Physical Sciences Division
Weekly Highlights for Week Ending 3/20/2002
*** Indicates item is appropriate for the HQ senior staff and may appear on the OBPR Web site: http://spaceresearch.nasa.gov
***INTERNATIONAL AND MULTI NASA CENTER COLLABORATION ON RADIATION SHIELDING MATERIALS: A team of investigators from Lawrence Berkeley National Laboratory, funded by NASA's Materials Science Program and the Japanese government, participated in four experiments at the particle accelerator in Chiba, Japan. The investigators measured energetic particle beams interacting with shielding material constituents. The beams used were representative of the ionizing radiation in space that poses a hazard for astronauts. In addition, the investigators joined a NASA supported group from Colorado State University to measure the response to high-energy atomic nuclei (HZE) particles of a tissue equivalent proportional counter (TEPC), similar to instruments used to monitor radiation on the Space Shuttle and ISS. Finally, they used their equipment to provide benchmark data for an inter-comparison of several space radiation flight instruments provided by NASA-Johnson Space Center (JSC), Japanese Space Agency-NASDA, European Space Agency (ESA) (through Kiel University), Waseda University, the Japanese National Institute of Radiological Sciences, the Bulgarian Academy of Sciences, and ERIL Research (USA).
EDUCATION and OUTREACH
MICROGRAVITY ELEMENTARY SCHOOL OUTREACH: Two members of the Microgravity Research Program Office (MRPO) outreach and education team, Twila Schneider and Allen Moore, along with Monica Hammond, Project Manager in the Microgravity Science and Applications Department at Marshall Space Flight Center (MSFC), visited a first grade class at Madison Academy in Madison, Alabama as part of their Alabama Space Week activities. The students were provided with information about gravity and microgravity, and helped build copier paper gloveboxes using the "NASA's Student Glovebox" Educator Guide. The students were also provided an opportunity to "work" in a middeck glovebox built by Allen Moore. One student acted as mission control while giving power up/power down instructions to a student acting as a payload specialist. (See attached image 009.jpg)
MICROGRAVITY SCIENCE DIVISION (MSD) PERSONNEL SERVE AS JUDGES IN NASA STUDENT COMPETITION: On 3/12/02 Glenn Research Center's (GRC) Microgravity Science Division personnel Nancy Hall, Nasser Rashidnia, Kathy Schubert, and Dennis Stocker served as judges for the NASA Student Involvement Program (NSIP) reviewing and ranking submissions for the GRC 6-state Education/Outreach region. The K-12 student submissions were judged for competitions in Mars exploration, Earth observation, and scientific & technical journalism.
GIRL SCOUTS LEARN ABOUT THE INTERNATIONAL SPACE STATION (ISS) AND MICROGRAVITY SCIENCE: On 3/9/02, members of Cleveland, Ohio Girl Scout Troop #1746 were provided a tour of Glenn Research Center to see why and how world-class science and world-class technology meet each other. The tour was conducted courtesy of Microgravity Science Division's Mike Doherty. The scouts toured the ISS U.S. Laboratory Mockup and the Telescience Support Center, enjoyed the life-size Lab mockup, and learned how telescience is currently being conducted on ISS. They learned of the potential positive impacts to life on Earth by the research being conducted by the Physics of Colloids in Space experiment currently residing on ISS -- exotic photonic crystals for future computers, colloids and food, and fractal gels and materials. The feedback on the entire event was very positive.
INTERNATIONAL TECHNOLOGY EDUCATION ASSOCIATION (ITEA) OUTREACH: Carla Rosenberg/National Center for Microgravity Research (NCMR) and Dennis Stocker (NASA/Glenn Research Center) were the Office of Biological and Physical Research (OBPR) representatives at the 2002 annual conference of the International Technology Education Association (ITEA). Ms. Rosenberg conducted a conference workshop, and both staffed the NASA exhibit, distributing OBPR educational product resources and conducting demonstrations with the Microgravity Demonstrator and Balloon Buster. The Physical Sciences Division Educator's Guide, "Microgravity: Earth and Space," which was produced by a joint project of the NASA Microgravity Research Program Office (MRPO) and ITEA, premiered at this conference, with initial distribution and a workshop by the technology-educator authors Brad and Terry Thode. In addition, Stocker introduced a draft design challenge, providing demonstrator requirements to technology educators so that they can challenge their high school students to design and build their own demonstration drop tower. The Dropping In a Microgravity Environment (DIME) competition was promoted as another design challenge for high school students; this will be a national competition in the coming 2002-2003 school year.
ISS FLIGHT PROGRAM
MICROGRAVITY RESEARCH PROGRAM OFFICE (MRPO) PAYLOAD OPERATIONS STATUS ON THE INTERNATIONAL SPACE STATION (ISS) UF1 STAGE: Have successfully completed Week#13 (3/10-16/02) of Increment 4 Utilization Flight-1 (UF-1) Stage, and have entered into Week#14. Virtually all MRPO payloads have completed their scheduled operations and are looking forward to a busy week involving plant growth, crystal growth, and the cell preservation phase. Several attempts at troubleshooting the Physics of Colloids in Space (PCS) payload have so far not been successful. The payload developer has focused attention on a corruption of the avionics system. Procedures have been developed and tested to carry out a final attempt at reviving this payload during the week of March 17.
PHYSICS OF COLLOIDS IN SPACE (PCS) ON ISS: Crew procedures are in place to enable ISS crew member Carl Walz to access and modify corrupted Basic Input/Output System (BIOS) settings, the most likely scenario that has prevented the EXPPCS flight system from booting-up since February 24th. A "hands on" procedure review was conducted at NASA Johnson Space Center this week by crew representative Janice Voss using high fidelity EXPPCS, Human Research Facility, and ISS engineering model hardware. The procedure was successfully conducted, Janice was able to execute the procedures with the EXPPCS Avionics Section engineering unit successfully booting up. Comments provided by Janice were incorporated to improve the clarity of the procedures. Crew time has been scheduled for setup and attempted repair of EXPPCS on Wednesday, March 20th.
MICROGRAVITY SCIENCE GLOVEBOX (MSG): The Marshall Space Flight Center's (MSFC) Microgravity Science and Applications Department (MSAD) Certification of Flight Readiness (CoFR) Review for the Integrated MSG Payload was conducted on 03/08/02. The MSAD CoFR Board signed the certification on 03/14/02, after resolution of actions from the review. The CoFR endorsements required by SSP 52054 were delivered to the Microgravity Research Program Office on 03/18/02. Installation of the MSG stowage items, including the Utilization Flight-2 (UF-2) Investigation hardware into the Multi-Purpose Logistics Module (MPLM), was completed at the Kennedy Space Center (KSC) on 03/16/02. Final MSG Facility closeout in the MPLM is scheduled for 03/20/02.
SOLID INFLAMMABILITY BOUNDARY AT LOW SPEED (SIBAL): The objective of this investigation, led by Prof. J. T'ien of CWRU, is to enhance the understanding of flame spread and determine the mechanisms that induce flammability limits over solid surfaces in low-speed flows. Fundamental understanding of the effects of flow environment and fuel geometry on flammability and flame spread has direct applications to spacecraft fire safety. The research is to be conducted in a continuous feed fuel dispensing device that will establish a spreading flame that is also stationary with respect to the laboratory, providing time for diagnostic probing of the flames. It is important to use a solid fuel with consistent properties for the intended study and with suitable characteristics for the continuous feed apparatus. The upward and downward flammability limits as a function of pressure in 1-g were determined for the cotton/fiberglass fuel planned for this flight experiment. For example, the upward and downward limits are 0.18 and 0.21 mole fraction oxygen, respectively at normal atmospheric pressure and increase as pressure is reduced. The one-sided flame behavior occasionally observed for this fuel was investigated further. When a one-sided flame appears, the spread rate is typically half of what it would be for the two-sided case. Also, the one-sided flame is less flammable, meaning that the extinction limiting oxygen percentage is higher for a given pressure compared to the two-sided case. On the modeling front, the concurrent flame spread model is used in microgravity over a thin solid fuel within a flow tunnel to determine the effectiveness of carbon dioxide, which is the primary extinguishing agent aboard the International Space Station (except in the Russian module). The parameters of interest are mole fraction of carbon dioxide in the jet stream, jet velocity, and area of the jet. Results show that the most effective extinguishment technique is to apply a high-velocity, high-concentration carbon dioxide jet to the flame. In this way, the mass flow rate of carbon dioxide required is minimized. However, if a flooding application is needed, applying carbon dioxide in a low velocity air stream will minimize the mass flow rate.
GRC PRESENTATION AT THE "SPACE BIOLOGY ON THE EARLY SPACE STATION WORKSHOP": Dr. DeVon Griffin (NASA GRC) made a presentation the Light Microscopy Module (LMM) capabilities and its potential use to conduct biological research. LMM will be located in the Fluids Integrated Rack (FIR) in the Destiny Module on ISS. The (LMM) will be a cutting edge research facility that offers a suite of the state-of-the-art diagnostics techniques used by the physical and biological scientists in their ground-based labs today. These diagnostic capabilities include: video microscopy to observe sample features including basic structures and dynamics, thin film interferometry, laser tweezers for colloidal particle manipulation and patterning, confocal microscopy to provide enhanced three-dimensional visualization of colloidal structures, and spectrophotometry to measure colloidal crystal photonic properties. In addition to using the confocal system, biological experiments can conduct fluorescence imaging by using the fiber-coupled output of Nd:YAG laser operating at 532 nm, the 437 nm line of a mercury arc, or appropriate narrow-band filtering of the FIR provided metal halide white light source. The presentation was well received. The workshop was held at NASA Ames Research Center on March 14-15, 2002.
POROUS GRAPHITE COMBUSTION EXPERIMENT: The objective to this research, led by Prof. H. Chelliah of University of Virginia, is to experimentally determine the oxidation rates, flame stand-off distances, and surface temperatures of a variety of porous, carbonaceous particles as they burn in microgravity to help further develop a detailed numerical model. This research is significant in understanding the details of the coal burning process which occurs by a two-stage combustion of small, porous particles, namely, rapid pyrolysis followed by slow char oxidation. The goal of achieving self-sustained particle combustion is now accomplished by three factors; (a) laser drilled particles (1mm glassy carbon spheres with roughly 75 micron drilled holes), (b) suspension of the particles using alumina (Al2O3) fibers, and (c) use of air enriched with oxygen, up to about 60%. Silicon carbide (SiC) fibers, which were used until recently, did not survive the hot, enriched oxygen conditions. Alumina fibers, with a lower reported melting point than SiC, were able to hold the particle in place up to about 15 s. It is believed that particle surface temperature for the present enriched air experiments must be well over 2500 K. Under these high temperature and oxygen rich conditions, SiC used previously did not survive long enough to hold the particle in field of view of the camera. During the recent KC-135 flight experiments, and the hardware performed nominally in most cases. The rotational stage that moves the particle in to the laser beam failed, but the particles could be moved by hand by opening the chamber door. A series of tests, all in 21% oxygen (due to not having a permit yet to fly with enriched oxygen) were done at different laser powers and using different carbon types to the mass burning rate. Since at 21% O2 the particles oxidize so slowly, often several parabolas were used for a single particle, turning the laser off in between. The video data is still being analyzed, as well as data from the spectrometer which had a low signal and may be insufficient quality to obtain the temperature. A collecting lens will need to be added in the future to circumvent this problem
FLUID PHYSICS RESEARCH SHOWCASED ON PUBLIC TV: Profs. Glasser and Shinbrot published a paper in the January 17 issue of the journal Nature. In their paper, titled "Shear Instabilities in Granular Flows," they report that breaking waves can form at the interface between two streams of grains flowing on an inclined plane. Prof. Shinbrot is an associate professor and Prof. Glasser is an assistant professor and associate director of the pharmaceutical engineering program in the department of Chemical and Biochemical Engineering, Rutgers University. They worked with a postdoctoral fellow, David J. Goldfarb, who is now at
the Schering-Plough Research Institute. Their results were also showcased on public television: the three researchers were interviewed for NJN (New Jersey Network) news and they appeared on the Science and Technology portion of the news on January 24. The researchers examined unstable shear waves, which have been long studied in fluid shear layers. These waves affect transport in the atmosphere and oceans, in addition to slipstream stability behind ships, airplanes and heat-transfer devices. Corresponding instabilities in granular flows have not been previously documented, despite the importance of these flows in geophysical and industrial systems. Shear transmission in granular flow is intrinsic to systems ranging from geophysical flows to industrial processing, and peculiarities in granular shear response have consequences that can be dramatic or commonplace. More spectacular examples include catastrophic events such as landslides and earthquakes, while more everyday examples include processing of products ranging from pharmaceuticals to catalysts. In the paper, the researchers examined two streams of colored sand, flowing at different velocities, down an inclined chute. Changes in either the shear rate or the angle of incline caused waves to appear abruptly at the interface of the streams. The researchers also analyzed a granular flow model that agreed qualitatively with the experimental data; the model suggests that the waves result from competition between shear and extensional strains in the flowing granular bed. The web site http://sol.rutgers.edu/~bglasser/Shear contains more information, including snapshots and videos of the waves. A Quicktime video of the news segment on public television is available at http://sol.rutgers.edu/~bglasser/temp/GlasserMovie.mov
Additional meetings and symposia can be found at: http://microgravity.grc.nasa.gov/ugml/ugmltext.htm
The MRPO Program Calendar can be found at: