'Sledgehammer' winds have led SpaceX to postpone its launch to Friday

Due to high altitude winds, Elon Musk has announced that SpaceX will postpone its second launch of the year for this Friday.

"Pushing launch to Friday due to extreme high altitude wind shear. Hits like a sledgehammer when going up supersonic," Musk Tweeted.

This is the fourth time in one week - since last Wednesday - that SpaceX has postponed its mission to launch the Boeing-made SES-9 satellite into space.

Cancellations aren't necessarily a sign that anything is wrong. And as of Sunday, the Falcon 9 rocket was reportedly in good health.

SpaceX is simply being extra careful to make sure everything goes smoothly once the rocket lifts off the ground.

The reason this launch has garnered such attention is because of an attempted rocket landing that will swiftly follow the launch.

SpaceX has been trying for over a year now to land the first stage of its Falcon 9 rockets onto an ocean platform. The attempt scheduled to take place after Friday's launch will be SpaceX's fourth try for success.

Despite the fact that SpaceX has stated that it has low expectations of success, these rocket landings are a novelty of 21st century spaceflight and worth getting excited about.