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Past Conference Papers:
Responsive Missions - General
| Paper Number RS1-2003-8002: I-Cone® for Rapid Response and Low cost Access to Space | |
| Michael J. Cully (Swales Aerospace), Peter Alea (Swales Aerospace), Nils Gustafsson (Saab Ericsson Space AB) | |
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| Abstract: I-Cone® is an innovative approach to providing payload launch opportunities while at the same time taking advantage of the excess launch vehicle performance available with the Evolved Expendable Launch Vehicle (EELV). The genesis of the I-Cone® concept is the integration of a standard set of space vehicle subsystems into a standard conical launch vehicle adapter, in effect creating an “intelligent cone: or I-Cone. The I-Cone® is capable of providing payloads and small satellites a Fast, Frequent, Flexible and Affordable (F3A) access to space. The I-Cone® concept is designed for use with the Delta IV and Atlas V (EELV) and is compatible with Delta II and Sea Launch Vehicles. The main I-Cone® structural components are derived from flight heritage payload adapters and separation systems, developed by Saab Ericsson (SE) Space, which minimizes the development risks and production costs. I-Cone® space vehicles can be essentially transparent to the Primary payload of a typical EELV manifest. The launch site processing flow for an I-Cone® has a “no impact” approach on the standard EELV Primary payload processing flow. The I-Cone® space vehicle concept is suited for a wide variety of technology demonstration and short term operational missions. The baseline concept features typical payload resources of a 100 kg of mass, with 150 Watts of orbit average power, and a standard downlink data rate of 2.0 Mbps. The baseline I-Cone® Space Vehicle is capable of providing a pointing accuracy of 10-50 arc·sec, a propulsion system with 90 kg of mono-propellant Hydrazine, and a mission life exceeding one year. The use of I-Cone® for Low Earth Orbit (LEO) missions is emphasized in this paper, although Geosynchronous Transfer Orbit (GTO) launch can be accommodated by the I-Cone® also. The modular approach to the I-Cone® space vehicle structure permits an extraordinary level of flexibility for meeting emerging specialized launch requirements. Micro-and nano-satellites can also be accommodated in an I-Cone® variation that incorporates a dispenser. Variations on the I-Cone® dispenser theme include a passive dispenser that provides additional propulsion and attitude control after separation from the launch vehicle. The I-Cone® concept can argument the potential return on investment for any EELV launch as it provides a cost effective and flexible solution particularly for Technology demonstration missions. This paper will first present what needs the I-Cone® design addresses for access to space. This paper will also provide the generic mission requirements for the I-Cone® design, describe baseline I-Cone® implementation architecture, discuss payload accommodations and provide baseline implementation. Finally this paper will discuss potential mission designs for which I-Cone® can be applied to. This paper is derived, in part, from a study performed in Reference 1. | |
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| Paper Number RS2-2004-3003: A Modular Design for Rapid-Response Telecons and Navigation Missions | |
| Phillip Davies (SSTL), Doug Liddle (SSTL), John Paffett (SSTL), Sir Martin Sweeting (SSTL), Alex da Silva Curiel (SSTL), Stuart Eves (SSTL) | |
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| Abstract: In order to achieve an ‘economy of scale’ with respect to payload capacity the major trend in telecommunications satellites is for larger and larger platforms. With these large platforms the level of integration between platform and payload is increasing leading to longer delivery schedules. The typical lifecycle for procurement of these large telecommunications satellites is now 3-6 years depending on the level of non-recurring engineering needed. Surrey Satellite Technology Ltd (SSTL) has designed a low-cost platform aimed at telecommunications and navigation applications. SSTL’s Geostationary Minisatellite Platform (GMP) is a new entrant addressing the lower end of the market with payloads up to 250kg requiring less than 1.5 kW power. The development of GMP was supported by the British National Space Centre through the MOSAIC Small Satellite Initiative. The main design goals for GMP are low-cost for the complete mission including launch and operations and a platform allowing flexible payload accommodation. GMP is specifically designed to allow rapid development and deployment with schedules typically between 1 and 2 years from contract signature to flight readiness. GMP achieves these aims by a modular design where the level of integration between the platform and payload is low. The modular design decomposes the satellite into three major components - the propulsion bay, the avionics bay and the payload module. Both the propulsion and avionics bays are reusable, largely unchanged, independent of the payload configuration. Such a design means that SSTL or a 3rd party manufacturer can manufacture the payload in parallel to the platform with integration taking place quite late in the schedule. In July 2003 SSTL signed a contract for ESA’s first Galileo navigation satellite known as GSTBV2/A. The satellite is based on GMP and ESA plan to launch it into a MEO orbit late in 2005. The second flight of GMP is likely to be in 2006 carrying a geostationary payload consisting of six Ku band transparent transponders. Once the platform is flight proven, SSTL will be able to offer it to commercial and institutional operators when there is an urgent need for capacity for example to introduce new services, for gap fillers, for frequency filing missions and for technology demonstration missions. | |
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| Paper Number RS2-2004-A006: NASA Requirements & Needs and their Relationship to Responsive Space | |
| Jaime Esper (GSFC) | |
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| Paper Number RS3-2005-2001: Coverage, Responsiveness, and Accessibility for Various "Responsive Orbits" | |
| James R. Wertz (Microcosm) | |
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| Abstract: We have evaluated 5 potential Responsive Orbits with the following conclusions with respect to coverage, responsiveness, payload to orbit for a small launch vehicle, and missions that they would be best suited for: • Cobra Orbits provide up to 4 hours of continuous access per day, 10 hours mean response time, low payload mass to orbit, very poor optical resolution, and are best used for communications. • Magic Orbits provide up to 1 hour of continuous access per day, 12 hours mean response time, low to moderate payload mass to orbit, poor optical resolution, and are also best for communications. • LEO Sun Synchronous Orbits provide 5 minutes of coverage once or twice per day, 6 hour mean response time, moderate payload mass to orbit, excellent optical resolution, and are best suited for visual or radar observations. • LEO Fast Access Orbits provide 5 minutes of coverage once or twice per day, 45 minute mean response time, moderate to high payload mass to orbit, excellent optical resolution, and are best suited for highly responsive visual or radar observations. • LEO Repeat Coverage Orbits provide 5 minutes of coverage every 90 minutes for 4 or 5 times in a row, 9 hour mean response time, high payload mass to orbit, excellent optical resolution, and are best suited for repeated visual or radar observations. Responsive orbits have the potential to provide means for communications and high-resolution surveillance anywhere in the world within hours of an identified demand. Collectively, these orbits provide excellent opportunities for transforming space from a strategic to a tactical asset and for doing missions that cannot now be done. Coupled with the launch vehicles being developed under the AF/DARPA/NASA FALCON program and emerging smallsat technology, there is excellent potential for new, low-cost missions that can transform the way space is used. | |
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| Paper Number RS3-2005-A005: Responsive Range | |
| Herb Bachner (FAA Space System Development Division) | |
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| Paper Number RS3-2005-A008: NASA Wallops Research Range | |
| Jay Pittman (WFF) | |
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| Paper Number RS3-2005-A012: Responsive Space: Applications and Implications for NASA | |
| (KSC) | |
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| Paper Number RS4-2006-1001: System Architecting Challenges of Changing Missions for a Flexible Mission Spacecraft | |
| John Bystroff (University of Southern California) | |
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| Abstract: Air Force Space Command has been a strong advocate of an operational responsive space (ORS) capability. Operationally responsive space, as described by Arthur Cebrowski, Director of Force Transformation, Office of the Secretary of Defense, involves establishing a mission need “driven by adaptive contingency planning cycles rather than predictive futures or scripted acquisition periods.” In practical terms, this means for a space system to be considered operationally responsive, identified mission needs require fulfillment within days or weeks, not the years the current acquisition process requires. One concept to fulfill responsive space requirements involves placing a flexible mission spacecraft (FMS) on-orbit. An FMS would have the capability to re-configure its bus and payload hardware and software to meet emerging mission requirements. Various new technologies, such as Software Defined Radio (SDR) and micro electro mechanical systems (MEMS) enable considering how to create a satellite with a malleable architecture. However, an FMS presents a significant system architecting challenge by its malleability. The challenge is not merely in its initial deployment, but in changing missions. To successfully support new mission requirements, an FMS must not only be able to change its own architecture, but it must be integrated with a mission architecture on the ground. It must support interfaces for the new mission along the entire stack of layered protocols from physical to application. The purpose of this paper is to highlight the system architectural challenges associated with an FMS in transitioning from supporting one mission to supporting a different one within the time-frame demanded of an “operationally responsive space system.” The challenges are first addressed with respect to satellite design concerns. The interface challenges with the ground mission infrastructures are then described with reference to the Open System Interconnect (OSI) model. Finally, it is proposed that the traditional waterfall spacecraft architecting approach is not suited to supporting an FMS mission change within the constraints demanded by ORS. Rather, the characteristics of the architecting environment for changing an on-orbit satellite design match closely with the situation faced in software development. Therefore, it is proposed that a spiral software development process provides a more viable architecting approach when changing an FMS mission. | |
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| Paper Number RS4-2006-1003: National Security Space Office Responsive Space Operation Architecture - Final Report Presentation | |
| Ed Kneller (US Navy) | |
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| Abstract: The National Security Space (NSS) Enterprise is facing a significant transformation as it moves from a Cold War posture to one capable of maintaining pre-eminence in a new environment of rapidly changing and unpredictable threats. Concurrent with this strategic transformation, the Partnership between the U.S. Government and the Industrial Base is increasingly challenged in its effort to deliver cost effective NSS systems. The NSSO Responsive Space Operations Architecture views Responsiveness as a critical attribute throughout the NSS Enterprise that must be greatly improved in order to surmount these challenges. The RSO Architecture Study assessed responsiveness across representative sectors of the enterprise and will recommend a set of capabilities for layered responsiveness as well as implementation vectors to effect the transformation. These capabilities can be broadly categorized into a First Response capability from pre-deployed systems; a Call-Up Response capability for the deployment of space, terrestrial and atmospheric systems; and a Government/Industrial Base Response to rapidly adapt to new strategic requirements and technological advances. | |
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| Paper Number RS4-2006-1004: Aggressive Surveillance as a Key Application Area for Responsive Space | |
| James R. Wertz (Microcosm), Richard Van Allen (Microcosm), Christopher J. Shelner (Microcosm) | |
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| Abstract: Traditional space-based surveillance is fundamentally strategic. Systems are expensive and take a long time to develop. Thus, they are intended primarily for global coverage and launched on a schedule largely unrelated to world events. Opponents may be aware of the broad system parameters, such as the orbit, and hide from the system when it is overhead. The goal of aggressive surveillance is to go after the opponent by being able to act or react quickly, at low cost, and in ways that cannot be predicted. In addition, aggressive surveillance allows us to take advantage of technology advances in the shortest possible time, thus significantly magnifying technological superiority. This paper describes key elements of aggressive surveillance and estimates the time and cost required for an initial implementation. These include, but are not limited to: • Low cost, responsive, scalable launch systems • Responsive communications and operations • Responsive orbits • Low cost surveillance payloads, such as visible or IR observation systems, wind lidar, and other potential detection systems • Agile spacecraft for responsive, on-orbit operations • Autonomous, on-board orbit control for the construction of virtual constellations and coordinated observations • Plug and play spacecraft and payload systems for rapid changes or insertion of new technology Initial systems can be developed with a total recurring cost per spacecraft (launch, spacecraft bus, payload, and 1 year of operations) between $15 and $20 million. After the process is initiated, the potential exists to truly change the way business is done in space – in defense, science, education, and commercial applications. In addition, the process and system are inherently scalable, such that savings in both cost and schedule can be rapidly extended to larger systems at a small fraction of the non-recurring cost and time normally associated with traditional, large space systems. | |
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| Paper Number RS4-2006-1006: Using Proven Aircraft Avionics Principles to Support a Responsive Space Infrastructure | |
| Randy Black (Honeywell Space Applications) | |
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| Abstract: Creating an engineering environment that supports responsive space involves a variety of interrelated disciplines. Included within these disciplines is the ability to quickly re-configure systems through plug-and-play hardware and software. Plug-and-play hardware as a concept has been progressing well throughout the electronics industry. Plug-and-play software has been somewhat more challenging. While some advances have been made through object-oriented architectures and model-based autocoding, software lags behind hardware in this area. Honeywell has experienced significant success for the past ten years fielding plug-and-play software at the application level. Using a combination of time and space partitioning, table-driven operations, and robust off-line development tools, Honeywell’s Integrated Modular Avionics (IMA) has produced significant savings in development cost and schedule. More importantly, modifications to either hardware or software are quickly and easily integrated into the overall system with minimal re-certification required. During the past decade, Honeywell has produced multiple implementations of this advanced avionics technology. One lesson learned is that specific implementation details are not as important as designing to key architectural principles. This paper describes several of those principles that have a proven track record of enabling rapid reconfiguration of system architectures. Architectural principles that support plug-and-play software applications, as well as minimizing the impact of hardware modifications, provide the core of a system design that is integral to an overall responsive space infrastructure. | |
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| Paper Number RS4-2006-2001: Responsive Air Launch Using F-15 Global Strike Eagle | |
| Timothy T. Chen (Boeing), Preston W. Ferguson (Boeing), David A. Deamer (Boeing) | |
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| Abstract: A near term military need exists for a capability to execute global strike, responsive spacelift and space control missions. This paper presents an innovative concept based on integrating off-the-shelf components to provide this capability, while avoiding technology development risk. The concept would utilize an F-15E with minimal modifications to provide a reusable first stage for the F-15GSE (Global Strike Eagle). The upper stages of the F-15GSE would consist of currently available solid rocket motors packaged to meet the mission requirements. The F-15GSE concept could provide an “all azimuth” capability from a single CONUS base while reducing the Delta-V required for orbital insertion by 5000 fps versus a ground launch rocket system. Advantages of an F-15GSE system include: increased mission flexibility, rapid response time without deployment of assets, multiple basing options and covert launches. Operational missions could be completed within two hours while on alert status with minimal infrastructure from CONUS or remote bases. Initially this concept could provide a low-cost demonstration of global strike, while military operational capability could be met with an expansion of fleet size. The F-15GSE would be capable of global reach with delivery of munitions including the Common Aero Vehicle (CAV) and also provide a LEO launch capability for microsats. Planned future upgrades are available to enhance capability for delivering heavier ballistic and orbital payloads. | |
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| Paper Number RS4-2006-3002: Responsive Tactical Space Using Micro-Satellites and Aerial Launching: The Prespective of a Small Nation | |
| Col. (Res.) Yoram Ilan-Lipovsky (Space and UAV Center), Tal Inbar (Space Research Center of the Fisher Institute for Air & Space Strategic Studies, Israel) | |
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| Abstract: During recent years, a growing interest in the world space community has awakened, regarding a new approach in the field of space technology. This approach is based on a new and revolutionary look at the needs of small nations in space and on technological innovations as well. The importance of responsive space for civilian purposes and for defense use – at the tactical level will be presented in detail in the article and presentation. Our Vision calls for many satellites working together in constellations on low earth orbit, providing continuous target coverage. Some of the satellites would be launched on demand from military or civilian aircrafts and will be placed in optimal and focused orbits. The platforms will be Micro Satellites. Among other aspects, the paper will deal with civil and defense needs and the relevancy of emerging technologies such as miniaturization, ion driven thrusters, Nano-technologies, laser communication, data fusion and advanced imaging, to the realization of this vision. The article will describe the unique status of a small nation, such as the state of Israel, and the benefits it could gain from responsive space guidelines, especially in the fields of aerial launch and micro satellites. The paper will address all aspects of the Responsive tactical micro satellites vision, applicable for a small nation, such as: • Analysis of the needs – military and civilian • Defining future missions for TMS (Tactical Micro Satellites) • A comprehensive study of the Launch On Demand (LOD) concept and focused orbits idea • Technical and financial aspects • Aerial Launching – detailed analysis of 2 main alternatives – launch from a fighter plane (such as the F-15) and from an airliner (such as 747 or 767) • Micro Satellites – architecture, basic design, the bus, payloads, propulsion and orbits • Constellations and satellite formations flying • The very low Earth orbit environment | |
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| Paper Number RS4-2006-4002: Pulling the Pieces Together at AFRL | |
| Peter M. Wegner (USAF AFRL/VS), Col. Rex R. Kiziah (USAF AFRL/VS) | |
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| Abstract: In partnership with Air Force Space Command, the Office of Force Transformation, and the other military services’ S&T and R&D organizations, the Space Vehicles Directorate of the Air Force Research Laboratory is aggressively pursuing the development of responsive space technologies and spacecraft. The Directorate has made responsive space one of its six core thrusts. The objective of the responsive space thrust is to develop and demonstrate the technologies that will enable spacecraft with the following attributes: • Operational within six days of call-up • Total mass (<400 kg) and low-cost (<$30M mission costs, including spacecraft, launch and operations) • Tasking and data dissemination utilizing existing warfighting equipment and architectures • Satellite payloads are taskable by theater commanders/forces with direct downlink/data dissemination into theater assets • Missions-tailored for a specific theater of operations In order to realize this objective, the responsive space thrust consists of a robust portfolio of technology investments, ground and space experiments, and strategic collaborations. Even beyond this thrust, the philosophy of utilizing small, low-cost satellites with valuable military capability is a key component of the Space Vehicles’ vision for the future. This philosophy and experimental approach is reflected in the recent, highly successful XSS-11 Spacecraft and the upcoming TacSat-2 and TacSat-3 experiments. This paper will discuss the work being performed by the Air Force Research Laboratory and its strategic partners to enable the future vision of low-cost, highly responsive, militarily useful spacecraft. This will include a discussion of the XSS-11 spacecraft and its highly successful experiments, current investments in plug-n-play technologies, the development of a modular spacecraft bus based upon these technologies, a ground-based test-bed to enable rapid experimentation with these technologies, and the TacSat-2 and TacSat-3 space flight experiments to explore the military utility of this new class of space systems. | |
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| Paper Number RS4-2006-6001: Issues and Implications of the Thermal Control System on the "Six Day Spacecraft" | |
| Andrew D. Williams (AFRL), Scott E. Palo (University of Colorado) | |
| View/Download:Presentation | Paper | |
| Abstract: The traditional approach to satellite design is a customized and highly optimized satellite bus. The primary design driver is to minimize mass but often at the expense of time and money. To meet the goals of Operationally Responsive Space (ORS), the satellite must be adaptable to different missions, changing threats, and emerging technologies. One of the subsystems that will be challenging for the development of robust and modular architectures is the Thermal Control Subsystem (TCS). To design the TCS, virtually every aspect of the mission, the satellite, and the components must be known. The overall goal of the engineer is to reduce the mass of the system by trading cost and engineering time. As a result, every design is unique and requires extensive design, modeling, analysis, and test programs. One philosophical approach to achieve the goals of responsive space in the near term is to separate the design and engineering of the payload from the bus. The bus would have a standard design providing a specific set of baseline capabilities and would have limited upgradeability. The disadvantage with most standardized bus development programs is that the bus eventually becomes obsolete and must be completely redesigned as new technologies are developed. One of the goals of the ORS program is the development of technologies that provide robust and flexible bus designs. The Space Avionics Plug-and-Play (SPA) system in development by Air Force Research Laboratory, Space Vehicles Directorate addresses the software and electrical interfaces, but other efforts are needed to address the mechanical and thermal interfaces. For responsive space, the ideal TCS would be modular and robust to accommodate the wide range of orbits, components, and payloads with minimal survival heater power. In addition, the design and assembly time must be dramatically decreased. The ultimate goal would be a TCS with an inherent plug-and-play capability. One hindrance is that the missions, payloads, and requirements for ORS are still somewhat nebulous. As a result, bus architectures and specific components have not been identified, which makes it difficult to derive even initial thermal system requirements. To provide a baseline for the TCS design and to help bound the problem for the development of thermal plug-and-play systems, the range of external and internal heat loads for small satellites are evaluated. From this analysis, the worst hot and cold cases are identified. Using these two cases, various design parameters are evaluated, and the feasibility of a one-size-fits-all approach is assessed. Finally, critical design parameters are identified and recommended figures of merit are established. | |
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| Paper Number RS4-2006-7002: Responsive Payload Accommodations and Integration Operations for Dedicated CubeSat Missions | |
| John M. Garvey (Garvey Spacecraft Corporation), Dr. Jordi Puig-Suari (California Polytechnic State University), Lori Brooks (California Polytechnic State University) | |
| View/Download:Presentation | Paper | |
| Abstract: A key factor to achieving responsive space operations is the availability of standardized payload accommodations that can simplify integration tasks and reduce costs. Several such standards are beginning to emerge in the very small end of the payload market that is characterized by the so-called CubeSat class of spacecraft. These also happen to be compatible with proposed nanosat launch vehicle (NLV) concepts that are intended to enable dedicated CubeSat missions that are free from the operational constraints associated with traditional secondary payload manifest opportunities. The Poly-Picosat Orbital Deployer (P-POD) under development by California Polytechnic University, San Luis Obispo (Cal Poly SLO) is one such system that is now transitioning to flight status. The viability and merits of such dedicated CubeSat missions was highlighted recently during flight testing of the Prospector 7 prototype reusable launch vehicle (RLV) that was developed by Garvey Spacecraft Corporation (GSC) and California State University, Long Beach (CSULB)). In this case, an engineering prototype of the P-POD unit manifested and then deployed a set of three simulated CubeSats twice within a period of just 3.5 hours. The entire program, from authority to proceed through launch, took only six months, as compared to lead times that are measured in years for larger launch systems. Future plans envision extending the operational environments that the P-POD will be evaluated under as the NLV development program transitions to higher-performance test vehicles. Besides continued evaluation of refined payload accommodations and integration techniques, it is anticipated that future CubeSat payloads will help monitor and characterize NLV payload environments. Throughout this endeavor, students from Cal Poly SLO, CSULB and other participating academic institutions will continue to gain valuable experience with flight hardware integration and responsive launch operations. | |
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| Paper Number RS4-2006-7003: Concept of Operations for Operationally Responsive Space | |
| Don Knight (General Dynamics C4 Systems) | |
| View/Download:Presentation | Paper | |
| Abstract: This paper provides a Concept of Operations (CONOPS) on how United States Strategic Command (USSTRATCOM) and theater Combatant Commands (COCOM) might deploy and employ, and how the services might organize, train, and equip an Operational Responsive Space (ORS) weapon system. Since this CONOPS only covers satellite systems, it uses the term ORS over Joint Warfighter Space (JWS) as JWS has evolved to include both space and near-space forces. While the paper does not necessarily reflect the views and/or positions of any service, combatant command, or Department of Defense, it is based upon over 30 different technical interchange meetings conducted over the last two years with a multiple of agencies involved with ORS. ORS satellites can augment Space Force Enhancement (SFE), Space Control (SC), and Space Force Application missions. For classification purposes, this paper only covers SFE operations, but also has some applicability to SC missions. Space Force Application requires its own separate CONOPS. The paper begins by identifying the various SFE missions an ORS could perform and recognizing that they fall into two natural orbit regimes: LEO and MAJIC. It then looks at four different trigger events that would cause the deployment of an ORS constellation. Next, the paper identifies launch parameters, constellation sizing, launch windows (to include a Time Phased Force Deployment List of ORS missions), and early orbit check-out timelines required to support the theater commander. Under employment, the paper first examines how the roles and responsibilities for an ORS would be divided between USSTRATCOM and the theater commander. It then presents how mission planning; collection; mission data downlinking; mission data processing; and telemetry, tracking and commanding would be accomplished. Switching to the services’ responsibilities, the paper provides an organizational structure to include the types and numbers of both the operational and acquisition units required. “Training the way we will fight” is a vital aspect of the warfighter acceptance of ORS and the paper identifies how peacetime training would be accomplished. The paper concludes with a table of allowance for equipping an ORS weapon system to include both an Initial and Final Operational Capability. | |
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| Paper Number RS7-2009-2002: Developing Autonomy Systems in ORS Timescales | |
| George Cancro (John Hopkins University Applied Physics Lab) | |
| View/Download:Presentation | Paper | |
| Abstract: Multiple methods exist for the development of on-board autonomy systems for spacecraft. Methods include rule-based systems, table-driven systems, scripting, and more advanced systems such as automated planning and model-based autonomy. Each of these autonomy development systems has unique advantages and disadvantages, but all of these systems fail to meet the timeliness requirements imposed by ORS. In order to develop autonomy systems in ORS timescales, a high-level user must be able to rapidly construct the autonomy system, rapidly test the autonomy system to ensure that the system will react correctly to faults, and then integrate the autonomy system into the spacecraft without interfering with other assembly processes. This paper describes a new development system, called ExecSpec, which rapidly develops and tests autonomy systems for Tier 2 or 3 ORS spacecraft. ExecSpec enables a high-level user to visually create spacecraft autonomy systems by drawing diagrams representing desired behavior or rapidly assembling an autonomy system from a diagram library. Once the diagrams are assembled, the autonomy system can be rapidly tested using visual stimulation of the diagrams by the user or through model checking, an advanced technique that performs an exhaustive search to find counter-examples where the diagrams violate requirements. Following testing, the diagrams are then loaded directly to the spacecraft via command into a generic, mission-independent, on-board interpreter. This enables a flexible method of integrating autonomy into the spacecraft process flow. This feature also allows a user to change diagrams post launch to support ORS Tier-1 activities or to modify the spacecraft functionality to work around post-launch issues. During operations, mission controllers can monitor execution of the system by viewing the design diagrams, which are animated according to telemetry from the on-board interpreter. Since the same diagram context is preserved from design through operations, mission operators can suggest changes directly to the design diagrams rather than writing change requests that have to interpreted and implemented by someone not involved in operations. This paper will contrast the ExecSpec system with current autonomy development methods in relationship to ORS development timescales. The paper will then describe the current state of the ExecSpec system which is currently at TRL 5. The paper will also detail a timeline for developing an autonomy system for an ORS mission with ExecSpec, showing each step of the process and how long it will take. Finally, this paper will demonstrate the process of modifying the same autonomy system in-flight. | |
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| Paper Number RS7-2009-3004: A New Paradigm for Responsive Space Missions | |
| Bill Jackson (Sierra Nevada Corporation Space Systems) | |
| View/Download:Presentation | Paper | |
| Abstract: SpaceDev (a subsidiary of Sierra Nevada Corporation) built and delivered the Trailblazer microsatellite as the first Operationally Responsive Space (ORS) “Jumpstart” mission, which was intended to demonstrate rapid assembly, integration, test, and launch processes. This “Jumpstart” mission was a multi-pronged effort to fly responsive payloads on the SpaceX Falcon 1 Flight 003 launch vehicle, which launched in August 2008 from Kwajalein Atoll in the Marshall Islands. This launch opportunity became available because the original payload for this launch had been de-manifested. The spacecraft was assembled, integrated, and tested at SpaceDev’s Poway, California facility. The rapid call-up time on this mission presented a number of difficult technical problems; including the absence of several critical long-lead items, a late flight radio change, a late requirement for encryption, lack of a ground station and mission operations center, and lack of any mission operations procedures. The SpaceDev Trailblazer team adopted an extremely aggressive “skunk works” approach that used a small, empowered, multi-disciplined team to meet difficult technical and schedule challenges. The SpaceDev team was able to demonstrate unusual flexibility and responsiveness by tailoring engineering processes to meet the demanding schedule. SpaceDev not only successfully delivered the Trailblazer satellite on budget and on schedule, but also developed a Mission Operations Center in Poway, and fielded much of the Ground Station equipment on Kwajalein. The Trailblazer satellite was launched on August 2, 2008. Unfortunately, a technical problem with the Falcon second stage separation sequence resulted in catastrophic failure of the launch vehicle, and the Trailblazer satellite did not achieve orbit. Despite the unfortunate launch vehicle failure, the Trailblazer program nevertheless made a number of significant accomplishments: ? Responsive spacecraft build and test (4 months) ? Responsive spacecraft-to-launch vehicle integration (< 1 week) ? Responsive Ground Station development ? Responsive Mission Operations Center development ? Responsive contracting and administration ? Successfully demonstrated an end-to-end launch call-up within 7 months of standing up the ORS office This paper will detail some of the many technical and programmatic challenges of this fast-paced program, and will discuss how SpaceDev was able to ultimately deliver a fully-functional spacecraft to ORS in just four months. | |
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| Paper Number RS7-2009-3007: Redefining the Word “Responsive” in ORS | |
| Stuart Eves (SSTL) | |
| View/Download:Presentation | Paper | |
| Abstract: The word "responsive" has been used in a temporal sense to define the Tier 1, 2, and 3 capabilities envisaged for ORS. The paper will demonstrate how small, agile satellites with a variety of possible operational modes can be used to perform a variety of different surveillance and communications functions, thereby offering a different, flexible form of "responsiveness" to the military users of the system. Some of these agile operational modes are possible with larger satellites, but many rely on the compact design of small satellites to deliver capabilities that are simply not feasible with larger, more strategically oriented designs. | |
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