An American skydiver has become the first person in the world to purposefully jump out of a plane at 7,620 metres (25,000 feet) without a parachute - and survive. 

Instead, 42-year-old Luke Aikins used a huge, 20-storey-high net to break his fall, after hurtling towards the ground at around 241 km/h (150 mph).

The stunt took 18 months and a whole lot of careful calculations to pull off - most importantly, a team of researchers had to make sure that the net was perfectly designed to slow Aikins down enough so he that wouldn't hit the ground, but not break his fall so quickly that it injured him. 

"Pay attention to the science and the math behind this. And we'll show you what's possible," said Aikins in the live-broadcast of the jump, which landed him in Simi Valley, California.

Aikins hasn't revealed exactly what material his net was made out of, but it was specially designed to be able to support the impact of his fall, while stretching enough to trap Aikins and stop him from bouncing straight back out again.

The 30 x 30 metre (100 x 100 feet) net - around the third of the size of a football field - was supported by four 61-metre-high (200-feet) cranes, putting it at a height of around 20 storeys.

There was also a second net below the first one, presumably in case something went wrong.

While free-falling through the air (something he'd done more than 18,000 times before this with a parachute), Aikins was guided by a high-tech system that showed him red lights on the landing site if he was off course, and green lights when he was heading in the right direction.

He was able to control his direction by angling his body against the wind - something that comes from years of practice.

His helmet also beeped faster as he headed closer to the centre of the net, and slower as he moved away from it.

He completed the jump face-down, before flipping onto his back at the last minute to land more gently. Within a few minutes he was up and hugging his family.

Before the stunt, he'd only trialled jumping into the net from 26 metres (87 feet), and according to NPR, he was originally going to wear a parachute as a back-up. But he changed his mind and took it off before jumping.

"I'm almost levitating, it's incredible," Aikins told the press after the jump.

He's not the first person to risk his life for science. Earlier this year, Norwegian physicist Andreas Wahl jumped off a building and had a gun shot at him to demonstrate the laws of physics.

And while we're always happy to see people putting their trust in science, let's all make a pact right now to never, ever try any of these stunts at home. Thank you.