Japan launched a $1.2 billion joint satellite mission with NASA on Thursday to measure global rain and snowfall, filling coverage gaps and anchoring an international orbital network to supply scientists and forecasters a radar-like snapshot of global precipitation every three hours.Data from the Global Precipitation Measurement satellite fleet will help predict a range of natural cataclysms, from floods and cyclones to drought and famine.The 8,500-pound satellite launched from southern Japan on Thursday is the network’s centerpiece, helping officials tie together disparate measurements into a single dataset, a one-stop shop for researchers interested in global precipitation patterns.