Navigation/traffic control satellite mission study. Volume 3 - System concepts

Satellite network for air traffic control, solar flare warning, and collision avoidanc

Mirror formation control in the vicinity of an asteroid

Two strategies are presented for the positioning and control of a spacecraft formation designed to focus sunlight onto a point on the surface of asteroid, thereby sublimating the material and ejecting debris creating thrust. In the first approach, the formation is located at artficial equilibrium points around the asteroid and controlled using the force from the solar radiation pressure. The second approach determines the optimal periodic formation orbits, subject to the gravitational perturbations from the asteroid, the solar radiation pressure and the control acceleration derived from a control law

Advanced dosimetry systems for the space transport and space station

Advanced dosimetry system concepts are described that will provide automated and instantaneous measurement of dose and particle spectra. Systems are proposed for measuring dose rate from cosmic radiation background to greater than 3600 rads/hr. Charged particle spectrometers, both internal and external to the spacecraft, are described for determining mixed field energy spectra and particle fluxes for both real time onboard and ground-based computer evaluation of the radiation hazard. Automated passive dosimetry systems consisting of thermoluminescent dosimeters and activation techniques are proposed for recording the dose levels for twelve or more crew members. This system will allow automatic onboard readout and data storage of the accumulated dose and can be transmitted to ground after readout or data records recovered with each crew rotation

Solar array electrical performance assessment for Space Station Freedom

Electrical power for Space Station Freedom will be generated by large Photovoltaic arrays with a beginning of life power requirement of 30.8 kW per array. The solar arrays will operate in a Low Earth Orbit (LEO) over a design life of fifteen years. This paper provides an analysis of the predicted solar array electrical performance over the design life and presents a summary of supporting analysis and test data for the assigned model parameters and performance loss factors. Each model parameter and loss factor is assessed based upon program requirements, component analysis, and test data to date. A description of the LMSC performance model, future test plans, and predicted performance ranges are also given

Delta launch of the TELESAT-G mission

Launch and deployment characteristics for the TELESAT-G (Anik-D) communications satellite are provided

Illuminance and luminance distributions of a prototype ambient illumination system for Space Station Freedom

Preliminary results of research conducted in the late 1970's indicate that perceptual qualities of an enclosure can be influenced by the distribution of illumination within the enclosure. Subjective impressions such as spaciousness, perceptual clarity, and relaxation or tenseness, among others, appear to be related to different combinations of surface luminance. A prototype indirect ambient illumination system was developed which will allow crew members to alter surface luminance distributions within an enclosed module, thus modifying perceptual cues to match crew preferences. A traditional lensed direct lighting system was compared to the prototype utilizing the full-scale mockup of Space Station Freedom developed by Marshall Space Flight Center. The direct lensed system was installed in the habitation module with the indirect prototype deployed in the U.S. laboratory module. Analysis centered on the illuminance and luminance distributions resultant from these systems and the implications of various luminaire spacing options. All test configurations were evaluated for compliance with NASA Standard 3000, Man-System Integration Standards