Here's why SpaceX canceled its launch twice — and when the next attempt will be

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CLICK HERE TO LEARN WHY THE LAUNCH WAS ABORTED.

Scrubbing a launch is not uncommon in the rocket business, nor is it necessarily a sign that something is wrong with the rocket, or its cargo.

There are a number of factors to consider when launching a rocket including weather, fuel temperatures, and boats that stray too close to the launch pad.

And as of Thursday evening, the rocket was reportedly in good health. So why the cancellations?

SpaceX was originally scheduled to launch the 11,750-pound SES-9 telecommunications satellite on Wednesday, Feb. 24 out of its launch site at Cape Canaveral in Florida.

However, because of inclement weather, the SpaceX launch team postponed the launch a few hours before the scheduled lift off. SpaceX later added that the launch was also postponed, in part, out of concerns with the rocket's fuel.

"Out of an abundance of caution, the team opted to hold launch for today to ensure liquid oxygen temperatures are as cold as possible in an effort to maximize performance of the vehicle," SpaceX stated on its webcast website.

SpaceX began using a new kind of fuel with its upgraded Falcon 9 rockets last December, which now run on deep cryo liquid oxygen (LOX). This fuel has the benefit of being more dense than other rocket propellants, so you can pack more of it into rocket fuel tanks — which adds to its power — but the trade-off is that you have to chill it at -340 degrees Fahrenheit.

After SpaceX postponed the launch on Wednesday, the next available launch window was for Thursday evening. Everything looked good on Thursday until, seemingly out of nowhere, the launch team held the countdown with just 1 minute and 40 seconds to go.

SpaceX has not announced details for why they called off the launch. What we know is that the launch team decided to hold as the LOX was being pumped into the rocket.

“Preliminary (information) is that we were … looking at how much time we had left in the count to finish loading the liquid oxygen, and at that time, the launch team decided that we would need to hold the countdown,” SpaceX commentator John Insprucker said during a live webcast, as reported by Fortune.

At this point, anyone who's followed SpaceX launches knows that these delays are relatively common. And, in the end, it's far wiser — and cheaper — to be safe than sorry.

Sunday's rocket launch is scheduled to happen at 6:46 p.m. ET followed shortly by another exciting, and potentially historic, rocket landing attempt.

The landing attempt will take place about 10 minutes after lift off, when the first stage will turn around and use GPS tracking to guide itself onto SpaceX's floating ocean platform called "Of Course I Still Love You." The platform will be floating about 400 miles off Florida's coast.

If SpaceX succeeds, it will be the first successful rocket landing on board an ocean platform. This will be its fourth attempt, and while the company has stated that it has low expectations of success, these rocket landings are a novelty of 21st century spaceflight and worth getting excited about.