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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,441 records · Page 80
All sourcesNASA NTRSDOE OSTI
NASA NTRS2022

How to Build a Rover: An Overview of the Mars 2020 Mission’s Vehicle System Testbed

While NASA’s Mars rover Perseverance continues to make groundbreaking achievements on the Red Planet, its twin is hard at work here on Earth. The Operational Perseverance Twin for the Integration of Mechanisms and Instruments Sent to Mars, or OPTIMISM, is the Mars 2020 Vehicle System Testbed (VSTB) rover operated by NASA Jet Propulsion Laboratory (JPL) in Pasadena, California. OPTIMISM’s home is the JPL Mars Yard; an outdoor field with red soil that simulates the terrain encountered by Perseverance. The VSTB is a full-scale engineering model of the flight rover, serving a number of functions to ensure mission operations can continue smoothly and on schedule. The VSTB possesses instrumentation, computers, mechanisms, cameras, and a Mobility subsystem that are nearly identical to its extraterrestrial twin. Its high fidelity allows the rover to be a highly effective tool to fully test system functionality and performance prior to commanding the flight rover. The early stages of building OPTIMISM began a few months prior to Perseverance departing JPL for Cape Canaveral, FL in early 2020. Electrical integration of the flight system avionics, and compatibility checkouts of the electrical ground support equipment ensured that the foundation of the electrical system was operational and in place. Next, the internal harnessing was installed and compatibility checks of the rover instrumentation and mechanisms were performed to confirm the system was prepared for full buildup. Finally, mechanical assembly of the rover chassis with its external components completed the integration of the system before it was moved to the Mars Yard for its initial phase of testing to perform verification & validation (V&V) of the Mobility subsystem requirements. By the time Perseverance landed at Jezero Crater in February 2021, the first phase of VSTB operations was underway. Surface guidance, navigation, and control (SGNC) testing for the Mobility subsystem ensured functionality and performance requirements were met for various capabilities such as visual odometry (VO), mapping, and automatic navigation (AutoNav). Subsequent integration of the robotic arm (RA) onto the VSTB enabled the V&V campaign for surface sampling operations (SSO) to commence. As the mission’s engineering operations (EO) have gotten underway, the VSTB has been utilized for an array of purposes including troubleshooting software anomalies, and performing dry-runs for first time activities (FTAs) prior to sending the commands to Perseverance. OPTIMISM will continue to serve mission critical functions as long as Perseverance is roving the Red Planet.

Rojas, Jose Trujillo↗
NASA NTRS2009

Development of a Large Field-of-View PIV System for Rotorcraft Testing in the 14- x 22-Foot Subsonic Tunnel

A Large Field-of-View Particle Image Velocimetry (LFPIV) system has been developed for rotor wake diagnostics in the 14-by 22-Foot Subsonic Tunnel. The system has been used to measure three components of velocity in a plane as large as 1.524 meters by 0.914 meters in both forward flight and hover tests. Overall, the system performance has exceeded design expectations in terms of accuracy and efficiency. Measurements synchronized with the rotor position during forward flight and hover tests have shown that the system is able to capture the complex interaction of the body and rotor wakes as well as basic details of the blade tip vortex at several wake ages. Measurements obtained with traditional techniques such as multi-hole pressure probes, Laser Doppler Velocimetry (LDV), and 2D Particle Image Velocimetry (PIV) show good agreement with LFPIV measurements.

Jenkins, Luther N.↗
NASA NTRS1971

SNAP-8 electrical generating system development program

The SNAP-8 program has developed the technology base for one class of multikilowatt dynamic space power systems. Electrical power is generated by a turbine-alternator in a mercury Rankine-cycle loop to which heat is transferred and removed by means of sodium-potassium eutectic alloy subsystems. Final system overall criteria include a five-year operating life, restartability, man rating, and deliverable power in the 90 kWe range. The basic technology was demonstrated by more than 400,000 hours of major component endurance testing and numerous startup and shutdown cycles. A test system, comprised of developed components, delivered up to 35 kWe for a period exceeding 12,000 hours. The SNAP-8 system baseline is considered to have achieved a level of technology suitable for final application development for long-term multikilowatt space missions.

Source record↗
NASA NTRS2022

SDTS Mezzanine Installation

A mezzanine was constructed around the Six-degree-of-freedom Dynamic Test System (SDTS) from January 14th to January 18th, 2022. It was a part of facility-wide upgrades to prepare SDTS for the future of NASA programs and will be used as a viewing platform for test customers to observe docking tests. This video shows an accelerated time lapse of the construction.

Susan R Winnitoy↗
NASA NTRS1981

Icing tunnel tests of a glycol-exuding porous leading edge ice protection system on a general aviation airfoil

A glycol-exuding porous leading edge ice protection system was tested. Results show that the system is very effective in preventing ice accretion (anti-ice mode) or removing ice from an airfoil. Minimum glycol flow rates required for anti-icing are a function of velocity, liquid water content in the air, ambient temperature, and droplet size. Large ice caps were removed in only a few minutes using anti-ice flow rates. It was found that the shed time is a function of the type of ice, size of the ice cap, angle of attack, and glycol flow rate. Wake survey measurements show that there is no significant drag penalty for the installation or operation of the system tested.

Kohlman, D. L.↗
NASA NTRS1971

SNAP-8 electrical generating system development program

The SNAP-8 program has developed the technology base for one class of multikilowatt dynamic space power systems. Electrical power is generated by a turbine-alternator in a mercury Rankine-cycle loop to which heat is transferred and removed by means of sodium-potassium eutectic alloy subsystems. Final system overall criteria include a five-year operating life, restartability, man rating, and deliverable power in the 90 kWe range. The basic technology has been demonstrated by more than 400,000 hours of major component endurance testing and numerous startup and shutdown cycles. A test system, comprised of developed components, delivered up to 35 kWe for a period exceeding 12,000 hours. The SNAP-8 system baseline is considered to have achieved a level of technology suitable for final application development for long-term multikilowatt space missions.

Source record↗
NASA NTRS2011

Maintaining Adequate CO2 Washout for an Advanced EMU via a New Rapid Cycle Amine Technology

Over the past several years, NASA has realized tremendous progress in Extravehicular Activity (EVA) technology development. This has been evidenced by the progressive development of a new Rapic Cycle Amine (RCA) system for the Advanced Extravehicular Mobility Unit (AEMU) Portable Life Support Subsystem (PLSS). The PLSS is responsible for the life support of the crew member in the spacesuit. The RCA technology is responsible for carbon dioxide (CO2) and humidity control. Another aspect of the RCA is that it is on-back vacuum-regenerable, efficient, and reliable. The RCA also simplifies the PLSS schematic by eliminating the need for a condensing heat exchanger for humidity control in the current EMU. As development progresses on the RCA, it is important that the sizing be optimized so that the demand on the PLSS battery is minimized. As well, maintaining the CO2 washout at adequate levels during an EVA is an absolute requirement of the RCA and associated ventilation system. Testing has been underway in-house at NASA Johnson Space Center and analysis has been initiated to evaluate whether the technology provides exemplary performance in ensuring that the CO2 is removed sufficiently enough and the ventilation flow is adequate enough to maintain CO2 1 Project Engineer, Space Suit and Crew Survival Systems Branch, Crew and Thermal Systems Division, 2101 NASA Parkway, Houston, TX 77058/EC5. washout in the AEMU spacesuit helmet of the crew member during an EVA. This paper will review the recent developments of the RCA unit, the testing results performed in-house with a spacesuit simulator, and the associated analytical work along with insights from the medical aspect on the testing.

Chullen, Cinda↗
NASA NTRS1991

Results of shuttle EMU thermal vacuum tests incorporating an infrared imaging camera data acquisition system

Manned tests in Chamber B at NASA JSC were conducted in May and June of 1990 to better quantify the Space Shuttle Extravehicular Mobility Unit's (EMU) thermal performance in the cold environmental extremes of space. Use of an infrared imaging camera with real-time video monitoring of the output significantly added to the scope, quality and interpretation of the test conduct and data acquisition. Results of this test program have been effective in the thermal certification of a new insulation configuration and the '5000 Series' glove. In addition, the acceptable thermal performance of flight garments with visually deteriorated insulation was successfully demonstrated, thereby saving significant inspection and garment replacement cost. This test program also established a new method for collecting data vital to improving crew thermal comfort in a cold environment.

Anderson, James E.↗
NASA NTRS1993

Human performance and physiological function during a 24-hr exposure to 1% bromotrifluoromethane (Halon 1301)

Performance and physiological measurements were obtained from four pairs of men exposed for 24 hr to 1% (10,000 ppm) Halon 1301 (bromotrifluoromethane, CBrF3) and to air with order counterbalanced using a double-blind protocol. Cognitive and motor performance was assessed before, during, and after the exposures using seven scales of the Automated Portable Testing System, which produced 13 measures of performance. Halon inhalation induced decrements in 2 of the 13 measures, but actual and estimated magnitudes of the decrements were no greater than 5% of baseline values. Physiological data were obtained before, during, and after the exposures from clinical chemistry analyses of blood and urine samples, pulmonary function tests, and monitoring of vital signs. Significant change during Halon inhalation was observed for 6 of the 52 variables assessed; however, all physiological values remained within clinically acceptable limits. No cardiovascular effects were noted. This study demonstrated that exposure to 1% Halon 1301 for 24 hr can produce minor disturbance of central nervous system function as assessed by cognitive tasks.

Randomized Controlled Trial↗
NASA NTRS1991

Collected notes from the Benchmarks and Metrics Workshop

In recent years there has been a proliferation of proposals in the artificial intelligence (AI) literature for integrated agent architectures. Each architecture offers an approach to the general problem of constructing an integrated agent. Unfortunately, the ways in which one architecture might be considered better than another are not always clear. There has been a growing realization that many of the positive and negative aspects of an architecture become apparent only when experimental evaluation is performed and that to progress as a discipline, we must develop rigorous experimental methods. In addition to the intrinsic intellectual interest of experimentation, rigorous performance evaluation of systems is also a crucial practical concern to our research sponsors. DARPA, NASA, and AFOSR (among others) are actively searching for better ways of experimentally evaluating alternative approaches to building intelligent agents. One tool for experimental evaluation involves testing systems on benchmark tasks in order to assess their relative performance. As part of a joint DARPA and NASA funded project, NASA-Ames and Teleos Research are carrying out a research effort to establish a set of benchmark tasks and evaluation metrics by which the performance of agent architectures may be determined. As part of this project, we held a workshop on Benchmarks and Metrics at the NASA Ames Research Center on June 25, 1990. The objective of the workshop was to foster early discussion on this important topic. We did not achieve a consensus, nor did we expect to. Collected here is some of the information that was exchanged at the workshop. Given here is an outline of the workshop, a list of the participants, notes taken on the white-board during open discussions, position papers/notes from some participants, and copies of slides used in the presentations.

Drummond, Mark E.↗
NASA NTRS2011

Solid Rocket Booster (SRB) - Evolution and Lessons Learned During the Shuttle Program

The Solid Rocket Booster (SRB) element integrates all the subsystems needed for ascent flight, entry, and recovery of the combined Booster and Motor system. These include the structures, avionics, thrust vector control, pyrotechnic, range safety, deceleration, thermal protection, and retrieval systems. This represents the only human-rated, recoverable and refurbishable solid rocket ever developed and flown. Challenges included subsystem integration, thermal environments and severe loads (including water impact), sometimes resulting in hardware attrition. Several of the subsystems evolved during the program through design changes. These included the thermal protection system, range safety system, parachute/recovery system, and others. Obsolescence issues occasionally required component recertification. Because the system was recovered, the SRB was ideal for data and imagery acquisition, which proved essential for understanding loads and system response. The three main parachutes that lower the SRBs to the ocean are the largest parachutes ever designed, and the SRBs are the largest structures ever to be lowered by parachutes. SRB recovery from the ocean was a unique process and represented a significant operational challenge; requiring personnel, facilities, transportation, and ground support equipment. The SRB element achieved reliability via extensive system testing and checkout, redundancy management, and a thorough postflight assessment process. Assembly and integration of the booster subsystems was a unique process and acceptance testing of reused hardware components was required for each build. Extensive testing was done to assure hardware functionality at each level of stage integration. Because the booster element is recoverable, subsystems were available for inspection and testing postflight, unique to the Shuttle launch vehicle. Problems were noted and corrective actions were implemented as needed. The postflight assessment process was quite detailed and a significant portion of flight operations. The SRBs provided fully redundant critical systems including thrust vector control, mission critical pyrotechnics, avionics, and parachute recovery system. The design intent was to lift off with full redundancy. On occasion, the redundancy management scheme was needed during flight operations. This paper describes some of the design challenges, how the design evolved with time, and key areas where hardware reusability contributed to improved system level understanding.

Kanner, Howard S.↗
NASA NTRS2011

Solid Rocket Booster (SRB) Flight System Integration at Its Best

The Solid Rocket Booster (SRB) element integrates all the subsystems needed for ascent flight, entry, and recovery of the combined Booster and Motor system. These include the structures, avionics, thrust vector control, pyrotechnic, range safety, deceleration, thermal protection, and retrieval systems. This represents the only human-rated, recoverable and refurbishable solid rocket ever developed and flown. Challenges included subsystem integration, thermal environments and severe loads (including water impact), sometimes resulting in hardware attrition. Several of the subsystems evolved during the program through design changes. These included the thermal protection system, range safety system, parachute/recovery system, and others. Because the system was recovered, the SRB was ideal for data and imagery acquisition, which proved essential for understanding loads, environments and system response. The three main parachutes that lower the SRBs to the ocean are the largest parachutes ever designed, and the SRBs are the largest structures ever to be lowered by parachutes. SRB recovery from the ocean was a unique process and represented a significant operational challenge; requiring personnel, facilities, transportation, and ground support equipment. The SRB element achieved reliability via extensive system testing and checkout, redundancy management, and a thorough postflight assessment process. However, the in-flight data and postflight assessment process revealed the hardware was affected much more strongly than originally anticipated. Assembly and integration of the booster subsystems required acceptance testing of reused hardware components for each build. Extensive testing was done to assure hardware functionality at each level of stage integration. Because the booster element is recoverable, subsystems were available for inspection and testing postflight, unique to the Shuttle launch vehicle. Problems were noted and corrective actions were implemented as needed. The postflight assessment process was quite detailed and a significant portion of flight operations. The SRBs provided fully redundant critical systems including thrust vector control, mission critical pyrotechnics, avionics, and parachute recovery system. The design intent was to lift off with full redundancy. On occasion, the redundancy management scheme was needed during flight operations. This paper describes some of the design challenges and technical issues, how the design evolved with time, and key areas where hardware reusability contributed to improved system level understanding.

Wood, T. David↗
NASA NTRSDate not supplied

Update on Planetary, Lunar, & Asteroid Natural Environment Testbed (PLANET)

At ISMSE15, the Planetary, Lunar, & Asteroid Natural Environment Testbed (PLANET) was introduced as an upcoming high-fidelity, combined-effects planetary surface environment laboratory. This year, we will present an update on the facility status, describing the procurement, installation, commissioning of the chamber in Huntsville, Alabama (USA). With NASA’s push to return to the Moon through the Artemis program, there is a clear need for more high-fidelity test chambers that can replicate multiple aspects of the lunar surface, especially the fine, dusty lunar soil known as regolith. The PLANET chamber is designed to fill this gap, enabling research & development, qualification, and verification testing in a combined lunar surface environment, at an affordable price, for government, commercial/industry, and academic partners. Features include a large regolith simulant bed, low energy electron and ion sources to replicate the solar wind, full-spectrum UV and Solar simulation, and a liquid nitrogen cryogenic shroud, all in a high-vacuum environment (as low as 10^-7 mbar). PLANET’s initial focus will be on the lunar environment, but other surface environments (Martian, asteroid, etc.) are also possible to simulate. Besides the environmental instrumentation, PLANET will be equipped with specialized test systems that the Space Environmental Effects Team has developed over the past two years, including an in-situ tribometer and uniform dust distribution system. The chamber is currently being manufactured, with plans to install in May 2024. This will be followed by outfitting and commissioning. The challenges and accomplishments seen during this process will be detailed, and data from the first tests performed in PLANET will be shared with the community.

environmental testing↗
NASA NTRS1990

Suspension systems for ground testing large space structures

A research program is documented for the development of improved suspension techniques for ground vibration testing of large, flexible space structures. The suspension system must support the weight of the structure and simultaneously allow simulation of the unconstrained rigid-body movement as in the space environment. Exploratory analytical and experimental studies were conducted for suspension systems designed to provide minimum vertical, horizontal, and rotational degrees of freedom. The effects of active feedback control added to the passive system were also investigated. An experimental suspension apparatus was designed, fabricated, and tested. This test apparatus included a zero spring rate mechanism (ZSRM) designed to support a range of weights from 50 to 300 lbs and provide vertical suspension mode frequencies less than 0.1 Hz. The lateral suspension consisted of a pendulum suspended from a moving cart (linear bearing) which served to increase the effective length of the pendulum. The torsion suspension concept involved dual pendulum cables attached from above to a pivoting support (bicycle wheel). A simple test structure having variable weight and stiffness characteristics was used to simulate the vibration characteristics of a large space structure. The suspension hardware for the individual degrees of freedom was analyzed and tested separately and then combined to achieve a 3 degree of freedom suspension system. Results from the exploratory studies should provide useful guidelines for the development of future suspension systems for ground vibration testing of large space structures.

Gold, Ronald R.↗
NASA NTRS1974

Steady-state and transient operation of a heat-pipe radiator system

Data obtained on a VCHP heat-pipe radiator system tested in a vacuum environment were studied. Analyses and interpretation of the steady-state results are presented along with an initial analysis of some of the transient data. Particular emphasis was placed on quantitative comparisons of the experimental data with computer model simulations. The results of the study provide a better understanding of the system but do not provide a complete explanation for the observed low VCHP performance and the relatively flat radiator panel temperature distribution. The results of the study also suggest hardware, software, and testing improvements.

Sellers, J. P.↗
NASA NTRS2007

Test Facilities Capability Handbook: Volume 1 - Stennis Space Center (SSC); Volume 2 - Marshall Space Flight Center (MSFC)

The John C. Stennis Space Center (SSC) is located in Southern Mississippi near the Mississippi-Louisiana state line. SSC is chartered as the National Aeronautics and Space Administration (NASA) Center of Excellence for large space transportation propulsion system testing. This charter has led to many unique test facilities, capabilities and advanced technologies provided through the supporting infrastructure. SSC has conducted projects in support of such diverse activities as liquid, and hybrid rocket testing and development; material development; non-intrusive plume diagnostics; plume tracking; commercial remote sensing; test technology and more. On May 30, 1996 NASA designated SSC the lead center for rocket propulsion testing, giving the center total responsibility for conducting and/or managing all NASA rocket engine testing. Test services are now available not only for NASA but also for the Department of Defense, other government agencies, academia, and industry. This handbook was developed to provide a summary of the capabilities that exist within SSC. It is intended as a primary resource document, which will provide the reader with the top-level capabilities and characteristics of the numerous test facilities, test support facilities, laboratories, and services. Due to the nature of continually evolving programs and test technologies, descriptions of the Center's current capabilities are provided. Periodic updates and revisions of this document will be made to maintain its completeness and accuracy.

Hensarling, Paula L.↗