Technology Evolution and Innovation in Spacecraft Communications

International Space Station: The Next Space Marketplace, 2000

During the past five years, using NASA's Advanced Communications Technology Satellite (ACTS), a group of NASA and industry participants have performed a series of experiments focusing on the interoperability of TCP lIP, ATM, and higher layer protocols and applications. These experiments have yielded very exciting results, including pro-forma configurations in the following areas: TCP lIP data transfer over geostationary satellite delays at speeds exceeding 500 Megabits per second using standard network hardware, computers, and operating systems Video, audio, and telephony over satellite links using ATM to engineer links with a constant Quality of Service for these time-sensitive applications Security overlays featuring encryption and IP firewalls at up to 155 Megabits per second Mobile satellite terminals that operate on ships, trucks, aircraft, and (eventually) spacecraft. This paper describes a proposed communications payload for the International Space Station, which supports the use of commodity industry-standard communications protocols to support direct user access to science instruments and experiment payloads from the ground. The payload concept, which is based entirely on commercial off-the-shelf products, was developed as a result of the five-year ACTS experiments program. 195

IEEE Communications Magazine, 1999

Satellite and Space Communications (SSC) Committee has provided a forum for technical interchange T" among those working in this field for nearly 40 years. It began in the early 1960s soon after it was recognized that the rocket capabilities demonstrated by the Soviet Union and United States in the late 1950s could readily be used to launch communications satellites. From that time, the development and impact of satellite communications has been revolutionary. In the early days, the major activity was associated with business, political and technical issues associated with the development and introduction of the first communications satellites. The technical community was occupied with the tradeoff studies associated with satellite orbits, frequency bands, and link design. However, the first communications satellites came along quickly with low earth orbit launches of Telstar and Relay in 1962, the first synchronous orbit satellite, Syncom, in 1963, and the launch of INTELSAT 1 and MOLNIYA 1 in 1965. Since that time, the field of satellite communications has continued to grow rapidly. Satellites have become dramatically larger, capable of increased capacity and employing rapidly developing light weight electronics technology, spacecraft control, and power generation and storage devices. Significant development went into sophisticated space-borne regional and spot-beam dual polarized antennas at both C-and Ku-band to increase payload capacity through frequency reuse techniques. Next, Very Small Aperture Terminal (VSAT) networks and applications, and direct broadcast satellite systems and technologies, were introduced. Quickly, the exploitation of the Ka-band frequencies for future growth became an important topic within the satellite communications community. During the 1970s and 1980s, major engineering efforts were devoted to the development of higher power amplifiers, lighter weight, improved performance microwave filters and circuit switches, and electric power generation and storage devices, which contributed to larger communications satellite payloads that fit the launch constraints of available launch vehicles. Eventually, systems that provide communications services to mobile terminals (e.g., ships, land vehicles, and aircraft) were developed. These systems exploited one of the major attributes of communications satellites, i.e., the capability to offer wireless services over a large service area. Today, communications satellites carry about one-third of voice and essentially all international television traffic. Significant advances in video compression and data protocol enhancement technology have made new and many previously

2000

The aerospace environment imposes straight operative conditions so every electronic system usually needs to be validated for these. The same way, communication systems need to be evaluated before their introduction in aerospace applications. In the paper we present a new methodology for the evaluation of communication systems in space applications. The methodology aims, by abstraction, at identifying all the critical aspects for the evaluation and at defining a standard and reusable framework in order to be applicable to any Communication Systems. The methodology has been applied for the evaluation of three Data Bus for satellite communications: 1553, 1-Wire and Profibus DP RS 485 based systems have been analyzed and evaluated 1 .

1994

This is a system description of the Naval Space Command (NAVSPACECOM) Space Surveillance Sensor System Digital Signal Processing Receiver (DSPR). Formerly known as NAVSPASUR, the Space Surveillance system began as an advanced research project in June 1958, was commissioned as an operational Naval command in February 1961, and is operated by NAVSPACECOM's Space Surveillance Processing Center in Dahlgren, Virginia. The DSPR is a real-time radar data acquisition and analysis system. Its function is to detect, with no prior information, all space objects whose orbits cross the continental United States and to compute their subsequent orbits. It provides vital satellite information in support of national defense mission objectives of space intelligence, satellite attack warning, satellite intercept support, and space mission support. This system description was prepared as part of a modernization program that has replaced DSPR hardware for which parts are no longer available. Volume 3 describes the operating system functions required by the applications software. Volume 4 describes the hardware interfaces between the major subsystems of the DSPR and identifies critical timing paths and interrupts between subsystems. Previously published, Volume 1 (NRL/FR/8154-93-9577) presents an overview of the hardware and software of the DSPR system, and Volume 2 (NRL/FR/8154-93-9578) discusses the function and capabilities of individual software and hardware components of each subsystem.

1997

Within the next few years the emergence of satellite-based personal communication networks operating from small low earth orbits to geostationary orbits offers viable solutions for contacts between two points on Earth. The idea is to use the same networks for communications links between small satellites and their ground stations. Will it be possible to call a satellite from a PC, e.g., like an answering machine from a phone? The paper presents concepts for the transfer of data between ground stations and low Earth orbiting small (scientific) satellites via a) commercial satellite-based communication networks, e.g. IRIDIUM, ORBCOMM, GLOBAL STAR, SIGNAL and b) geostationary communication satellites, e.g. INMARSAT. The potentialities which lie in these concepts will be discussed. Operational and technical constraints will be pointed out. The results are the outputs of a study sponsored by the German Space Agency DARA to analyze the potential of cost reduction in mission operations for small satellites as part of its effort to reduce the overall mission cost.

Satellite Systems - Design, Modeling, Simulation and Analysis [Working Title], 2020

The objective of this chapter is to provide a comprehensive end-to-end overview of existing communication subsystems residing on both the satellite bus and payloads. These subsystems include command and mission data handling, telemetry and tracking, and the antenna payloads for both command, telemetry and mission data. The function of each subsystem and the relationships to the others will be described in detail. In addition, the recent application of software defined radio (SDR) to advanced satellite communication system design will be looked at with applications to satellite development, and the impacts on how SDR will affect future satellite missions are briefly discussed.

It is difficult to implement electronic mail and computer conferencing in areas where no public data networks exist. Even where the PDNs do exist, these systems can benefit from the use of more appropriate communication techniques. The use of an inexpensive communication satellite in a low-level orbit (100-5000 kms high), operating a relatively narrow band transceiver (offering 64 Kbps to 256 Kbps of throughput) is proposed. It would employ a frequency below 3000 MHz to enable the use of antennas with low directivity and low cost direct reception equipment on the ground. The satellite would carry an on-board computer. Polling ground stations, it would collect and store messages, which it would distribute around the world. The proposed satellite is promising for use in modern forms of telegraphy particularly relevant to the developing world.

Acta Astronautica, 2002

Broadcasting Satellite Systems (BSS) have experienced a constant growth in the last years. Nowadays the traditional concept of broadcasting networks as distributors of passive content to the end user is deeply changing toward the more challenging large-scale provision of interactive multimedia services. The paper will present the more likely trends in emerging Satellite Broadcasting Missions addressing the impact of new requirements on system architectures.

… of the International MultiConference of Engineers …, 2008

Satellite Communication is one of the most impressive spin-offs from the space programmes and has made a major contribution to, indeed totally altered, the patterns of International communication. Communication by satellite evolved from the simple technology of "Early Bird" to the highly sophisticated present-day satellites" [1]. The potential of the outer space as a communication hub is great and at the heart of this is the satellite. This paper aims at developing a micro-satellite, which can be used for educational purposes as well as a stepping stone for further complex developments. Data from this satellite will be formatted on the basis of the CCSDS (Consultative Committee for Space Data Systems) standards before transmission. We will also highlight one of the simplest designs of the micro satellite CanSat (Satellite in a can) at university level with most cheaply and easily available resources ever highlighted for the Space Education in Asia.

1990

A prototype integrated environment, the Advanced Satellite Workstation (ASW), which was developed and delivered for evaluation and operator feedback in an operational satellite control center, is described. The current ASW hardware consists of a Sun Workstation and Macintosh II Workstation connected via an ethernet Network Hardware and Software, Laser Disk System, Optical Storage System, and Telemetry Data File Interface. The