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The Nancy Grace Roman Space Telescope, set to launch in 2026, will bring unprecedented precision to measurements of weak gravitational lensing. Because weak lensing is an inherently small signal, it is imperative to minimize systematic errors in measurements as completely as possible; this will ensure that the lensing measurements can be used to their full potential when extracting cosmological information. In this paper, we use laboratory tests of the Romandetectors, simulations of the RomanHigh Latitude Survey observations, and the proposed Romanimage combination pipeline to investigate the magnitude of detector read noise biasing on weak lensing measurements from Roman. First, we combine lab-measured detector noise fields with simulated observations and propagate these images through the Romanimage combination pipeline, Imcom. We characterize the specific signatures of the noise fields in the resultant images and find that noise contributes to the combined images most strongly at scales relevant to physical characteristics of the detector including PSF shape, chip boundaries, and roll angles. We then measure shapes of simulated stars and galaxies and determine the magnitude of noise-induced shear bias on these measurements. We find that star shape correlations satisfy the system noise requirements as defined by the RomanScience Requirements Document. However, for galaxies fainter than mAB≃ 24, correction for noise correlations will be needed in order to ensure confidence in shape measurements in any observation band.

Geosynchronous orbits are appealing for solar or astrophysical observatories because they permit continuous data downlink at high rates. The radiation environment in these orbits presents unique challenges, however. This paper describes both the characteristics of the radiation environment in geosynchronous orbit and the mechanisms by which this radiation generates backgrounds in photon detectors. Shielding considerations are described, and a preliminary shielding design for the proposed Wide-Field InfraRed Survey Telescopeobservatory is presented as a reference for future space telescope concept studies that consider a geosynchronous orbit.