Communicating bioastronautics research to students, families and the nation

The National Space Biomedical Research Institute (NSBRI) is supporting the National Aeronautics and Space Administration's (NASA) education mission through a comprehensive Education and Public Outreach Program (EPOP) that communicates the excitement and significance of space biology to schools, families, and lay audiences. The EPOP is comprised of eight academic institutions: Baylor College of Medicine, Massachusetts Institute of Technology, Morehouse School of Medicine, Mount Sinai School of Medicine, Texas A&M University, University of Texas Medical Branch Galveston, Rice University, and the University of Washington. This paper describes the programs and products created by the EPOP to promote space life science education in schools and among the general public. To date, these activities have reached thousands of teachers and students around the US and have been rated very highly.     

Spectral signatures of photosynthesis. I. Review of Earth organisms

Why do plants reflect in the green and have a "red edge" in the red, and should extrasolar photosynthesis be the same? We provide (1) a brief review of how photosynthesis works, (2) an overview of the diversity of photosynthetic organisms, their light harvesting systems, and environmental ranges, (3) a synthesis of photosynthetic surface spectral signatures, and (4) evolutionary rationales for photosynthetic surface reflectance spectra with regard to utilization of photon energy and the planetary light environment. We found the "near-infrared (NIR) end" of the red edge to trend from blue-shifted to reddest for (in order) snow algae, temperate algae, lichens, mosses, aquatic plants, and finally terrestrial vascular plants. The red edge is weak or sloping in lichens. Purple bacteria exhibit possibly a sloping edge in the NIR. More studies are needed on pigment-protein complexes, membrane composition, and measurements of bacteria before firm conclusions can be drawn about the role of the NIR reflectance. Pigment absorbance features are strongly correlated with features of atmospheric spectral transmittance: P680 in Photosystem II with the peak surface incident photon flux density at approximately 685 nm, just before an oxygen band at 687.5 nm; the NIR end of the red edge with water absorbance bands and the oxygen A-band at 761 nm; and bacteriochlorophyll reaction center wavelengths with local maxima in atmospheric and water transmittance spectra. Given the surface incident photon flux density spectrum and resonance transfer in light harvesting, we propose some rules with regard to where photosynthetic pigments will peak in absorbance: (1) the wavelength of peak incident photon flux; (2) the longest available wavelength for core antenna or reaction center pigments; and (3) the shortest wavelengths within an atmospheric window for accessory pigments. That plants absorb less green light may not be an inefficient legacy of evolutionary history, but may actually satisfy the above criteria.     

固冲发动机三维内流场数值计算与应用

利用三维隐式有限体积ＴＶＤ格式求解Ｎ－Ｓ／Ｅｕｌｅｒ方程组,数值模拟固体燃料冲压发动机（ＳＦＲＪ）突扩燃烧室、补燃室和喷管的统一内流场,研究了从亚声速到跨声速到超声速的整个工作过程,揭示了ＳＦＲＪ内复杂的流场结构,并与试验进行对比研究,数值结果与试验吻合很好。     

双时间步长加权ENO-强紧致高分辨率格式及在叶轮机械非定常流动中的应用

在非结构网格下,针对非定常三维N-S方程组发展了一种双时间步长高精度快速迭代格式。该格式在时间上具有二阶精度,在空间上将r=3的加权ENO格式与强紧致格式相结合去处理N-S方程中的对流项以及离散方程的右端项,并用四阶精度的紧致格式去计算N-S方程中的粘性项。典型的3个算例从不同侧面对格式进行了考核。计算表明:该算法具有高效率与高分辨率的特征,所得的计算结果与相关实验数据比较吻合,初步表明了该算法可以在非结构网格下模拟非定常流动的物理过程。      

The Diverse Planetary Ingassing/Outgassing Paths Produced over Billions of Years of Magmatic Activity

Space Science Reviews - Accretion onto black holes is an efficient mechanism in converting the gas mass-energy into energetic outputs as radiation, wind and jet. Tidal disruption events, in which...     

Progress of super-pressure balloon development: A new “tawara” concept with improved stability

The super-pressure balloon (SPB) has been expected to be a flight vehicle that can provide a long flight duration to science. Since 1997, we have developed the SPB. Now we are at the phase of developing an SPB of a practical size. In 2009, we carried out a test flight of a pumpkin-shaped SPB with a 60,000 m³ volume. The undesirable result of this flight aroused us to resolve the deployment instability of the pumpkin-shaped SPB, which has been known as one of the most challenging issues confronting SPB development. To explore this deployment issue, in 2010, we carried out a series of ground tests. From results of these tests, we found that an SPB design modified from pumpkin, named “tawara”, can be a good candidate to greatly improve the deployment stability of the lobed SPB.     

A follow-up of in-orbit observations of radiation-induced effects in commercial of the shelf memories on-board Alsat-1

This paper presents a follow-up of the results of an 8-year study on radiation effects in commercial off the shelf (COTS) memory devices operating within the on-board data handling system of the Algerian micro-satellite Alsat-1 in a Low-Earth Orbit (LEO). A statistical analysis of single-event upset (SEU) and multiple-bit upset (MBU) activity in commercial memories on-board the Alsat-1 primary On-Board Computer (OBC-386) is given. The OBC-386 is an Intel 80C386EX based system that plays a dual role for Alsat-1, acting as the key component of the payload computer as well as the command and control computer for the micro-satellite. The in-orbit observations show that the typical SEU rate at Alsat-1’s orbit is 4.04 × 10⁻⁷ SEU/bit/day, where 98.6% of these SEUs cause single-bit errors, 1.22% cause double-byte errors, and the remaining SEUs result in multiple-bit and severe errors.