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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 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

Crack healing behavior of hot pressed silicon nitride due to oxidation

It is shown that limited oxidation of an MgO-containing, hot-pressed silicon nitride ceramic at 800 deg C and above results in increased strength due to crack healing. Slight oxidation of the surface produces enstatite and cristobalite which fills in cracks. More extensive oxidation leads to strength degradation due to the formation of new flaws by the evolution of N2 gas at the surface. The apparent fracture toughness also increased at 800 deg C and above due to oxidation. Bonds formed between the two surfaces of the crack during oxidation leads to a reduction in stress intensity at the crack tip, suggesting that valid high-temperature toughness values cannot be obtained in an air environment. The increase in strength due to crack healing by oxidation can be achieved without compromising the fatigue properties of the silicon nitride ceramic.

Choi, S. R.↗
NASA NTRS1991

Thermoelectric properties of hot pressed p-type SiGe alloys

This paper presents the results of measurements of electrical resistivity, Seebeck coefficient, thermal conductivity, as well as Hall carrier concentration, and mobility, for hot pressed SiGe 80 at. pct Si-20 at. pct Ge (SiGe) thermoelectric materials containing 0.24-3.0 at. pct boron. The carrier concentration was varied by annealing and quenching at different high temperatures. Figure-of-merit, Z, was found to be 0.60 +/- 0.03 x 10 exp -3/K over a carrier concentration range from 1.8- 3.5 x 10 exp -20/cu cm. This result is very encouraging from a production standpoint, since the dopant concentration is not critical.

Bajgar, Clara↗
NASA NTRS1991

Thermoelectric properties of hot-pressed fine particulate powder SiGe alloys

A novel material system and its fabrication technique have been defined and applied to the production of SiGe thermoelectric material through the hot pressing of 50-100 A ultrafine particulates into 80/20 SiGe. Relative to conventionally processed SiGe, a reduction of thermal conductivity of up to 40 percent is achieved in conjunction with an enhancement of material figure-of-merit of the order of 10-15 percent.

Beaty, John S.↗
NASA NTRS1994

Optically Aligned Drill Press

Precise drill press equipped with rotary-indexing microscope. Microscope and drill exchange places when turret rotated. Microscope axis first aligned over future hole, then rotated out of way so drill axis assumes its precise position. New procedure takes less time to locate drilling positions and produces more accurate results. Apparatus adapted to such other machine tools as milling and measuring machines.

Adderholdt, Bruce M.↗
NASA NTRS1990

STS-32 Post-Flight Crew Press Conference

Video footage of the post-flight press conference of STS-32 is presented. The footage is narrated by the crew, and it covers the following topics: launch, deployment of Syncom IV-5, retrieval of the Long Duration Exposure Facility, in-orbit activities, and the landing.

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NASA NTRS1993

Thermal conductance of pressed metallic contacts augmented with Indium foil or Apiezon-N (tm) grease at liquid helium temperatures

The thermal conductance of pressed contacts which have been augmented with Indium foil or Apiezon-N (tm) grease was measured over the temperature range of 1.6 to 6.0 K, with applied forces from 22 N to 670 N. The sample pairs were fabricated from OFHC copper, 6061-T6 aluminum, free-machining brass, and 304 stainless steel. Although the thermal conductance was found to increase with increasing applied contact force, the force dependence was less than in earlier work. The addition of Indium foil or Apiezon-NT grease between the contact surfaces resulted in an improvement over uncoated surfaces ranging from a factor of approximately 3 for stainless steel to an order of magnitude for copper contacts.

Salerno, Louis J.↗
NASA NTRS1991

[STS-43 Post Flight Press Conference]

The flight crew (Blaha, Baker, Low, Adamson, and Lucid) present and discuss their STS-43 Space Shuttle Mission in this press conference video. This mission was the first flight to deploy the Tracking Data and Relay Satellite (TDRS), the primary payload. A large number of secondary payload experiments were performed. The included: several cell tissue growth and enzyme analysis experiments; a Lower Body Negative Pressure Experiment; optic coupling and flame front propagation/combustion physics experiments; The Space Station Heat Pipe Advanced Radiator Experiment (SHARE) for the Space Station; a crystal control device evaluation; a software and hardware systems checkout for the Shuttle; some flight tests of the new orbiter auto-pilot system; some materials tests on polymer membranes; the Zero Gravity physics experiments; and the Space Shuttle Backscatter Ultraviolet Experiment. Earth views included: the Kuwait oil fires; cloud cover; and B/W lightning footage.

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NASA NTRS1992

STS-46 Post Flight Press Conference

At a post flight press conference, the flight crew of the STS-46 mission (Cmdr. Loren Shriver, Pilot Andrew Allen, Mission Specialists Claude Nicollier (European Space Agency (ESA)), Marsha Ivins (Flight Engineer), Jeff Hoffman (Payload Commander), Franklin Chang-Dias, and Payload Specialist Franco Malerba (Italian Space Agency (ISA))) discussed their roles in and presented video footage, slides and still photographs of the different aspects of their mission. The primary objectives of the mission were the deployment of ESA's European Retrievable Carrier (EURECA) satellite and the joint NASA/ISA deployment and testing of the Tethered Satellite System (TSS). Secondary objectives included the IMAX Camera, the Limited Duration Space Environment Candidate Materials Exposure (LDVE), and the Pituitary Growth Hormone Cell Function (PHCF) experiments. Video footage of the EURECA and TSS deployment procedures are shown. Earth views were extensive and included Javanese volcanoes, Amazon basin forest ground fires, southern Mexico, southern Bolivian volcanoes, south-west Sudan and the Sahara Desert, and Melville Island, Australia. Questions from reporters and journalists from Johnson Space Center and Kennedy Space Center were discussed.

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NASA NTRS1994

Shoemaker-Levy Comet Impact with Jupiter Press Briefing

A press briefing about the impact of the G fragment of Comet Shoemaker-Levy on the planet Jupiter is presented. The briefing occurred on July 18, 1994 just hours after the impact. Still black and white pictures taken from the Hubble Space Telescope are presented. Eugene Shoemaker, co-discoverer of the Comet, and Heidi Hammel, Principal Investigator for the Hubble Imaging team at MIT present preliminary results of the study of images and answer questions about the impact and the results of the impact on Jupiter.

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NASA NTRS1992

Galileo Earth/Moon 2 Press Conference Live from JPL

The end of a press conference and short views of the Earth from the two Earth-Moon flybys of the Galileo spacecraft are presented. An audio playback of the Plasma Wave Instrument is also presented. The views of the Earth are from December 11, 1990, December 8, 1992 and December 22, 1992. The views from December 11, 1990 show panoramic views of the Earth as seen from space, the views from December 8, 1992 show close-up views of the Earth, and the views from December 22, 1992 include some simulations from the views taken on December 8, 1992.

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NASA NTRS1992

Galileo Press Conference from JPL

This two-tape Jet Propulsion Laboratory (JPL) video production presents a Dec. 8, 1992 press conference held at JPL to discuss the final Galileo spacecraft encounter with Earth before beginning its journey to Jupiter. The main theme of the conference was centered on the significance of the 2nd and final Earth/Moon flyby as being the spacecraft's last planetary encounter in the solar system before reaching Jupiter, as well as final flight preparations prior to its final journey. Each person of the five member panel was introduced by Robert MacMillan (JPL Public Information Mgr.) before giving brief presentations including slides and viewgraphs covering their area of expertise regarding Galileo's current status and future plans. After the presentations, the media was given an opportunity to ask questions of the panel regarding the mission. Mr. Wesley Huntress (Dir. of Solar System Exploration (NASA)), William J. ONeill (Galileo Project Manager), Neal E. Ausman, Jr. (Galileo Mission Director), Dr. Torrence V. Johnson (Galileo Project Scientist) and Dr. Ronald Greeley (Member, Imaging Team, Colorado St. Univ.) made up the panel and discussed topics including: Galileo's interplanetary trajectory; project status and performance review; instrument calibration activities; mission timelines; lunar observation and imaging; and general lunar science. Also included in the last three minutes of the video are simulations and images of the 2nd Galileo/Moon encounter.

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NASA NTRS1999

STS-103 Discovery Launch Scrub Press Conference

A press conference held on December 16, 1999, to explain the reason behind NASA's decision to delay the Discovery's launching by a period of 24 hrs is presented. According to Ron Dittemore, Space Shuttle Program Manager, the STS-103 team delayed the launch because they need extra time to check one vendor's manufacturing processes, after an x-ray inspection revealed that an improper weld rod was used to weld one of the pressuring lines (called NPS lines) in the ET (external tank). Mr. Dittemore explained that since it is in the ET (not a major load carrying structure and rebuild after each flight), it did not pose any danger to the STS-103 flight. However, the same vendor also manufactured some parts of the orbiter and the team wanted to make sure that the quality of the vendor's manufacturing processes is robust before launching the orbiter to space. He also answered some reporters' questions.

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NASA NTRS1988

STS-26 Preflight Press Briefing: Other Payloads

This NASA KSC video release presents a press conference that discusses the commercial development and NASA science Mid-deck payloads of Discovery STS-26. Larry Delucas (Univ. Alabama-Birmingham, Center for Macromolecular Crystallography), Chris Podsiadly (3-M Co., Marshall Space Flight Center's (MSFC's) Rep. for Material Processing) and Ed Valentine (MSFC) present discussions of the science and commercial development that surround the Physical Vapor Transport of Organic Solids-2 (PVTOS-2) payload. Their presentations are followed by a question and answer period for journalists from scientific journals.

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NASA NTRS1988

STS-26 Preflight Press Briefing: Shuttle System Changes

This NASA KSC video release presents a press conference that discusses the major system changes implemented on the shuttle in preparation for the launch of Discovery STS-26. Richard A. Colonna (Mgr. Orbiter and GFE Projects office) and an unidentified colleague present discussions involving hazard analysis, landing safety, launch abort/crew escape and major modidfications made to the Space Shuttle Boosters. Their presentations are followed by a question and answer period for journalists from scientific journals.

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NASA NTRS1988

STS-26 Preflight Press Briefing: Crew Escape/Crew Equipment

This NASA KSC video release presents part of a press conference held prior to Discovery flight STS-26, the first shuttle mission flown following the 51-L Challenger accident. The five member panel present individual viewgraph discussions followed by a question and answer period for the benefit of scientific journalists. William A. Chandler (Asst. to the Dir. of Engineering and the NSTS program) gives a brief overview of the crew escape system followed by Steven Nagel's (Astronaut) presentation on crew equipment. Robert Rice (Crew Escape System Manager) describes the flight test program and the innovative pyrotechnics system test program. Tim Pelischek (Pole Design Team) gives an assessment of the critical design review and Ricardo Machin reviews aerodynamic flight tests performed at Texas A&M and California. The second part of the video includes Robert Crippen's (Deputy Dir. of Operations, Kennedy Space Center) overview of NASA Management, the organizational changes and actions taken to meet the Roger's Commission recommendations.

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NASA NTRS1988

STS-26 Preflight Press Briefing: Shuttle Systems Changes (2)

This NASA KSC video release presents part of a press conference held prior to Discovery flight STS-26, the first shuttle mission flown following the 51-L Challenger accident. The video includes presentations by Gerald Smith (Solid Rocket Booster (SRB) Project Manager) and Joe Lombardo (Space Shuttle Main Engine (SSME) Project Manager) discussing the major changes that were made to the SRB and SSME between 51-L and STS-26. Mr. Smith's talk centered on the changes and redesigns made to the solid rocket motor field joint, the case to nozzle joint, the SRB aft skirt, and the ET aft attach ring. Mr. Lombardo discusses test data evaluation, SSME inspections and the SSME heat exchanger in particular.

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NASA NTRS1988

STS-26 Preflight Press Briefing: Flight Crew and TDRS

This NASA KSC video release presents part of a press conference held prior to Discovery flight STS-26, the first shuttle mission flown following the 51-L Challenger accident. The first portion of the video presents the 5 member flight crew, (Frederick H. Hauck, Commander, Richard O. Covey, Pilot, John M. Lounge, Mission Specialist, George D. Nelson, Mission Specialist, and David C. Hilmers, Mission Specialist) answering questions posed by scientific journalists. Inquiries are made regarding the approximately 250 changes implemented on the orbiter and boosters, failures that occurred during 51-L, astronaut attitudes about flying the first mission since the Challenger accident, and the issue of range safety. The second part of the video includes viewgraph presentations given by Dr. Dale W. Harris (TDRS Project Manager, Goddard Space Flight Center(GSFC)) and Gary A. Morse (Network Director, GSFC) that discuss the primary payload, the NASA Tracking and Data Relay Satellite-3 (TDRS-3) that is attached to an Inertial Upper Stage (IUS), and is the second TDRS deployed.

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NASA NTRS1988

STS-26 Preflight Press Briefing: 5 Man Crew

This NASA KSC video release presents part of a press conference held prior to Discovery flight STS-26, the first shuttle mission flown following the 51-L Challenger accident. The video opens with a statement from Commander Frederick H. Hauck, and the introductions of crew members, Richard O. Covey, Pilot, and mission specialists, John M. Lounge, George D. Nelson, and David C. Hilmers. Some of the questions posed by scientific journalists addressed the following subjects: launch preparation in the month prior to flight, astronaut family anxieties in light of the Challenger accident, extent of safety measures made prior to flight, flight readiness firing, the crew escape system, civilians in space, conservative mission design, astronaut selection, mission turnaround and launch rate, and the ability to maintain a high level of scrutiny regarding safety on future missions.

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