Physical Sciences Division
Weekly Highlights for Week Ending 3/14/2002
*** Indicates item is appropriate for the HQ senior staff and may appear on the OBPR Web site: http://spaceresearch.nasa.gov
MSD PERSONNEL SERVE AS JUDGES IN NASA STUDENT COMPETITION: On March 12, MSD 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 Glenn 6-state E/O region. The K-12 student submissions were judged for competitions in Mars exploration, Earth observation, and scientific & technical journalism. http://www.nsip.net/
SHUTTLE FLIGHT PROGRAM
MICROGRAVITY RESEARCH PROGRAM OFFICE (MRPO) PARTICIPATION IN STS-107 MISSION INTEGRATE2) AT JOHNSON SPACE CENTER (JSC): Microgravity Research Program Office (MRPO) employees will participate in MITS#2 to be held on 3/20/02 in Building 30 at the Johnson Space Center in preparation for the STS-107 flight. The training session will simulate STS-107 Flight Day 8 on-orbit activities and is expected to engage NASA management teams, MRPO science teams, and the Spacehab payload flight controller team on nominal and off-nominal flight conditions. STS-107 is currently scheduled for a launch date of 7/11/02.
ISS FLIGHT PROGRAM
PHYSICS OF COLLOIDS IN SPACE (PCS) ON ISS: Troubleshooting continues on the EXPPCS flight system computer boot-up problem experienced on Sunday evening, February 24th. During this week, the crew executed further troubleshooting procedures to help EXPPCS greatly narrow down the range of possible reasons for the failure to boot. The two remaining areas of possible cause are a problem with the EXPPCS Central Processing Unit (CPU) or a problem with the EXPPCS CPU-to-hard drive SCSI connection (specifically that is, either a problem with the EXPPCS cabling or a corrupted Basic Input Output System (BIOS) configuration file). The last scenario appears most likely as the EXPPCS team is able, by disabling the BIOS on our ground based Engineering Unit and trying to boot up, to reproduce the same power draw profile as was seen during the February 24th on-orbit failure to boot. As a result, EXPPCS has looked in great detail into the various BIOS settings (CMOSS, flash memory, and factory BIOS) resident on our CPU card and feels that the EXPPCS flight system CPU configuration settings have been corrupted or erased. The EXPPCS science and operations team continues to appreciate the crew's timely response to our requests for help, and also the Program's flexibility in re-scheduling the crew. Continued troubleshooting by the ISS crew will be required with the goal of on-orbit repair, leading to completion of the EXPPCS science objectives. A set of crew procedures has been written to enable the crew to update the EXPPCS BIOS settings using a keyboard and monitor owned by the Human Research Facility (HRF) and already on orbit. An OCR for this operation has been written and submitted.
INTERAGENCY PERSONNEL ACT (IPA) APPOINTEE TO WORK WITH MARSHALL SPACE FLIGHT CENTER'S (MSFC) RADIATION SHIELDING MATERIALS PROGRAM: Prof. Abdulnasser Barghouty of Roanoke College has been appointed under the Interagency Personnel Act to assist with the Radiation Shielding Materials Program here at MSFC, effective 2/25/2002. Prof. Barghouty has considerable experience working on radiation transport through shielding and modeling nuclear cross-sections, which are needed for radiation analysis.
GRC PRESENTATIONS AT NASA 2002 CELL SCIENCE CONFERENCE: NASA GRC personnel gave two presentations at the Cell Science Conference held in Palo Alto 2/26-2/28. Both of which were extremely well received. The first presentation was given by Dr. John Kizito (NCMRFC/GRC) in Session 6: Biological Response to Physical Forces. This presentation summarizing the work he and Dr. Emily Nelson (GRC) have been performing on the ARC Cell Specimen Chamber was entitled "Uncoupling Mass Transport Issues from the Decrease of Forces on Cells in Microgravity: Predicting the Mass Transport and Forces on Cells in a Perfused and Stirred Culture System." The presentation included 3-D simulation movies of flow in the CSC based on some of their preliminary analysis. The second presentation was given by Dr. DeVon Griffin (GRC) in Session 7: Cell Culture Technology. It summarized the capabilities of Light Microscopy Module (LMM) and was entitled "The Light Microscopy Module: A Potential On-Orbit Resource for Biological Research." In addition, an exhibit on LMM was also provided. This included a large display board containing visuals of the LMM and its capability, the one-page informational handouts, logo stickers, and a DVD playing movies of some of the LMM imaging capabilities. Dr. Griffin provided a 3-minute presentation at the exhibit for the guests as a part of the conference activities.
EXPERIMENTAL COMPARISON OF A LIQUID-CRYSTAL POINT-DIFFRACTION NTERFEROMETER (LCPDI) AND A COMMERCIAL PHASE-SHIFTING INTERFEROMETER AND METHODS TO IMPROVE LCPDI ACCURACY: Fluid Physics PI Dr. DeVon Griffin (GRC) and his Co-I Dr. Marshall (University of Rochester) compare the phase measurements of a fused-silica witness sample made with a liquid-crystal point-diffraction interferometer (LCPDI) with measurements made with a Zygo Mark IV xp phase-shifting interferometer and find close agreement. Two phase-shift-error sources in the LCPDI that contribute to measurement discrepancies are frame-to-frame intensity changes caused by the dichroism of the dye and alignment distortions of the host liquid crystal. An empirical model of the phase-shift error caused by the host alignment distortions is presented and used to investigate the performance of two different phase-detection algorithms. It is suggested that by proper choice of LCPDI fabrication parameters and phase-acquisition methods, the device's accuracy can be significantly improved. The point-diffraction interferometer (PDI) is an elegantly simple device for characterizing optical wave-front quality. A distinct advantage of the PDI design is its modifications of the PDI to incorporate the phase-shifting technique are described in the literature, however, the liquid-crystal point-diffraction interferometer (LCPDI) is particularly attractive because of its simplicity, ease of use, and low manufacturing cost. The LCPDI maintains the advantages of the conventional PDI while providing the ability to phase shift the object beam wave-front relative to the reference wave-front. The results are reported in the following paper:
Mark J. Guardalben, Lutao Ning, Nieraj Jain, Devon J. Battaglia, and Kenneth L. Marshall, "Experimental comparison of a liquid-crystal point-diffraction interferometer (LCPDI) and a commercial phase-shifting interferometer and methods to improve LCPDI accuracy," Applied Optics, Vol. 41, No. 7, pp 1353- 1365 March 2002.
DENSITY-DRIVEN UNSTABLE FLOWS OF MISCIBLE FLUIDS IN A HELE-SHAW CELL:
Fluid Physics PI Prof. Meiburg (University of California at Santa Barbara ) investigated density-driven instabilities between miscible fluids in a vertical Hele-Shaw cell by means of experimental measurements, as well as two- and three-dimensional numerical simulations. The experiments focus on the early stages of the instability growth, and they provide detailed information regarding the growth rates and most amplified wavenumbers as a function of the governing Rayleigh number Ra. They identify two clearly distinct parameter regimes: a low-Ra, `Hele-Shaw' regime in which the dominant wavelength scales as (1/Ra) and a high-Ra `gap' regime in which the length scale of the instability is 5 times the gap width. The experiments are compared to a recent linear stability analysis based on the Brinkman equation. The analytical dispersion relationship for a step-like density profile reproduces the experimentally observed trend across the entire Ra range. Nonlinear simulations based on the two- and three-dimensional Stokes equations indicate that the high-Ra regime is characterized by an instability across the gap, whereas in the low-Ra regime a spanwise Hele-Shaw mode dominates. The results are reported in the following paper:
J. Fernandez , P. Kurowski , P. Petitjeans and E. Meiburg, "Density-driven unstable flows of miscible fluids in a Hele-Shaw cell," J. Fluid Mech. (2002), vol. 451, pp. 239 - 260.
STUDIES OF NUCLEATION AND GROWTH, SPECIFIC HEAT AND VISCOSITY OF UNDERCOOLED MELTS OF QUASICRYSTALS AND POLYTETRAHEDRAL-PHASE-FORMING ALLOYS: The Science Concept Review (SCR) dry-run was held for Dr. Kenneth Kelton of Washington University on Thursday, 2/28/2002. The dry-run committee consisted of Dr. Bill Kaukler, University of Alabama in Huntsville (UAH), and Marshall Space Flight Center Drs. Alex Lehoczky , Richard Grugel, and Ed Ethridge, with Dr. Mike Robinson presiding as Project Scientist. Dr. Kelton passed the dry run after considerable constructive discussions with the panel. Dr. Kelton is studying quasicrystal formation using the European Space Agency Microgravity Science Laboratory-Electromagnetic Levitator (MSL-EML) hardware and plans to proceed to complete the SCR in September 2002.
Additional meetings and symposia can be found at: http://microgravity.grc.nasa.gov/ugml/ugmltext.htm
The MRPO Program Calendar can be found at:
March 18-22, 2002, 2002 American Physical Society March Meeting, Indianapolis, IN
April 20-23, 2002, 2002 American Physical Society April Meeting, Albuquerque, NM
April 22-25 2002, 2002 Applied Computational Research Society Joint Meeting: Computational Micro And Nano Technology, International Conference on Computational Nano Science , Modeling & Simlation of Microsystems
San Juan Marriott Resort, San Juan, Puerto Rico
May 9-11, 2002, Fundamental Physics Investigator Workshop, laguna Cliffs Marriott Resort, Dana Point, CA