| 1. |
- Bazzocchi, Michael C. F., et al.
(author)
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Asteroid detumbling for redirection missions
- 2018
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In: 2018 IEEE Aerospace Conference. - : IEEE Computer Society. - 9781538620144
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Conference paper (peer-reviewed)abstract
- In order to accomplish most asteroid redirection missions, rotational control of the asteroid body is required. Small near-Earth asteroids tend to exhibit a significant range of rotational and tumbling properties. This work provides an analysis of asteroid detumbling using a formation of spacecraft. Through an orbiter and three landed thruster spacecraft, a low-thrust detumbling maneuver is performed on two illustrative asteroids. The asteroid scenarios are designed such that they reflect the characteristics of possible redirection scenarios. In particular the geometries, densities, angular velocities, and masses of the asteroids are adjusted according to available asteroid data to provide two unique redirection scenarios. The asteroid and spacecraft specifications are outlined, as well as the formulations for the detumbling maneuver. The results of the maneuver are discussed along with the key detumbling parameters and timeframe required.
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| 2. |
- Gannous, A., et al.
(author)
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Bridging the gap between testing and safety certification
- 2018
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In: IEEE Aerospace Conference Proceedings. - : IEEE Computer Society. - 9781538620144 ; , s. 1-18
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Conference paper (peer-reviewed)abstract
- DO-178C and its supplement DO-331 provide a set of objectives to be achieved for any development of airborne software systems when model-driven development approaches are in use. Fail-safeMBT is an academic recently proposed model-based approach for testing safety-critical systems. Fail-safeMBT is a potential innovative testing process that needs compelling arguments to be adopted for the development of aeronautical software. In this paper, we reduce the gap between industrial settings and academic settings by adopting the safety case approach and derive substantiation data aimed at arguing Fail-safeMBT compliance with the standards. We explain Fail-safeMBT processes in compliance with software process engineering Meta-Model 2.0, then apply Fail-safeMBT on the Autopilot system. Finally, we link Fail-safeMBT outputs to DO-178/DO-331 process elements, then we derive a substantiation from Fail-safeMBT outputs to support the compelling arguments for achieving certification objectives. Thus, we provide a validation of Fail-safeMBT in the avionic domain.
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| 3. |
- Pomares, Jorge, et al.
(author)
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Spacecraft visual servoing with adaptive zooming for non-cooperative rendezvous
- 2018
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In: 2018 IEEE Aerospace Conference. - : IEEE Computer Society. - 9781538620144
-
Conference paper (peer-reviewed)abstract
- The utilization of zooming cameras during a non-cooperative rendezvous in space is investigated in this paper. An image-based controller, utilizing visual servoing techniques usually applied to ground-based robotic systems, is designed for the particular problem of far-to-close approach of a spacecraft to a non-cooperative object. The controller directly utilizes the visual features from image frames of the noncooperative target for computing both attitude and orbital maneuvers concurrently. The additional feature derived from the utilization of the zooming camera gives a greater versatility to the maneuvers if compared with the classic fixed optics approaches. The stability of the proposed controller is proven analytically in the invariant space, and its viability is explored through the application to a realistic space debris removal scenario
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| 4. |
- Satpute, Sumeet, 1987-, et al.
(author)
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Concurrent Manuever Planning for Geostationary Satellites
- 2018
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In: 2018 IEEE Aerospace Conference. - : IEEE Computer Society. - 9781538620144
-
Conference paper (peer-reviewed)abstract
- In this paper, a planning method is developed using convex optimization for concurrent station keeping and momentum unloading maneuvers of geostationary satellites equipped with on-off electric thrusters. Prediction models for coupled orbital and attitude dynamics are used for generating concurrent maneuver plans. Since the satellite's attitude dynamics is fast compared to the orbital dynamics, a dual-rate model is proposed for addressing time scale differences of the two coupled systems. Based on such a model, a convex optimization problem is formulated and solved in a receding horizon form, which minimizes the fuel consumption and the number of required maneuvers. The proposed algorithm is verified using numerical simulations, taking into account major perturbations in the geostationary environment. The performance of the proposed method is analyzed in terms of fuel consumption and constraint enforcement.
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