Solar Cell Degradation Due to Proton Belt Enhancements During Electric Orbit Raising to GEO

Abstract

The recent introduction of all‐electric propulsion on geosynchronous satellites enables lower‐cost access to space by replacing chemical propellant. However, the time period required to initially raise the satellite to geostationary orbit (GEO) is around 200 days. During this time the satellite can be exposed to dynamic increases in trapped flux, which are challenging to model. To understand the potential penalty of this new technique in terms of radiation exposure, the influence of several key parameters on solar cell degradation during the electric orbit raising period has been investigated. This is achieved by calculating the accumulation of nonionizing dose through time for a range of approaches. We demonstrate the changes in degradation caused by launching during a long‐lived (hundreds of days) enhancement in megaelectron volt trapped proton flux for three different electric orbit raising scenarios and three different thicknesses of coverglass. Results show that launching in an active environment can increase solar cell degradation due to trapped protons by ∼5% before start of service compared with a quiet environment. The crucial energy range for such enhancements in proton flux is 3–10 MeV (depending on shielding). Further changes of a few percent can occur between different trajectories, or when a 50‐μm change in coverglass thickness is applied.

Sequential Low-Thrust Orbit-Raising of All-Electric Satellites

“…A change in the material will require new training of the neural network; however, the methodology proposed here will remain the same. The empirical constants A , C, and D x for the triple junction solar cell, under consideration in this paper, are found to be 1, 0.306, and 3.63 × 10 9 MeV/g, respectively [53]. For orbits with high altitudes, damage dose will start to decrease as the inner Van Allen belt is mostly prominent in the vicinity of LEO and MEO.…”

“…The power degradation due to radiation is compared with a similar orbit-raising mission scenario presented in Ref. [53], in which case the remaining power after the transfer turned out to be 81.9 percent of the beginning-of-life power. Our degradation computation is close (79.98 percent), and the difference is likely due to the difference in maneuvering strategies.…”

Optimization of Radial Diffusion Coefficients for the Proton Radiation Belt During the CRRES Era

“…Gallagher et al, 2000;Denton et al, 2006;Ozhogin et al, 2012;Chu et al, 2017) allows better approximations. In addition, there is now a strong need for physics-based modelling of the inner zone given its increasing utilisation by commercial spacecraft (Lozinski et al, 2019;Horne & Pitchford, 2015).…”

OMEP-EOR: A MeV proton flux specification model for electric orbit raising missions

“…The CRRES PROTEL (Violet et al, 1993) instrument has provided good measurements in this region during less than two years in 1990 and 1991. This data has been extensively used to study the dynamics of the proton belt (Gussenhoven et al, 1996;Hudson et al, 1995;Lozinski et al, 2019). The solid state telescopes (SST) onboard the THEMIS constellation (Angelopoulos, 2009) have provided proton measurements since 2007, but it showed severe contamination in the MeV energy range due to electrons (McFadden et al, 2009).…”

“…One of the main effects of the radiative environment on EOR satellites is the degradation of the solar cells due to the proton-induced non ionizing dose (Anspaugh, 1996;Messenger et al, 2014), which leads to a degradation of the cell performance and reduces the available onboard power. It is known that these degradations are mainly driven by the proton fluxes between 1 and 10 MeV (Lozinski et al, 2019).…”