SEARCH · Engineering Papers
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Testing method for spacecraft response during environmental testing equivalent to its response to excitation by sinusoidal transients in flight
Environmental test control methods for improving quality and reducing costs, noting standardized specifications and information collection for administration
Environmental tests of manual globe valves for high pressure helium storage tanks
Environmental testing of nickel-cadmium, silver-zinc, silver-cadmium, and zinc-oxygen batteries for spacecraft power supplies
An environmental test facility is described which allows in-situ measurements for evaluation of near real time sinergistic effects of combined space environments.
Acoustic spectrum averager for Mariner spacecraft environmental tests, calculating rms average 1/3 octave spectrum bands in real time
The Environmental Development Testing program supported the development test efforts of the Mars 2020 Sampling and Caching Subsystem from May to November 2015. The engineering prototype Brassboard Corer was attached to a five degree-of-freedom robotic arm to execute a 96-test matrix of ambient and low pressure tests in the 10 ft. thermal vacuum chamber at the NASA Jet Propulsion Laboratory, California Institute of Technology. The Pretest, Test, and Post Test procedures are described, and some preliminary results are discussed. Data and observations from this test campaign inform the future development of the software and hardware toward the Mars 2020 flight design, including the next iteration of the rock coring drill, the Engineering Development Unit Corer.
Environmental testing and material characteristics of multilayer printed circuit boards
Environmental testing of potentiometer for servoactuator
The development of an European satellite market over the last 10 years, the industrialization of space applications, and the new requirements from satellite prime contractors have led INTESPACE to increase the test center's environmental testing capacities through the addition of a new thermal-vacuum test facility of impressive dimensions referred to as the SIMMER. The SIMMER is a simulator specifically created for the purpose of conducting acceptance tests of satellites and of large structures of the double launching ARIANE IV or half ARIANE V classes. The chamber is 8.3 meters long with a diameter of 10 meters. The conceptual design of a chamber in the horizontal plane and at floor level is in a view to simplify test preparation and to permit final electrical checks of the spacecraft in its actual test configuration prior to the closing of the chamber. The characteristics of the SIMMER complies with the requirements being currently defined in terms of thermal-vacuum tests: (1) thermal regulation (temperatures cycling between 100 K and 360 K); (2) clean vacuum (10(exp -6) mbar); (3) 600 measurement channels; and (4) 100 000 cleanliness class. The SIMMER is located in INTESPACE's space vehicle test complex in which a large variety of environmental test facilities are made available for having a whole test program completed under one and a same roof.
This report focuses on the limited environmental testing of the AMOLED display performed as an engineering evaluation by The NASA Johnson Space Center (JSC)-specifically. EMI. Thermal Vac, and radiation tests. The AMOLED display is an active-matrix Organic Light Emitting Diode (OLED) technology. The testing provided an initial understanding of the technology and its suitability for space applications. Relative to light emitting diode (LED) displays or liquid crystal displays (LCDs), AMOLED displays provide a superior viewing experience even though they are much lighter and smaller, produce higher contrast ratio and richer colors, and require less power to operate than LCDs. However, AMOLED technology has not been demonstrated in a space environment. Therefore, some risks with the technology must be addressed before they can be seriously considered for human spaceflight. The environmental tests provided preliminary performance data on the ability of the display technology to handle some of the simulated induced space/spacecraft environments that an AMOLED display will see during a spacecraft certification test program. This engineering evaluation is part of a Space Act Agreement (SM) between The NASA/JSC and Honeywell International (HI) as a collaborative effort to evaluate the potential use of AMOLED technology for future human spaceflight missions- both government-led and commercial. Under this SM, HI is responsible for doing optical performance evaluation, as well as temperature and touch screen studies. The NASA/JSC is responsible for performing environmental testing comprised of EMI, Thermal Vac, and radiation tests. Additionally, as part of the testing, limited optical data was acquired to assess performance as the display was subjected to the induced environments. The NASA will benefit from this engineering evaluation by understanding AMOLED suitability for future use in space as well as becoming a smarter buyer (or developer) of the technology. HI benefits from the environmental testing results by understanding its performance limitations/shortcomings to improve subsequent generations of AMOLED technology. Note that the AMOLED used in this test was not deSigned for the space environment but rather for commercial/industrial terrestrial applications.
A set of multi-junction GaAs/Ge solar array test coupons were subjected to a sequence of 5-year increments of combined environmental exposure tests. The purpose of this test program is to understand the changes and degradation of the solar array panel components, including its ESD mitigation design features in their integrated form, after multiple years (up to 15) of simulated geosynchronous space environment. These tests consist of: UV radiation, electrostatic discharge (ESD), electron/proton particle radiation, thermal cycling, and ion thruster plume exposures. The solar radiation was produced using a Mercury-Xenon lamp with wavelengths in the UV spectrum ranging from 230 to 400 nm. The ESD test was performed in the inverted-gradient mode using a low-energy electron (2.6 - 6 keV) beam exposure. The ESD test also included a simulated panel coverglass flashover for the primary arc event. The electron/proton radiation exposure included both 1.0 MeV and 100 keV electron beams simultaneous with a 40 keV proton beam. The thermal cycling included simulated transient earth eclipse for satellites in geosynchronous orbit. With the increasing use of ion thruster engines on many satellites, the combined environmental test also included ion thruster exposure to determine whether solar array surface erosion had any impact on its performance. Before and after each increment of environmental exposures, the coupons underwent visual inspection under high power magnification and electrical tests that included characterization by LAPSS, Dark I-V, and electroluminescence. This paper discusses the test objective, test methodologies, and preliminary results after 5 years of simulated exposure.
Test process, milestones and inputs are unknowns to first-time users of the Specialized Environmental Test Complex. The User Test Planning Guide aids in establishing expectations for both NASA and non-NASA facility customers. The potential audience for this guide includes both internal and commercial spaceflight hardware/software developers. It is intended to assist their test engineering personnel in test planning and execution. Material covered includes a roadmap of the test process, roles and responsibilities of facility and user, major milestones, facility capabilities, and inputs required by the facility. Samples of deliverables, test article interfaces, and inputs necessary to define test scope, cost, and schedule are included as an appendix to the guide.
The objective of the Surface Water and Ocean Topography (SWOT) Mission is to make global measurements of sea surface and terrestrial water heights. The SWOT Observatory consists of the Spacecraft Bus, supplied by CNES, and the Payload Module, provided by JPL. The Spacecraft Bus is a carrier of the Payload Module, which includes all the science instruments. The Spacecraft Bus components have been environmentally verified by CNES and the Payload Module components verified by JPL. The Payload Module was delivered to CNES in June 2021 for integration with the Spacecraft Bus to form the Observatory, which is in the process of undergoing a full set of environmental tests before launch. This paper focuses on the environmental test and analysis program at the assembly (unit), subsystem, and module level for the Payload Module hardware that JPL is responsible for verifying. Even though an Earth-orbiting mission like SWOT is not considered to be at extreme environments, SWOT’s environmental verification program does illustrate the standard System Integration and Test (SIT) process for hardware integration and environmental testing to ensure all hardware have been properly qualified to meet all mission environments. Typical space environmental test and analysis campaign includes acoustics vibration, shock, thermal vacuum, venting/pressure, radiation, electrostatic discharge, EMC/EMI/magnetics, and meteoroids. Environmental test and analysis metrics are presented in this paper. This paper also shows the complex integration process that involves multi-organizations and the latest status on the Observatory environmental test campaign.
The placement of solar cell modules in various climates and locations throughout the world results in different degrees and combinations of environmental stresses. Coupled with a design lifetime goal of 20 years, early detection and correction of module design deficiencies can result in significantly better long-term economics. This paper describes an environmental test research program for developing qualification requirements and procedures for flat-plate solar cell modules. A multiple iterative approach for establishing and evaluating test requirements is discussed as well as the rationale for the selection of levels and durations for the current qualification tests. The status of study efforts involving optical surface soiling, encapsulation delamination, and voltage bias-humidity testing is reviewed.
The prototype Pool Boiling Experiment (PBE) flew on the STS-47 mission in September 1992. This report describes the purpose of the experiment and the environmental qualification testing program that was used to prove the integrity of the prototype hardware. Component and box level vibration and thermal cycling tests were performed to give an early level of confidence in the hardware designs. At the system level, vibration, thermal extreme soaks, and thermal vacuum cycling tests were performed to qualify the complete design for the expected shuttle environment. The system level vibration testing included three axis sine sweeps and random inputs. The system level hot and cold soak tests demonstrated the hardware's capability to operate over a wide range of temperatures and gave the project team a wider latitude in determining which shuttle thermal altitudes were compatible with the experiment. The system level thermal vacuum cycling tests demonstrated the hardware's capability to operate in a convection free environment. A unique environmental chamber was designed and fabricated by the PBE team and allowed most of the environmental testing to be performed within the project's laboratory. The completion of the test program gave the project team high confidence in the hardware's ability to function as designed during flight.
Payload G-534, the prototype Pool Boiling Experiment (PBE), is scheduled to fly on the STS-47 mission in September 1992. This paper describes the purpose of the experiment and the environmental qualification testing program that was used to prove the integrity of the hardware. Component and box level vibration and thermal cycling tests were performed to give an early level of confidence in the hardware designs. At the system level, vibration, thermal extreme soaks, and thermal vacuum cycling tests were performed to qualify the complete design for the expected shuttle environment. The system level vibration testing included three axis sine sweeps and random inputs. The system level hot and cold soak tests demonstrated the hardware's capability to operate over a wide range of temperatures and gave wider latitude in determining which shuttle thermal attitudes were compatible with the experiment. The system level thermal vacuum cycling tests demonstrated the hardware's capability to operate in a convection free environment. A unique environmental chamber was designed and fabricated by the PBE team and allowed most of the environmental testing to be performed within the hardware build laboratory. The completion of the test program gave the project team high confidence in the hardware's ability to function as designed during flight.
Requirement specifications for environmental laboratory test chamber complex design, fabrication, and testing