specific purpose of this research was to develop a PC based system which could handle processing of twenty channels of acquired physiological data in addition to the necessary duplex communication protocols that would, for example, permit a patient in Atlanta, GA to be trained by a clinician stationed in San Jose, CA. Sixteen channels of physiological data and 20 channels of processed data are included.
Source record↗
Output-Based Adaptive Meshing Applied to Space Launch System Booster Separation Analysis
This paper presents details of Computational Fluid Dynamic (CFD) simulations of the Space Launch System during solid-rocket booster separation using the Cart3D inviscid code with comparisons to Overflow viscous CFD results and a wind tunnel test performed at NASA Langley Research Center's Unitary PlanWind Tunnel. The Space Launch System (SLS) launch vehicle includes two solid-rocket boosters that burn out before the primary core stage and thus must be discarded during the ascent trajectory. The main challenges for creating an aerodynamic database for this separation event are the large number of basis variables (including orientation of the core, relative position and orientation of the boosters, and rocket thrust levels) and the complex flow caused by the booster separation motors. The solid-rocket boosters are modified from their form when used with the Space Shuttle Launch Vehicle, which has a rich flight history. However, the differences between the SLS core and the Space Shuttle External Tank result in the boosters separating with much narrower clearances, and so reducing aerodynamic uncertainty is necessary to clear the integrated system for flight. This paper discusses an approach that has been developed to analyze about 6000 wind tunnel simulations and 5000 flight vehicle simulations using Cart3D in adaptive-meshing mode. In addition, a discussion is presented of Overflow viscous CFD runs used for uncertainty quantification. Finally, the article presents lessons learned and improvements that will be implemented in future separation databases.
Booster↗
A mechanical adapter for installing mission equipment on large space structures
A mechanical attachment adapter was designed, constructed, and tested. The adapter was was included in a simulation program that investigated techniques for assembling erectable structures under simulated zero-g conditions by pressure-suited subjects in a simulated EVA mode. The adapter was utilized as an interface attachment between a simulated equipment module and one node point of a tetrahedral structural cell. The mating performance of the adapter, a self-energized mechanism, was easily and quickly demonstrated and required little effort on the part of the test subjects.
Lefever, A. E.↗
Space Physiology and Medicine
The state of knowledge in space physiology and medicine are reviewed. Overviews of manned space flight, the space environment, spaceflight systems and procedures, physiological adaptation to space flight, health maintenance of space crew members, and medical problems of space flight are presented.
Nicogossian, Arnauld E.↗
Deep Space Network Antenna Monitoring Using Adaptive Time Series Methods and Hidden Markov Models
The Deep Space Network (DSN)(designed and operated by the Jet Propulsion Laboratory for the National Aeronautics and Space Administration (NASA) provides end-to-end telecommunication capabilities between earth and various interplanetary spacecraft throughout the solar system.
Antenna DSN↗
L1 Adaptive Control Law for Flexible Space Launch Vehicle and Proposed Plan for Flight Test Validation
This paper explores application of the L1 adaptive control architecture to a generic flexible Crew Launch Vehicle (CLV). Adaptive control has the potential to improve performance and enhance safety of space vehicles that often operate in very unforgiving and occasionally highly uncertain environments. NASA s development of the next generation space launch vehicles presents an opportunity for adaptive control to contribute to improved performance of this statically unstable vehicle with low damping and low bending frequency flexible dynamics. In this paper, we consider the L1 adaptive output feedback controller to control the low frequency structural modes and propose steps to validate the adaptive controller performance utilizing one of the experimental test flights for the CLV Ares-I Program.
Kharisov, Evgeny↗
Adapting Waste Processing for Space Applications
It has been estimated that on a 1-year mission, a four-astronaut crew will produce approximately 2,600 kg of waste materials. The current International Space Station practice for waste management is a stow and jettison model in which the trash is simply ejected. The immediate challenge waste poses for long duration space flight is that it represents unproductive mass. Longer term, waste accumulation on planetary surfaces will also pose challenges. A waste management/disposal solution is greatly needed. Simultaneously, significant research and development efforts are being made to enable in-situ resource extraction and recovery for lunar and Mars surface operations. A waste management solution could free up volume, reduce mass and thereby propellant needs, as well as contribute to resource recovery for spacecraft, and eventually, surface operations. The adaptation of many chemical engineering unit operations to the microgravity environment is critical to achieve this goal. An ideal spacecraft waste treatment system would convert waste into useful gases. It should be largely self-sustaining in that it should have the ability to recycle commodities to avoid imposing mass penalties associated with transporting feedstock on the spacecraft at launch. At NASA KSC, a model of what such a system would look like is being developed. In addition, the team has recently completed a suborbital flight campaign with a combustion reactor to demonstrate rudimentary conversion in a microgravity environment and identify challenges for future design. This presentation will discuss what a full waste treatment system could look like, point out challenges relating to various unit operations involved in such a system, and highlight recent progress in space waste management research and development.
Waste Processing↗
[Individual peculiarities of adaptation to long-term space flights: 24-hour heart rhythm monitoring]
Presented are results of studying 24-hr variability of the cardiac rhythm which characterizes individual difference in reactions of two crew members to the same set of stresses during a 115-day MIR mission. Spacelab (USA) cardiorecorders were used. Data of monitoring revealed significantly different baseline health statuses of the cosmonauts. These functional differences were also observed in the mission. In one of the cosmonauts, the cardiac regulation changed over to a more economic functioning with the autonomous balance shifted towards enhanced sympathetic activity. After 2-3 months on mission he had almost recovered pre-launch level of regulation. In the other, the regulatory system was appreciably strained at the beginning of the mission as compared with preflight baseline. Later on, on flight months 2-3, this strain kept growing till a drastic depletion of the functional reserve. On return to Earth, this was manifested by a strong stress reaction with a sharp decline in power of high-frequency and grow in power of very low frequency components of the heart rhythm. The data suggest that adaptation to space flight and reactions in the readaptation period are dependent on initial health status of crew members, and functional reserve.
long duration↗