SpaceX cargo resupply
The Falcon 9 launched a cargo resupply mission to the ISS and landed the first stage upright afterwards, on April 8, 2016. SpaceX

Early Monday morning on the East Coast, or late Sunday evening on the West Coast, Elon Musk was on Twitter and wanted to make sure everyone knew about his autonomous recovery ship named “Of course I still love you.” Musk replied to a story written by The Verge about a cargo ship that will operate without a crew by 2020 with a photo of his autonomous ship, designed for recovering his reusable rockets, with the phrase “Umm …”

The vessel “Of course I still love you,” is an ocean platform that Musk’s company SpaceX calls an "autonomous spaceport drone ship." It’s used as a landing platform for the first stages of rockets that launch heavy payloads to space and it is, as Musk pointed out, unmanned.

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The ship measures 300 feet by 100 feet and has wings attached to it that extend the width of it to 170 feet, says SpaceX. Additionally, the ship doesn’t anchor while awaiting the rocket’s first stage return, it relies on thrusters to keep it in place. While it does carry the 14 story tall rockets that have a landing span of 70 feet, it’s not exactly a cargo ship.

The ship The Verge wrote about is the first ever designed solely to autonomously transport cargo around the world. Instead of a crew the automated ship uses GPS, radar, cameras and sensors to traverse the ocean and other ships in it, reported The Verge. While the ship won’t be fully autonomous when it first launches, it will reach autonomy in stages with the last one hopefully completed by 2020. The ship is the result of a collaboration between technology company Kongsberg Gruppen and Yara International.

The cargo ship will produce zero emissions and will be able to take 100 containers of fertilizer about 40 miles from where it’s products to Larvik, Norway. It does a very different job than the autonomous ships of SpaceX. The Yara Birkeland ship will handle everything from docking and loading up the ship to avoiding collisions and unloading at its destination.

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While Musk’s tweet made a point, that the Yara Birkeland is not the first crewless ship ever, the specifics have to be noted. It’s difficult to compare his ships with the autonomous cargo ship as they have fairly different capabilities and tasks. The Verge has since added clarification into the story about the autonomous cargo ship, but Musk has yet to acknowledge it.