Key points
- Rocket Lab releases a germanium-free space solar cell
- 31.5% efficiency and 40% lower cell mass
- China's US germanium export ban suspended until November 27
- Space Systems was 81% of second-quarter revenue
Rocket Lab (RKLB) has made available a space solar cell built without germanium. Conventional multijunction space solar cells use germanium substrates, and China is the leading producer of germanium in the world.
The cell is called IMM Apex. Brad Clevenger, president of Rocket Lab USA, said in the September 8 announcement that "customers gain access to a high-efficiency, lightweight, germanium-free product that combines proven reliability with faster production times." The solar business sits within Rocket Lab's Space Systems segment.
IMM Apex builds on an inverted metamorphic cell line with more than a decade of flight heritage. The earlier IMM technology powered NASA's Ingenuity Mars Helicopter and has been powering satellites on orbit, according to the release. What is new is the production release, with a Beginning of Life conversion efficiency of 31.5% and a cell mass 40% below conventional cells.
Rocket Lab describes IMM Apex as a mechanical and electrical drop-in replacement for heritage germanium cells, which the company says lets customers integrate it into existing systems "without major investments to re-tool for new cell technology." The release gives no price, names no customer for the cell, and does not say how much of Rocket Lab's solar output is now germanium-free.
What germanium does in a satellite solar panel
A space solar cell stacks several semiconductor layers so each one absorbs a different slice of the spectrum. The conventional way to build that stack is to grow the layers on a germanium wafer, which acts as the base the rest of the cell is fabricated on. The US Geological Survey lists germanium wafers used as substrates for multijunction space solar cells as one of the metal's main US end uses, and notes that a company in St. George, Utah makes those wafers, mostly for satellite solar cells, from imported and recycled germanium.
Germanium metal in Europe at 99.999% purity went from $1,550 per kilogram in January 2024 to $2,950 in September that year, according to the same survey. China supplied 51% of US germanium metal imports over 2020 to 2023. Washington has also funded expansion of the Utah plant. The Defense Department awarded 5N Plus, which makes space-qualified germanium substrates in St. George, $14.4 million in April 2024, Semiconductor Today reported. The company said it received a further $18.1 million in federal funding in January 2026.
China's export restrictions added another supply concern. On December 3, 2024, China's Ministry of Commerce issued a notice saying that "in principle, the export of the relevant dual-use items gallium, germanium, antimony, and superhard materials to the United States is not permitted," in a translation published by Georgetown's Center for Security and Emerging Technology. The same notice prohibits exporting dual-use items to US military users or for military uses. Beijing suspended that ban on November 9, 2025, and the commerce ministry said the suspension runs until November 27, 2026.
Where Rocket Lab's solar business came from
Rocket Lab bought the business rather than building it. The company closed its $80 million purchase of SolAero Holdings on January 18, 2022, picking up a solar cell plant in Albuquerque, New Mexico. That left Rocket Lab as one of only two domestic manufacturers of radiation-resistant compound semiconductors, Via Satellite reported in 2024. In June 2024 the Commerce Department signed a non-binding memorandum of terms to put $23.9 million of CHIPS Act money into the Albuquerque plant, with New Mexico adding $25.5 million, to lift compound semiconductor output by half within three years, per the same report.
More than 1,100 satellites now on orbit run on Rocket Lab solar products, per the September 8 release. The company has supplied space-grade solar technology to the James Webb Space Telescope and to NASA's Artemis lunar program.
Space Systems brought in $189.5 million of Rocket Lab's record $234.1 million of second-quarter revenue, the company reported in its quarterly filing, which is 81% of the total by our arithmetic. That figure covers the whole Space Systems segment, not solar products alone. Launch Services accounted for the other $44.6 million. Backlog reached a record $2.36 billion at the end of the quarter, Rocket Lab said with the results. Rocket Lab builds satellites as well as launching them, which not every publicly traded space company does.
Rocket Lab shares traded at $63.43 on Friday afternoon. The solar release went out after the close on September 8, when the stock finished at $65.87. Shares closed at $61.96 on Thursday.
