Long Beach–based space company Rocket Lab has launched a new space-grade solar cell that addresses a key supply chain bottleneck for spacecraft and satellites, while maintaining modern efficiency standards. The solar cell is called Inverted Metamorphic (IMM) Apex, which is produced without germanium substrates. Germanium is a scarce mineral critical to the production of highly efficient radiation-hardened solar cells. Most modern satellites and spacecraft need solar arrays for power generation, and many legacy solar cells on satellites use germanium substrates.
According to the company, the cells are 40% lighter than existing solar cells in the same class, and have a beginning of life solar conversion efficiency of 31.5%. As of 2026, some of the highest performing solar cells that rely on elements like germanium deliver a conversion efficiency around 32%. Silicone-based cells provide around 20% efficiency. While this isn’t the most efficient solar cell the company produces, the omission of germanium removes the supply chain pressure associated with the material. The cells also have the ability to slot into existing solar arrays without the need for redesign.
Rocket Lab also recently announced the introduction of silicon-based solar arrays specifically aimed at powering orbital data centers, suggesting a diversified solar array offering for multiple orbital applications. Apex was built on Rocket Lab’s existing flight-proven solar cells, which were used to power NASA’s Ingenuity Mars helicopter. A new version of the Ingenuity helicopter planned for NASA’s upcoming Skyfall mission will have rotor blades that break the sound barrier.
Germanium is a bottleneck for solar cell production because it’s relatively scarce and it’s used in high-demand materials like fiber optics. China used to be the primary supplier of germanium to the U.S., contributing approximately 41% in 2024. Bans instituted by China from 2023 to 2025 placed strain on its availability. These restrictions are part of a series of political maneuvers between China and the U.S., which also saw China making breakthroughs in homegrown chip manufacturing in response to restrictions on lithography machines.
The scarcity of germanium combined with global geopolitical factors means its cost has risen sharply. In January 2025 the price of European-sourced germanium was $3,150 per kilogram, which rose to over $5,000 per kilogram by October of the same year. China remains the leading producer of germanium, with imports to the U.S. shared by Belgium, Canada, Germany, and Russia.
While the silicon materials used by SpaceX are a viable alternative to current solar cell technology, silicon-based solar cells have limited utility in geostationary orbits or missions to deep space. Solar cell degradation in low Earth orbit is far more contained, where satellites are replaced every five to seven years. Silicon-based solar arrays used by SpaceX are also cheaper, which is necessary given the thousands of Starlink satellites currently in orbit. 
While less efficient silicon cells can be viable on larger solar arrays, deep space satellites already require even larger arrays due to less intense sunlight exposure, which can become a problem where stowed volumes are constrained. Rocket Lab may have an opportunity to see commercial success for the IMM Apex solar cells, however only time will tell.

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