Outdoor Experiments
Stardust
Stardust is a for-profit startup aiming to secure government contracts to manufacture, disperse, and monitor reflective particles in the stratosphere. Though some details are lacking, the company claims to have conducted outdoor experiments and plans further outdoor testing of its technology.
Status
| Status | Undisclosed |
| Start/End | Undisclosed / Undisclosed |
| Location | Undisclosed |
| Type | Stratospheric Aerosol Injection |
| Experiment Type | Undisclosed |
| Funded By | Awz Ventures, SolarEdge, LowerCarbon Capital, Exor, Future Positive, Future Ventures, Never Lift Ventures, Starlight Ventures, Nebular, Lauder Partners, Attestor, Kindred Capital, Orion Global Advisors, Earth.now, Matt Cohler |
Description
Stardust claims to have developed a particle suitable for stratospheric aerosol injection (SAI), which it suggests is safer than the most studied potential material for SAI – sulphates. The company is seeking to patent this particle, and its composition has not been disclosed.
According to a 2023 “pitch deck” shared with potential investors, Stardust had already conducted outdoor experiments using “test particles” at low altitudes. These experiments were not revealed to the public until reporting in late 2025. An upcoming experiment, planned to start in April 2026, aims to test these particles inside modified jets flying at a height of 18 km (about 11 miles). Rather than releasing the particles, air from the stratosphere would be sucked into the jet, where the experiment would take place. Stardust has not revealed any further details of its experiments.
Stardust did not respond to our request for information on its experiments. Details for this page were drawn from reporting by Politico:
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