But in 2018, Kevin Bell at the Public Employees for Environmental Responsibility (Peer), a US environmental organisation, was contacted by a space industry whistleblower. The insider told Bell that California-based Apollo Fusion had developed a new mercury-based thruster and was beginning to promote it to satellite manufacturers.
‘The whistleblower had contacted at least two other environmental organisations before us who had not responded or taken them seriously, as well as at least one state regulatory agency,’ says Bell. ‘I suppose they were just working their way through the environmental phone book and I happened to be the one that believed them.’
