Design of a set of orbital platforms to raise and lower the orbit of nanosatellites efficiently without using propellant, as a major piece of infrastructure for a space-based nanosatellite economy.

Author: Juan José García Ortiz
University Carlos III Madrid (Spain)

Space activities and attainability are constrained nowadays due to the high cost of rocketry employed put payloads in orbit. This study aims to design, analyze and optimize a network of orbital relay stations that can act as orbital energy accumulators to support other space missions.

The sustainability of such network lies in a balance between payloads being orbited and deorbited.

To test the viability of the proposed network, simulated missions are implemented in a programming environment in a way that can reproduce numerically the behaviour of the network in missions of increasing complexity. The design optimization of such missions is then performed assisted with a built-in genetic algorithm.

The results gathered prove that the energetic balance can be achieved providing an operation with minimal degradation. Proper mission design and station orbit spacing are key in defining suitable design conditions that yield the best case performance and the genetic algorithm is applicable to reduce the losses in off-design operating conditions.

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Design and fabrication of a thrust balance to measure a pulsed plasma thruster thrust force. This permits to verify the operation of the developed PPT thruster and identify potential improvements.

Author: Andrés Cabello López
University Carlos III Madrid (Spain)

A design of a torsional thrust stand has been developed to test a µPPT at Carlos III University facilities. The proposed design is able to measure single impulses in the range of 5 − 100 µNs and thrust forces in repetitive shot operation of 1 − 100 µN with a sensitivity of 0.776 µm/s/µNs and 6.365 µm/µN respectively. The resolution is estimated in 400 nNs and 100 nN. Two approaches have been faced to model the response of the balance: a simple pendulum analysis, and a flexible beam study. The contribution of both models allows covering the effects induced on the deflection by damping, the different punctual masses and the harmonic normal modes that arise due to the excitation of the thruster.

After an analysis of the requirements imposed and considering the different alternatives for all the subsystems and sensors needed, a complete design has been provided, searching for a convenient, simple, accurate and economical solution. The asymmetrical swing-gate configuration proposed employs a pair of flexural pivots and fits in the prescribed vacuum chamber. The linear displacement response is measured with a confocal chromatic optical pen and the damping is introduced with an eddy current system that can be manually regulated. The calibration method proposed is performed with a parallel plate capacitor to generate electrostatic forces and impulses in the range of the ones exerted by the PPT. A levelling system and alternatives as coaxial liquid connectors or batteries to
decouple the power supply lines from the exterior are also described to improve the performance of the stand and reduce the overall error. Finally, a complete CAD model has been developed.

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Refurbishment of an unused vacuum chamber for nanosatellite components testing under vacuum conditions (in accordance to ECSS  standards). The activities include the design and fabrication of a support structure for the vacuum chamber, the definition and purchasing of all necessary chamber components and a preliminary vacuum level testing.

University Carlos III Madrid (Spain)

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Creation of a versatile experimental set up to generate a plasma under controlled conditions in a tube. This experimental setup will permit to characterize the effects of the ionospheric plasma over the surfaces of nanosatellite components.

University Carlos III Madrid (Spain)

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Subsystems of ASTREA-C

Design of a small sounding rocket test platform to test nanosatellite components under a launch-like environment. The final outcome is a test plaftorm equipped with accelerometers to determine the mechanical (quasistatic and time-varying) loads to the payload and the shock of a parachute aperture.

University Carlos III Madrid (Spain)

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avionics bay assembly

Design and development of a prototype of a low-power (<30W) pulsed plasma thruster (PPT) system, with solid propellant and that can fit within 1U.

University Carlos III Madrid (Spain)

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Development of a free-space high speed data transmission optical link for the communication among nearby nanosats. The foreseen outcome is a basic prototype of a high speed nanosat photonic link.

University Carlos III Madrid (Spain)

Simulink FSK System scheme

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Design of a photonic sub-system based on a tunable Laser source (VCSEL) to interrogate on-board optical fiber sensors (FBGs) of temperature and strain. The activities include the design and manufacturing of the auxiliary electronics, the design of the temperature control for compact implementation, the characterization of the functional demonstrator in the dedicated electronics/photonics lab, and the design of space qualification tests for the FBG sensor. The final foreseen outcome is a prototype of a compact sub-system for FBG interrogation on nanosatellites.

University Carlos III Madrid (Spain)

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Manufacturing of a 3D model of the winning nanosatellite of the preliminary design competitions.

University Carlos III Madrid (Spain)

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