BBC News By Richard Morris image captionLord West is a former cyber-security minister The Royal Navy and Britain's merchant fleet, along with most others around the world, rely on satellites for navigation - but what happens if they don't work? It's a question that troubles the former First Sea Lord, Lord West of Spithead, who has spent months trying to find out if the UK has a back-up plan. "My concern is that those people who are not friends with us are looking at ways to knock out satellite communications," he says. "I thought I'd ask the government, I thought they'd have processes, but it became very clear from their answers that they don't understand what the problem is.