SatCons 101

Learn about the fundamentals of satellites, including the history of their use, the reasons why satellites are launched, and their operational life cycles. The video describes the basic functional elements of satellites and the challenges of operating them in the harsh environment of space, as well as the kinds of orbits they inhabit. It also provides information on the ways that satellites can fail.

In this module, the theory of satellite constellations — coordinated groups of satellites with a collective function — is presented. Examples of both large and small constellations are given along with details of their uses for both communications and non-communications purposes. Uses are suggested for both military and civilian applications.

The various effects of the processes by which satellites are launched, operated and de-orbited is explored in this module. It traces the effects on the environment from launch and ascent through the atmosphere to re-entry and disposal. Failure of satellites in space and damage to them through collisions is discussed, along with the resulting hazards associated with the generation of space debris.

This is the first of two SatCons 101 modules describing the impacts of the operation of large satellite constellations on astronomy. In this module, the effects on optical and infrared astronomy in particular are presented. Examples are provided, including the presence of bright streaks in astronomical images; how satellites can affect spectroscopic observations; and the tendency of satellites and space debris to raise the diffuse brightness of the night sky. Lastly, it considers how thermal radiation from satellites and debris can harm infrared astronomy.

This second of two SatCons 101 modules describing the impacts of the operation of large satellite constellations on astronomy considers effects of satellites on the operation of radio telescopes. Topics presented include how access to the radio frequency spectrum is allocated; the phenomenon of radio frequency interference; and how the properties of radio transmitters aboard satellites can yield harmful interference to radio telescopes.

The presence of large numbers of satellites in orbit around the Earth has effects beyond their impacts to astronomy. This module discusses the cultural significance of night skies and how the presence of many bright, moving objects in our skies presents a challenge to communities that access the night sky for recreation, tourism and/or religious practice. It raises concerns about the lack of consultation with these groups in making decisions that affect the appearance of the night sky, and it presents emerging research results suggesting that satellites may even impact the activities of some wildlife species.

This module reviews the international legal framework governing the human use of outer space and the ways in which national and international laws govern the deployment and operation of satellites. It explores the way in which existing environmental laws may interact with space activities; asks whether outer space is a legal 'commons'; and considers ways in which the rights of all users of space under the law may be preserved with the goal of promoting safe and sustainable space operations.

In this module of SatCons 101, information is provided on how astronomers and commercial space operators are seeking solutions that limit the negative effects of large satellite constellations on astronomical observations. Mitigations described include accurately predicting satellite positions; image processing techniques that can 'back-correct' for the presence of satellite trails in images; altering the properties of satellites to make them less conspicuous; and the rapid and efficient disposal of satellites at the end of their service lives to prevent generating orbital debris.