| 1. |
- Ahlgren, Niklas, et al.
(författare)
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PRISMA Mission Extension : Adapting Mission Operations to New and Changing Mission Objectives
- 2012
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Ingår i: SpaceOps 2012 Conference. - Reston, Virigina : American Institute of Aeronautics and Astronautics.
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Konferensbidrag (refereegranskat)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.
(författare)
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The Prisma Formation Flying Demonstrator : Overview and Conclusions from the Nominal Mission
- 2012
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Ingår i: Advances in the Astronautical Sciences. - 0065-3438. ; 144, s. 441-460
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Tidskriftsartikel (refereegranskat)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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| 3. |
- Chapuis, T, et al.
(författare)
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FFIORD Architecture and Operational Concepts
- 2010
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Ingår i: Proceedings of DASIA 2010 Data Systems In Aerospace, by Ouwehand, L. ESA-SP 682. - 9789292212469
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Konferensbidrag (refereegranskat)abstract
- This paper presents the architecture and the operational concepts of the Formation Flying In Orbit Ranging Demonstation experiment (FFIORD) which is part of the PRISMA mission. This technological experiment, lead by CNES, is based on a specific Radio Frequency subsystem manufactured by Thales Alenia Space. The objectives are to assess the performances of the Flying Formation RF sensor (FFRF) and to validate the algorithms developed for various Formation Flying scenarios.
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| 4. |
- Delpech, M, et al.
(författare)
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Flight demonstration of formation flying capabilities for future missions (NEAT Pathfinder)
- 2014
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Ingår i: Acta Astronautica. - : Elsevier BV. - 0094-5765 .- 1879-2030. ; 105:1, s. 82-94
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Tidskriftsartikel (refereegranskat)abstract
- PRISMA is a demonstration mission for formation-flying and on-orbit-servicing critical technologies that involves two spacecraft launched in low Earth orbit in June 2010 and still in operation. Funded by the Swedish National Space Board, PRISMA mission has been developed by OHB-Sweden (formerly Swedish Space Corporation) with important contributions from the German Aerospace Centre (DLR/GSOC), the French Space Agency (CNES), and the Technical University of Denmark (DTU). The paper focuses on the last CNES experiment achieved in September 2012 that was devoted to the preparation of future astrometry missions illustrated by the NEAT and mu-NEAT mission concepts. The experiment consisted of performing the type of formation maneuvers required to point the two-satellite axis to a celestial target and maintain it fixed during the observation period. Achieving inertial pointing for a LEO formation represented a new challenge given the numerous constraints from propellant usage to star tracker blinding. The paper presents the experiment objectives in relation with the NEAT/mu-NEAT mission concept, describes its main design features along with the guidance and control algorithms evolutions and discusses the results in terms of performances achieved during the two rehearsals.
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| 5. |
- Karlsson, Thomas, et al.
(författare)
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PRISMA IRIDES : PERFORMANCE AT THE END OF THE DRIFT PHASE & PLANNED RENDEZVOUS EXPERIMENTS
- 2014
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Ingår i: 9th International ESA Conference on Guidance, Navigation & Control Systems, Oporto, Portugal.
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Konferensbidrag (refereegranskat)abstract
- PRISMA was launched on June 15, 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 with additional support from DLR, CNES, and DTU.PRISMA consists of two spacecraft: Mango and Tango. The Mango spacecraft is 3-axis stabilized and has a propulsion system providing full 3D orbit control. Tango is 3-axis stabilized with a solar magnetic control system and does not have orbit control capability. The two spacecraft were launched clamped together into a 700 km SSO and Tango was successfully separated from Mango on August 11, 2010.In April 2013, when both the nominal and extended mission phases were successfully completed, new objectives were assigned to the Mango spacecraft and the Tango spacecraft was shut down permanently. An eighteen month journey was started towards a new, non-cooperative space object to demonstrate rendezvous and inspection within an experiment called IRIDES (Iterative Reduction of Inspection Distance with Embedded Safety). The baseline rendezvous target is Picard.Since the start of IRIDES, the Mango spacecraft has completed a large series of optimized orbit manoeuvres that has put the spacecraft on a drift towards the new object. The rendezvous is expected in the second half of 2014 and will demonstrate optical relative navigation technologies and the characterization of the rendezvous object and its motion with the use of the on-board video system. The rendezvous strategy within IRIDES includes a series of collision free drift manoeuvres past the rendezvous object successively reducing the closest relative distance. The demonstrated technologies for this rendezvous are believed to play an important role in the future developments associated with space debris mitigation.The paper gives a brief introduction to PRISMA including a retrospective of the different achievements made in the mission. The paper then describes the optimized orbit manoeuvres made to acquire the drift orbit. The status of the drift finalization is then given where the initial manoeuvres performed to finalize the drift are described. The final part of the paper describes the planned activities within the rendezvous phase with focus on the IRIDES experiment.
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| 6. |
- Karlsson, Thomas, et al.
(författare)
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The PRISMA story : Achievements and final escapades
- 2013
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Ingår i: 5th International Conference on Spacecraft Formation Flying Missions & Technologies, Munich, Germany.
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Konferensbidrag (refereegranskat)abstract
- The Prisma mission is divided into four phases; the nominal mission, the extended mission, the external parties’ mission and the final mission. The milestones switching from one phase to the next are unique occasions that have brought the mission forward, whereof some were planned before the launch of the satellites and some were adaptations along with the development of the mission timeline. In particular, the current execution of the final phase contains Mango alone operation, which means Mango has abandoned Tango and has started a journey on its own for transfer to and rendezvous with a still to be decided space debris object. The rendezvous will be performed based upon TLE and angular measurements from the on-board camera and after the rendezvous a visual inspection and characterization of the object will be performed, utilizing the on board high resolution PR camera. This paper explains these milestones and the turn of events leading up to the events that were not planned. It also describes the past mission phases in a broader sense and the current final phase in more detail.
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| 7. |
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| 8. |
- Larsson, Robin, 1981-, et al.
(författare)
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Flight Results from SSC'€™s GNC Experiments within the PRISMA Formation Flying Mission
- 2010
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Ingår i: 61st International Astronautical Congress. - 9781617823688 ; , s. 6032-6041
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Konferensbidrag (refereegranskat)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. |
- Matko, Drago, et al.
(författare)
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Lessons learned from Space-SI Experiments on PRisma Mission
- 2013
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Ingår i: 45th International Conference on Spacecraft Formation Flying Missions & Technologies, Munich, Germany.
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Konferensbidrag (refereegranskat)abstract
- In the paper several lessons learned from the set of formation flying experiments, performed by the Slovenian Centre of Excellence for Space Sciences and Technologies (Space-SI) and OHB Sweden with Prisma Mango (for Main) and Tango (for Target) satellites in September 2011, are reviewed. First experiment performed was In-flight simulated radar interferometry where one satellite simulated SAR transmitter and receiver, and the other receiver only. Second experiment was the Observation of non-co-operative objects - space debris. On the basis of the space debris Two Line Elements, Mango was reoriented to point the Mango’s vision based camera towards the point of closest approach and several images were taken in a sequence. A challenging task is the close observation of the space debris. In our experiment Tango was simulating the debris and its 3D model was reconstructed from the shots taken by Mango. Next lesson was learned from the In-flight simulated distributed instrument where Tango was acting as the holder of the optical system with lenses and/or mirrors while Mango was acting as the holder of detectors. The last but not the least lesson learned from the experiments was acquired from the critical evaluation of formation flying models.
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| 10. |
- Matko, Drago, et al.
(författare)
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Validation of Astrodynamic Formation Flying Models Against SPACE-SI Experiments with Prisma Satellites
- 2012
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Ingår i: 26th Annual AIAA/USU Conference on Small Satellites, Logan, Utah, USA.
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Konferensbidrag (refereegranskat)abstract
- In this paper several astrodynamical formation flying models are assessed against the experimental results derived from the SPACE-SI formation flying experiments performed in September 2011 with the OHB Sweden developed Prisma satellites Mango and Tango. In these formation flying experiments critical manoeuvres for three types of missions were investigated with respect to in-orbit performances. The experiments included parallel flying with in track displacement demonstrating high-resolution optical dual satellite imaging and radar interferometric constellation, circumvolution as well as encircling of the target demonstrating debris observation and parallel flying with the radial displacement demonstrating fractionated spacecraft and accurate pointing of the formation. The astrodynamic data of the experiment are used to verify several formation flying models including a nonlinear model, a linear Hill-Clohessy-Wiltshire model, STK models with four propagators (Earth mass point, J2, default HPOP and HPOP with all disturbances) and the hereby originally proposed extension to the Hill-Clohessy-Wiltshire model, a linear model for orbits with small eccentricities.
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