Elon MuskReuters/Bobby Yip

SpaceX, led by tech magnate Elon Musk, tried to fire off one of its Falcon 9 rockets tonight from Cape Canaveral, Florida.

However, engineers ultimately scrubbed the launch.

This marks the company's third fruitless attempt to get the rocket and its satellite payload off the ground since Wednesday, February 24.

The rocket was supposed to take off at 6:46 p.m. ET, but two problems forced SpaceX to give up.

An errant boat and supercooled oxygen

SpaceX Falcon 9 rocket at launchpad The Falcon 9 rocket on the launchpad in Cape Canaveral, Fla., on February 28, 2016. SpaceX

Right after SpaceX filled up its rocket with cryogenic fuel (a critical step in the launch countdown), a ship in the Atlantic Ocean slipped past a predetermined safety zone.

Musk said via Twitter that the company was "scrambling" to get the vessel to move, since — should anything go wrong — SpaceX didn't want to pose a threat to the people on board:

The boat eventually moved out of the way, and SpaceX resumed the countdown.

However, right at the T-minus-0 mark when the rocket should have launched, engineers called for an abort. A few minutes later, around 7:30 p.m. ET, they completely scrubbed the day's attempt.

It's uncertain what caused the last-minute abort, but Musk seemed to blame it on the boat:

Temperatures were a big concern going into this launch.

The rocket is specially designed to hold liquid oxygen that's much colder than normal — a blistering minus-340 degrees Fahrenheit — allowing it to store more of the oxidizer, achieve bigger, thrust and reach higher altitudes.

But any delay can cause ambient air to drastically heat up that oxygen and trigger problems. In this case, it seems the liquid oxygen (which burns the rocket fuel, called RP-1) and liquid helium (which helps pressurize and push out the propellants) got too warm.

John Insprucker, an announcer on the SpaceX live webcast, said it's not yet known when the company will attempt another launch.

Not your average rocket

The payload for Sunday night's launch wasn't all that unusual: It's a communications satellite called SES-9 that should bring better coverage over Asia.

But the 229-foot-tall Falcon 9 rocket is a very odd bird.

Most rockets cost tens or hundreds of millions of dollars, yet sink to the ocean bottom after they deliver a payload to space. After boosting SES-9 into geostationary orbit, however, the Falcon 9 will try to autonomously land a huge piece of itself on a robotic ship at sea.

SpaceX attempted this on two separate occasions in the past year, but both rockets toppled onto the robo-ship and blew up into fireballs. (A third Falcon 9 was equipped to land, too, but never got the chance because it exploded shortly after launch.)

spacex falcon 9 rocket landing first stage The first stage of a Falcon 9 rocket trying to land on a drone ship. (It exploded right after this photo.) SpaceX/Public Domain

In fact, the company said in a press release that "a successful landing is not expected" for its next attempt.

Translation: We think our rocket will most likely explode into bits when it tries to land itself.

Still, the stakes can't be ignored.

Each of SpaceX's Falcon 9 rockets costs about $60 million. If SpaceX can land even part of that hardware, clean it up, and refuel it for a future launch, it'd be a history-making event.

It might also help usher in an era of spaceflight that's radically less expensive. Musk has said that a 100-fold cost reduction is possible, should his rocket-recycling scheme prove as repeatable and reliable as flying an airplane.

And there's reason to believe SpaceX just might succeed this time. On December 21, 2015, the company launched and landed a Falcon 9 rocket on solid ground.

It's not a robotic platform wobbling in the Atlantic Ocean, but it's still pretty impressive.

Now if only they could only get the new rocket off the ground.