SpaceX has successfully launched and landed the second Falcon 9 rocket in roughly 48 hours — giving SpaceX two wins in its “weekend doubleheader.” The nearly back-to-back launches are a show of strength for the company that has said it intends to up the pace of its launches.

The rocket took off today from California’s Vandenberg Air Force Base at 4:25PM ET, and delivered 10 satellites into orbit for the communications company Iridium. It’s the company’s ninth launch of 2017, and, six months in, are the most completed by SpaceX in a single year.

The rocket’s 230-foot-tall first stage, which houses nine engines, then touched down on the drone ship called Just Read the Instructions floating in the Pacific Ocean. Musk warned earlier in the day that the landing might be tricky, and weather conditions were described as borderline.

Launch at 1:25 delivering 10 satellites for Iridium. Droneship repositioned due to extreme weather. Will be tight. https://t.co/6ZcSG29B74 — Elon Musk (@elonmusk) June 25, 2017

Nevertheless, the rocket stuck the landing — marking SpaceX’s lucky 13th successful landing overall, and its eighth at sea. In fact, SpaceX hasn’t lost a rocket during an attempted landing since early last summer. Today’s leaves their landing streak still going strong with nine successes.

Sped up version of today's rocket landing on the Droneship Just Read the Instructions (guess it did) A post shared by Elon Musk (@elonmusk) on Jun 25, 2017 at 2:41pm PDT

That’s a big deal, because being able to consistently land the Falcon 9’s first stages means SpaceX can reuse them. Refurbishing used rockets — which otherwise can cost tens or even hundreds of millions of dollars to custom-build for each mission — is key to cutting launch costs.

Today’s Falcon 9 was a new one sporting larger, upgraded titanium hypersonic grid fins. SpaceX founder and CEO Elon Musk tweeted that these are made out of a single piece of cast and cut titanium, and that they can withstand the heat of reentry without shielding. After the launch, Musk tweeted: “New titanium grid fins worked even better than expected. Should be capable of an indefinite number of flights with no service.”

Closeup of the titanium grid fins. Not painted, as they glow red hot during a fast reentry. pic.twitter.com/Ltrq1Prg2m — Elon Musk (@elonmusk) June 25, 2017

The successful delivery of 10 Iridium satellites to space brought Iridium’s satellite count up to 20. That’s more than a quarter of the way to the planned 75-satellite constellation intended to boost phone and data coverage worldwide, and enable better aircraft tracking.

The back-to-back launches are the closest together so far for SpaceX, which launched a refurbished Falcon 9 booster just over 48 hours ago on Friday at Florida’s Kennedy Space Center. The reused rocket had previously delivered the first 10 Iridium satellites into orbit. On Friday, it sent Bulgaria’s first communications satellite to space, and the rocket’s first stage then landed on the “Of Course I Still Love You” drone ship in the Atlantic. It was the second ever successful landing of a reused rocket — but it was a little bumpy. Musk tweeted:

Rocket is extra toasty and hit the deck hard (used almost all of the emergency crush core), but otherwise good — Elon Musk (@elonmusk) June 23, 2017

SpaceX hadn’t planned for this weekend to be quite so busy. Friday’s launch was originally scheduled for last weekend, but it was scrubbed so a problematic valve could be replaced in the cone that holds the satellite (called the fairing). But the increased pace doesn’t seem to have harmed SpaceX’s track record of successful landings — and this weekend’s doubleheader is an early sign that SpaceX may be able to live up to its goal of more frequent launches.

Update June 25th, 5:40PM ET: Updated to include results of satellite deployment.