SpaceX to Try Rocket Landing During Satellite Launch Thursday: Watch Live

Falcon 9 on the Pad

Update, 6:55 p.m. EST Thursday (Feb. 25): SpaceX has called off Thursday's planned launch of the SES-9 communications satellite and the attempted landing of the company's Falcon 9 rocket on a ship at sea, apparently because of issues with the loading of liquid-oxygen propellant onto the booster. It is unclear at the moment when the next launch attempt will be. (The original launch preview story is below.)

SpaceX will try again to land the first stage of its Falcon 9 rocket on a robotic ship Thursday (Feb. 25), and you can watch all the spaceflight action live online.

The rocket landing attempt will come during the launch of the SES-9 commercial communications satellite for SpaceX customer SES. Liftoff is scheduled to take place at 6:46 p.m. EST (2346 GMT) Thursday from Cape Canaveral Air Force Station in Florida; you can watch it live here at Space.com, courtesy of SpaceX.

The liftoff and landing try were originally scheduled to take place Wednesday (Feb. 24), but SpaceX pushed things back a day.

"Team opting to hold launch for today. Looking to try again tomorrow; window also opens at 6:46pm ET. Rocket and spacecraft remain healthy," company representatives said Wednesday afternoon via SpaceX's Twitter account, @SpaceX, about 30 minutes before the planned liftoff.

You can also watch the action live directly via SpaceX, at http://www.spacex.com/webcast or https://www.youtube.com/watch?v=Ml1RO4IcOG0.

If everything goes perfectly, the Falcon 9's first stage will separate about 2.5 minutes into flight. While the second stage carries SES-9 to geostationary transfer orbit (GTO), the first stage will perform a series of engine burns and come back for a vertical touchdown on "Of Course I Still Love You," one of SpaceX's two "autonomous spaceport drone ships," which will be stationed in the Atlantic Ocean off the Florida coast.

But SES-9's journey to GTO will make the rocket landing difficult, SpaceX representatives said.

"Given this mission's unique GTO profile, a successful landing is not expected," they wrote in an SES-9 mission overview.

SpaceX has attempted drone-ship landings three times before — in January 2015, April 2015, and just last month — and each time nearly pulled off the historic maneuver. The January 2016 try, for example, would have worked if all four of the Falcon 9 first stage's landing legs had worked properly, SpaceX founder and CEO Elon Musk has said. (One leg didn't latch securely, causing the booster to topple over and explode on the drone ship's deck.)

In December 2015, SpaceX succeeded in soft-landing the Falcon 9 first stage back on terra firm at Cape Canaveral, marking the first time this had ever been done during an orbital launch. (Blue Origin, the company established by Amazon.com founder Jeff Bezos, landed its New Shepard vehicle in November, but that milestone occurred during a suborbital test flight.)

These landing maneuvers are part of SpaceX's effort to develop fully and rapidly reusable rockets — technology that could reduce the cost of spaceflight by a factor of 100, Musk has said.

Follow Mike Wall on Twitter @michaeldwall and Google+. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.

Copyright 2016 SPACE.com, a Purch company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.