News: Photovoltaics
29 June 2026
Ascent Solar’s thin-film space solar products undamaged in atomic oxygen exposure tests
Ascent Solar Technologies Inc of Thornton, CO, USA – which designs and makes lightweight, flexible copper indium gallium diselenide (CIGS) thin-film photovoltaic (PV) panels that can be integrated into consumer products, off-grid applications and aerospace applications – has announced the results of its preliminary atomic oxygen (AO) exposure testing for its space-grade thin-film PV products. Testing has shown significant resilience to atomic oxygen in low Earth orbit (LEO).
AO is a highly reactive and energetic particle that is the most predominant in LEO. Interaction with AO causes damage to many materials in the form of shrinking, cracking, erosion and oxidation. Specialty coatings and chemical treatments are often the most effective approach to enhancing the resilience of space-faring polymers, metal surfaces and composites.
In LEO, AO often degrades solar arrays by eroding the polymers used in blanket construction (which hampers their flexibility and exposes their electrical components to damage) and oxidizing metallic interconnects. AO can directly interact with compounds that cover the solar cells, causing oxidation that reduces their transmission of light to the photoactive portion of the cell, ultimately yielding less power over time.
Although silicon and gallium arsenide (GaAs) solar technologies are widely used in LEO, their long-term performance is often significantly encumbered by the highly reactive AO environment. Exposed cover glass adhesives, polymer encapsulants, interconnect coatings, and other protective materials are susceptible to erosion and degradation over time of a few percent to more than 10% over several years in LEO. This erosion contributes to power loss and reduced array lifespan. AO mitigation is a critical design consideration for ensuring reliable long-term operation.
Ascent has completed several rounds of AO exposure testing, with highly favorable results for space-grade products that include 1mil FEP (fluorinated ethylene propylene) film as the primary barrier and encapsulant. With exposure rates equivalent to that of six months on orbit at the altitude of the International Space Station (400km), results indicate zero loss of power. Ascent is moving forward with additional advanced AO exposure testing, simulating longer mission durations in this AO-rich environment.
“These positive results represent yet another critical value proposition of our PV technology, enabling spacecraft operators to endure the punishing conditions of space,” says CEO Paul Warley. “With best-in-class lightweight panels, a highly flexible and rollable form factor, as well as resilience to the stresses of launch, our PV continues to prove itself to be the best choice for orbital power systems, especially as the commercial space market continues its rapid orbital infrastructure expansion in the coming years.”
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