Engineering topics

Roberts, Barry C.

Publications and source records attributed to Roberts, Barry C..

27 records · Page 2

NASA NTRS2004

Strong Updraft Feature Associated with Hurricane Earl During Landfall

On 2-3 September 1998 hurricane Earl made landfall along the Gulf of Mexico coast, east of Panama City, FL. The University of Alabama in Huntsville Mobile Integrated Profiling System (MIPS) was located at the airport in Tallahassee, FL and made measurements of Earl with a 915 MHz Doppler wind profiler as the system moved across the Florida panhandle. As the center of Earl approached MIPS, a particularly strong updraft feature, having a magnitude of approx. 15 m/s within the lowest 3.0 km above ground level was associated with a rain band. An analysis of the changes hurricane Earl underwent as it made landfall are presented. Measurements used include surface thermodynamic and pressure observations, lightning data, National Weather Service Doppler Weather Surveillance Radar (WSR-88D) data, and Geostationary Earth Orbiting Satellite (GOES) data. Then an analysis focusing on the boundary layer properties and the updraft feature's depth, intensity and duration as measured by the MIPS 915 MHz Doppler wind profiler are presented.

Roberts, Barry C.↗

NASA NTRS2002

Natural Atmospheric Environment Model Development for the National Aeronautics and Space Administration's Second Generation Reusable Launch Vehicle

The National Aeronautics and Space Administration (NASA) recently began development of a new reusable launch vehicle. The program office is located at Marshall Space Flight Center (MSFC) and is called the Second Generation Reusable Launch Vehicle (2GRLV). The purpose of the program is to improve upon the safety and reliability of the first generation reusable launch vehicle, the Space Shuttle. Specifically, the goals are to reduce the risk of crew loss to less than 1-in-10,000 missions and decreased costs by a factor of 10 to approximately $1,000 per pound of payload launched to low Earth orbit. The program is currently in the very early stages of development and many two-stage vehicle concepts will be evaluated. Risk reduction activities are also taking place. These activities include developing new technologies and advancing current technologies to be used by the vehicle. The Environments Group at MSFC is tasked by the 2GRLV Program to develop and maintain an extensive series of analytical tools and environmental databases which enable it to provide detailed atmospheric studies in support of structural, guidance, navigation and control, and operation of the 2GRLV.

Roberts, Barry C.↗

NASA NTRS2002

Reference and Standard Atmosphere Models

This paper describes the development of standard and reference atmosphere models along with the history of their origin and use since the mid 19th century. The first "Standard Atmospheres" were established by international agreement in the 1920's. Later some countries, notably the United States, also developed and published "Standard Atmospheres". The term "Reference Atmospheres" is used to identify atmosphere models for specific geographical locations. Range Reference Atmosphere Models developed first during the 1960's are examples of these descriptions of the atmosphere. This paper discusses the various models, scopes, applications and limitations relative to use in aerospace industry activities.

Johnson, Dale L.↗

NASA NTRS2002

Atmospheric Models for Engineering Applications

This paper will review the historical development of reference and standard atmosphere models and their applications. The evolution of the U.S. Standard Atmosphere will be addressed, along with the Range Reference Atmospheres and, in particular, the NASA Global Reference Atmospheric Model (GRAM). The extensive scope and content of the GRAM will be addressed since it represents the most extensive and complete 'Reference' atmosphere model in use today. Its origin was for engineering applications and that remains today as its principal use.

Johnson, Dale L.↗

NASA NTRS2000

A Comparison of the Automated Meteorological Profiling System High Resolution Flight Element to the Kennedy Space Center 50 MHz Doppler Wind Profiler

Wind profile measurement and the simulation of aerodynamic loads on a launch vehicle play an important role in determining launch capability and post launch assessment of the vehicle's performance. To date, all United States range certified wind profile measurement systems have been based on balloon tracking. Since the 1960's, the standard used by the National Aeronautics and Space Administration and the Air Force at the Cape Canaveral Air Station (CCAS) for detailed wind profile measurements has been the radar tracked, aerodynamically stabilized Jimsphere balloon system. Currently, the Air Force is nearing certification and operational implementation of the Automated Meteorological Profiling System (AMPS) at CCAS and Vandenburg Air Force Base (VAFB). AMPS uses the Global Positioning System for tracking the Jimsphere balloon. It is anticipated that the AMPS/Jimsphere, named the High Resolution Flight Element (HRFE), will have equivalent, or better resolution than the radar tracked Jimsphere, especially when the balloon is far downrange, at a low elevation angle. By the 1980's, the development of Doppler Wind Profilers (DWP) had become sufficiently advanced to justify an experimental measurement program at Kennedy Space Center (KSC). In 1989 a 50 MHz DWP was installed at KSC. In principal, the 50 MHz DWP has the capability to track the evolution of wind profile dynamics within 5 minutes of a launch. Because of fundamental differences in the measurement technique, there is a significant time and space differential between 50 MHz DWP and HRFE wind profiles. This paper describes a study to quantify these differences from a sample of 50 MHz DWP/HRFE pairs obtained during the AMPS certification test program.

Roberts, Barry C.↗

NASA NTRS1997

Current Activities and Capabilities of the Terrestrial Environment Group at NASA's Marshall Space Flight Center

The National Aeronautics and Space Administration (NASA) designated Marshall Space Flight Center (MSFC) the center of excellence for space transportation. The Aerospace Environments and Effects (AEE) team of the Electromagnetics and Aerospace Environments Branch (EL23) in the Systems Analysis and Integration Laboratory at MSFC, supports the center of excellence designation by providing near-Earth space, deep space, planetary, and terrestrial environments expertise to projects as required. The Terrestrial Environment (TE) group within the AEE team maintains an extensive TE data base. Statistics and models derived from this data are applied to the design and development of new aerospace vehicles, as well as performance enhancement of operational vehicles such as the Space Shuttle. The TE is defined as the Earth's atmospheric environment extending from the surface to orbital insertion altitudes (approximately 90 km).

Roberts, Barry C.↗

NASA NTRS1992

Sorbent-Bed Crop-Drying System

Proposed aeration system helps reduce spoilage of stored grain or other crop stored in bulk. Air circulates through bin, sorbent bed, and heat exchanger. Outside air cools circulating air in heat exchanger. Sensors measure temperature and humidity, and adjust dampers to obtain requisite temperature and humidity. Suitable for grain bins and shipping barges.

Roberts, Barry C.↗

NASA NTRS1990

Phase III Simplified Integrated Test (SIT) results - Space Station ECLSS testing

During 1989, phase III testing of Space Station Freedom Environmental Control and Life Support Systems (ECLSS) began at Marshall Space Flight Center (MSFC) with the Simplified Integrated Test. This test, conducted at the MSFC Core Module Integration Facility (CMIF), was the first time the four baseline air revitalization subsystems were integrated together. This paper details the results and lessons learned from the phase III SIT. Future plans for testing at the MSFC CMIF are also discussed.

Roberts, Barry C.↗

NASA NTRS1990

Facility for generating crew waste water product for ECLSS testing

An End-use Equipment Facility (EEF) has been constructed which is used to simulate water interfaces between the Space Station Freedom Environmental Control and Life Support Systems (ECLSS) and man systems. The EEF is used to generate waste water to be treated by ECLSS water recovery systems. The EEF will also be used to close the water recovery loop by allowing test subjects to use recovered hygiene and potable water during several phases of testing. This paper describes the design and basic operation of the EEF.

Buitekant, Alan↗