Over the past year, San Francisco space startup Planet Labs sent a trickle of shoebox-sized satellites into space. Next month, it will send a deluge when its new fleet of 28 “Doves” launch. It announced today that it will do so with the help of $52 million in Series B funding, led by Russian entrepreneur Yuri Milner. Felicis Ventures, Lux Capital, Industry Ventures and Ray Rothrock also joined as new investors. Planet Labs’ satellites take images of the Earth, which can provide data to the agriculture, environmental and other industries. The images are available to anyone for a fee.