Start your Sunday morning off right by watching a SpaceX rocket launch and landing. The company’s Falcon 9 is slated to launch from Cape Canaveral, Florida tomorrow, carrying a Dragon cargo capsule filled with nearly 5,500 pounds of supplies to the International Space Station. About 10 minutes after take off, the majority of the rocket will return to the Cape and attempt to land at SpaceX’s ground-based landing site, called Landing Zone 1.
It’s SpaceX’s tenth cargo resupply mission for NASA, but the launch is extra special given where the rocket is launching from. The Falcon 9 will take off from a pad at a site on the Cape called Launch Complex 39A. The pad is part of NASA’s Kennedy Space Center, and it’s been home to the biggest space missions of the past 50 years. The Apollo 11 mission launched from 39A, as well as the final flight of the Space Shuttle program in 2011.
The 39A pad has been dormant since then. But in 2014, SpaceX signed a 20-year lease with NASA to move into Launch Complex 39A and update the pad to support launches of the company’s Falcon 9 rocket and its future heavy-life vehicle, the Falcon Heavy. That refurbishment process has taken a while. “We had to reconfigure all the propellant systems,” CEO Elon Musk told The Verge in a direct message on Twitter. Before SpaceX moved in, the ground systems at the launch pad were made to support the Space Shuttle, which ran on liquid hydrogen and liquid oxygen. The Falcon 9, on the other hand, runs on a form of kerosene and liquid oxygen that’s much colder than what the Shuttle used.
The launch wasn’t supposed to take place from 39A, though. In fact, the plan was for the mission to happen last year from SpaceX’s other site at Cape Canaveral Air Force Station called Launch Complex 40. However, the launch was pushed back after one of SpaceX’s Falcon 9 rockets exploded on the pad at LC40 during a routine fueling procedure. The pad was badly damaged, and the company was forced to ground all of its rockets as it investigated the launch. In January, SpaceX said it had identified the source of the failure and was taking steps to ensure it wouldn’t happen again. The company then successfully returned to flight by launching one of its Falcon 9s from Vandenberg Air Force Base in California.
SpaceX’s Dragon capsule is carrying up a number of critical science experiments and technologies to the station. The vehicle will deliver strains of the deadly superbug MRSA to the ISS, so that astronauts can study how the bacteria behaves in microgravity. A piece of technology called SAGE-III is also headed up to the station, where it will be mounted to the outside of the ISS in order to study the ozone of Earth. And a module called Raven will also be traveling to space inside the Dragon’s trunk to test out a new type of navigation system for space.
Take off is scheduled for 9:39AM ET on Sunday, and afterward, the first stage of the Falcon 9 will attempt to touch down on Landing Zone 1. It’ll be the third ground landing attempt for SpaceX, but the first one to occur during they daytime. Leading up to the launch, weather wasn’t looking good for the mission, but conditions seem to have improved just before the weekend; there is a 70 percent chance that the weather will be favorable.
Meanwhile, SpaceX said on Friday it was investigating a helium leak in the upper portion of the rocket, but the problem hasn’t hindered the company from moving forward with the launch. Musk noted that an “abort trigger” had been added at T-60 seconds to liftoff, in case the leak caused enough of a loss in pressure. While the leak didn’t seem to be a problem for the first launch attempt on Saturday, the launch was aborted due to a “thrust vector control issue” in the vehicle’s upper stage.
NASA’s coverage of the event begins at 8:45AM ET, while SpaceX’s webcast begins 20 minutes prior to launch.
Update February 18th, 10:10AM ET: The launch was supposed to take place on Saturday, February 18th at 10:01AM ET. But the launch was aborted just 13 seconds before liftoff out of an “abundance of caution,” thanks to a vector control issue in the upper stage of the vehicle. SpaceX will try to launch again on Sunday at 9:39AM ET.