Analysis of the staging maneuver and booster glideback guidance for a two-stage, winged, fully reusable launch vehicle

One of the promising launch concepts that could replace the current space shuttle launch system is a two-stage, winged, vertical-takeoff, fully reusable launch vehicle. During the boost phase of ascent, the booster provides propellant for the orbiter engines through a cross-feed system. When the vehicle reaches a Mach number of 3, the booster propellants are depleted and the booster is staged and glides unpowered to a horizontal landing at a launch site runway. Two major design issues for this class of vehicle are the staging maneuver and the booster glideback. For the staging maneuver analysis, a technique was developed that provides for a successful separation of the booster from the orbiter over a wide range of staging angles of attack. A longitudinal flight control system was developed for control of the booster during the staging maneuver. For the booster glide back analysis, a guidance algorithm was developed that successfully guides the booster from the completion of the staging maneuver to a launch site runway while encountering many off-nominal atmospheric, aerodynamic, and staging conditions

Elemental Distribution in Bone Impacted by Bacterial Diseases

Previous work, by this and other authors, noted several elements in bones and teeth are distributed non-uniformly. It was theorized that elemental distributions may be accentuated in the case of bacterial infections. Regions of bone surrounding Dental Abscess and Tuberculosis lesions were identified from, Varden (AdHa-1) and LeVesconte, Ontario; San Pedro, Belize and Kellis II Cemetery, Egypt. The abscess cavities were excised intact and cross-sectioned through the identified lesion. Elemental distributions in the bones were obtained using Synchrotron X-ray Fluorescence mapping. Maps of Zinc, Copper, Iron and Bromine were collected from the samples. The elements included in this study displayed no correlation between distribution patterns and the presence of a dental abscess. This conclusion is limited to the elements studied. Other elements or possible effects on bone structure, crystallinity or elemental chemistry will need to be addressed in future work. However, it was found that Zinc concentration correlates with active bone formation areas

Understanding the Barriers to Carbon Farming on Private Lands

Climate change caused by manmade greenhouse gas emissions is one of the most important challenges facing society today. Through effective management for carbon sequestration private agricultural lands could become an important part of the solution to this problem. This paper explores the many different methods that farmers, ranchers, and landowners could use to implement sequestration on their land and examines the barriers to further participation in these projects by reviewing the challenges in the world’s current carbon offset markets and offering possible solutions

NASA Global Hawk: A New Tool for Earth Science Research

Scientists have eagerly anticipated the performance capability of the National Aeronautics and Space Administration (NASA) Global Hawk for over a decade. In 2009 this capability becomes operational. One of the most desired performance capabilities of the Global Hawk aircraft is very long endurance. The Global Hawk aircraft can remain airborne longer than almost all other jet-powered aircraft currently flying, and longer than all other aircraft available for airborne science use. This paper describes the NASA Global Hawk system, payload accommodations, concept of operations, and the first scientific data-gathering mission: Global Hawk Pacific 2009

Performance of a circular body earth-to-orbit winged transport with various strap-on boosters

Various types of twin strap-on boosters were evaluated by applying them to a core vehicle. The core vehicle has a clipped delta wing and a simple circular body, and is equipped with five Space Shuttle main engines. The only propellants in the core vehicle are liquid oxygen and liquid hydrogen. The strap-on boosters investigated include the current Shuttle solid rocket motors with steel cases and advanced solids with graphite composite filament-wound cases. Also, two types of liquid-oxygen/hydrocarbon boosters were investigated - one pair without crossfeed to the core vehicle and one with. The payloads obtained were tabulated for various assumptions, such as power levels on the core vehicle engines, number of engines, and maximum allowable flight dynamic pressures. The payload for the core vehicle with two filament-wound Shuttle solid rocket strap-on boosters was 83,000 lb and the payload for two liquid strap-ons with crossfeed was 84,000 lb. The core vehicle with Shuttle solid rocket strap-on boosters is regarded as a near term technology system

NASA Global Hawk: A Unique Capability for the Pursuit of Earth Science

For more than 2 years, the NASA Dryden Flight Research Center has been preparing for the receipt of two Advanced Concept Technology Demonstration Global Hawk air vehicles from the United States Air Force. NASA Dryden intends to establish a Global Hawk Project Office, which will be responsible for developing the infrastructure required to operate this unmanned aerial system and establishing a trained maintenance and operations team. The first flight of a NASA Global Hawk air vehicle is expected to occur in 2008. The NASA Global Hawk system can be used by a variety of customers, including U.S. Government agencies, civilian organizations, universities, and state governments. A combination of the vehicle s range, endurance, altitude, payload power, payload volume, and payload weight capabilities separates the Global Hawk unmanned aerial system from all other platforms available to the science community

The mission oriented terminal area simulation facility

The Mission Oriented Terminal Area Simulation (MOTAS) was developed to provide an ATC environment in which flight management and flight operations research studies can be conducted with a high degree of realism. This facility provides a flexible and comprehensive simulation of the airborne, ground-based and communication aspects of the airport terminal area environment. Major elements of the simulation are: an airport terminal area environment model, two air traffic controller stations, several aircraft models and simulator cockpits, four pseudo pilot stations, and a realistic air-ground communications network. MOTAS has been used for one study with the DC-9 simulator and a series of data link studies are planned in the near future

Berlin Re-Visited: Nikita Khrushchev's Influence in the American Pressroom

Existing research suggests that in most cases, foreign elites hold influence over the domestic media coverage of international crises only when they are considered to be hostile. This is unsurprising, as it is often their hostile rhetoric that drives the events of the crisis. Thus far, however, there has been no distinction made between the various types of rhetoric these hostile leaders engage in, or how different categories of statements might have different degrees of influence on domestic media coverage. For example, might these foreign leaders’ more benign public utterances, that do not change the status quo of a crisis, still have an impact on how salient the press views the issue? This study attempts to fill this gap. Specifically, I study the influence of the non-status-quo-changing statements of Soviet Premier Nikita S. Khrushchev on American media coverage of the Berlin Crisis of 1958-1960. This period was selected as a case study for the following reasons: (1) U.S. President Dwight D. Eisenhower displayed a strong reticence to publicly commit to a specific course of action, largely forgoing his role as president to guide policy discourse at the outset of the crisis, (2) Premier Khrushchev was viewed in the American media as being the ultimate voice in the formation of Soviet foreign policy, giving him outsized influence on the direction of the crisis, and (3) the historical memory of the Berlin blockade of 1948-1949 predisposed the American media to pay attention to the crisis and view it as urgent. An analysis of New York Times articles was conducted and suggests that Khrushchev’s non-status-quo-changing “propaganda” did have some influence on how salient the crisis was in the news; however, this influence was only seen during periods of high tension, suggesting that these effects are conditional on the media’s preexisting levels of interest