Piloted simulations for atmosphere reentry of space vehicles
Review of piloted atmospheric reentry simulation studies in general research and in support of X-15 and Mercury projects - fixed cockpit simulators
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Review of piloted atmospheric reentry simulation studies in general research and in support of X-15 and Mercury projects - fixed cockpit simulators
A series of realistic simulation studies is being conducted as a cooperative effort between the European Centre for Medium Range Weather Forecasts (ECMWF), the National Meteorological Center (NMC), and the Goddard Laboratory for Atmospheres (GLA), to provide a quantitative assessment of the potential impact of future observing systems on large scale numerical weather prediction. A special objective is to avoid the unrealistic character of earlier simulation studies. Following a brief review of previous simulation studies and real data impact tests, the methodology for the current simulation system will be described. Results from an assessment of the realism of the simulation system and of the potential impact of advanced observing systems on numerical weather prediction and preliminary results utilizing this system will be presented at the conference.
Crew comments indicate that Space Shuttle simulator seats place crewmembers in a position different from that of the actual Orbiter seats. The crew feel that they launch in a different position, and with a different reach and visibility, from that in which they had trained. This study examined three factors in differences between training and flight positions. Key dimensions, which were considered important to spatial orientation, were compared in the Orbiters and simulators. These were dimensions such as seat back to glare shield and seat pan to overhead. The differences between flight and training crew equipment, and how these differences may contribute to the problem were discussed with engineers and technicians responsible for the equipment. Eye position measurements were taken on subjects to assess any differences that could be attributed to different ingress methods in the Orbiters and the simulators. This report presents the data, analysis, and recommendations.
To realize quality microgravity science on the International Space Station, many microgravity facilities will utilize the Active Rack Isolation System (ARIS). Simulation capabilities for ARIS will be needed to predict the microgravity environment. This paper discusses the development of a simulation model for use in predicting the performance of the ARIS in attenuating disturbances with frequency content between 0.01 Hz and 10 Hz. The derivation of the model utilizes an energy-based approach. The complete simulation includes the dynamic model of the ISPR integrated with the model for the ARIS controller so that the entire closed-loop system is simulated. Preliminary performance predictions are made for the ARIS in attenuating both off-board disturbances as well as disturbances from hardware mounted onboard the microgravity facility. These predictions suggest that the ARIS does eliminate resonant behavior detrimental to microgravity experimentation. A limited comparison is made between the simulation predictions of ARIS attenuation of off-board disturbances and results from the ARIS flight test. These comparisons show promise, but further tuning of the simulation is needed.
Optimal temperature control design using IBM 7094 digital computer program for thermal environment simulation of stabilized multisurfaced earth- orbiting spacecraft structure
At Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud (INFN-LNS), the development of intense ion and proton sources has been supported by a great deal of work on the modelling of microwave generated plasmas for many years. First, a stationary version of the particle-in-cell code was developed for plasma modelling starting from an iterative strategy adopted for the space charge dominated beam transport simulations. Electromagnetic properties of the plasma and full-waves simulations are now affordable for non-homogenous and non-isotropic magnetized plasma via “cold” approximation. The effects of Coulomb collisions on plasma particles dynamics was implemented with the Langevin formalism, instead of simply applying the Spitzer 90° collisions through a Monte Carlo technique. A wide database of different cross sections related to reactions occurring in a hydrogen plasma was implemented. The next step consists of merging such a variety of approaches for retrieving an “as-a-whole” picture of plasma dynamics in ion sources. The preliminary results will be summarized in the paper for a microwave discharge ion source designed for intense and high quality proton beams production, proton source for European Spallation Source project. Even if the realization of a predictive software including the complete processes involved in plasma formation is still rather far, a better comprehension of the source behavior is possible and so the simulations may support the optimization phase.
The use of concentrators to improve the performance of solar arrays in deep space was tested in a simulated deep space environment. The results of these tests are presented and discussed. Areas of discussion include cell temperature performance in a low temperature, low illumination environment with and without concentration, concentration ratios, and theoretical analysis versus test results. Tests were conducted on a series/parallel configuration and individual cells.
Modifications to interim visual space flight simulator
Safety hazards during space environment simulator operations
For missions beyond low Earth orbit to the moon or Mars, space explorers will encounter a complex radiation field composed of various ion species with a broad range of energies. Such missions pose significant radiation protection challenges that need to be solved in order to minimize exposures and associated health risks. An innovative galactic cosmic ray simulator (GCRsim) was recently developed at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL). The GCRsim technology is intended to represent major components of the space radiation environment in a ground analog laboratory setting where it can be used to improve understanding of biological risks and serve as a testbed for countermeasure development and validation. The current GCRsim consists of 33 energetic ion beams that collectively simulate the primary and secondary GCR field encountered by humans in space over the broad range of particle types, energies, and linear energy transfer (LET) of interest to health effects. A virtual workshop was held in December 2020 to assess the status of the NASA baseline GCRsim. Workshop attendees examined various aspects of simulator design, with a particular emphasis on beam selection strategies. Experimental results, modeling approaches, areas of consensus, and questions of concern were also discussed in detail. This report includes a summary of the GCRsim workshop and a description of the current status of the GCRsim. This information is important for future advancements and applications in space radiobiology.
Over the years, computer modeling has been used extensively in many disciplines to solve engineering problems. A set of computer program tools is proposed to assist the engineer in the various phases of the Space Station program from technology selection through flight operations. The development and application of emulation and simulation transient performance modeling tools for life support systems are examined. The results of the development and the demonstration of the utility of three computer models are presented. The first model is a detailed computer model (emulation) of a solid amine water desorbed (SAWD) CO2 removal subsystem combined with much less detailed models (simulations) of a cabin, crew, and heat exchangers. This model was used in parallel with the hardware design and test of this CO2 removal subsystem. The second model is a simulation of an air revitalization system combined with a wastewater processing system to demonstrate the capabilities to study subsystem integration. The third model is that of a Space Station total air revitalization system. The station configuration consists of a habitat module, a lab module, two crews, and four connecting nodes.
New tools for data access and visualization promise to make the analysis of space plasma data both more efficient and more powerful, especially for answering questions about the global structure and dynamics of the Sun-Earth system. We will show how new existing tools (particularly the Virtual Space Physics Observatory-VSPO-and the Visual System for Browsing, Analysis and Retrieval of Data-ViSBARD; look for the acronyms in Google) already provide rapid access to such information as spacecraft orbits, browse plots, and detailed data, as well as visualizations that can quickly unite our view of multispacecraft observations. We will show movies illustrating multispacecraft observations of the solar wind and magnetosphere during a magnetic storm, and of simulations of 3 0-spacecraft observations derived from MHD simulations of the magnetosphere sampled along likely trajectories of the spacecraft for the MagCon mission. An important issue remaining to be solved is how best to integrate simulation data and services into the Virtual Observatory environment, and this talk will hopefully stimulate further discussion along these lines.
Neutral Buoyancy simulations which were conducted to validate the crew systems interface as it relates to space telescope on-orbit maintenance and contingency operations is discussed. The initial concept validation tests using low fidelity mockups is described. The entire spectrum of proposed space telescope refurbishment and selected contingencies using upgraded mockups which reflect flight hardware are reported. Findings which may be applicable to future efforts of a similar nature are presented.
The flight of the Spacelab 3 microgravity laboratory onboard the Space Shuttle Challenger in May 1985 enabled electroconvection experiments to be conducted using the goephysical fluid flow cell instrument. Experimental results are presented which illustrate the variety of convection achieved by varying the imposed radial and latitudinal temperature gradients, rotation rates, and the strength of the electrostatic gravity. These results are compared with those obtained from nonlinear three-dimensional simulations and good agreement is found.
Desigg and performance of SNAP-8 nuclear reactor simulator for nonnuclear testing of space power systems
This paper states the requirements for, describes the overall architecture of, and identifies the future work involved in developing the DS1 Testbed spacecraft simulation.
Virtual Reality (VR) is a set of breakthrough technologies that allow a human being to enter and fully experience a 3-dimensional, computer simulated environment. A true virtual reality experience meets three criteria: (1) It involves 3-dimensional computer graphics; (2) It includes real-time feedback and response to user actions; and (3) It must provide a sense of immersion. Good examples of a virtual reality simulator are the flight simulators used by all branches of the military to train pilots for combat in high performance jet fighters. The fidelity of such simulators is extremely high -- but so is the price tag, typically millions of dollars. Virtual reality teaching and training methods are manifestly effective, and we have therefore implemented a VR trainer for the International Space Welding Experiment. My role in the development of the ISWE trainer consisted of the following: (1) created texture-mapped models of the ISWE's rotating sample drum, technology block, tool stowage assembly, sliding foot restraint, and control panel; (2) developed C code for control panel button selection and rotation of the sample drum; (3) In collaboration with Tim Clark (Antares Virtual Reality Systems), developed a serial interface box for the PC and the SGI Indigo so that external control devices, similar to ones actually used on the ISWE, could be used to control virtual objects in the ISWE simulation; (4) In collaboration with Peter Wang (SFFP) and Mark Blasingame (Boeing), established the interference characteristics of the VIM 1000 head-mounted-display and tested software filters to correct the problem; (5) In collaboration with Peter Wang and Mark Blasingame, established software and procedures for interfacing the VPL DataGlove and the Polhemus 6DOF position sensors to the SGI Indigo serial ports. The majority of the ISWE modeling effort was conducted on a PC-based VR Workstation, described below.
For missions beyond low Earth orbit to the Moon or Mars, astronauts will encounter a complex space radiation field composed of various ion species with a broad range of energies. Such missions pose significant radiation protection challenges that need to be managed to minimize astronaut exposures and associated health risks. An innovative galactic cosmic ray simulator (GCRsim) was recently developed for the NASA Space Radiation Laboratory at Brookhaven National Laboratory. The GCRsim technology is intended to recapitulate major components of the space radiation environment in a ground-analog laboratory setting. It is used for experimental studies to improve the understanding of biological risks and act as a test bed for counter measure development and validation. Currently, the GCRsim consists of 33 energetic ion beams that collectively simulate the primary and secondary GCR field encountered by astronauts over the broad range of particle types, energies, and linear energy transfer (LET) of interest to human health effects. A virtual workshop was held in December 2020 to assess the status of NASA's GCRsim and attendees examined various aspects of simulator design, with an emphasis on beam selection strategies. Modeling approaches, experimental constraints, areas of consensus, and questions of concern were also discussed in detail. An overview of the workshop considerations and discussion for research strategies that are important for future advancements and applications in space radio biology are presented.