Rocket Lab is buying Iridium Communications in an $8 billion cash-and-stock deal – equipping the rocket maker with a global satellite network and wireless spectrum in what looks like a bid to compete against Elon Musk’s SpaceX.

Rocket Lab (RKLB.O) struck an $8 billion deal to acquire satellite communications provider Iridium Communications (IRDM.O) on Monday, betting that owning everything from rockets to satellite networks ...