Van Romero (New Mexico Institute of Mining and Technology), William H. Ryan (Magdalena Ridge Observatory, New Mexico Institute of Mining and Technology), Eileen V. Ryan (Magdalena Ridge Observatory, New Mexico Institute of Mining and Technology)
Keywords: NROC, Non-resolved Object Characterization
Abstract:
A space object’s general characteristics can be substantially influenced by changes in the magnetosphere, ionosphere, and thermosphere environments. These space weather effects can vary according to the space object’s orbit, position relative to certain regions in space, the severity of solar activity, and many other factors. Outcomes can range from minor and easily recoverable to total breakdown. Further, technology has advanced such that satellite components have become smaller and smaller, and these micro-systems are increasingly more susceptible to the highly energetic solar particles associated with intense activity. Therefore, additional study of the significance of space weather events on Earth-orbiting objects would be beneficial.
A rotating rocket body in orbit experiences a magnetic torque due to the Earth’s magnetic field that results in an exponential decay of its rotational frequency and a variation on the axis of rotation. The Photometric Periods of Artificial Satellites (McCants, 2007) database consists of over 60,000 period measurements, mostly visually acquired, dating back to 1958. Although this database validates this predicted exponential decay in rotation rate, many anomalies have been observed, including increased rotational frequencies. Theories for the causes of these anomalies range from leaking fuel tanks to interaction with the local space environment.
Our program aims to complement the current visual database through CCD and video photometric observations of rotating rocket bodies using a portable 0.35-meter telescope and the Magdalena Ridge Observatory’s 2.4-meter telescope. The goal is to generate a detailed astrometric and photometric database for a small set of targets at different orbital altitudes in order to study the variability in orbital motion and the rotational angular momentum vector, particularly during times of high solar activity. The National Oceanic and Atmospheric Administration (NOAA) provides daily information and forecasts of solar variations, so correlation of ground-based observations with enhanced periods of activity is immanently feasible. By studying these effects for the somewhat simplistic case of a rocket body, we hope to provide the necessary data required to predict the effects on working satellites of a more complex shape.
%Z McCants, M., PPAS Database. http://www.io.com/~mmccants/bwgs/index.html
Date of Conference: September 12-15, 2007
Track: Non-resolved Object Characterization