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NASA NTRS1998

Methods and Techniques for Risk Prediction of Space Shuttle Upgrades

Since the Space Shuttle Accident in 1986, NASA has been trying to incorporate probabilistic risk assessment (PRA) in decisions concerning the Space Shuttle and other NASA projects. One major study NASA is currently conducting is in the PRA area in establishing an overall risk model for the Space Shuttle System. The model is intended to provide a tool to predict the Shuttle risk and to perform sensitivity analyses and trade studies including evaluation of upgrades. Marshall Space Flight Center (MSFC) and its prime contractors including Pratt and Whitney (P&W) are part of the NASA team conducting the PRA study. MSFC responsibility involves modeling the External Tank (ET), the Solid Rocket Booster (SRB), the Reusable Solid Rocket Motor (RSRM), and the Space Shuttle Main Engine (SSME). A major challenge that faced the PRA team is modeling the shuttle upgrades. This mainly includes the P&W High Pressure Fuel Turbopump (HPFTP) and the High Pressure Oxidizer Turbopump (HPOTP). The purpose of this paper is to discuss the various methods and techniques used for predicting the risk of the P&W redesigned HPFTP and HPOTP.

Hoffman, Chad R.↗
NASA NTRS1998

NASA Langley Scientific and Technical Information Output: 1997

This document is a compilation of the scientific and technical information that the Langley Research Center has produced during the calendar year 1997. Included are citations for Formal Reports, Conference Publications, High-Numbered Technical Memorandums, Contractor Reports, Journal Articles and Book Publications, Meeting Presentations, Technical Talks, and Patents.

Stewart, Susan H.↗
NASA NTRS1998

Data Analysis of a Space Experiment: Common Software Tackles Uncommon Task

Presented here are the software adaptations developed by laboratory scientists to process the space experiment data products from three experiments on two International Microgravity Laboratory Missions (IML-1 and IML-2). The challenge was to accommodate interacting with many types of hardware and software developed by both European Space Agency (ESA) and NASA aerospace contractors, where data formats were neither commercial nor familiar to scientists. Some of the data had been corrupted by bit shifting of byte boundaries. Least-significant/most-significant byte swapping also occurred as might be expected for the various hardware platforms involved. The data consisted of 20 GBytes per experiment of both numerical and image data. A significant percentage of the bytes were consumed in NASA formatting with extra layers of packetizing structure. It was provided in various pieces to the scientists on magnetic tapes, Syquest cartridges, DAT tapes, CD-ROMS, analog video tapes, and by network FIP. In this paper I will provide some science background and present the software processing used to make the data useful in the months after the missions.

Wilkinson, R. Allen↗
NASA NTRS1998

Reflight of the First Microgravity Science Laboratory: Quick Turnaround of a Space Shuttle Mission

Due to the short flight of Space Shuttle Columbia, STS-83, in April 1997, NASA chose to refly the same crew, shuttle, and payload on STS-94 in July 1997. This was the first reflight of an entire mission complement. The reflight of the First Microgravity Science Laboratory (MSL-1) on STS-94 required an innovative approach to Space Shuttle payload ground processing. Ground processing time for the Spacelab Module, which served as the laboratory for MSL-1 experiments, was reduced by seventy-five percent. The Spacelab Module is a pressurized facility with avionics and thermal cooling and heating accommodations. Boeing-Huntsville, formerly McDonnell Douglas Aerospace, has been the Spacelab Integration Contractor since 1977. The first Spacelab Module flight was in 1983. An experienced team determined what was required to refurbish the Spacelab Module for reflight. Team members had diverse knowledge, skills, and background. An engineering assessment of subsystems, including mechanical, electrical power distribution, command and data management, and environmental control and life support, was performed. Recommendations for resolution of STS-83 Spacelab in-flight anomalies were provided. Inspections and tests that must be done on critical Spacelab components were identified. This assessment contributed to the successful reflight of MSL-1, the fifteenth Spacelab Module mission.

Simms, Yvonne↗
NASA NTRS1998

Space Station Cathode Design, Performance, and Operating Specifications

A plasma contactor system was baselined for the International Space Station (ISS) to eliminate/mitigate damaging interactions with the space environment. The system represents a dual-use technology which is a direct outgrowth of the NASA electric propulsion program and, in particular, the technology development efforts on ion thruster systems. The plasma contactor includes a hollow cathode assembly (HCA), a power electronics unit, and a xenon gas feed system. Under a pre-flight development program, these subsystems were taken to the level of maturity appropriate for transfer to U.S. industry for final development. NASA's Lewis Research Center was subsequently requested by ISS to manufacture and deliver the engineering model, qualification model, and flight HCA units. To date, multiple units have been built. One cathode has demonstrated approximately 28,000 hours lifetime, two development unit HCAs have demonstrated over 10,000 hours lifetime, and one development unit HCA has demonstrated more than 32,000 ignitions. All 8 flight HCAs have been manufactured, acceptance tested, and are ready for delivery to the flight contractor. This paper discusses the requirements, mechanical design, performance, operating specifications, and schedule for the plasma contactor flight HCAs.

Patterson, Michael J.↗
NASA NTRS1996

Research and Technology, 1995

This report presents some of the challenging research and technology accomplished at NASA Ames Research Center during FY95. The accomplishments address almost all goals of NASA's four Strategic Enterprises: Aeronautics and Space Transportation Technology, Space Sciences, Human Exploration and Development of Space, and Mission to Planet Earth. The report's primary purpose is to inform stakeholders, customers, partners, colleagues, contractors, employees, and the American people in general about the scope and diversity of the research and technology activities. Additionally, the report will enable the reader to know how these goals are being addressed.

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NASA NTRS1998

Integrated Airport Surface Operations

The current air traffic environment in airport terminal areas experiences substantial delays when weather conditions deteriorate to Instrument Meteorological Conditions (IMC). Research activity at NASA has culminated in the development, flight test and demonstration of a prototype Low Visibility Landing and Surface Operations (LVLASO) system. A NASA led industry team and the FAA developed the system which integrated airport surface surveillance systems, aeronautical data links, DGPS navigation, automation systems, and controller and flight deck displays. The LVLASO system was demonstrated at the Hartsfield-Atlanta International Airport using a Boeing 757-200 aircraft during August, 1997. This report documents the contractors role in this testing particularly in the area of data link and DGPS navigation.

Koczo, S.↗
NASA NTRS1998

X-34 Main Propulsion System Design and Operation

The X-34 program is a joint industry/government program to develop, test, and operate a small, fully-reusable hypersonic flight vehicle, utilizing technologies and operating concepts applicable to future Reusable Launch Vehicle (RLV) systems. The vehicle will be capable of Mach 8 flight to 250,000 feet altitude and will demonstrate an all composite structure, composite RP-1 tank, the Marshall Space Flight Center (MSFC) developed Fastrac engine, and the operability of an advanced thermal protection systems. The vehicle will also be capable of carrying flight experiments. MSFC is supporting the X-34 program in three ways: Program Management, the Fastrac engine as Government Furnished Equipment (GFE), and the design of the Main Propulsion System (MPS). The MPS Product Development Team (PDT) at MSFC is responsible for supplying the MPS design, analysis, and drawings to Orbital. The MPS consists of the LOX and RP-1 Fill, Drain, Feed, Vent, & Dump systems and the Helium & Nitrogen Purge, Pressurization, and Pneumatics systems. The Reaction Control System (RCS) design was done by Orbital. Orbital is the prime contractor and has responsibility for integration, procurement, and construction of all subsystems. The paper also discusses the design, operation, management, requirements, trades studies, schedule, and lessons learning with the MPS and RCS designs.

Champion, R. J., Jr.↗
NASA NTRS1959

Evaluation of Transpiration-Cooled Turbine Blades with Shells of "Poroloy" Wire Cloth

An experimental investigation was made to evaluate the durability and permeability of a group of transpiration-cooled, strut-supported turbine blades. The porous shells were formed from a woven-wire material. The blades were fabricated by a contractor for the Bureau of Aeronautics. The results of permeability tests indicated that the shell material exhibited large random variations in local permeability, which result in excessive coolant flows and very nonuniform cooling. For this reason no heat-transfer evaluations were made because any results would have been inconclusive. Four blades were investigated for structural soundness in a turbo-jet engine operating at a turbine-inlet temperature of approximately 1670 deg F and a turbine tip speed of approximately 1305 feet per second. The maximum temperature of the porous-shell material was approximately 1050 deg F. Inspection of the first two blades after 10 minutes of engine operation revealed that the tips of both of the blades had failed. For the second pair of blades, an improved tip cap was provided by the use of built-up weld extending from strut tip to shell. One of these blades was then operated for 33 hours without failure, and was found to be in good condition at the end of this time. The second blade of this second pair failed within the first 10 minutes of operation because of a poor bond between shell and strut lands.

Richards, Hadley T.↗
NASA NTRS1959

1958 NASA/USAF Space Probes (Able-1): Summary - Volume 1

Early in calendar year 1958 Space Technology Laboratories, Inc. (STL) (then Space Technology Laboratories, a division of the Ramo-Wooldridge Corp.) developed for the Air Force Ballistic Missile Division (AFBMD) an Advanced Re-entry Test Vehicle (ARTV) for the purpose of testing ballistic missile nose cones at the full range of 5500 nautical miles. The two-stage ARTV utilized the Thor ballistic missile and the second stage propulsion system developed for the Vanguard program. In late 1957 and early 1958, STL/AFBMD prepared studies of various missile combinations which could be utilized for space testing. The Thor, in combination with the Vanguard second and third stages, was one of the vehicles considered which offered a very early capability of placing a reasonable payload in a lunar orbit. These STL/AFBMD studies were presented to various appropriate groups including the Killian, Millikan, H. J . Stewart Committees; Headquarters, Air Research and Development Command, and ARDC Centers. Subsequently the Advanced Research Projects Agency (ARPA) contacted STL relative to the availability of hardware for an early lunar shot. By utilizing existing spares already purchased for the ARTV, and by making use of the ARTV contractors already in being, it appeared feasible to launch by the third quarter of calendar year 1958 a payload which would be captured by the moon's gravitational force. On 27 March 1958, ARPA directed STL to proceed with a program of three lunar shots. As much as possible, these shots were to utilize existing ARTV spare hardware and impose no interference with the ballistic missile programs. In September this program was transferred to the direction of the National Aeronautics and Space Administration (NASA). On 17 August 1958 the first launching of the Able-1 vehicle was attempted, but the flight was terminated by a propulsion failure of the first stage. Subsequent launchings were attempted on 13 October and 8 November 1958. Of these launchirigs the October attempt was the most successful. Although the payload did not reach the vicinity of the moon, a maximum altitude of 71,700 was attained, and useful scientific data was obtained from the instrumentation.

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NASA NTRS1997

NASA Worldwide Emergency Medical Assistance

In an effort to maintain employee health and welfare, ensure customer satisfaction, and to deliver high quality emergency medical care when necessary to employees located overseas, NASA has instituted a new contract with International SOS Assistance INC. International SOS Assistance INC. will provide civil servants and contractors engaged in official NASA business with many services upon request during a medical or personal emergency. Through the years, International SOS Assistance INC. has developed the expertise necessary to provide medical service in all remote areas of the world. One phone call connects you to the SOS network of multilingual staff trained to help resolve travel, medical, legal, and security problems. The SOS network of critical care and aeromedical specialists operates 24 hours a day, 365 days a year from SOS Alarm Centers around the world. This exhibit illustrates the details of the NASA-International SOS Assistance INC. agreement.

Martin, George A.↗
NASA NTRS1996

[MODIS Investigation]

The objectives of the last six months were: (1) Complete sensitivity analysis of fluorescence; line height algorithms (2) Deliver fluorescence algorithm code and test data to the University of Miami for integration; (3) Complete analysis of bio-optical data from Southern Ocean cruise; (4) Conduct laboratory experiments based on analyses of field data; (5) Analyze data from bio-optical mooring off Hawaii; (6) Develop calibration/validation plan for MODIS fluorescence data; (7) Respond to the Japanese Research Announcement for GLI; and (8) Continue to review plans for EOSDIS and assist ECS contractor.

Abbott, Mark R.↗
NASA NTRS1998

Composite Bus Structure for the SMEX/WIRE Satellite

In an effort to reduce the weight and optimize the structural design of the Small Explorer (SMEX) Wide-Field Infrared Explorer (WIRE) spacecraft, it has become desirable to change the material and construction from mechanically fastened aluminum structure to a fully bonded fiber-reinforced composite (FRC) structure. GSFC has developed the WIRE spacecraft structural bus design concept, including the instrument and launch vehicle requirements. The WIRE Satellite is the fifth of a series of SMEX satellites to be launched once per year. GSFC has chosen Composite Optics Inc. (COI) as the prime contractor for the development and procurement of the WIRE composite structure. The detailed design of the fully bonded FRC structure is based on COI's Short Notice Accelerated Production SATellite ("SNAPSAT") approach. SNAPSAT is a state of the art design and manufacturing technology for advanced composite materials which utilizes flat-stock detail parts bonded together to produce a final structural assembly. The structural design approach adopted for the WIRE structure provides a very viable alternative to both traditional aluminum construction as well as high tech. molded type composite structures. This approach to composite structure design is much less costly than molded or honeycomb sandwich type composite construction, but may cost slightly more than conventional aluminum construction on the subsystem level. However on the overall program level the weight saving achieved is very cost effective, since the primary objective is to allocate more mass for science payloads.

Rosanova, Giulio G.↗
NASA NTRS1997

Validation of Framework Code Approach to a Life Prediction System for Fiber Reinforced Composites

The grant was conducted by the MMC Life Prediction Cooperative, an industry/government collaborative team, Ohio Aerospace Institute (OAI) acted as the prime contractor on behalf of the Cooperative for this grant effort. See Figure I for the organization and responsibilities of team members. The technical effort was conducted during the period August 7, 1995 to June 30, 1996 in cooperation with Erwin Zaretsky, the LERC Program Monitor. Phil Gravett of Pratt & Whitney was the principal technical investigator. Table I documents all meeting-related coordination memos during this period. The effort under this grant was closely coordinated with an existing USAF sponsored program focused on putting into practice a life prediction system for turbine engine components made of metal matrix composites (MMC). The overall architecture of the NMC life prediction system was defined in the USAF sponsored program (prior to this grant). The efforts of this grant were focussed on implementing and tailoring of the life prediction system, the framework code within it and the damage modules within it to meet the specific requirements of the Cooperative. T'he tailoring of the life prediction system provides the basis for pervasive and continued use of this capability by the industry/government cooperative. The outputs of this grant are: 1. Definition of the framework code to analysis modules interfaces, 2. Definition of the interface between the materials database and the finite element model, and 3. Definition of the integration of the framework code into an FEM design tool.

Gravett, Phillip↗
NASA NTRS1998

EUVE Observations of the Hyades Giants

The contractor describes EUVE and ROSAT observations of the Hyades K0 III giants theta(sup 1(vB 71 = HR 1411) and gamma$ (vB 28 = HR 1346) Tau, and ASCA observations of theta(sup 1) Tau. The coronal activity of these "clump" giants is intermediate between that of the Sun and of high-activity stars such as RS CVn systems. There is no evidence for significant short or long term variability up to several years. Modeling of the individual and combined spectra suggest that these two X-ray and EUV- bright Hyades giants resemble in their activity levels another clump giant, beta Cet, with a peak in the emission measure distribution near log T approx. 6.8, reminiscent of the Capella emission measure "bump."

Stern, Robert A.↗
NASA NTRS1998

Development of an Outreach Program for NASA: "NASA Ambassadors"

The NASA Ambassadors Program is designed to present the excitement and importance of NASA's programs to its customers, the general public. Those customers, which are identified in the "Science Communications Strategy" developed by the Space Sciences Laboratory at the MSFC, are divided into three categories: (1) Not interested and not knowledgeable; (2) Interested but not knowledgeable; and (3) Science attentive. In it they recognize that it makes the most sense to attempt to communicate with those described in the last two categories. However, their plan suggests that the media and the educational institutions are the only means of outreach. The NASA Ambassadors Program allows NASA to reach its target audience directly. Steps to be taken in order for the program to commence: (1) MSFC chooses to support the NASA Ambassadors Program - decision point; (2) Designate an "Office In Charge". (3) Assign the "Operation" phase to in-house MSFC personnel or to a contractor - decision point; (4) Name a point of contact; (5) Identify partners in the program and enlist their assistance; (6) Process an unsolicited proposal from an outside source to accomplish those tasks which MSFC chooses to out-source.

Lebo, George↗
NASA NTRS1998

The 1997 NASA Aerospace Battery Workshop

This document contains the proceedings of the 30th annual NASA Aerospace Battery Workshop, hosted by the Marshall Space Flight Center on November 18-20, 1997. The workshop was attended by scientists and engineers from various agencies of the U.S. Government, aerospace contractors, and battery manufacturers, as well as international participation in like kind from a number of countries around the world. The subjects covered included nickel-cadmium, nickel-hydrogen, nickel-metal hydride, lithium, lithium-ion, and silver-zinc technologies, as well as various aspects of nickel electrode design.

Brewer, Jeffrey C.↗
NASA NTRS1997

Research and Technology

As the NASA Center responsible for preparing and launching space missions, the John F. Kennedy Space Center (KSC) is placing increasing emphasis on its advanced technology development program. This program encompasses the efforts of the entire KSC team, consisting of Government and contractor personnel, working in partnership with academic institutions and commercial industry. This edition of the KSC Research and Technology 1997 Annual Report covers the efforts of these contributors to the KSC advanced technology development program, as well as our technology transfer activities.

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