[Update: The Falcon Heavy launch was a success.]

SpaceX is ready to launch its biggest rocket yet on Tuesday afternoon from Cape Canaveral, Florida.

CEO Elon Musk's space company is aiming to launch Falcon Heavy for the first time. A successful flight would make the rocket the most powerful in use today – at a fraction of the cost of any other comparable rocket ever built. Musk has noted before that failure is a possibility for the demonstration flight, saying there is a "lot that can go wrong."

Falcon Heavy is now in place on launch pad 39A at NASA's Kennedy Space Center. The company will have until 4:00 p.m. EST to attempt a launch, or the mission will be scrubbed to a later day.

At liftoff Falcon Heavy will create a combined 5 million pounds of thrust – or the equivalent of about 18 Boeing 747 aircraft at takeoff. Musk has called it the "most powerful rocket in the world by a factor of two," and its payload is estimated to be nearly three times that of the former Space Shuttles, as well as the currently operating Delta IV Heavy and Ariane 5 ES rockets.

SpaceX also plans to attempt a recovery of Falcon Heavy's three boosters, returning two to the ground at Cape Canaveral and the final third to the company's autonomous drone ship floating off the Florida coast.