A Silicon Valley startup, Apollo Fusion Inc., founded by in 2016 by a Google VP and a professor of aerospace engineering, is trying to develop a better and more cost-efficient propulsion system. The catch? The company plans to use mercury as its fuel.
Mercury use is not a new concept: NASA has similarly considered it in the 1970s, but stayed away from the powerful neurotoxin because of concerns of contamination on the ground. A small dose of mercury can affect a person’s IQ, damage their motor skills and decrease memory performance. However, industry experts agree that despite the safety hazards, mercury has better performance than other fuel sources, such as xenon or krypton.
Some investors thus far seem convinced: the company has already received $10 million in venture funding to develop the breakthrough technology. Co-founder and Chief Executive Officer Michael Cassidy reassured Bloomberg, who first reported the story: “We are also committed to maintaining a low impact on the environment.”
On Earth, the rules regarding mercury use are stringent. The US government limits the mercury use in batteries and requires coal-fired power plants to use equipment that removes mercury from exhaust. What’s more, 128 countries signed the Minamata Convention that aims to reduce mercury emissions worldwide.
The caveat here is that the rules do not apply to Earth’s atmosphere – especially to satellites, which are under the purview of the Federal Communications Commission. The FCC does not monitor substances launched into space. “It’s a regulatory blind spot big enough to launch a satellite through,” says Kevin Bell, staff counsel at Public Employees for Environmental Responsibility, a nonprofit advocacy group.
So far, more than 80,000 satellites have flown in orbit, and approximately 2,000 remain operational. However, the numbers are expected to grow exponentially. For example, SpaceX plans to launch more than 4,000 satellites to provide a low-cost Internet service. Various companies have filed applications to send more than 20,000 satellites in the next 10 years.
Opponents worry that if Apollo Fusion’s mercury-driven technology catches on widely, the environmental impact could be significant. A constellation of 1,000 satellites would release 20 metric tons of mercury – in comparison, the entire United States currently emits about 50 metric tons per year. The argument against the mercury propulsion systems focuses on the fact that mercury would eventually return to Earth, contaminating oceans and soil. “It’s a very heavy element that is not going to easily escape the Earth’s gravity,” Steve Brooks, an associate professor of aerospace engineering at the University of Tennessee at Knoxville, told Bloomberg. “Almost all of the mercury that you put up there will find its way back down.”
At the moment, the technology and companies who are working with Apollo remain shrouded in mystery, and more announcements are surely coming. The bottom line is this: if Apollo succeeds, they can be opening the door for low-cost, high-power engines for satellites and spacecraft. If they are not, however, they risk creating a toxic atmosphere back on Earth.
Photo: RoscosmosJessica Zeitz