Tiny satellites from Silicon Valley may help track North Korea missiles

American intel analysts detected indications of an impending launch days before the missile firing

For years before North Korea fired its first intercontinental ballistic missile this week, the Pentagon and intelligence experts had sounded a warning: Not only was the North making progress quickly, spy satellite coverage was so spotty that the United States might not see a missile being prepared for launch.

That set off an urgent but quiet search for ways to improve America’s early-warning ability — and the capability to strike missiles while they are on the launchpad. The most intriguing solutions have come from Silicon Valley, where the Obama administration began investing in tiny, inexpensive civilian satellites developed to count cars