Editor's note: Read our recap of the launch here.

A little over a year ago, SpaceX pulled off a showy first launch for its new rocket, the Falcon Heavy. The flight dispatched founder Elon Musk’s cherry-red Tesla convertible, with an empty spacesuit dubbed Starman in the driver’s seat, on a multimillion-year journey around the solar system. After the launch, the rocket’s three first-stage boosters returned to Earth to attempt an unprecedented synchronized landing.

Now that rocket is getting ready to fly again. The Falcon Heavy represents SpaceX’s ambition of competing for lucrative heavy-launch commercial and government contracts, which would require transporting payloads weighing more than 40,000 pounds into geosynchronous orbit. If this second flight is successful, the Falcon Heavy will be much closer to satisfying the military’s strict requirements and landing those deals.

The first commercial flight of the Falcon Heavy, from Kennedy Space Center in Florida, is expected to launch at 6:35 pm ET today (Thursday). Originally scheduled to fly on Sunday, the launch was delayed twice due to unfavorable weather conditions. This mission will carry a Saudi Arabian telecommunications satellite, dubbed Arabsat 6A, into a geosynchronous orbit, where it will provide television, internet, and telephone services for countries in the Middle East, Africa, and Europe. A few minutes after launch, SpaceX will attempt to land each of the rocket’s three first stage boosters—two on landing pads near the launch site and one on a floating drone ship 600 miles off the coast. Last year, SpaceX successfully brought two boosters back to land, but fuel issues prevented the center core from sticking its landing.

[#video: https://www.youtube.com/embed/TXMGu2d8c8g

As the most powerful operational rocket in existence by a factor of two, the Falcon Heavy is nothing short of a technological marvel. With the thrust equivalent of about 18 747 airliners, it can hoist around 140,000 pounds into low Earth orbit and 58,000 pounds into geosynchronous orbit, more than enough to handle the 13,000 pound Arabsat. The Falcon Heavy’s main selling point, however, is that it is the only heavy launch vehicle in the world that has reusability baked into its design.

Each of the Falcon Heavy’s three first-stage boosters are borrowed directly from SpaceX’s flagship Falcon 9 rocket, so named for the nine Merlin engines that provide its thrust. Unlike the Falcon Heavy’s first flight, which used an older model of booster, today’s vehicle will consist of three new block 5 engine cores. SpaceX first launched the block 5 Falcon 9 rocket last May, and has flown these boosters 13 times since. The block 5 is designed to fly at least 10 times with minimal refurbishment between launches, and it offers a 7 percent increase in thrust over its predecessors.

If the Falcon Heavy can prove its mettle, it could cut the cost of heavy launches dramatically. Since 2004, the US heavy launch market has been dominated by the United Launch Alliance’s Delta IV heavy rocket, which has half the lift capability at approximately four times the cost. A single ride on the Delta IV heavy has been quoted at around $350 million, whereas a Falcon Heavy launch starts at $90 million for a brand-new rocket, a price point that may go as low as $70 million for launches using previously flown boosters.

For companies looking to launch a large satellite, the savings are significant. But SpaceX will likely find its biggest customer in the US government. The existence of the Falcon Heavy could be good news for future deep-space exploration missions, which often require heavy-launch capability to throw the spacecraft to Mars and beyond. These missions already have to fight to justify their cost, and between 10 and 20 percent of a mission price tag is generally reserved for the launch itself. If NASA can shave tens of millions of dollars off the cost of sending its spacecraft to other planets, these savings could, in principle, be used to develop exploration missions that would have otherwise been defunded.