SpaceX is in the business of making rockets reusable, and on Tuesday Elon Musk tweeted a video of one of the ways the company makes that happen.

Musk posted a video of a multimillion-dollar SpaceX reusable rocket part falling to Earth (after being used to protect the delivery of a satellite to orbit) and then being caught by a giant net on a boat in the middle of the ocean.

The piece of equipment is called a "fairing," or more colloquially a "nose cone," which protects satellites as they are launched into space, according to SpaceX. Once the rocket is launched into space, the fairing — which has parachutes and guidance technology attached — falls away. After all, fairings are expensive: A SpaceX fairing runs about $6 million, according to CNBC.

TWEET: Rocket fairing falling from space (higher res)

The first time SpaceX successfully caught a fairing was in June.

"We've just recently been successful in catching the nose cone of the rocket. ... that is a crazy exercise with [a] boat that's basically a giant catcher's mitt. The actual complexity of recovering the fairing is so nuts. Like, I'm not sure we should've done it," Musk said on "CBS Sunday Morning" in July.

The fairing falls from space with incredible speed and velocity, Musk said.

"It comes in hot," Musk said on "CBS Sunday Morning," with "super-heated plasma and sparks and stuff flying off of it."

"It's coming in at basically five times faster than a bullet from an assault rifle. It's insane," Musk said. "And then it hits the atmosphere, it goes subsonic [flying at a speed less than that of sound]. We deploy the parachutes. And the parachute itself is a steerable parachute.... So it's steering itself down...."

The boat also moves itself into place to catch the fairing.

"[T]he boat closes a data link with each fairing half. And the boat adjusts course automatically. And then the two just maneuver to touch each other," Musk says. "It's insane!"

TWEET: Rocket launch Hoping to catch the fairing in a few mins

SpaceX's goal is to build a fully reusable rocket to bring the per-launch cost down.

"Full and rapid reusability is the holy grail of access to space and is a fundamental step towards it, without which we cannot become a multi-planet species," Musk said on "CBS Sunday Morning." "We cannot have a base on the moon. We cannot have a city on Mars without full and rapid reusability. This is why we've been working so hard towards reusability at SpaceX and put a tremendous amount of engineering into achieving reusability of the boost stage and now of the fairing."

TWEET: View from the fairing during the STP-2 mission; when the fairing returns to Earth, friction heats up particles in the atmosphere, which appear bright blue in the video

Tuesday's video of the fairing being caught by a boat was from a launch of SpaceX's Falcon 9 rocket which launched from Cape Canaveral Air Force Station in Cape Canaveral, Florida.

See also:

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