Solestial To Equip Atomos Space Tugs With Solar Arrays

Solar energy startup, Solestial, has unveiled its plans to provide solar arrays for space tugs developed by Denver-based startup Atomos Space.

The collaboration involves Atomos testing a small photovoltaic panel from Solestial on an upcoming orbital transfer vehicle (OTV) demonstration, scheduled to launch aboard a SpaceX Transporter rideshare flight in early 2024.

In addition, Solestial will supply at least 20 kW of ultra-thin, low mass, radiation-hardened solar blankets to power two of Atomos' solar-electric OTVs, anticipated to take flight between late 2024 and early 2025. The company said its 20-micron thick cells demonstrate over 20% efficiency.

Atomos' decision to partner with Solestial is rooted in the superior performance and cost-effectiveness of Solestial's technology.

"In terms of 'kilowatts of output per kilogram of array, Solestial's solution was really best in class… We can get 20 kilowatts of solar arrays for less than 100 kilograms." - Vanessa Clark, Co-Founder and CEO of Atomos

The solar arrays are a critical component for Atomos' OTVs, which are designed to facilitate rapid transportation of commercial and government satellites between low-Earth orbit and geostationary orbit, as well as within geostationary transfer orbits. The limitations of current solar array technology and chemical propulsion in achieving these mission objectives, make Solestial's technology a pivotal enabler for Atomos' business and its customers.

Credit : Atomos

Stan Herasimenka, Co-founder and CEO of Solestial, stressed the significance of being an "alpha customer" for Atomos and the trust that this entails in both the team and the technology.

Solestial is actively conducting stress tests on its technology on the ground and has also dispatched small solar panels to various customers for on-orbit demonstrations.

Their silicon solar cells have been validated by the French Alternative Energies and Atomic Energy Commission under sunlight at 90 C (194 F), affirming their efficacy in countering radiation damage under sunlight at elevated temperatures, a crucial factor in space applications. This means the cells essentially self-heal under radiation damage.

Solestial’s silicon solar cells open circuit voltage dropped by only 4% and maintained 96% of initial value after being exposed to radiation equivalent to 10 years in low Earth orbit.

“Annealing of radiation damage in silicon is straightforward at high temperatures, for example, above 200-250°C, but this is not useful for applications in space as these temperatures are rarely, if ever, experienced in situ...The differentiation factor here is that Solestial’s cells can cure radiation damage at normal operating temperatures for solar panels in space.” - Romain Cariou, Space Silicon Solar Applications Expert, CEA. “

The partnership between Atomos and Solestial was cultivated during their participation in the 2019 Techstars accelerator program, where the respective founders first connected. This collaboration follows successful fundraising efforts by both companies, with Solestial raising $10 million and Atomos securing $5 million in 2022.

Solestial plans to open a manufacturing facility capable of producing 10 MW per year of solar blankets in 2025.