Drag reduction through shape optimisation for satellites in Very Low Earth Orbit

Walsh, Jonathan R.; Berthoud, Lucy; Allen, Christian B

doi:10.1016/j.actaastro.2020.09.018

Cited by 29 publications

(14 citation statements)

References 26 publications

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“…The state-of-the-art in the field of spacecraft shape design is described in Refs. [17,18,19,20]. In the available literature, the satellite shape variations are solely modifications of the front and rear geometries of the body individually and in combination, whereby the internal volume of the bodies is changed.…”

Section: State-of-the-art Of Satellite Shape Optimisationmentioning

confidence: 99%

“…The variation of the tail angle can be limited to 8 • according to Ref. [20] since there is only limited improvement in drag for larger angles due to a small refill angle of the void behind the body, i.e. the Mach angles of the atmospheric constitutes.…”

Section: State-of-the-art Of Satellite Shape Optimisationmentioning

confidence: 99%

“…Additionally, Ref. [20] concludes that there is a greater drag reduction potential for satellites with elongated shapes in general. For the given boundary and environmental conditions, a maximum reduction in drag of up to 35 % has been calculated for an elongated body by the variation of the front and rear geometries in combination (see Ref.…”

Section: State-of-the-art Of Satellite Shape Optimisationmentioning

confidence: 99%

“…For the given boundary and environmental conditions, a maximum reduction in drag of up to 35 % has been calculated for an elongated body by the variation of the front and rear geometries in combination (see Ref. [20]). However, the internal satellite volume is significantly reduced by this and thus the results are hardly qualitatively comparable to the results of the initial body without geometry changes.…”

Section: State-of-the-art Of Satellite Shape Optimisationmentioning

confidence: 99%

See 3 more Smart Citations

Optimisation of VLEO Satellite Geometries for Drag Minimisation and Lifetime Extension

Hild¹,

Traub²,

Pfeiffer³

et al. 2022

Preprint

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The utilisation of the Very Low Earth Orbit (VLEO) region offers significant application specific, technological, operational, and cost benefits. However, attaining sustained and economically viable VLEO flight is challenging, primarily due to the significant, barely predictable and dynamically changing drag caused by the residual atmosphere, which leads to a rapid deterioration of any spacecraft's orbit unless mitigated by a combination of active and passive techniques. This article addresses one passive method by optimising satellite shapes in order to achieve a minimisation of the atmospheric drag force and thus extension of operational lifetime. Contrary to previous investigations in the field, a constant internal volume is maintained to account for the placement of satellite instruments and payload inside the structure. Moreover, the satellite geometry is not varied heuristically but optimised via a numerical 2D profile optimisation specifically developed for this purpose. From the resulting optimal satellite profiles, 3D satellite bodies are derived, which are then verified via the Direct Simulation Monte Carlo method within the open-source particle code PICLas. In addition, rather unconventional designs, i.e. ring geometries, which are based on the assumption of fully specular particle reflections, are proposed and assessed. The optimised satellite geometries offer pure passive lifetime extensions of up to 46 % compared to a GOCE like reference body, while the above-mentioned ring geometries achieve passive lifetime extensions of more than 3000 %. Finally, the article presents design recommendations for VLEO satellites in dependence of different surface properties.

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Section: State-of-the-art Of Satellite Shape Optimisationmentioning

confidence: 99%

Section: State-of-the-art Of Satellite Shape Optimisationmentioning

confidence: 99%

Section: State-of-the-art Of Satellite Shape Optimisationmentioning

confidence: 99%

Section: State-of-the-art Of Satellite Shape Optimisationmentioning

confidence: 99%

See 2 more Smart Citations

Optimisation of VLEO Satellite Geometries for Drag Minimisation and Lifetime Extension

Hild¹,

Traub²,

Pfeiffer³

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

“…The increased atmospheric density at VLEO altitudes poses challenges such as increased atmospheric drag and disturbance forces, however, work is ongoing to address these challenges through the development of air-breathing propulsion systems [11,12], aerodynamic control surfaces [13], and aerodynamic materials [14]. No consistent definition of VLEO orbits has been agreed upon, with upper bounds of 300km, 450km, and 500km commonly suggested [15][16][17]. For the purposes of this work an upper limit of 400km is used.…”

Section: Introductionmentioning

confidence: 99%

Investigation of very low Earth orbits (VLEOs) for global spaceborne lidar

et al. 2022

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Very low Earth orbits (VLEOs) have been proposed as a beneficial space mission regime due to their propensity to increase instrument spatial resolution and reduce launch cost per unit mass. However, for visual instruments, these benefits come at the cost of a decreased instrument swath width. This reduction results in longer revisit periods for regions on Earth and longer time until global coverage is achieved. Conversely, light detection and ranging (lidar) as an active remote sensing technique, can benefit from larger swath widths at lower altitudes, due to the increased signal-to-noise ratio. Investigation of this relationship shows that lidar swath width is inversely proportional to altitude squared, and, as a result, the number of spacecraft required to provide a desired lidar coverage also decreases approximately in inverse proportion to altitude squared. Investigation of suitable propulsion systems shows that although propellant mass and number of thrusters required for orbit maintenance increases with decreasing altitude, the overall system mass, and hence launch cost, will, in general, tend to decrease with decreasing altitude due to the lower number of spacecraft required. For a given mission, spacecraft bus, and propulsion system, a VLEO altitude can be identified that will result in the minimum overall mission cost.

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