Space shuttle engineering and operations support. Isolation between the S-band quad antenna and the S-band payload antenna. Engineering systems analysis

The isolation between the upper S-band quad antenna and the S-band payload antenna on the shuttle orbiter is calculated using a combination of plane surface and curved surface theories along with worst case values. A minimum value of 60 db isolation is predicted based on recent antenna pattern data, antenna locations on the orbiter, curvature effects, dielectric covering effects and edge effects of the payload bay. The calculated value of 60 db is significantly greater than the baseline value of 40 db. Use of the new value will result in the design of smaller, lighter weight and less expensive filters for S-band transponder and the S-band payload interrogator

Limitations on Ku-band communications due to multipath

The earth and orbiter body reflections involving the Tracking Data Relay Satellite (TDRS)/orbiter communications link are evaluated. Recommendations address operational conditions in order to avoid critical multipath impacts, modulation preferences during acquisition, and preferred scan limit implementation

An analysis of point-to-point communication for application to the lunar flyer program

Determining optimum frequency for point-to-point communication in vicinity of line-of-sight horizon on lunar surfac

Flexible blade antenna Patent

Flexible monopole antenna with broad bandwidth and low voltage standing wave rati

Shuttle orbiter S-band quad antenna switching evaluation

Automatic switching of the shuttle orbiter S-band quad antennas by the orbiter on-board computers was evaluated. The development and use of an extensive computer program to determine antenna switch position states as a function of time for various orbital activities is described. The selection of the optimum quad antenna element at any given time is based on the look angle to the appropriate Tracking Data Relay Satellite (TDRS). It is shown that a 2.4 second period is required for updating the S-band quad antenna switch state based on a maximum roll rate of 2 deg per second. The possibility of a variable update period is suggested since the 2 deg per second attitude rate is seldom encountered and would, for example, dictate approximately 248,000 on-board computer calculations during Reference Mission 2. The average number of antenna switch state changes was found to be in the range of 1,300 for Reference Mission 2

Shuttle orbiter C-band beacon antenna location study

A recommendation for the location of the Space Shuttle C-Band Beacon Antenna(s) to be used during Approach and Landing Tests was made. The study has included an Orbiter-to-ground radar look angle evaluation, a vehicle shadowing evaluation and extensive 1/10-scale antenna pattern measurements. Locations were limited to the cutouts for the S-Band Quads and Hemis to minimize skin perturbation. The results show that a single C-Band Antenna located in the lower Hemi cutout will provide optimum coverage and eliminate the need for switching and the undesirable interferometer effects of two antennas

Tourists’ and Residents’ Values for Maintaining Working Landscapes of the ‘Old West’

The value of agricultural landscapes to tourists and local residents is not captured in the marketplace. Landowners provide stewardship over these valuable landscape attributes, but do not receive any ‘uncaptured’ value. Through real estate markets, it is easy to reveal the value of converting landscapes, but less easy to understand the value of not converting them. Redistributive policies have the potential to provide incentives to landowners to act on behalf of these other stakeholders by lowering the opportunity cost of (raising the returns to) open lands stewardship. This article will examine this issue for a rural county in Colorado. Tourist and resident demographics and travel behavior will be identified. The value of ranch open space that currently is not reflected in the market will be estimated and further discussed in terms of its implications for the local economy. Policy implications for the local decision makers to capture this currently ‘uncaptured’ value of ranch open space will be briefly explored

Astronaut space suit communication antenna

Astronaut space suit communication antenna consists of a spring steel monopole in a blade-type configuration. This antenna is mounted in a copper cup filled with a potting compound that is recessed in the center to facilitate bending the blade flat for stowing when not in use

Submillimeter observations of solar limb-brightening in the total solar eclipse of 31 July 1981

Eight flights of the Kuiper Airborne Observatory (KAO) were devoted to solar observation. The successful observation of a total solar eclipse was accomplished. The observations were made simultaneously at 30, 50, 100, and 200 microns. The successful adaptation of the KAO for solar observations thus provided the most detailed data to date in this spectral band. The results from a preliminary analysis of the KAO data are summarized: (1) the 200 micron limb is extended about 3 arc sec above the 30 micron limb, indicating the prescence of cool dense material up to the altitudes of spicules; (2) strong radial darkening of the quiet sun intensity profile appeared at 200 microns, probably an indication that hot material in the low chromosphere is recessed into vertical magnetic flux tubes embedded in a cooler nonmagnetic substrate, which obscures the heated material approaching the limb; (3) active regions were observed to undergo a strong increase in contrast above the quiet sun background at wave lengths of 100 microns and longer; and (4) the moon was mapped for use as a photometric standard for determining the absolute intensity of the sun in all four wavelength bands