Water Vapor Imagery: A New Observation for Weather Analysis

Water vapor imagery is now available routinely from weather satellites for use in meteorological operations. Research during the past 5 years has provided insight concerning the physical interpretation of this data under varying atmospheric moisture and temperature distributions. Investigations have also identified new applications for use in operational weather analysis and forecasting. The water vapor patterns and the changes of these patterns with time, relate to upper tropospheric flow, the jet stream, tropopause breaks, the intensification of thunderstorms, and tropical storm motion. Animated hourly water vapor imagery will become available next year for use by National Weather Service (NWS) field forecasters. It will provide them with a new diagnostic tool for short range forecasts.     

Tracing the evolutionary path for space technologies

Proliferation and pace of advancing technologies warrant policy and strategic decision-making. Without thinking ahead, companies can loose marketshare and countries can yield comparative advantage. The rate at which burgeoning technologies progress, however, can make it difficult for corporations and governments alike to discern or better anticipate critical junctures in technology developments. This paper presents a conceptual, multidimensional framework, the “evolutionary path”, for understanding the stages of technological development in the civil space area. The analysis draws from three case studies — communications satellites, computers, and launch vehicles — and shows how the implications and developments of new, breakthrough technologies differ from the incremental technology upgrades or the later emergence of interconnected systems and infrastructures.     

Factors controlling activity of zirconia-titania for photocatalytic oxidation of ethylene.

Small photocatalytic devices were developed to remove ethylene from closed plant growth units flown in space. The devices utilized sol-gel-derived catalyst pellets of zirconia-titania. This study was undertaken to understand the significance of different factors on the photocatalytic activity of the catalyst. Increasing reaction temperatures and decreasing humidity of the air significantly increased oxidation of ethylene. The quantity of ethylene oxidized per unit time increased linearly with increasing flow rates, and increasing concentrations of ethylene. Zirconia-titania pellet size and heel depth had little effect on oxidation of ethylene. Platinizing the zirconia-titania significantly increased ethylene oxidation. The catalyst was found to absorb large quantities of water when the humidity of the air stream was elevated and this greatly decreased catalytic activity.     

Lunar Reconnaissance Orbiter Camera (LROC) Instrument Overview

The Lunar Reconnaissance Orbiter Camera (LROC) Wide Angle Camera (WAC) and Narrow Angle Cameras (NACs) are on the NASA Lunar Reconnaissance Orbiter (LRO). The WAC is a 7-color push-frame camera (100 and 400 m/pixel visible and UV, respectively), while the two NACs are monochrome narrow-angle linescan imagers (0.5 m/pixel). The primary mission of LRO is to obtain measurements of the Moon that will enable future lunar human exploration. The overarching goals of the LROC investigation include landing site identification and certification, mapping of permanently polar shadowed and sunlit regions, meter-scale mapping of polar regions, global multispectral imaging, a global morphology base map, characterization of regolith properties, and determination of current impact hazards.     

Stochastic-constraints method in nonstationary hot-cluttercancellation. II. Unsupervised training applications

For pt. I see ibid., vol. 34, pp. 1271-1292 (1998). This paper considers the use of “stochastically constrained” spatial and spatio-temporal adaptive processing in multimode nonstationary interference (“hot clutter”) mitigation for scenarios that do not allow access to a group of range cells that are free from the backscattered sea/terrain signal (“cold clutter”). Since supervised training methods for interference covariance matrix estimation using the cold-clutter-free ranges are inappropriate in this case, we introduce and analyze adaptive routines which can operate on range cells containing a mixture of hot and cold clutter and possible targets (unsupervised training samples). Theoretical and simulation results are complemented by surface-wave over-the-horizon data processing, recently collected during experimental trials in northern Australia     

Rethinking public–private space travel

On May 24, 2012 SpaceX's Dragon capsule was launched and in doing so became the first commercially built vehicle to berth with and carry cargo to the International Space Station (ISS). It successfully completed its mission and returned to the Pacific Ocean on May 31, 2012.¹ The docking of Dragon represented a historic moment where a commercial enterprise managed to achieve that which had previously only been accomplished by governments. “In the history of spaceflight – only four entities have launched a space capsule into orbit and successfully brought it back to Earth: the United States, Russia, China, and SpaceX”.² While this is a monumental accomplishment for private industry, we cannot ignore the value of public–private partnerships and the role that government played in enabling this incredible achievement.In this paper I will examine how public–private partnerships are enabling the development of the commercial space industry, viewed through the lens of the Rethinking Business Institutional Hybrid Framework put forward by University of Oxford professors Marc Ventresca and Alex Nichols in their Rethinking Business MBA course. I intend to demonstrate that the NASA versus Commercial Space argument is a false dichotomy and that only by working together can both sectors continue to push the boundaries of space travel and exploration. I plan to do this by first discussing how the NASA-SpaceX partnership came about and the reasoning behind it. I will then explore what a public–private partnership (PPP) is, as compared to other government privatization schemes, and explain why Space Act Agreements are significantly different from anything done previously. I will then analyze the impact of these agreements and outline their benefits in order to demonstrate the value they create, especially in areas of mutual value creation and economic development.     

Retrieval of a wind profile from the Galileo Probe telemetry signal

Ultrastable oscillators onboard the Galileo Probe and Orbiter will permit very accurate determinations of the frequency of the Probe's telemetry signal as the Probe descends from a pressure level of several hundred mb to a level of about 20 bars. Analysis of the time-varying frequency can provide, in principle, a unique and important definition of the vertical profile of the zonal wind speed in the Jovian atmosphere. In this paper, we develop a protocol for retrieving the zonal wind profile from the Doppler shift of the measured frequency; assess the impact of a wide range of error sources on the accuracy of the retrieved wind profile; and perform a number of simulations to illustrate our technique and to assess the likely accuracy of the retrieval.Because of unavoidably large uncertainties in the absolute frequencies of the oscillators, we use time-differenced frequencies in our analysis. Nevertheless, it is possible to recover absolute wind speeds as well as wind shears, since the Orbiter/Probe geometry changes significantly during the Probe relay link. We begin with the full relativistic Doppler shift equation. Through the use of power series expansions and a basis function representation of the wind profiles, we reduce the basic equation to a set of linear equations that can be solved with standard linear least-squares techniques.There are a very large number of instrumental and environmental factors that can introduce errors into the measured signal or to the recovery of zonal winds from the data. We provide estimates of the magnitudes of all these error sources and consider the degree to which they may be reduced by a posteriori information as well as the results of calibration tests. The most important error source is the a posteriori uncertainty in the Probe's entry longitude. The accuracy of the retrieved winds is also limited by errors in the Probe's descent velocity, as obtained from atmospheric parameters measured by several Probe experiments, and in the a posteriori knowledge of secular drifts in the oscillators' frequencies during the relay link, due, for example, to aging and radiation damage.Our simulations indicate that zonal winds may be retrieved from the Doppler data to an accuracy of several m s^-1. Therefore, it may be possible to discriminate among alternative models for the basic drive of the zonal winds, since they differ significantly in the implied zonal wind profile.     

Materials trade study for lunar/gateway missions.

The National Aeronautics and Space Administration (NASA) administrator has identified protection from radiation hazards as one of the two biggest problems of the agency with respect to human deep space missions. The intensity and strength of cosmic radiation in deep space makes this a 'must solve' problem for space missions. The Moon and two Earth-Moon Lagrange points near Moon are being proposed as hubs for deep space missions. The focus of this study is to identify approaches to protecting astronauts and habitats from adverse effects from space radiation both for single missions and multiple missions for career astronauts to these destinations. As the great cost of added radiation shielding is a potential limiting factor in deep space missions, reduction of mass, without compromising safety, is of paramount importance. The choice of material and selection of the crew profile play major roles in design and mission operations. Material trade studies in shield design over multi-segmented missions involving multiple work and living areas in the transport and duty phase of space mission's to two Earth-Moon co-linear Lagrange points (L1) between Earth and the Moon and (L2) on back side of the moon as seen from Earth, and to the Moon have been studied. It is found that, for single missions, current state-of-the-art knowledge of material provides adequate shielding. On the other hand, the choice of shield material is absolutely critical for career astronauts and revolutionary materials need to be developed for these missions. This study also provides a guide to the effectiveness of multifunctional materials in preparation for more detailed geometry studies in progress.     

In situ microbial detection in Mojave Desert soil using native fluorescence

We report on the use of a portable instrument for microbial detection in the Mojave Desert soil and the potential for its use on Mars. The instrument is based on native fluorescence and employs four excitation wavelengths combined with four emission wavelengths. A soil dilution series in which known numbers of Bacillus subtilis spores were added to soil was used to determine the sensitivity of the instrument. We found that the fluorescence of the biological and organic components of the desert soil samples studied can be as strong as the fluorescence of the mineral component of these soils. Using the calibration derived from B. subtilis spores, we estimated that microbial content at our primary sampling site was 10(7) bacteria per gram of soil, a level confirmed by phospholipid fatty acid analysis. At a nearby site, but in a slightly different geological setting, we tested the instrument's ability to map out microbial concentrations in situ. Over a ～50 m diameter circle, soil microbial concentrations determined with the B. subtilis calibration indicate that the concentrations of microorganisms detected varies from 10(4) to 10(7) cells per gram of soil. We conclude that fluorescence is a promising method for detecting soil microbes in noncontact applications in extreme environments on Earth and may have applications on future missions to Mars.