At 14:13 UTC on March 30th 2018, SpaceX launched a Falcon 9 from foggy Vandenberg Air Force Base. Although designated F9-52 this was the 51st Falcon 9 launch. Using a v1.2 variant booster, the rocket delivered 10 Iridium NEXT satellites into orbit. This was the fifth of eight planned Iridium NEXT missions.
From Vandenberg AFB Space Launch Complex 4 East, the first stage of the rocket lasted 2 minutes 34 seconds, separating a few seconds after. The second engine fired for 6 minutes 23 seconds. This part of the webcast was purposefully cut short due to a NOAA remote sensing licensing requirements. This is an issue with SpaceX not having the right licence to broadcast images from certain parts of space. This burn placed the rocket in a roughly 180 x 625 km parking orbit. The Thales Alenia Space satellite then deployed an hour after launch, after a second brief 11 second burn. This put the satellites into a 625km x 86.6 deg orbit.
The rocket used another “Fairing 2.0”, which is slightly larger than usual, but equipped with recovery systems. These systems include thrusters, a guidance system, and a parafoil. The ship, named Mr Steven has a large net to capture the halves of the fairing. Again, the ship failed to catch one of the fairings, due to a parachute system issue. In a tweet by Elon Musk, it was reported that the GPS guided parafoil twisted so the fairing impacted the water at high speed. He also said that SpaceX are doing helicopter drop tests to fix the issue.
Five of the six previously used Falcon 9 vehicles have been fully expended, this was the tenth flight of a previously-flown Falcon 9 first stage. Four of these ten have been purposely expended during their second flight. The first stage (B1041.2) was previously flown during the Iridium NEXT 3 launch on October 9th, 2017. It performed the 2 minute 34 second boost, and performed what SpaceX call a “simulated landing” into the ocean. SpaceX appear to be only launching a reused stages for one reflight, with the soon to launch “block 5” likely to be reused multiple times. Currently the company only have 4 first stages that might be flown, with one allocated for the upcoming CRS-14 dragon resupply mission.