Historic SpaceX Rocket Landing: What Will Be Different Today

This time, SpaceX will try to stick the landing on a drone ship.

Launching from Vandenberg Air Force Base in California, SpaceX will try for the third time to land its Falcon 9 on a barge floating in the open ocean. Previous attempts had come close to landing on the barge but were destroyed when they narrowly missed the mark and suffered crash landings.


What Comes Next

If all goes according to plan, the Falcon 9's first stage will separate from its payload once it has left Earth's atmosphere. Cold gas thrusters will help the rocket complete a flip maneuver that will bring it barreling back toward Earth.

A series of engine burns will help control the rocket and as it nears Earth, while grid fins will provide aerodynamic guidance. Engines will ignite one final time before the rocket -- hopefully -- will land upright on the drone ship.

Why Not Just Do It on Land?

Musk said drone ship landings are needed for "high velocity missions," which would allow payloads, such as satellites, to reach a higher orbit. Nailing the landing is huge for SpaceX and space travel as a whole because Musk has previously said he believes reusing rockets -- which cost as much as a commercial airplane -- could reduce the cost of access to space by a factor of one hundred.

What Makes the Falcon 9 So Special?

While conventional rockets burn up on re-entry, SpaceX designed the Falcon 9 to be able to withstand the heat and land vertically so the rocket can be used again on a future launch. The Falcon 9 SpaceX returned to Earth last month has been inspected, and Musk said is free of damage and capable of firing again.

What Happened With Previous Attempts?

SpaceX's attempt this month will come nearly one year to the day the company made its first landing attempt on a drone ship and will mark their third attempt at an ocean landing. Video from one attempt shows just how close the rocket came to landing on the barge.

Get real-time updates as this story unfolds. To start, just "star" this story in ABC News' phone app. Download ABC News for iPhone here or ABC News for Android here.