Post-launch update: Despite some last minute concerns about strong winds and a wayward boat, SpaceX launched on Saturday morning from Vandenberg Air Force Base. The Falcon 9 rocket made a picturesque ascent, delivering its payload of 10 large satellites into low-Earth orbit (they should reach their final 625km orbit about 90 minutes after launch). The first stage then descended back to Earth and, for the first time, an on board camera provided views all the way down.

The rocket then stuck its landing on Just Read the Instructions, marking the first time the company has landed a booster in the Pacific Ocean.

First stage has landed on Just Read the Instructions pic.twitter.com/W0EoLaO4YR — SpaceX (@SpaceX) January 14, 2017

Original story: Today SpaceX will attempt to launch its Falcon 9 rocket for the first time since a fueling accident on Sept. 1, 2016, which destroyed the booster and its satellite payload on the launch pad. The instantaneous launch window for Saturday's attempt opens at 12:54pm ET (17:54pm UK), with liftoff occurring from Space Launch Complex 4E at Vandenberg Air Force Base in California.

After a rather quick investigation into the September accident, in which SpaceX concluded that one of three composite overwrapped pressure vessels inside the rocket's second stage liquid oxygen tank failed, the company has modified the fueling process. By taking a slower approach with its load and go fueling method, SpaceX expects to put less stress on the pressure vessels.

During SpaceX's last successful mission, the launch of JCSAT-16 in August, fueling of kerosene and liquid oxygen both began 35 minutes before launch. Now the company says kerosene loading will begin 70 minutes before launch, with liquid oxygen fueling beginning at 45 minutes prior.

Saturday's launch will boost 10 Iridium NEXT satellites to a 625-km orbit. These are the first 10 of 70 next generation satellites that SpaceX will launch for Iridium and its mobile voice and data satellite communications network. After boosting the satellites into space, the first stage of Falcon 9 will attempt a landing on the Just Read the Instructions droneship in the Pacific Ocean. The webcast should begin about 20 minutes before Saturday's launch window opens.

The launch attempt comes at a critical time for SpaceX, which has had two accidents with its Falcon 9 rocket in less than two years. A report released Friday suggested the company has gone from being moderately profitable to sustaining significant losses in the wake of those accidents. So now the company must begin flying its workhorse Falcon 9 rocket safely, and often. That effort starts Saturday.