MATE - User's manual. Study simulation of space station dynamics Final report
Computer manual for implementing digital program in space station dynamics simulation
Gaitens, M. J.↗
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Computer controlled vent and pressurization system
The Centaur space launch vehicle airborne computer, which was primarily used to perform guidance, navigation, and sequencing tasks, was further used to monitor and control inflight pressurization and venting of the cryogenic propellant tanks. Computer software flexibility also provided a failure detection and correction capability necessary to adopt and operate redundant hardware techniques and enhance the overall vehicle reliability.
Cieslewicz, E. J.↗
Marshall Space Flight Center CFD overview
Computational Fluid Dynamics (CFD) activities at Marshall Space Flight Center (MSFC) have been focused on hardware specific and research applications with strong emphasis upon benchmark validation. The purpose here is to provide insight into the MSFC CFD related goals, objectives, current hardware related CFD activities, propulsion CFD research efforts and validation program, future near-term CFD hardware related programs, and CFD expectations. The current hardware programs where CFD has been successfully applied are the Space Shuttle Main Engines (SSME), Alternate Turbopump Development (ATD), and Aeroassist Flight Experiment (AFE). For the future near-term CFD hardware related activities, plans are being developed that address the implementation of CFD into the early design stages of the Space Transportation Main Engine (STME), Space Transportation Booster Engine (STBE), and the Environmental Control and Life Support System (ECLSS) for the Space Station. Finally, CFD expectations in the design environment will be delineated.
Schutzenhofer, Luke A.↗
Space Debris Surfaces - Probability of no penetration versus impact velocity and obliquity
A collection of computer codes called Space Debris Surfaces (SD-SURF), have been developed to assist in the design and analysis of space debris protection systems. An SD-SURF analysis will show which obliquities and velocities are most likely to cause a penetration to help the analyst select a shield design best suited to the predominant penetration mechanism. Examples of the interaction between space vehicle geometry, the space debris environment, and the penetration and critical damage ballistic limit surfaces of the shield under consideration are presented.
Elfer, N.↗
Guidance of space vehicles by radio measurements and command. appendix a - correcting velocity components. appendix b - magnitude of the maneuver. appendix c - outline of the method of computing the orbit.
Correction of space trajectories by small midcourse maneuvers governed by impulse which is computed on the ground from radio measurements and sent by radio to the space probe
GUIDANCE (MOTION)↗
Human and Robotic Space Mission Use Cases for High-Performance Spaceflight Computing
Spaceflight computing is a key resource in NASA space missions and a core determining factor of spacecraft capability, with ripple effects throughout the spacecraft, end-to-end system, and the mission; it can be aptly viewed as a "technology multiplier" in that advances in onboard computing provide dramatic improvements in flight functions and capabilities across the NASA mission classes, and will enable new flight capabilities and mission scenarios, increasing science and exploration return per mission-dollar.
flight computing↗
ISS General Resource Reel
This video is a collection of computer animations and live footage showing the construction and assembly of the International Space Station (ISS). Computer animations show the following: (1) ISS fly around; (2) ISS over a sunrise seen from space; (3) the launch of the Zarya Control Module; (4) a Proton rocket launch; (5) the Space Shuttle docking with Zarya and attaching Zarya to the Unity Node; (6) the docking of the Service Module, Zarya, and Unity to Soyuz; (7) the Space Shuttle docking to ISS and installing the Z1 Truss segment and the Pressurized Mating Adapter (PMA); (8) Soyuz docking to the ISS; (9) the Transhab components; and (10) a complete ISS assembly. Live footage shows the construction of Zarya, the Proton rocket, Unity Node, PMA, Service Module, US Laboratory, Italian Multipurpose Logistics Module, US Airlock, and the US Habitation Module. STS-88 Mission Specialists Jerry Ross and James Newman are seen training in the Neutral Buoyancy Laboratory (NBL). The Expedition 1 crewmembers, William Shepherd, Yuri Gidzenko, and Sergei Krikalev, are shown training in the Black Sea and at Johnson Space Flight Center for water survival.
Source record↗
BALLIST: A computer program to empirically predict the bumper thickness required to prevent perforation of the Space Station by orbital debris
A computer program called BALLIST that is intended to be a design tool for engineers is described. BALLlST empirically predicts the bumper thickness required to prevent perforation of the Space Station pressure wall by a projectile (such as orbital debris) as a function of the projectile's velocity. 'Ballistic' limit curves (bumper thickness vs. projectile velocity) are calculated and are displayed on the screen as well as being stored in an ASCII file. A Whipple style of spacecraft wall configuration is assumed. The predictions are based on a database of impact test results. NASA/Marshall Space Flight Center currently has the capability to generate such test results. Numerical simulation results of impact conditions that can not be tested (high velocities or large particles) can also be used for predictions.
Rule, William Keith↗
A Computational Study of Plume Modeling for Space Launch System Abort Scenarios
A series of viscous CFD simulations depicting Space Launch System (SLS) post Mode-1abort scenarios are conducted and analyzed. The primary purpose of these simulations is to study the effect of launch abort vehicle attitude control motor (ACM) and abort motor(AM) plume modeling fidelity on the drag of the aborted core stage. The simulations are first conducted with a fully-coupled, multi-species and chemically reacting model for the freestream gases and the solid rocket abort motor combustion products. Following this, equivalent species are created for the ACM and AM exhaust gases. These equivalent species aim to provide near the same results for core stage drag as the chemically reacting model at a significantly lower computational cost. Finally, the exhaust gases are modeled as calorically perfect air. It was concluded that under most scenarios, both the equivalent species and the perfect air models predict the drag of the aborted core stage sufficiently close to that predicted by the chemically reacting simulations. In these cases, the flow and geometry conditions did not induce significant changes in the composition of the ‘true’ exhaust gas via afterburning of the combustion products. For cases where this was not the case, the properties of the essentially frozen equivalent species and perfect air models deviated from the true mixture, yielding unsatisfactory results. Finally, the accuracy improvements by using the chemically reacting model are weighed against the significant increase in associated computational costs. It was found that the simplified exhaust gas models are at least 4 times less expensive than the chemically reacting model. This may justify the judicious use of these simple models in future work.
CFD↗
A Computational Study of Plume Modeling for Space Launch System Abort Scenarios
A series of viscous CFD simulations depicting Space Launch System (SLS) post Mode-1abort scenarios are conducted and analyzed. The primary purpose of these simulations is to study the effect of launch abort vehicle attitude control motor (ACM) and abort motor(AM) plume modeling fidelity on the drag of the aborted core stage. The simulations are first conducted with a fully-coupled, multi-species and chemically reacting model for the freestream gases and the solid rocket abort motor combustion products. Following this, equivalent species are created for the ACM and AM exhaust gases. These equivalent species aim to provide near the same results for core stage drag as the chemically reacting model at a significantly lower computational cost. Finally, the exhaust gases are modeled as calorically perfect air. It was concluded that under most scenarios, both the equivalent species and the perfect air models predict the drag of the aborted core stage sufficiently close to that predicted by the chemically reacting simulations. In these cases, the flow and geometry conditions did not induce significant changes in the composition of the ‘true’ exhaust gas via afterburning of the combustion products. For cases where this was not the case, the properties of the essentially frozen equivalent species and perfect air models deviated from the true mixture, yielding unsatisfactory results. Finally, the accuracy improvements by using the chemically reacting model are weighed against the significant increase in associated computational costs. It was found that the simplified exhaust gas models are at least 4 times less expensive than the chemically reacting model. This may justify the judicious use of these simple models in future work.
CFD↗
A Monte Carlo photocurrent/photoemission computer program
A Monte Carlo computer program was developed for the computation of photocurrents and photoemission in gamma (X-ray)-irradiated materials. The program was used for computation of radiation-induced surface currents on space vehicles and the computation of radiation-induced space charge environments within space vehicles.
Chadsey, W. L.↗
Overview of Space Science and Information Research Opportunities at NASA
It is not possible to review all the opportunities that NASA provides to support the Space Science Enterprise, in the short amount of time allotted for this presentation. Therefore, only a few key programs will be discussed. The programs that I will discuss will concentrate on research opportunities for faculty, graduate and postdoctoral candidates in Space Science research and information technologies at NASA. One of the most important programs for research opportunities is the NASA Research Announcement or NRA. NASA Headquarters issues NRA's on a regular basis and these cover space science and computer science activities relating to NASA missions and programs. In the Space Sciences, the most important NRA is called the "Research Opportunities in Space Science or the ROSS NRA. The ROSS NRA is composed of multiple announcements in the areas of structure and evolution of the Universe, Solar System exploration, Sun-Earth connections, and applied information systems. Another important opportunity is the Graduate Student Research Program (GSRP). The GSRP is designed to cultivate research ties between a NASA Center and the academic community through the award of fellowships to promising students in science and engineering. This program is unique since it matches the student's area of research interest with existing work being carried out at NASA. This program is for U.S. citizens who are full-time graduate students. Students who are successful have made the match between their research and the NASA employee who will act as their NASA Advisor/ Mentor. In this program, the student's research is primarily accomplished under the supervision of his faculty advisor with periodic or frequent interactions with the NASA Mentor. These interactions typically involve travel to the sponsoring NASA Center on a regular basis. The one-year fellowships are renewable for up to three years and over $20,000 per year. These and other important opportunities will be discussed.
Green, James L.↗
Extracting and Interpreting Electrochemical Impedance Spectra (EIS) from Physics-Based Models of Lithium-Ion Batteries
This paper implements a highly efficient algorithm to extract electrochemical impedance spectra (EIS) from physics-based battery models (e.g., a P2D model). The mathematical approach is different from how EIS is practiced experimentally. Experimentally, the voltage (current) is harmonically perturbed over a wide range of frequencies and the amplitude and phase shift of the corresponding current (voltage) is measured. The experimental approach can be implemented in simulation software, but is computationally expensive. The approach here is to determine locally linear state-space models from the full physical model. The four Jacobian matrices that are the basis of the state-space models can be derived by numerical differentiation of the physical model. The EIS is then extracted from the state-space model using computationally efficient matrix-manipulation techniques. The algorithm can evaluate the full EIS at an instant in time during a transient, independent of whether the battery is in a stationary state. The approach is also able to separate the full-cell impedance to evaluate partial EIS, such as for a battery anode alone. Although such partial EIS is difficult to measure experimentally, the partial EIS provides valuable insights in interpreting the full-cell EIS.
25 ENERGY STORAGE↗
Interesting viewpoints to those who will put Ada into practice
Ada will most probably be used as the programming language for computers in the NASA Space Station. It is reasonable to suppose that Ada will be used for at least embedded computers, because the high software costs for these embedded computers were the reason why Ada activities were initiated about ten years ago. The on-board computers are designed for use in space applications, where maintenance by man is impossible. All manipulation of such computers has to be performed in an autonomous way or remote with commands from the ground. In a manned Space Station some maintenance work can be performed by service people on board, but there are still a lot of applications, which require autonomous computers, for example, vital Space Station functions and unmanned orbital transfer vehicles. Those aspect which have come out of the analysis of Ada characteristics together with the experience of requirements for embedded on-board computers in space applications are examined.
Carlsson, Arne↗
SpaceCube v2.0 Space Flight Hybrid Reconfigurable Data Processing System
This paper details the design architecture, design methodology, and the advantages of the SpaceCube v2.0 high performance data processing system for space applications. The purpose in building the SpaceCube v2.0 system is to create a superior high performance, reconfigurable, hybrid data processing system that can be used in a multitude of applications including those that require a radiation hardened and reliable solution. The SpaceCube v2.0 system leverages seven years of board design, avionics systems design, and space flight application experiences. This paper shows how SpaceCube v2.0 solves the increasing computing demands of space data processing applications that cannot be attained with a standalone processor approach.The main objective during the design stage is to find a good system balance between power, size, reliability, cost, and data processing capability. These design variables directly impact each other, and it is important to understand how to achieve a suitable balance. This paper will detail how these critical design factors were managed including the construction of an Engineering Model for an experiment on the International Space Station to test out design concepts. We will describe the designs for the processor card, power card, backplane, and a mission unique interface card. The mechanical design for the box will also be detailed since it is critical in meeting the stringent thermal and structural requirements imposed by the processing system. In addition, the mechanical design uses advanced thermal conduction techniques to solve the internal thermal challenges.The SpaceCube v2.0 processing system is based on an extended version of the 3U cPCI standard form factor where each card is 190mm x 100mm in size The typical power draw of the processor card is 8 to 10W and scales with application complexity. The SpaceCube v2.0 data processing card features two Xilinx Virtex-5 QV Field Programmable Gate Arrays (FPGA), eight memory modules, a monitor FPGA with analog monitoring, Ethernet, configurable interconnect to the Xilinx FPGAs including gigabit transceivers, and the necessary voltage regulation. The processor board uses a back-to-back design methodology for common parts that maximizes the board real estate available. This paper will show how to meet the IPC 6012B Class 3A standard with a 22-layer board that has two column grid array devices with 1.0mm pitch. All layout trades such as stack-up options, via selection, and FPGA signal breakout will be discussed with feature size results. The overall board design process will be discussed including parts selection, circuit design, proper signal termination, layout placement and route planning, signal integrity design and verification, and power integrity results. The radiation mitigation techniques will also be detailed including configuration scrubbing options, Xilinx circuit mitigation and FPGA functional monitoring, and memory protection.Finally, this paper will describe how this system is being used to solve the extreme challenges of a robotic satellite servicing mission where typical space-rated processors are not sufficient enough to meet the intensive data processing requirements. The SpaceCube v2.0 is the main payload control computer and is required to control critical subsystems such as autonomous rendezvous and docking using a suite of vision sensors and object avoidance when controlling two robotic arms.
Xilinx FPGA↗
Discovering causal structure with reproducing-kernel Hilbert space ε -machines
We merge computational mechanics’ definition of causal states (predictively equivalent histories) with reproducing-kernel Hilbert space (RKHS) representation inference. The result is a widely applicable method that infers causal structure directly from observations of a system’s behaviors whether they are over discrete or continuous events or time. A structural representation—a finite- or infinite-state kernel ϵ-machine—is extracted by a reduced-dimension transform that gives an efficient representation of causal states and their topology. In this way, the system dynamics are represented by a stochastic (ordinary or partial) differential equation that acts on causal states. We introduce an algorithm to estimate the associated evolution operator. Paralleling the Fokker–Planck equation, it efficiently evolves causal-state distributions and makes predictions in the original data space via an RKHS functional mapping. We demonstrate these techniques, together with their predictive abilities, on discrete-time, discrete-value infinite Markov-order processes generated by finite-state hidden Markov models with (i) finite or (ii) uncountably infinite causal states and (iii) continuous-time, continuous-value processes generated by thermally driven chaotic flows. The method robustly estimates causal structure in the presence of varying external and measurement noise levels and for very high-dimensional data.
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
Design Space Exploration for MDO on a Teraflop Computer
The objective of this work was to develop global optimization techniques suitable for identifying promising regions in high dimensional aircraft configuration design space. Different optimization methods have been examined to evaluation their ability to efficiently search the design space to locate promising regions. Multistart local optimization methods as well as global search techniques were examined and modified to compare their performance on high dimensional design space.
Haftka, Raphael↗
3D Position and Velocity Vector Computations of Objects Jettisoned from the International Space Station Using Close-Range Photogrammetry Approach
Measurement of the jettisoned object departure trajectory and velocity vector in the International Space Station (ISS) reference frame is vitally important for prompt evaluation of the object s imminent orbit. We report on the first successful application of photogrammetric analysis of the ISS imagery for the prompt computation of the jettisoned object s position and velocity vectors. As post-EVA analyses examples, we present the Floating Potential Probe (FPP) and the Russian "Orlan" Space Suit jettisons, as well as the near-real-time (provided in several hours after the separation) computations of the Video Stanchion Support Assembly Flight Support Assembly (VSSA-FSA) and Early Ammonia Servicer (EAS) jettisons during the US astronauts space-walk. Standard close-range photogrammetry analysis was used during this EVA to analyze two on-board camera image sequences down-linked from the ISS. In this approach the ISS camera orientations were computed from known coordinates of several reference points on the ISS hardware. Then the position of the jettisoned object for each time-frame was computed from its image in each frame of the video-clips. In another, "quick-look" approach used in near-real time, orientation of the cameras was computed from their position (from the ISS CAD model) and operational data (pan and tilt) then location of the jettisoned object was calculated only for several frames of the two synchronized movies. Keywords: Photogrammetry, International Space Station, jettisons, image analysis.
Papanyan, Valeri↗