ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / The NASA Space-based Telemetry and Range Safety (STARS) program has developed and tested a low cost Ku-Band transmitter alternative for TDRSS applications based on an existing IRIG shaped offset quaternary phase shift keying (SOQPSK) transmitter. This paper presents information related to the implementation of this low cost system, as well as performance measurements of the alternative TDRSS transmitter system compared with an existing QPSK TDRSS transmitter.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Collecting and analyzing vehicle performance data is an essential part of the launch process. Performance data is used to determine mission success. Performance data also provides essential feedback to the launch vehicle design engineers. This feedback can be used to improve the overall vehicle design and thereby improve the probability of a successful launch. Various Telemetry products are used to gather and process critical information on board launch vehicles. Data is transmitted by RF links to fixed or mobile receiving stations. These Telemetry products are ruggedized for the extreme launch environments. This paper discusses the use of video telemetry as a means of providing launch vehicle performance data.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / An agile RF routing system has been developed which utilizes phasing techniques to direct signal power to any one of four orthogonally mounted antennae, or either set of two antennae mounted 180° apart on a launch vehicle. The system has been integrated into a telemetry transmitter and has shown superior performance to traditional methods of antennae switching. The unit is self-correcting to maintain maximum RF power at the desired antenna port(s) across a dynamic mission environment. Due to its low loss and high reliability, this method of antennae switching provides a robust RF link.

International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Consultative Committee for Space Data Systems (CCSDS) has issued a Recommendation CCSDS 401.0-B for Radio Frequency and Modulation Systems to be used in Earth stations and spacecraft. Part of this Recommendation is a standardized design tool for link budget computations. This design tool is intended to assist spacecraft designers in preparing the power and performance designs of their spacecraft for communicating with existing standard ground stations. The present CCSDS Recommendation addresses a link design typical for that found with the Deep Space Network (DSN). DSN link analyses use a large subset of link-specific parameters not of any particular use if the space data link passes through the Tracking and Data Relay Satellite System (TDRSS). The link architecture also differs in that the TDRSS parameter set needs to include an extra link through the satellite (two-hop) link versus a DSN-type link which is single-hop. Conversely, the treatment of ranging, PN coding requirements, and TDRSS acquisition and data group formalities are either not of the same format or not present at all on the DSN-type links. The baseline CCSDS 401 design tool is a Microsoft Excel spreadsheet that can run on an IBM PC or compatible computer. This baseline spreadsheet has been modified to account for the differences between baseline CCSDS model and TDRSS link operations. The paper will discuss the modifications made to the spreadsheet for the TDRSS system details. We will also present example usages of the spreadsheet.

The NASA Space Network (SN), which consists of the geosynchronous Tracking and Data Relay Satellite (TDRS) constellation and its associated ground elements, is a critical national space asset that provides near-continuous, high-bandwidth telemetry, command, and communications services for numerous spacecraft and launch vehicles. The Space Network includes several key ground system elements, one of which is the White Sands Complex Data Interface Service Capability (WDISC). The WDISC has undergone multiple cycles of modification and technology refresh over its lifetime, making test automation an attractive option for reducing system verification and validation cost. This paper considers the implementation of automated testing for the WDISC as a case study in technology sustainment, discusses the principal benefits and challenges of implementing test automation for a legacy system, and presents findings that demonstrate the effectiveness of such automation models.

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / An S-band telemetry transmitter has been developed for Expendable Launch Vehicles (ELV's) that can downlink data through NASA's Tracking and Data Relay Satellite System (TDRSS). The transmitter operates in the 2200 to 2300 MHz range and provides a number of unique features to achieve optimum performance in the launch vehicle environment: · Commandable QPSK or BPSK modulation format. · Data rates up to 10 Mbps. · Commandable concatenated coding provides superior link performance. · Premodulation filtering produces excellent spectral containment characteristics. · Phase noise of less than 3 degrees rms is maintained through launch and ascent vibration profiles. · A 30 watt nominal RF output power provides a robust RF link. · Two RF antenna output ports with commandable selection of all power out to either port or power split evenly between ports. · Operating modes and conditions of the unit can be monitored through a number of bilevel and analog outputs. · A ruggedized mechanical design provides a reliable communications link for launch vehicle environments.

ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / The National Aeronautics and Space Administration (NASA) Space Network (SN) consists of a Space Segment, composed of the Tracking and Data Relay Satellite (TDRS) fleet, and a Ground Segment that includes the White Sands Ground Terminal (WSGT), Second TDRS Ground Terminal (STGT) and the Guam Remote Ground Terminal (GRGT). Collectively, the SN Ground Segment is commonly referred to as the White Sands Complex (WSC). Traditional methods of latency and performance measurement across the component links of network have relied on the use of simplified test patterns and basic data formats that are often specific to the instruments providing the measurements. These tests do not often correlate to the operational data normally transferred through the network. This paper discusses an alternative approach to performance measurement within the Space Network. By embedding and extracting performance metrics directly within simulated data sets that closely resemble operational traffic, performance measurement can be combined with link verification and validation to provide a single, comprehensive set of test and measurement activities.

International Telemetering Conference Proceedings / October 26-29, 1987 / Town and Country Hotel, San Diego, California / Engineering requirements and design characteristics of the coherent throughput relay system which supports East Coast pre-launch checkout of NASA's Space Shuttle and its Payloads are presented. The Relay system is required to provide communications through NASA's Tracking and Data Relay Satellite System for the Shuttle and Payload-Users while they are encapsulated in the launch preparation facilities at the John F. Kennedy Space Center and the Eastern Test Range, Florida. The Relay system is required to be transparent to its users' data at all rates up to three MB/s at S-band and 300 MB/s at Ku-band. Noise and group-delay distortion are major contributors to wide band RF signal degradation. These were major factors in the Relay system design. Antenna design, pointing angle and location were constrained by the need to maximize end-to-end RF signal isolation at both S-band and KU-band, simultaneous forward and return frequencies. System characteristics and link analysis are also presented. In addition, a similar Data Relay located at Vandenberg Air Force Base is briefly described.

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / The future of range operations in the area of expendable launch vehicle (ELV) support is unquestionably headed in the direction of space-based rather than land- or air-based assets for such functions as metric tracking or telemetry data collection. To this end, an effort was recently completed by the Air Force’s Eastern Range (ER) to certify NASA’s Tracking and Data Relay Satellite System (TDRSS) as a viable and operational asset to be used for telemetry coverage during future Titan IV/Centaur launches. The test plan developed to demonstrate this capability consisted of three parts: 1) a bit error rate test; 2) a bit-by-bit compare of data recorded via conventional means vice the TDRSS network while the vehicle was radiating in a fixed position from the pad; and 3) an in-flight demonstration to ensure positive radio frequency (RF) link and usable data during critical periods of telemetry collection. The subsequent approval by the Air Force of this approach allows future launch vehicle contractors a relatively inexpensive and reliable means of telemetry data collection even when launch trajectories are out of sight of land-based assets or when land- or aircraft-based assets are not available for support.

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The transmission of high-rate telemetry data for space-based relay systems yields unique system requirements. The NASA Space-based Telemetry and Range-Safety (STARS) study evaluated system design requirements during Phase-1 flight tests. STARS Phase-2 efforts include the development of a high-rate transmitter and antenna system to demonstrate prototype system performance capabilities and new technologies for future operational systems to be incorporated into the NASA Next Generation Launch Technology (NGLT) vehicles. Phase-2 Range User (telemetry) system performance requirements and a prototype implementation approach are presented.