Hypersonic Research Vehicle (HRV) real-time flight test support feasibility and requirements study. Part 2: Remote computation support for flight systems functions

The requirements are assessed for the use of remote computation to support HRV flight testing. First, remote computational requirements were developed to support functions that will eventually be performed onboard operational vehicles of this type. These functions which either cannot be performed onboard in the time frame of initial HRV flight test programs because the technology of airborne computers will not be sufficiently advanced to support the computational loads required, or it is not desirable to perform the functions onboard in the flight test program for other reasons. Second, remote computational support either required or highly desirable to conduct flight testing itself was addressed. The use is proposed of an Automated Flight Management System which is described in conceptual detail. Third, autonomous operations is discussed and finally, unmanned operations

Store-and-Forward Message Relay using Microsatellites: The UoSAT-3 PACSAT Communications Payload

One of the most promising applications for small satellites in the 10-50 kg class is store-and-forward message relay. A single store-and-forward message relay satellite in a polar orbit can provide a global communications network carrying electronic mail, digitized voice, images or computer data. With appropriate choice of link characteristics, small, low cost ground terminals can be used. When designing an inexpensive microsatellite system to provide store-and-forward communications to small ground terminals, the engineer must challenge the standard assumptions made concerning such things as link frequency, modulation techniques, error-control, and multiple-access arbitration. Beginning with experiments on its UoSAT-2 satellite, the Spacecraft Engineering Research Unit at the University of Surrey (UK) - in collaboration with AMSAT and VITA - has been investigating store-and-forward communications using microsatellites. The UoSAT-2 store-and-forward transponder used a relatively slow 8-bit CPU with only 96 kbytes of message store, but it has been used by stations world-wide, demonstrating system feasibility. The latest experiments undertaken by Surrey will qualify a commercial-capacity microsatellite store-and-forward system. The onboard transponder is based on a 8-MHz, 16-bit, 80C186 CPU, multitasking operating software and 4 Mbytes of RAM message store. The UoSAT/SST modular microsatellite bus provides 9600 baud FSK communications links and other support facilities for the store and forward mission. This payload was launched on the UoSAT-3 satellite in January 1990, and is now successfully operating in orbit

Adaptability of a Catalog Spacecraft Bus to Diverse Science Missions

Over the past decade, the concept of using “offthe- shelf” Spacecraft (SC) buses for space science and earth science missions has become widespread. A “common bus” design approach has been used for Geosynchronous (GEO) communications satellites since the early 1970’s. The success of using common bus designs for the manufacture of GEO communications satellites is due to the commonality of mission requirements and orbit geometry. Science missions, on the other hand, each have unique mission and instrument payload requirements that can vary widely, encompassing orbit geometry, instrument type and configuration, science target, SC attitude, operations concept, and launch scenario. One of the most visible and successful implementations of “off-the-shelf” SC for science applications is the NASA Goddard Space Flight Center (GSFC) Rapid Spacecraft Development Office (RSDO) catalog, first released in 1997. In the current catalog (Rapid II), there are twenty-three different SC buses manufactured by eight aerospace companies. This paper provides a case study describing the adaptation of Spectrum Astro’s SA-200HP (High Performance) RSDO catalog SC bus to two very different Low Earth Orbiting (LEO) science missions, Coriolis and Swift, which were both procured via the RSDO. Coriolis is a Department-of-Defense-sponsored sunsynchronous earth observation satellite whose primary instrument, WindSat, is designed to precisely measure the ocean surface wind vector. Swift is a low inclination NASA Medium Explorer (MIDEX) mission to detect and characterize Gamma Ray Bursts (GRBs). The Swift Observatory carries three separate telescopes. In addition to describing how the catalog SC bus was applied to these missions, this paper discusses the unique features and benefits of the catalog bus approach to both the procuring agency and the industry bus provider. Misconceptions associated with the use of the catalog bus approach are also discussed

Spacecraft design project: Low Earth orbit communications satellite

This is the final product of the spacecraft design project completed to fulfill the academic requirements of the Spacecraft Design and Integration 2 course (AE-4871) taught at the U.S. Naval Postgraduate School. The Spacecraft Design and Integration 2 course is intended to provide students detailed design experience in selection and design of both satellite system and subsystem components, and their location and integration into a final spacecraft configuration. The design team pursued a design to support a Low Earth Orbiting (LEO) communications system (GLOBALSTAR) currently under development by the Loral Cellular Systems Corporation. Each of the 14 team members was assigned both primary and secondary duties in program management or system design. Hardware selection, spacecraft component design, analysis, and integration were accomplished within the constraints imposed by the 11 week academic schedule and the available design facilities

Technologies and methods employed to design a university-class microsatellite, according to ESA Standards

The objective of this thesis is the study of the applicability of ESA (European Space Agency) standards to university-class microsatellites missions. At the same time the university microsatellite design technologies used to manufacture EduSAT spacecraft have been investigated in depth and ESA standards have been applied during the EduSAT mission phases. Afterwards a micro satellite optical payload for in-orbit space environment monitoring has been designed, exploiting useful instruments provided by ESA ECSS (European Cooperation for Space Standardization) standards

Diwata-2: Earth Observation Microsatellite with a Compact Bus System, ElectronicallyTunable Multi-spectral Imager, and Amateur Radio Communications Capability

The microsatellite Diwata-2 was launched into the 600-km Sun-Synchronous Orbit (SSO) last October 29, 2018. It has a low-power, low-complexity, compact bus structure, capable of Earth observation and remote sensing mission through a 5-meter resolution Near-Infrared (NIR) High Precision Telescope (HPT) and a 125-meter resolution Space-borne Multispectral Imager (SMI) with two Liquid Crystal Tunable Filters (LCTF). The LCTF operates as an electronic-based band reconfiguration filter allowing for more than 600-channels of wavelength variation. As a secondary mission, Diwata-2 has full-duplex FM voice communications capability via a non-board module utilizing the amateur radio band at a 5W power requirement from mobile ground users. The structure has a 500-mm cubic external dimension, with JAXA’s Payload Attached Fairing (PAF) rocket interface and deployment mechanism. Deployable solar array panels (DSAP) were also introduced to increase the power generation capabilities of the microsatellite. The importance of detailed structural-mechanical models for finite-element analysis allowed for accurate structural simulation results. The observed accuracy is within 5-Hz for the first two modes compared to the actual vibration test results. Lastly, strict management of in-flight procedures allowed for consistent satellite performance, while modification of satellite maneuver based on imaging observation results improved target pointing accuracy to within 5-km

Mission Information and Test Systems Summary of Accomplishments, 2011

This annual report covers the activities of the NASA DRFC Mission Information and Test Systems, which includes the Western Aeronautical Test Range, the Simulation Engineering Branch, the Information Services and the Dryden Technical Laboratory (Flight Loads Lab). This report contains highlights, current projects and various awards achieved during in 201

Economically sustainable public security and emergency network exploiting a broadband communications satellite

The research contributes to work in Rapid Deployment of a National Public Security and Emergency Communications Network using Communication Satellite Broadband. Although studies in Public Security Communication networks have examined the use of communications satellite as an integral part of the Communication Infrastructure, there has not been an in-depth design analysis of an optimized regional broadband-based communication satellite in relation to the envisaged service coverage area, with little or no terrestrial last-mile telecommunications infrastructure for delivery of satellite solutions, applications and services. As such, the research provides a case study of a Nigerian Public Safety Security Communications Pilot project deployed in regions of the African continent with inadequate terrestrial last mile infrastructure and thus requiring a robust regional Communications Satellite complemented with variants of terrestrial wireless technologies to bridge the digital hiatus as a short and medium term measure apart from other strategic needs. The research not only addresses the pivotal role of a secured integrated communications Public safety network for security agencies and emergency service organizations with its potential to foster efficient information symmetry amongst their operations including during emergency and crisis management in a timely manner but demonstrates a working model of how analogue spectrum meant for Push-to-Talk (PTT) services can be re-farmed and digitalized as a “dedicated” broadband-based public communications system. The network’s sustainability can be secured by using excess capacity for the strategic commercial telecommunication needs of the state and its citizens. Utilization of scarce spectrum has been deployed for Nigeria’s Cashless policy pilot project for financial and digital inclusion. This effectively drives the universal access goals, without exclusivity, in a continent, which still remains the least wired in the world

Experiments applications guide: Advanced Communications Technology Satellite (ACTS)

This applications guide first surveys the capabilities of the Advanced Communication Technology Satellite (ACTS) system (both the flight and ground segments). This overview is followed by a description of the baseband processor (BBP) and microwave switch matrix (MSM) operating modes. Terminals operating with the baseband processor are referred to as low burst rate (LBR); and those operating with the microwave switch matrix, as high burst rate (HBR). Three very small-aperture terminals (VSATs), LBR-1, LBR-2, and HBR, are described for various ACTS operating modes. Also described is the NASA Lewis link evaluation terminal. A section on ACTS experiment opportunities introduces a wide spectrum of network control, telecommunications, system, and scientific experiments. The performance of the VSATs is discussed in detail. This guide is intended as a catalyst to encourage participation by the telecommunications, business, and science communities in a broad spectrum of experiments