Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 2610.28942

Optimized Bragg Grating Liquid Crystal Solar Sail

Sai Keshav Sasanapuri·Xiulian·Shan·Grover A. Swartzlander Jr
View original source ↗Read source document ↗Export metadata ↓

Abstract

We have designed a thin 3-layer sun-facing diffractive Bragg reflector comprised of a chiral polymeric liquid crystal film. Using Rigorous Coupled-Wave Analysis (RCWA), the stack was optimized to maximize the transverse radiation pressure force across the wavelength band 0.47 - 1.67 micrometers. The optimized structure operates on a single polarization state of light. A two structure stack, each operating on a different state of polarization, is predicted to provide a transverse momentum transfer efficiency of 51%. This study demonstrates how a wavelength selective Bragg grating may be used both as a sunshade to scatter sunlight away from the Earth, and as a solar sail for maintaining a prescribed orbit (such as the Earth-Sun L1 point) owing to the momentum transfer efficiency.

Explore related subjects

physics.space-phphysics.optics

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Sai Keshav Sasanapuri, Xiulian, Shan, Grover A. Swartzlander Jr. 2026-10-20. Optimized Bragg Grating Liquid Crystal Solar Sail. https://arxiv.org/abs/2610.28942

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

An Implicit Conservative Finite Volume Scheme with Poisson Brackets for the Steady-State Transport of Galactic Cosmic Rays

Galactic cosmic rays (GCRs) pose a persistent radiation hazard to astronauts and spacecraft in the heliosphere. Modeling their transport is essential for understanding how the solar wind and heliospheric magnetic field shape their spatial distributions and energy spectra. Timely predictions require solving for the particle distribution function much faster than real time, but explicit numerical schemes are restricted by the stability limit on the time step. In this Letter, we present an implicit conservative finite-volume scheme for kinetic equations formulated with Poisson brackets. This scheme conserves particle number, maintains the total-variation-diminishing property, achieves second-order spatial accuracy, and remains stable for time steps far beyond the explicit limit, while reaching quasi-steady states in less than ~1/100 of the computational time required for the explicit scheme, as demonstrated by numerical tests. We apply this scheme to the Parker transport equation along magnetic field lines in the background solar wind during Carrington rotation 2211, where it reaches steady-state GCR distributions within 10 iterations, about 1000 times faster than the explicit scheme. The GCR proton spectrum averaged over 27 days agrees with AMS-02 measurements to within 10%. The simulation also yields a realistic radial intensity gradient and captures the Forbush decrease features associated with three stream interaction regions observed at Earth.

physics.space-ph↗
arXiv2026

Multifidelity Monte Carlo for Efficient Estimation of Drag-Coefficient Statistics in Rarefied Satellite Aerodynamics

Very-low-Earth-orbit analyses require reliable uncertainty estimates for the aerodynamic drag coefficient, but repeated direct simulation Monte Carlo (DSMC) evaluations are expensive. We investigate whether cheaper collisionless models can reduce the computational cost of estimating DSMC-based drag statistics across different geometries. We also test whether improvements in the mean carry over to a variance reconstructed from two separately estimated raw moments. In the multifidelity Monte Carlo (MFMC) estimator, PICLas DSMC provides the high-fidelity response, while PICLAS test-particle Monte Carlo (TPMC) and the free-molecular Sentman panel model provide low-fidelity control variates. The benchmark contains four canonical Cube cases and scaled GOCE-like and CHAMP-like surface models. Each paired evaluation uses the same physical-input sample in all three models, and the reference values use 450 physically distinct DSMC evaluations per case. At the same estimation cost, DSMC-TPMC-Sentman MFMC reduces the RMSE of the mean drag coefficient in every tested case and budget, with median gains of 1.50-3.03. Variance estimation is less consistent: the three-model estimator improves three cases, performs close to HF-only Monte Carlo in two cases, and fails for GOCE-like. In that case, Sentman is only weakly correlated with the DSMC variance-related responses. Removing Sentman eliminates the negative estimates and improves the variance RMSE, although the decision to remove it was made after inspecting the results. MFMC therefore improves mean estimation reliably at reduced computational cost, but each low-fidelity model must be assessed separately for variance estimation.

physics.space-ph↗
arXiv2026

A Catalog of Dispersive Ionospheric and Plasmaspheric Arcs from Cislunar and Lunar-surface GNSS Radio Occultations

This dataset is a catalog of 263 dispersive arcs induced by ionospheric and plasmaspheric occultation observed in GNSS signals recorded by the Lunar GNSS Receiver Experiment (LuGRE) payload during Blue Ghost Mission 1 (BGM1), in cislunar space and on the lunar surface. Occultation arcs are identified and classified as ingress, egress or tangent by combining independently GPS and Galileo dual-frequency observables and computing the rate of the total electron content (ROT) and ROT index (ROTI), and are validated through a geometric criterion based on the grazing altitude of the tangent point. No distinction is made between the ionospheric and plasmaspheric contributions to each arc, which is treated as a single dispersive signature. For each arc, the catalog provides timing, grazing altitude, summary ROT/ROTI/$Δ$STEC attributes, the geomagnetic activity level, and time series of leveled slant total electron content (STEC), not corrected for instrumental biases, ROT, ROTI, tangent-point position and local time. The HDF5 (Hierarchical Data Format version 5) file contains a header with dataset-wide metadata and per-class statistics, and one entry per arc. It enables rapid selection of occultation arcs for statistical studies and targeted analyses, and complements ground-based and low Earth orbit radio-occultation data during the declining phase of solar cycle 25.

physics.space-ph↗