| 1. |
- Ahlgren, Niklas, et al.
(author)
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PRISMA Mission Extension : Adapting Mission Operations to New and Changing Mission Objectives
- 2012
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In: SpaceOps 2012 Conference. - Reston, Virigina : American Institute of Aeronautics and Astronautics.
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Conference paper (peer-reviewed)abstract
- The PRISMA in-orbit test-bed was launched in June 2010 to demonstrate strategies and technologies for formation flying and rendezvous. OHB Sweden is the prime contractor for the project which is funded by the Swedish National Space Board (SNSB) with support from DLR, CNES, and DTU. In early September of 2011, 15 months after launch, all primary mission objectives of the PRISMA formation flying satellites had been achieved and mission success was declared. Since a significant amount of delta-V capability still remained an open call for new experiments was issued, inviting both old and new experimenters to use the capabilities of the formation. Several interested parties took the opportunity to perform their own experiments with an existing platform, each coming with new mission objectives not previously planned to be flown on the PRISMA satellites. Some of these experiments were close to what had already been achieved within the nominal mission, but some included new ways of using the formation not envisioned by the spacecraft designers. The new experiments span from data collection in specific relative orbits, with a separation from a few meters to several kilometers, to entirely new modules within the on-board software. Changing from a pre-planned technology demonstration mission to operating a commercial resource required adaptation of the original operational concept, taking into account the different levels of experience of the customers and managing the satellites between experiments. This paper describes how these new mission objectives were integrated in operations and how a sometimes very short turn-around between initial concept and experiment execution was implemented with the aid of well established validation processes, high degrees of on-board autonomy and a flexible operations team.
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| 2. |
- Bodin, Per, et al.
(author)
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Guidance, navigation, and control experiments on the PRISMA in-orbit test bed
- 2007
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In: 58th International Astronautical Congress, IAC-07-C1. - 9781605601502 ; , s. 4461-4470
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Conference paper (peer-reviewed)abstract
- PRISMA will demonstrate Guidance, Navigation and Control strategies for advanced autonomous formation flying and rendezvous. The Swedish Space Corporation (SSC) is the prime contractor for the project which is funded by the Swedish National Space Board (SNSB). The project is further supported by the German Aerospace Center (DLR), the Technical University of Denmark (DTU), and the French Space Agency (CNES). PRISMA consists of two spacecraft: MAIN and TARGET. The MAIN satellite is 3-axis stabilized and has full 3D delta-V maneuverability that is independent of the spacecraft's attitude. The TARGET satellite has a simplified, yet 3-axis stabilizing, magnetic attitude control system and no orbit maneuver capability. This paper presents the PRISMA Guidance, Navigation, and Control (GNC) subsystem. The paper gives a mission summary and an overview of the GNC subsystem with its hardware and software configuration. It also explains how the orbit control functions contain advanced fuel optimal Model Predictive Control (MPC). It is shown how the GNC software is developed using model based automatic coding technology implemented with Matlab/Simulink. The paper then summarizes the different GNC experiments to be performed by SSC. Finally, an overview of the test approach for the subsystem is given.
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| 3. |
- Bodin, Per, et al.
(author)
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PRISMA : an in-orbit test bed for guidance, navigation, and control experiments
- 2009
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In: Journal of Spacecraft and Rockets. - : American Institute of Aeronautics and Astronautics (AIAA). - 0022-4650 .- 1533-6794. ; 46:3, s. 615-623
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Journal article (peer-reviewed)abstract
- This paper presents system-level hardware-in-the-loop real-time simulation results for three different guidance, navigation, and control experiments designed for in-flight demonstration on the PRISMA formation-flying satellite mission. The mission consists of two spacecraft: Main and Target The Main satellite has full orbit control capability, whereas Target is attitude-controlled only. Launch is planned for November 2009. The simulation results presented demonstrate the feasibility and readiness for flight as well as the expected in-flight performance. The three experiments include Global Positioning System and vision-based formation flying for two spacecraft in both passive and forced motion. In addition to these simulation results, the paper gives an overview of the PRISMA mission in general and the guidance, navigation, and control experiments in particular. The hardware-in-the-loop real-time test environment is also presented.
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| 4. |
- Bodin, Per, et al.
(author)
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System test results from the GNC experiments on the PRISMA in-orbit test bed
- 2011
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In: Acta Astronautica. - : Elsevier BV. - 0094-5765 .- 1879-2030. ; 68:7, s. 862-872
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Journal article (peer-reviewed)abstract
- The PRISMA in-orbit test bed will demonstrate guidance, navigation, and control strategies for spacecraft formation flying and rendezvous. The project is funded by the Swedish National Space Board and the prime contractor is the Swedish Space Corporation. The project is further supported by the German Aerospace Center, the Technical University of Denmark, and the French Space Agency. PRISMA was launched on June 15, 2010 and after three weeks of operations, all on-board systems and units have passed an initial commissioning phase. Separation of the two PRISMA satellites from each other is expected by mid-August 2010. PRISMA consists of two spacecraft: MAIN and TARGET. The MAIN spacecraft has full orbit control capability while TARGET is attitude controlled only. The Swedish Space Corporation is responsible for three groups of guidance, navigation, and control experiments. These experiments include GPS- and vision-based formation flying during which the spacecraft will fly in passive as well as forced motion. The three experiments are: autonomous formation flying, proximity operations with final approach/recede maneuvers, and autonomous rendezvous. This paper presents system test results from two of these experiments as obtained with the flight-ready system. The system tests consist of a series of simulations performed on the flight model spacecraft with a large amount of hardware in the loop.
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| 5. |
- Bodin, Per, et al.
(author)
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The Prisma Formation Flying Demonstrator : Overview and Conclusions from the Nominal Mission
- 2012
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In: Advances in the Astronautical Sciences. - 0065-3438. ; 144, s. 441-460
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Journal article (peer-reviewed)abstract
- The PRISMA in-orbit testbed was launched on June 15, 2010 to demonstrate strategies and technologies for formation flying and rendezvous. OHB Sweden (OHB-SE) is the prime contractor for the project which is funded by the Swedish National Space Board with additional support from the German Aerospace Center (DLR), the French National Space Center (CNES), and the Technical University of Denmark (DTU). In August 2011, PRISMA completed its nominal mission and during the fall of 2011, several additional activities have been performed under a mission extension program. The mission qualifies a series of sensor and actuator systems including navigation using GPS, Vision Based and RF technology as well as a propulsion system based on environmentally friendly propellant technology. The mission also includes a series of GNC experiments using this equipment in closed loop. Separate experiments are implemented by OHB-SE, DLR, and CNES and the paper provides an overview and conclusions from the nominal mission flight results from these experiments.
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| 6. |
- Chasset, Camille, et al.
(author)
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3-Axis magnetic control : flight results of the TANGO satellite in the PRISMA mission
- 2013
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In: CEAS Space Journal. - : Springer Science and Business Media LLC. - 1868-2502 .- 1868-2510. ; 5:1-2, s. 1-17
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Journal article (peer-reviewed)abstract
- PRISMA implements guidance, navigation and control strategies for advanced formation flying and rendezvous experiments. The project is funded by the Swedish National Space Board and run by OHB-Sweden in close cooperation with DLR, CNES and the Danish Technical University. The PRISMA test bed consists of a fully manoeuvrable MANGO satellite as well as a 3-axis controlled TANGO satellite without any ΔV capability. PRISMA was launched on the 15th of June 2010 on board DNEPR. The TANGO spacecraft is the reference satellite for the experiments performed by MANGO, either with a "cooperative" or "non-cooperative" behaviour. Small, light and low-cost were the keywords for the TANGO design. The attitude determination is based on Sun sensors and magnetometers, and the active attitude control uses magnetic torque rods only. In order to perform the attitude manoeuvres required to fulfil the mission objectives, using any additional gravity gradient boom to passively stabilize the spacecraft was not allowed. After a two-month commissioning phase, TANGO separated from MANGO on the 11th of August 2010. All operational modes have been successfully tested, and the pointing performance in flight is in accordance with expectations. The robust Sun Acquisition mode reduced the initial tip-off rate and placed TANGO into a safe attitude in <30 min. The Manual Pointing mode was commissioned, and the spacecraft demonstrated the capability to follow or maintain different sets of attitudes. In Sun/Zenith Pointing mode, TANGO points its GPS antenna towards zenith with sufficient accuracy to track as many GPS satellites as MANGO. At the same time, it points its solar panel towards the Sun, and all payload equipments can be switched on without any restriction. This paper gives an overview of the TANGO Attitude Control System design. It then presents the flight results in the different operating modes. Finally, it highlights the key elements at the origin of the successful 3-axis magnetic control strategy on the TANGO satellite.
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| 7. |
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| 8. |
- Larsson, Robin, 1981-, et al.
(author)
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Flight Results from SSC'€™s GNC Experiments within the PRISMA Formation Flying Mission
- 2010
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In: 61st International Astronautical Congress. - 9781617823688 ; , s. 6032-6041
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Conference paper (peer-reviewed)abstract
- The PRISMA in-orbit test-bed was launched on June 15, 2010. The mission will demonstrate strategies and technologies for formation flying and rendezvous. The Swedish Space Corporation (SSC) is the prime contractor for the project which is funded by the Swedish National Space Board (SNSB) with additional support from the German Aerospace Center (DLR), the French National Space Center (CNES) and the Technical University of Denmark (DTU). The PRISMA mission consists of two spacecraft: Mango and Tango. The Mango spacecraft is 3-axis stabilized and is equipped with a propulsion system providing full 3D orbit control capability. Tango is also 3-axis stabilized but with a simplified solar magnetic control system. The Tango spacecraft does not have any orbit control capability. The two spacecraft were launched clamped together into a 700 km altitude sun synchronous dawn-dusk orbit. After an initial commissioning campaign, Tango was separated from Mango on August 11. The mission includes the flight qualification of a series of sensor and actuator systems as well as the in-flight execution of a range of GNC experiments using this equipment. The spacecraft are equipped with Vision Based, GPS, RF-sensor navigation systems and has three different types of propulsion. The different GNC experiments are conducted by the participating organizations and this paper focuses on SSCs experiments. These consist of Autonomous Formation Flying, Proximity Operations with Final Approach/Recede Maneuvers, and Autonomous Rendezvous. By the beginning of September 2010, all essential equipment on the two satellites has been fully commissioned and the initial parts of the Autonomous Formation Flying have been initiated. The Autonomous Formation Flying is demonstrating aspects of flight in passive relative orbits and the transfer between different such orbits. The navigation is based on GPS and the control framework is linear Model Predictive Control (MPC) implemented for an arbitrary orbit, including eccentric orbits. This paper will focus on these earliest results from SSCs GNC experiments. The paper also contains a brief PRISMA system description and an overview of the GNC subsystem together with the SSCs GNC experiments.
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| 9. |
- Larsson, Robin, 1981-, et al.
(author)
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GPS navigation based proximity operations by the PRISMA satellites-flight results
- 2011
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In: 4th International Conference on Spacecraft Formation Flying Missions & Technologies. ; , s. 18-20
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Conference paper (peer-reviewed)abstract
- This paper presents flight results and lessons learned from the Proximity FormationFlying experiment developed and executed by SSC on the Swedish PRISMA mission.The paper will cover the design, flight results, operational aspects as well as lessonslearned. Proximity operations in PRISMA consist of forced-motion flight of Mangoaround Tango in the ranges from about 50 m down to 2 m. The forced motion is eitherdirectly around Tango or around a virtual structure defined about the Tango spacecraft.The purpose of the virtual structure is to mimic the circumflight about a large object withappendages and no-fly zones, such as the International Space Station (ISS).
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| 10. |
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