Space Shuttle Program - Tin Whisker Mitigation
Space Shuttle Program implemented tin whisker remediation strategy following discovery of tin whiskers in Orbiter hardware.
SEARCH · Search NASA
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.
Space Shuttle Program implemented tin whisker remediation strategy following discovery of tin whiskers in Orbiter hardware.
Artificial Intelligence (AI) represents a vital common space support element needed to enable the civil space program and commercial space program to perform their missions successfully. It is pointed out that advances in AI stimulated by the Space Station Program could benefit the U.S. in many ways. A fundamental challenge for the civil space program is to meet the needs of the customers and users of space with facilities enabling maximum productivity and having low start-up costs, and low annual operating costs. An effective way to meet this challenge may involve a man-machine system in which artificial intelligence, robotics, and advanced automation are integrated into high reliability organizations. Attention is given to the benefits, NASA strategy for AI, candidate space station systems, the Space Station as a stepping stone, and the commercialization of space.
NASA manned space flight programs and use of Apollo spacecraft and launch vehicles in manned missions
This paper describes the Space Test Program (STP) which provides access to space for the DOD-wide space research and development (R&D) community. STP matches a ranked list of sanctioned experiments with available budgets and searches for the most cost effective mechanisms to get the experiments into space. The program has successfully flown over 350 experiments, using dedicated freeflyer spacecraft, secondary space on the Space Shuttle, and various host satellites.
Dr. Aaron Cohen, Director of NASA Johnson Space Center, discusses management issues as they have appeared in the manned space flight programs.
International participation in the U.S. Space Station program is examined. Proposed Space Station mission studies to be conducted by Canada, Japan, and Europe are described; the establishment and implementation of these programs is discussed. The use of the Space Station as a laboratory, test center, and manufacturing area, and the commercial applicability of the Space Station are analyzed.
The International Space Station (ISS) Program (ISSP) establishes the technical requirements for the safe design, development, test and operation of end items. End items include, but are not limited to: ISS hardware/elements (inclusive of Contractor Furnished Equipment (CFE) and Government Furnished Equipment (GFE)), payload/science hardware, Visiting Vehicles (VV), logistics, crew psychological support items, tools, spare instruments and assemblies, including waste. SSP 41000, System Specification for the International Space Station, provides performance and design requirements for ISS and contains many ISS level safety and design requirements that must be considered when developing end item specification documents for ISS end items. SSP 51721, ISS Safety Requirements, exists to further define the safety requirements to be applied to end items developed for ISS
Nonlinear programming in Banach space, considering saddle value problem
The Waves in Space Plasmas (WISP) program is a joint international effort involving instrumentation to be designed and fabricated by funding from NASA and the National Research Council of Canada. The instrumentation, with a tentatively planned payload for 1986, can be used to perturb the plasma with radio waves to solve problems in ionospheric, atmospheric, magnetospheric, and plasma physics. Among the ionospheric and plasma phenomena to be investigated using WISP instrumentation are VLF wave-particle interactions; ELF/VLF propagation; traveling ionospheric disturbances and gravity wave coupling; equatorial plasma bubble phenomena; plasma wave physics such as mode-coupling, dispersion, and instabilities; and plasma physics of the antenna-plasma interactions.
Space systems interacting with the space plasma environment charge to potentials of a few tens of volts positive in interplanetary space or on the lunar surface in daylight, a few hundred volts negative in the dark lunar plasma wake and in some regions of the Earth s radiation belts, and to multiple kilovolt negative potentials for worst case conditions in the Earth s magnetosphere near geostationary orbit. Good design practices are required to assure that space systems operate successfully in these environments without detrimental effects due to transient currents and insulator failure produced by electrostatic discharges. Cold lunar environments in particular are challenging because detrimental effects of charging are often exacerbated by cold, highly resistive dielectrics which can integrate charge for long periods of time. We will describe the cold plasma and energetic particle environments relevant to lunar missions responsible for surface and bulk charging of space systems and discuss program requirements under development for assuring that systems operate successfully in these environments.
Astronaut Marsha Ivins tracks the history of America's space program, from Alan Shepard's Mercury flight to Space Shuttle flight STS-26.
Introducing composite vessels into the Space Shuttle Program represented a significant technical achievement. Each Orbiter vehicle contains 24 (nominally) Kevlar tanks for storage of pressurized helium (for propulsion) and nitrogen (for life support). The use of composite cylinders saved 752 pounds per Orbiter vehicle compared with all-metal tanks. The weight savings is significant considering each Shuttle flight can deliver 54,000 pounds of payload to the International Space Station. In the wake of the Columbia accident and the ensuing Return to Flight activities, the Space Shuttle Program, in 2005, re-examined COPV hardware certification. Incorporating COPV data that had been generated over the last 30 years and recognizing differences between initial Shuttle Program requirements and current operation, a new failure mode was identified, as composite stress rupture was deemed credible. The Orbiter Project undertook a comprehensive investigation to quantify and mitigate this risk. First, the engineering team considered and later deemed as unfeasible the option to replace existing all flight tanks. Second, operational improvements to flight procedures were instituted to reduce the flight risk and the danger to personnel. Third, an Orbiter reliability model was developed to quantify flight risk. Laser profilometry inspection of several flight COPVs identified deep (up to 20 mil) depressions on the tank interior. A comprehensive analysis was performed and it confirmed that these observed depressions were far less than the criterion which was established as necessary to lead to liner buckling. Existing fleet vessels were exonerated from this failure mechanism. Because full validation of the Orbiter Reliability Model was not possible given limited hardware resources, an Accelerated Stress Rupture Test of a flown flight vessel was performed to provide increased confidence. A Bayesian statistical approach was developed to evaluate possible test results with respect to the model credibility and thus flight rationale for continued operation of the Space Shuttle with existing flight hardware. A non-destructive evaluation (NDE) technique utilizing Raman Spectroscopy was developed to directly measure the overwrap residual stress state. Preliminary results provide optimistic results that patterns of fluctuation in fiber elastic strains over the outside vessel surface could be directly correlated with increased fiber stress ratios and thus reduced reliability.
NASA's Civil Space Technology Initiative encompasses among its major elements the Earth-to-Orbit Propulsion Program (ETOPP) for future launch vehicles, which is budgeted to the extent of $20-30 million/year for the development of essential technologies. ETOPP technologies include, in addition to advanced materials and processes and design/analysis computational tools, the advanced systems-synthesis technologies required for definition of highly reliable LH2 and hydrocarbon fueled rocket engines to be operated at significantly reduced levels of risk and cost relative to the SSME. Attention is given to the technology-transfer services of ETOPP.
The U.S. space launch program no longer dominates the world and is now playing 'catch-up' with the world's first commercial launch company, Arianespace. A healthy U.S. commercial launch program is essential and will assure continued low-cost military access to space. The effort to regain the lead in commercial space launch market has been hindered by declining Department of Defense budgets. President Clinton's space policy prohibits expensive new launch vehicles and limits the Department of Defense to low cost upgrades of existing launch vehicles. The U.S. government created the space sector and must ensure a smooth and effective split from the emerging commercial space program in order to regain world dominance. Until U.S. government and commercial ties are severed, the Department of Defense must consider commercial space launch interests when making military decisions. Ariane provides an excellent 'bench mark' for the U.S. to base future launch vehicle upgrades. Ariane advantages were identified and low-cost recommendations have been made. If the U.S. sets the target of first equaling and then surpassing Ariane by incorporating these recommendations, then the U.S. could once again dominate the world commercial launch market and ensure low cost military access to space.
Following two years of relatively low-level exploratory work, the Materials Science and Manufacturing in Space program is now in a phase of expansion toward higher levels of effort. The main thrust of this effort is toward initiation of a research and development program on the Space Shuttle missions that can prepare the way for possible commercial manufacturing operations on permanently orbiting space stations. Experiment capabilities currently being planned for the Space Shuttle will be based on an inventory of reusable general-purpose equipment that can be configured in many different ways to meet individual experiment requirements. It is expected that this approach can support very large numbers of experiments and make flight opportunities accessible to many potential experimenters who would not be prepared to involve themselves in the development of flight hardware.
An overview of the NASA Wiring for Space Applications Program and its relationship to NASA's space technology enterprise is given in viewgraph format. The mission of the space technology enterprise is to pioneer, with industry, the development and use of space technology to secure national economic competitiveness, promote industrial growth, and to support space missions. The objectives of the NASA Wiring for Space Applications Program is to improve the safety, performance, and reliability of wiring systems for space applications and to develop improved wiring technologies for NASA flight programs and commercial applications. Wiring system failures in space and commercial applications have shown the need for arc track resistant wiring constructions. A matrix of tests performed versus wiring constructions is presented. Preliminary data indicate the performance of the Tensolite and Filotex hybrid constructions are the best of the various candidates.
Accomplishments and goals of u.s. national space program
John Glenn's historic return to space was a primary focus of the STS 95 space shuttle mission; however, the 83 science payloads aboard were the focus of the flight activities. One of the payloads, the Hubble Space Telescope Orbital System Test (HOST), was flown in the cargo bay by the NASA Goddard Space Flight Center. It served as a space flight test of upgrade components for the telescope before they are installed in the shuttle for the next Hubble Space Telescope servicing mission. One of the upgrade components is a cryogenic cooling system for the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). The cooling is required for low noise in the receiver's sensitive electronic instrumentation. Originally, a passive system using dry ice cooled NICMOS, but the ice leaked away and must be replaced. The active cryogenic cooler can provide the cold temperatures required for the NICMOS, but there was a concern that it would create vibrations that would affect the fine pointing accuracy of the Hubble platform.