Ascent extends CIGS testing beyond low Earth orbit

Ascent Solar Technologies is expanding testing of its flexible CIGS photovoltaic technology beyond low Earth orbit, with new in-house characterisation campaigns planned for medium Earth orbit, geostationary orbit, and other higher-energy radiation environments. The work is due to continue through the fourth quarter of 2026.

The programme follows earlier testing associated with NASA that Ascent says showed the potential for its copper indium gallium selenide technology to recover from radiation exposure through self-annealing. The new work will examine whether comparable behaviour persists under the more demanding radiation conditions expected at higher orbital altitudes.

Radiation tolerance is a central qualification issue for spacecraft photovoltaics because energetic particles can damage semiconductor material and progressively reduce electrical output. The rate and nature of that degradation vary with orbit, mission duration, shielding, cell construction, and the radiation spectrum encountered by the spacecraft.

That makes performance in one orbital regime an incomplete guide to another. Low Earth orbit exposes hardware to a different environment from the regions encountered by spacecraft in medium Earth orbit or geostationary orbit, where accumulated radiation can impose tougher requirements on power-generation hardware intended to operate for long periods.

CIGS gives Ascent a different mechanical and materials architecture from the rigid solar cells used on many spacecraft. Its photovoltaic material is deposited as a thin film on a flexible substrate, allowing arrays to be designed around low mass and compact stowage as well as electrical output.

Those attributes become useful only if the cells retain predictable performance throughout the intended mission. Spacecraft power systems are sized around more than beginning-of-life efficiency: designers have to consider degradation, mass, deployment architecture, operating temperature, radiation exposure, and the power expected to remain available towards the end of the mission.

NASA research has previously reported strong radiation tolerance and self-healing behaviour in CIGS cells under some conditions. Ascent’s current programme is narrower than claiming complete immunity to radiation damage. It is intended to establish whether the recovery behaviour seen in earlier work remains significant when the material is exposed to the harsher conditions associated with MEO, GEO, and other high-energy environments.

That requires characterising both the initial damage and the extent of any subsequent recovery. A useful space-power technology has to provide engineers with sufficiently predictable degradation data to model array performance over a mission, rather than simply demonstrate that an irradiated laboratory sample can regain some output afterwards.

The orbital expansion also broadens the applications Ascent is considering. The company cites on-orbit servicing and assembly, space-based solar power, orbital data centres, and other emerging spacecraft concepts among markets seeking lightweight power systems capable of operating across several orbital regimes.

Those applications have very different power levels and mission profiles, so a positive materials result would not qualify one photovoltaic design automatically for all of them. Array structure, deployment mechanisms, electrical architecture, thermal behaviour, mechanical loading, and complete spacecraft qualification would remain separate engineering requirements.

Ascent operates an R&D centre and a 5MW nameplate manufacturing facility in Thornton, Colorado, giving it an in-house route from materials development into production. That capability is relevant to qualification because flight customers need consistent material and process control across production hardware, not simply favourable results from individual research cells.

The company says increased requests for multi-orbit solar solutions prompted the broader test campaign. Customer interest does not establish suitability for those missions, but it gives the characterisation programme a defined commercial target: determining whether the low-mass CIGS architecture can maintain useful performance as radiation conditions become more severe.

The tests planned through Q4 should provide a clearer boundary around those claims. If the recovery behaviour remains measurable under higher-energy exposure, Ascent will have additional evidence for extending its space-power platform beyond LEO. If it does not, the data will still define the degradation engineers must allow for when deciding where flexible CIGS arrays can be used realistically.