Search

After the successful Global Coverage of the Digital Elevation Model, the TanDEM-X Science phase was initiated in September of 2014, dedicated to the demonstration of innovative techniques and experiments. The TanDEM-X Science phase had a large impact on the TerraSAR-X/TanDEM-X Mission Planning System. The two main challenges were the formation flying changes and the activation of a new acquisition mode, the so called Dual Receive Antenna (DRA) acquisition mode. This paper describes all actions and quantitative analyses performed in order to achieve the twofold target of the Mission Planning System: a) support the new TanDEM-X mission’s requirements, while b) proceed seamlessly with the TerraSAR-X mission fulfilling both its scientific and commercial demands. Regarding the first objective, several system reconfigurations are presented which were executed either due to the new flying formations or due to enabling the new DRA acquisition mode. In parallel, various analyses are included for the ground station visibilities of each formation and the distribution of the S- and X-Band contacts. For the second objective, it is presented how, via new concepts and mechanisms, it was possible to continue the TerraSAR-X mission undisturbed. Statistical analyses depict their successful integration and performance in the operational system. As a heritage of the TanDEM-X Science phase, the statistical analyses have become a very useful tool for the daily operations of both satellites and missions.

The NOAA-NASA jointly-acquired Joint Polar Satellite System (JPSS) will replace the afternoon orbit component and ground processing system of the current Polar-orbiting Operational Environmental Satellites (POES). The ground system, known as the ‘Common Ground System (CGS)’, and developed by Raytheon Intelligence, Information and Services (IIS) provides command, control, and communications (C3) and data processing and product delivery. The CGS currently flies the Suomi NPP (S-NPP) satellite and routes mission data to U.S. ground facilities, where it processes the data into mission products and provides them to US weather centrals. The CGS also supports various levels of data acquisition, routing and processing for multiple other missions across the globe today, with plans for incorporation of more missions in the future. CGS’s data processing capability (the Interface Data Processing Segment, or IDPS) processes the satellite data from S-NPP and provides environmental data products (including Sensor Data Records (SDRs) and Environmental Data Records (EDRs)) to the NOAA Satellite Operations Facility (NSOF). As data processing algorithms evolve, these changes will have to migrate into the operational system. In the past, operationalizing science algorithms and integrating them into active systems often required months of work. In order to significantly shorten the time and effort required for this activity, Raytheon has developed tools, processes, and techniques to enable rapid algorithm integration into the CGS. These include the Algorithm Development Library (ADL), the Binary Algorithm Adapter (BAA), and the Accelerated Release Cycle (ARC). This paper describes the tools and processes CGS has implemented to speed the science to operations implementation process, as well as comparisons between implementation timelines before and after the tools were in place.

The European Space Agency is preparing an operational system for routine Earth Observation called Copernicus (previously known as GMES, Global Monitoring for Environment and Security), a joint initiative of the European Commission and the European Space Agency (ESA), designed to support a sustainable European information network by monitoring, recording and analyzing environmental data and events around the globe. The Copernicus program will consist of five different families of satellites being the first three missions Sentinel -1, -2 and -3.

The NOAA-NASA jointly-acquired Joint Polar Satellite System (JPSS) will replace the afternoon orbit component and ground processing system of the current Polar-orbiting Operational Environmental Satellites (POES). The ground system, known as the ‘Common Ground System (CGS)’, and developed by Raytheon Intelligence, Information and Services (IIS) provides command, control, and communications (C3) and data processing and product delivery. The CGS currently flies the Suomi NPP satellite and routes mission data to U.S. ground facilities, where it processes the data into mission products and provides them to US weather centrals. Full volume data traffic is now flowing from the satellite through CGS’s C3, data processing, and data delivery systems. Ground system performance is critical for this operational system. As part of early system checkout, Raytheon measured all aspects of data acquisition, routing, processing, and delivery to ensure operational performance requirements are met, and will continue to be met throughout the mission. Two key metrics relating to the most important operational measures, availability and latency for Raw Data Records (RDRs), SDRs, and EDRs are discussed.

The French space agency (Centre National d’ Etudes Spatiales, CNES) and The Canadian Space Agency (CSA) are partnering to launch space science balloons in Canada. On one hand, Canada will provide and maintain the brand new mid-latitude launch site in Timmins, Ontario, designed with CNES support, and built by the City of Timmins, as well as several key services such as the aerostat post flight recoveries, the coordination with flight authorities and various ground safety services. On the other hand, CNES will supply and operate the aerostats, now equipped with a new command control system named NOSYCA, and offer frequent flight opportunities worldwide to the Canadian user’s community, thereby providing an ideal platform for scientists and engineers to test technologies and advance space science. In over 40 years, CNES has developed a vast experience in the field of stratospheric balloon flights, with more than 3 500 launches from a worldwide network of sites. Yet, taking into account the rising population density in the over flown areas, the increasing safety requirements and the need for a more reliable and performing system for scientific payloads management, CNES decided five years ago to develop a complete (onboard and ground segments) new operational system. NOSYCA takes advantage of the CNES knowhow in the field of balloon avionics, and of up to date technologies like IP or Wi-Fi communication links, low consumption onboard transceivers, and the use of specifically qualified COTS. In parallel, CNES was also looking for a launch site at mid-latitude for science missions (among them PILOT, an astronomy payload) using large stratospheric balloons, flying for more than ten hours: Timmins has been identified as the best location in Canada based on rigorous selection criteria. The latitude, wind and weather conditions, the low population density in key areas surrounding the city and optimal on-site infrastructure meet the stringent national and international security regulations governing balloon launch and recovery systems. Timmins also has the advantage of offering good launch conditions all year-round, as well an ease of access via an airport serviced by multiple airlines on a daily basis. This paper presents both the new CNES aerostat system, the Timmins launch site infrastructure, and the preparation status of the first launch campaign in Canada, foreseen in 2013.

In the past few years much of the global ATM research community has proposed advanced systems based on Trajectory-Based Operations (TBO). The concept of TBO uses four-dimensional aircraft trajectories as the base information for managing safety and capacity. Both the US and European advanced ATM programs call for the sharing of trajectory data across different decision support tools for successful operations. However, the actual integration of TBO systems presents many challenges. Trajectory predictors are built to meet the specific needs of a particular system and are not always compatible with others. Two case studies are presented which examine the challenges of introducing a new concept into two legacy systems in regards to their trajectory prediction software. The first case describes the issues with integrating a new decision support tool with a legacy operational system which overlap in domain space. These tools perform similar functions but are driven by different requirements. The difference in the resulting trajectories can lead to conflicting advisories. The second case looks at integrating this same new tool with a legacy system originally developed as an integrated system, but diverged many years ago. Both cases illustrate how the lack of common architecture concepts for the trajectory predictors added cost and complexity to the integration efforts.

Building on the development of the playbook® concept for control of Unmanned Aerial Systems developed by Smart Information Flow Technology (SIFT) (Miller, Goldman, Funk, Wu and Pate (2003), the Army Aeroflightdynamics directorate extended and tested this concept. Similar to a quarterback calling a play in football, the UAS operator can call a “play” that tasks multiple heterogeneous UAS simultaneously. This frees up the operator from having to input way-points and manually coordinate the UASs. Several simulations were run to test the boundaries and conditions under which this technique would be useful. Plays were consistently shown to result in better performance and lower operator workload. This was true even when a series of experiments were conducted that were specifically designed to look at plays in conditions where they might not be optimal. Following this work, flight demonstrations highlighted the technical maturity of the technique. A second flight demonstration flew tactically correct and high value plays as judged by Army UAS operators. Playbook® is a well-tested, mature technology; the next step should be development and transition of an operational system.

Over the last decade interplanetary telecommunication capabilities have been significantly expanded--specifically in support of the Mars exploration rover and lander missions. NASA is continuing to drive advances in new, high payoff optical communications technologies to enhance the network to Gbps performance from Mars, and the transition from technology demonstration to operational system is examined through a hybrid RF/optical approach. Such a system combines the best features of RF and optical communications considering availability and performance to realize a dual band trunk line operating within characteristic constraints. Disconnection due to planetary obscuration and solar conjunction, link delays, timing, ground terminal mission congestion and scheduling policy along with space and atmospheric weather disruptions all imply the need for network protocol solutions to ultimately manage the physical layer in a transparent manner to the end user. Delay Tolerant Networking (DTN) is an approach under evaluation which addresses these challenges. A multi-hop multi-path hybrid RF and optical test bed has been constructed to emulate the integrated deep space network and to support protocol and hardware refinement. Initial experimental results characterize several of these challenges and evaluate the effectiveness of DTN as a solution to mitigate them.

EUMETSAT has been providing operational meteorological satellite data services to European and US (via NOAA) national weather centers since the launch of Metop-A in October 2006. The service is characterized by high availability requirements and low latency delivery, essential for the accuracy of numerical weather predictions. However, further improvements in the data delivery timeliness would clearly have benefits to accuracy and availability of short-term weather predictions. To this end, EUMETSAT, together with partners in NOAA, NASA and the US National Science Foundation embarked on a project to provide an Antarctic Data Acquisition (ADA) capability using the McMurdo Ground Station. Coupled with the existing downlink of global data at Svalbard in the Arctic this would reduce the latency by close to a factor of two, benefiting from downlinks near each pole. The challenge was to introduce this major improvement to a key system requirement on an already operational system, without impacting the availability or quality of existing services during the integration and testing of the ADA and after its introduction into the operational system. Touching almost every element of the system design and operation, including the satellite operation, the Svalbard satellite data management, the EUMETSAT central site product generation and dissemination facilities, as well as NOAA processing and dissemination facilities, this paper highlights the challenges faced by the Project and the process by which risks to on-going operational services were minimized and non-intrusive testing possibilities were put in place. Conclusions are drawn concerning the aspects of this process which were critical to its success, such as the extensive configuration management

In 2008, NASA's Earth Sciences Missions Operations (ESMO) at Goddard Space Flight Center (GSFC) directed the Earth Observing System Data Operations System (EDOS) project to provide a prototype system to assess the feasibility of high rate data capture for the Japan Aerospace Exploration Agency's (JAXA) Advanced Land Observing Satellite (ALOS) spacecraft via NASA's Tracking and Data Relay Satellite System (TDRSS). The key objective of this collaborative effort between NASA and JAXA was to share science data collected over North and South America previously unavailable due to limitations in ALOS downlink capacity. EDOS provided a single system proof-of-concept in 4 months at White Sands TDRS Ground Terminal The system captured 6 ALOS events error-free at 277 Mbps and delivered the data to the Alaska Satellite Facility (ASF) within 3 hours (May/June '08). This paper describes the successful rapid prototyping approach which led to a successful demonstration and agreement between NASA and JAXA for operational support. The design of the operational system will be discussed with emphasis on concurrent high-rate data capture, Level-O processing, real-time display and high-rate delivery with stringent latency requirements. A similar solution was successfully deployed at Svalbard, Norway to support the Suomi NPP launch (October 2011) and capture all X-band data and provide a 30-day backup archive.

Metop-A, Europe’s first polar-orbiting meteorological satellite lifted into orbit from the Baikonur Cosmodrome in Kazakhstan atop a Soyuz launcher on 19 October 2006, marking a new era of weather and climate monitoring for Europe. Metop-A will shortly be joined in orbit by Metop-B, scheduled for launch by another Soyuz rocket also from Baikonur in May 2012. Preparing for the launch of Metop-A proved to be a challenge for EUMETSAT, especially in the area of readying the EPS ground system a system originally designed to simultaneously operate two satellites but only validated at the time to support one. Operations preparation activities for Metop-B began in 2009, starting with the evolution and revalidation of the ground system to support two separate spacecraft data streams. Thereafter, the EPS/Metop operations concept was modified to operate two satellites via a single operational ground segment with a single unified operations team. Key to this process was the definition and implementation of the operations concept for a dual-satellite system. This included defining the most effective approach to handle satellite and system procedure modifications, including taking maximum advantage of interpreted procedures (using STOL language) for spacecraft procedures. The definition and validation of the operations concept led naturally into the successful development and validation of the required operations procedures and databases, the training of the operations team and the completion of the operational rehearsals prior to launch. All performed while ensuring continuity of the operational services from the Metop-A satellite to the EUMETSAT user community. This paper will also present the lessons learned from the Metop-B preparations that may be usefully applied in the lead up to the introduction of the third Metop satellite.

The primary function of administering the United States’ National Airspace System (NAS) is the air traffic controller task of actively monitoring assigned aircraft and resolving the conflicts (i.e. losses of minimum separations between aircraft) anticipated some time in the future. The transformation of the current NAS is a planned evolution and will rely on communication digitally between air and ground and between aircraft with the use of enhanced trajectory-based operations and automation tools. To mitigate the safety risks of increased traffic growth and effectively designing automation to aid in the separation management task, research and development is required to improve the accuracy and usability of decision support tools. The paper presents the performance of an experimental strategic conflict probe model used in the development and validation of enhanced separation management concepts. Furthermore, this papers reports on a comprehensive design of experiment optimizing its performance and a comparison of its capability to an advanced operational system.

For the first time, a CNES remote operations center in Toulouse will be involved in the tactical operations of a Martian rover in order to operate the ChemCam science instrument in the framework of the NASA MSL (Mars Science Laboratory) mission in 2012. CNES/CESR and LANL have developed and delivered to JPL the ChemCam (Chemistry Camera) instrument located on the top of mast and in the body of the rover. This instrument incorporates a Laser-Induced Breakdown Spectrometer (LIBS) and a Remote Micro-Imager (RMI) for determining elemental compositions of rock targets or soil samples at remote distances from the rover (2-7 m). An agreement has been achieved for operating ChemCam, alternatively, from Toulouse (FR) and Los Alamos (NM, USA), through the JPL ground data system in Pasadena (CA, USA) for a complete Martian year (2 years on Earth). After a brief overview of the MSL mission, this paper presents the instrument, the mission operational system and JPL organization requirements for the scientific investigators (PI and Co-Is). This paper emphasizes innovations applied on the ground segment components and on the operational approach to satisfy the requirements and constraints due to these shared and distributed operations over the world.

ESA's Space Environment Information System (SPENVIS) is a system of models of the space environment and its effects on materials (e.g. spacecraft). It covers the natural radiation belts, solar energetic particles, cosmic rays, plasmas, and micro-particles. SPENVIS currently integrates 35 distinct models, with new ones being added regularly. The underlying models arise from many years of research, supported by national and international space agencies, resulting in a variety of tools to investigate the Sun-Earth connection and near-earth environment. SPENVIS was originally developed as a browserbased research tool that collects these tools together, being capable of recreating the full range of conditions in most of the solar system. In recent years SPENVIS has been further developed into an Operational System. In addition to enhancing the modeling capabilities, this required an enhancement to the customer perspective, i.e. ease-of-use, consistency, stability, runtime, support, etc. SPENVIS is now available as a web-based or standalone application. As a Spacecraft Operational Support System, SPENVIS is further tailored to preferentially reproduce the current radiation environment for a range of common LEO, MEO and GEO orbits, and predict likely future variability and effects via a purpose designed user interface. It will also accept autonomous input data regarding the real-time space environment via a variety of ISES-standard alerts and reports. This paper presents the latest developments, with particular significance for the satellite operations community.

Increasing numbers of military integrated platforms and weapon systems are completing a GPS receiver upgrade to the Selective Availability Anti-Spoofing Module (SAASM) as mandated by CJCSI 6140. SAASM GPS receivers provide the next generation security architecture. Once fully operational, this architecture will provide the new capabilities of unclassified black keys, multiple user networks and extended GPS functions such as over-the-air-rekeying (OTAR), contingency recovery and signal authentication. The functions will largely be implemented through the satellite signals themselves. However, the on-orbit signals are not yet available. While qualified at the card level, these integrated navigation and weapon systems equipped with SAASM receivers could not be fully exercised at the operational system level to verify their overall integrated functionality. In order to fill this testing gap and gain the ability to check out the SAASM functionality of a fully integrated weapon system, the 746th Test Squadron (746 TS) developed a mobile simulation asset that provides the necessary set of simulated SAASM test signals. These specialized signals can be fed to an unmodified, operationally-configured platform running on its own power without removing black boxes in order to exercise the SAASM functions while the platform is in the operational state. The asset is called the SAASM Integrated System Evaluator and Reporter (SAASM-ISER). The 746 TS has recently added GPS receiver autonomous integrity monitoring (RAIM) functionality testing to this capability as well. This presentation will describe SAASM-ISER, what it can do and how it has been used.

*† As routine space operations extend beyond earth orbit, the ability for ground infrastructures to take on new launch vehicle systems and a more complex suite of spacecraft and payloads has become a new challenge. The U.S. Vision for Space Exploration and its Constellation Program provides opportunities for our space operations community to meet this challenge. Presently, as new flight and ground systems add to the overall groundbased and space-based capabilities for NASA and its international partners, specific choices are being made as to what to abandon, what to retain, as well as what to build new. The total ground and space-based infrastructure must support a long-term, sustainable operation after it is all constructed, deployed, and activated. This paper addresses key areas of engineering concern during conceptual design, development, and routine operations, with a particular focus on: (1) legacy system reusability, (2) system supportability attributes and operations characteristics, (3) ground systems design trades and criteria, and (4) technology application survey. Each key area explored weighs the merits of reusability of the infrastructure in terms of: engineering analysis methods and techniques; top-level facility, systems, and equipment design criteria; and some suggested methods for making the operational system attributes (the “-ilities”) highly visible to the design teams and decisionmakers throughout the design process.

According to the roadmap of the Vision for USA Space Exploration announced in 2004, the Space Shuttle will be retired no later than 2010. This retirement means the International Space Station (ISS) will have no descent transportation systems except Soyuz capsule until the USA’s new Crew Exploration Vehicle (CEV) will be operational around 2014. The payload capacity of the Soyuz is only 50 kg. This means, from 2010 to 2013, there will be no descent vehicle whose payload is heavier than 50 kg. For the ascent to the ISS, there are three options, the Progress, ESA's Automated Transfer Vehicle (ATV) and JAXA's H-II Transfer vehicle (HTV). The HTV is an unmanned earth-orbital transfer vehicle. It is 10 m in length and 4.4 m in diameter and can carry up to six tones of logistic payloads. It will be launched on the H-IIB which is a heavy lift version of the H-IIA. Currently, the HTV and the H-IIB are planned to make their first flight in 2008. The HTV has two payload carrier sections: a pressurized section and an unpressurized section. To enhance the HTV capability, JAXA has been studying a re-entry system since 2004. In the previous study in 2004, attaching importance to lower development cost, a small capsule which has the capability of 50 kg payload to retrieve some biological or biomedical samples from the International Space Station (ISS) was selected and studied. When an operational system is fielded, the most important factor will be the transportation cost per unit mass of payload to be returned to earth. However, such a cost will be extremely high for a small capsule, due to its low capability of retrievable mass. In 2005, feasibility studies have therefore been conducted to look at using a larger capsule and to consider reuse in order to reduce the cost. Some candidate concepts are selected and evaluated. This paper presents these concept studies and the results of evaluation studies.

§Low earth orbit constellations significantly increase the burden for ground-based systems management. Efficient, accurate management requires that ground station and satellite operators are well-trained. Scenario-based training, in which trainees practice handling specific situations using faithful simulations of the equipment they will use on the job has proven to be an extremely effective method for both training and certification. Effectiveness is increased when it is coupled with intelligent tutoring. Intelligent tutoring systems (ITS) improve on training simulations by assessing the trainee’s actions and providing individualized guidance. Development of training simulators often lags behind development of the operational systems, with the result that simulators are often not available or up to date when they are most needed (e.g., when training operators on new or modified systems). Also, practical deployment of intelligent tutoring systems is hindered by the time and expense required to prepare the needed knowledge representations. We report on the development of tools to address both these issues. Three strategies enable rapid development. For both simulation and tutoring, the first strategy is to develop systems that are scenario-specific. This strategy permits the systems to be simpler and easier to develop. The second strategy is to employ easily manipulated representations for the simulation behavior and tutoring knowledge, and provide graphical user interfaces to edit these representations that facilitate development by training instructors with little outside support. The third strategy is to minimize the need for development. For simulation, this means maintaining a high degree of fidelity with little programming by incorporating screen captures of the operational system, and by enabling integration of existing simulation codes. For tutoring, this means capturing the bulk of the tutoring knowledge by simply recording the actions of instructors as they demonstrate the correct manner of handling the scenario. These strategies are embodied in two systems developed by Stottler Henke for the Air Force. TaskSim is a simulation framework to facilitate rapid development of scenario-based training simulations. Task Tutor Toolkit™ is an intelligent tutoring system that enables instructors to create scenario-specific tutors through a three-step process: demonstrate, generalize and annotate.

The success of the operational space systems that our nation currently relies upon for National Security is largely attributable to the well-constructed precursor research and development, test and evaluation (RDT&E) missions that focused on transforming immature technologies into reliable and operable solutions. Unfortunately, as valuable as these RDT&E missions have proven to be in the past, they are consistently under-funded and forced to execute on excessively ambitious development schedules. Due to these constraints, space mission development teams that serve the RDT&E community are faced with a number of unique technical and programmatic challenges. The Air Force Research Laboratory’s Space Vehicles Directorate (AFRL/VS) and the Department of Defense Space Test Program (STP) are two organizations that have partnered on more than 85 missions since 1968 to develop, launch, and operate RDT&E space missions. They have repeatedly come up with creative solutions to the problem of getting developmental technologies into an appropriate environment for evaluation. When possible, they develop ground tests or simulations targeted at giving the operational customer confidence that a technology can add an effective and reliable capability to their next-generation space asset. When ground testing is insufficient, they look for low-cost opportunities to get payloads into space. These include “piggybacking” an experimental payload on an operational spacecraft or, until recently, using excess space on the Space Shuttle. However, when experiment requirements are sufficiently restrictive to prohibit such partnerships, AFRL and STP are forced to choose the more costly option of developing, launching, and operating a dedicated RDT&E spacecraft. In order to make a convincing case for a dedicated RDT&E program, an organization must perform a Cost-Benefit Analysis and demonstrate that they can complete the mission and retrieve relevant data for a relatively low price. If the cost of the RDT&E effort is not sufficiently small compared to the operational system it will benefit or if the mission can’t return relevant data in time to benefit a planned operational system, the program is at risk of being cancelled. For these reasons, severe budgetary and schedule constraints are common to all AFRL or STP missions. In an effort to meet cost constraints, AFRL and STP often bundle numerous experimental technologies that need access to a similar space environment and on-orbit resources on a single spacecraft bus. This approach benefits the entire RDT&E community by making the most efficient use of available bus and launch vehicle resources, but more importantly, it makes the program executable by combining the funding and advocacy of several different organizations. Ironically, this approach, intended to make the program executable from a programmatic standpoint, threatens its success from a technical perspective. Each payload and funding organization comes with requirements and constraints that magnify the overall complexity of the program. Therefore, engineering and test efforts, introduced to meet and validate these requirements, inevitably extend the development schedule and increase program costs. To combat this, AFRL and STP have taken various approaches throughout the mission lifecycle to accelerate their development schedules, without sacrificing cost or system reliability. In the areas of test and operations, they currently employ one of two strategies. Their mission successes and failures are testaments to the benefits and drawbacks of each approach. This paper seeks to compare and contrast the “decoupled test and operations” approach, used by such missions as C/NOFS and Coriolis, with the “coupled test and operations” approach, adopted by the XSS-11 and Roadrunner missions. Space 2004 Conference and Exhibit 28 30 September 2004, San Diego, California AIAA 2004-5822

This paper addresses the cost saving and schedule saving approach to requirements verification being used on the Air Force Subscale Aerial Target (AFSAT) program. The BQM-167A unmanned aircraft is a jet powered, highly maneuverable, multi-role UAV that is currently being supplied to the USAF as a subscale target used to simulate enemy aircraft and missile threats. Production aircraft must be fielded in 2005 to avoid an inventory shortfall; therefore, the desire to accelerate production aircraft availability created a need to validate the system’s performance in a compressed time frame. Comprehensive wind tunnel testing and extremely accurate component models were used to develop a highly accurate flight simulation providing accurate system performance throughout the flight envelope. The simulator will augment the flight test demonstration by providing performance information in areas where a series of flights would be required to completely demonstrate the vehicle’s capabilities. A 2-phase, 12-flight program will be used to verify that system requirements are met and the flight envelope is adequately defined to proceed with production. The first 6 flights will validate the simulation accuracy using linear and nonlinear Autopilot Dynamic Response tests throughout the flight envelope. Additionally, the first 6 flights will demonstrate the Key Performance Parameters and other specific performance requirements for the system. The following 6 flights and associated simulation work will define the operational envelope and provide operational system experience for the operation and maintenance personnel. This flight test program will be started in October 2004 and is scheduled for completion in April 2004.

Introduction The Cassini Saturn Mission’s operational system enables one of NASA’s most complex and challenging deep space scientific missions ever. Cassini is a combined NASA Saturn orbiter and European Space Agency provided Titan atmospheric Probe with 12 orbiter and 6 probe instruments supporting 27 diverse science investigations. Taking advantage of the nearly seven year cruise to Saturn, the Mission Operations System (MOS) post-launch development team at the Jet Propulsion Laboratory has implemented a system to support the science phase of the mission that has successfully overcome many development challenges that will face future missions both big and small. Many development challenges revolved around the difficulty of system engineering a large, diverse, highly collaborative operational system that spans 10 US and 4 European operations sites, required the development or adaptation of 84 ground software programs, and required both development and validation of the system in a limited time while simultaneously supporting cruise operations.

1. Objective The objective of this paper is to show how, in the framework of the ESA Automated Transfer Vehicle (ATV) Program, a complex, multi-organizational operational system is being implemented such that the operations procedures can be prepared and used in a compatible manner, limiting the need for duplication of production effort and re-validation, while ensuring coordinated configuration control across the end-to-end system.

Reusable Launch Vehicles (RLVs) hold the promise of dramatically changing the nature of military space operations. However, there is no available database to help us understand what an RLV can do, how large the associated ground crew and infrastructure need to be, and how rapidly such a vehicle can be inspected, serviced, and flown again. A Reusable Access to Space Technology Demonstrator can serve to generate new operability data, validate performance predictions, and test advanced technologies before government or commercial organizations decide whether to develop an operational system. This paper presents a concept for such a demonstrator that could be developed at low risk, yet have operational capability for launching small payloads to orbit.

There are many different avenues available to the entrepreneur seeking to commercialize UAVs. One of these potential avenues is the commercial fishing industry. While the fishing industries may offer some unique opportunities for business success and early profitability, they also have numerous, equally unique, requirements and restrictions that will likely represent major hurdles to be overcome by a business developer within this arena. In order to ensure success, a UAV developer must learn to deal with the critical issues of business case paradigms; end-user adaptability; maritime launch; maritime recovery; survivability; system autonomy; endurance; payload performance; and operational system integration as well as numerous regulatory issues.

This is a technology survey paper based on the findings of the Space Based Laser Affordability & Architecture Study (A&AS)*. This paper discusses the current approach being taken by the Air Force and Ballistic Missile Defense Organization (BMDO) to develop the Space Based Laser and the projected technology needs necessary to field an operational Space Based Laser weapon system. The A&AS identified four major technology areas requiring significant improvement in capabilities beyond the current state-of-the-art. These areas include: the development of large deployable optics, improvements in wavefront control and jitter suppression, and laser power. In addition, improvements in long-range acquisition, tracking and pointing, pervasive space vehicle technologies, modeling and simulation, and ground testing will be required to develop, test and field the operational system.

The National Aeronautics and Space Administration (NASA) is addressing airport capacity enhancements during instrument meteorological conditions through the Terminal Area Productivity (TAP) program. Within TAP, the Reduced Spacing Operations (RSO) subelement at the NASA Langley Research Center is developing an Aircraft VOrtex Spacing System (AVOSS). AVOSS will integrate the output of several systems to produce weather dependent, dynamic wake vortex spacing criteria. These systems provide current and predicted weather conditions, models of wake vortex transport and decay in these weather conditions, and reql-time feedback of wake vortex behavior from sensors. The goal of the NASA program is to provide the research and development to demonstrate an engineering model AVOSS in real-time operation at a major airport. The demonstration is only of concept feasibility, and additional effort is required to deploy an operational system for actual aircraft spacing reduction. This paper describes the AVOSS system architecture, a wake vortex facility established at the Dallas-Fort Worth Internaional Airport (DFW), initial operational experience with the AVOSS system, and emerging considerations for subsystem requirements. Results of the initial system operation suggest a significant potential for reduced spacing.

This paper discusses testing conducted to evaluate the interface between cargo airdrop systems and the C17A aircraft and to devise modifications, if required, to optimize performance. Two hundred and twenty eight tests were conducted between 199 1 and 1994. Tests included Low Velocity Airdrops (LVAD), Low Altitude Parachute Extraction System (LAPES), "'Mission Systems Engineer, Member AIAA "yhief C17A Mission Systems, Associate Fellow AIAA This paper is declared a work of the U.S. Government and is not subject to copyright protection in the United States. and Container Delivery System (CDS). The approach was to evaluate airflow, do a load build up to the heaviest operational system, and to scope the entire cargo airdrop family of systems. The C-17A aircraft performed satisfactorily on all the scenarios tested. A few modifications were needed to perform cargo airdrops. Line bags were needed for heavy airdrops (LVAD and LAPES). Existing line bags were modified to optimize performance. Aircraft modifications were required in order to have satisfactory LAPES performance. Forward anchor cable stops were needed for CDS.

Although it is now generally acceprvti that a reusable launch vehicle (RLV) is becoming a practical proposition for di-nmatically reducing launch costs, the large devclopment cost of such a vehicle has so far pi-evented any single nation, or group of nations, from proceeding to develop an operational system. In addition, there is a lack of consensus between the major space faring nations concerning the design of such a vehicle, with arguments for and against air hruathirig and rocket powered solutions. The paper assesses the problems associated with the establishment of an international project by considering the political, economic and technical factors that arise, and by reference to examples of previous, large scale, international projects. Finally, mechanisms for initiating international collaboration in this area are explored.

A possible operational system scenario for providing satellite communications services to the future aviation community was analyzed. The system concept relies on a Ka-band (20/30 GHz) satellite that utilizes multibeam antenna (MBA) technology. The aircraft terminal uses an extremely small aperture antenna as a result of using this higher spectrum at Ka-band. The satellite functions as a relay between the aircraft and the ground stations. The ground stations function as interfaces to the existing terrestrial networks such as the Public Service Telephone Network (PSTN). Various system tradeoffs are first examined to ensure optimized system parameters. High level performance specifications and design approaches are generated for the space, ground, and aeronautical elements in the system. Both technical and economical issues affecting the feasibility of the studied concept are addressed with the 1995 timeframe in mind.

A review of the X-30 technology demonstration concept is presented, and differences in concept and requirements between a demonstrator and an operational system are discussed. How changes for operational capability can affect vehicle design are considered and a methodology used to estimate the effects of these changes is offered. Attention is given to the feasibility of operational NASP derived vehicles.

A major cooperative effort between west and east bloc nations in developing a new space system for detecting ships and aircraft in distress is discussed. The compatible working of the SARSAT system developed by Canada, France, and the US and the COSPAS system developed by the Soviet bloc is summarized, and the SARSAT system is described. The method of location determination is presented, and the ELT and EPIRB, space segment, local user terminal, and mission control center subsystems of the SARSAT system are surveyed, showing block diagrams and data on spacecraft orbital parameters and ELT/EPIRB BECON characteristics. The current problem of ground-based interference is discussed. An outline of future development activities leading to the implementation of a fully operational system is included.

The Shuttle Entry Air Data System (SEADS) is the implementation of a new concept in air data systems, with application to entry vehicles. This concept incorporates an array of flush orifices in the nose and forward fuselage of the vehicle and a new flowfield modeling concept for the analysis of flight data and the determination of the required air data parameters. Although the SEADS has not been fully demonstrated, a developmental analysis capability has been assembled and demonstrated. This analytical capability has been used to analyze selected Development Flight Instrumentation (DFI) pressure data from STS-1 through STS-4 and determine angle of attack and freestream dynamic pressure. The results of this study verify the potential of the SEADS as a highly fault tolerant operational air data system. In addition, the transition of SEADS from its present status as an experimental system to an operational system is shown to be readily achievable.

An Air Force research program has produced performance estimates for the colloid core nuclear reactor rocket engine concept. These values are parametrically varied to determine their individual influence on an advanced nuclear upper stage to the Space Transportation System. Pessimistic and optimistic performance of the concept is estimated. The concept is compared with other propulsion schemes on the basis of velocity capability (as an indication of performance) and the mass which must be initially boosted into orbit (as an indication of cost). Based upon the analysis, it is concluded that the concept warrants further consideration for development as a future operational system. (10 references) (auth)