How Satellites Could Make You Sick

Industry insiders say a space startup’s fuel could pose serious health risks on Earth

Underneath its Silicon Valley sheen, Apollo Fusion Inc. may be keeping a toxic secret. In Mountain View, Calif., a mile from the Google headquarters where its co-founder and several of its scientists used to work, the space startup is trying to develop better, cheaper propulsion systems for a new generation of satellites. Investors led by LinkedIn Corp. co-founder Reid Hoffman handed the two-year-old company $10 million in venture funding earlier this year, on the promise of breakthrough technology that Hoffman has said will “enable the second space race.” But if Apollo sticks with a plan it has shared with some potential customers, the losers may include everyone on Earth.

Apollo Fusion has designed its propulsion systems to use mercury as a fuel, according to four industry insiders with direct knowledge of its technology. NASA began moving away from mercury in the 1970s, owing to concerns about contamination on the ground. Even tiny doses of mercury, a powerful neuro toxin, can impair a person’s cognitive functions, leading to lower IQ, impeded motor skills, and decreased memory. Apollo pitched the toxic element as part of its technology to potential customers as recently as this summer, three of the insiders say. All four spoke on condition of anonymity, because they’d signed nondisclosure agreements. Propulsion experts say mercury is a tempting choice, despite the safety hazards, because its performance is better than that of alternatives like xenon or krypton.