Update: SpaceX aborted the launch with 13 seconds to go, citing the issue with the positioning of an engine nozzle that’s responsible for steering the rocket in the second stage as the cause. The company said it was exercising “an abundance of caution” in postponing the launch, but wanted to be absolutely sure. The next launch window is at 9:38 AM ET on Sunday morning.

Update #2: Watch SpaceX’s second attempt.

At 10:01 AM ET (7:01 AM PT) SpaceX is set to launch a Falcon 9 rocket carrying a Dragon spacecraft for a resupply mission to the International Space Station. The Dragon vessel has 5,500 pounds of supplies for the ISS crew, including experiment support materials for over 250 studies and research projects. You can watch the launch live above, with the webcast kicking off approximately 20 minutes ahead of the launch window.

CRS-10 is the first launch for SpaceX from Launch Complex 39A (LC-39A), which is located at NASA’s Kennedy Space Center in Florida. The CRS-10 mission is, as the name indicates, SpaceX’s tenth resupply mission for the ISS, of a planned total of 20 maximum under the contract that SpaceX was awarded by NASA for commercial resupply services.

The launch will put Dragon into orbit, and then two days from now if all goes well the ISS crew will use the Canadarm2 robotic arm to capture the capsule and dock it with the station in order to transfer over the supplies. Dragon will stay at the ISS for around one month, then return to Earth with a planned water landing in the Pacific Ocean.

This launch is significant in a number of ways: It’s the first SpaceX launch from LC-39A, for instance, and the first Dragon mission since SpaceX’s return to flight after an explosion destroyed one of its rockets pre-launch last September, and its second flight since that incident in total. It’ll also be watched closely because, as SpaceX CEO Elon Musk noted Friday, engineers detected a “very small” leak in the rocket’s upper stage late in the day. This has been deemed not a threat to launch status, however, and to counter its potential impact there’s now an additional opportunity to abort the launch at T-60 in case any problems are detected specifically related to the leak.

SpaceX is also trying to recover its first stage rocket from the Falcon 9 used today, and will attempt to have it return the Landing Zone 1 at Cape Canaveral, which is a bit of a different process from its more recent attempts to recover rockets via its autonomous drone ship at sea.