SpaceX nails a tricky fourth rocket landing at sea

SpaceX is good enough at sea-based rocket landings that they've nearly become commonplace. The private spaceflight outfit has successfully landed a Falcon 9 rocket aboard a drone ship for the fourth time, or its sixth landing overall. And this wasn't a particularly easy trip, either. On top of the inherent challenges of a sea landing, the destination for the rocket's payload (the JCSAT-16 communications satellite) meant that the vehicle had to contend with both "extreme velocities" and high re-entry heat.

No, SpaceX still hasn't reused a rocket yet -- that's happening in the fall. However, the touchdown suggests that the company might just meet its objective of launching a rocket every two weeks by the end of 2016. There are no guarantees that it'll land every time (just ask SpaceX what happened in June), but the success rate is now consistent enough that Elon Musk and crew can expect that rockets will return intact.