Hacker News Reader

Comment by aphextron | Hacker News Reader

I'm far more interested in what these guys are working on with the Flyboard (https://www.youtube.com/watch?v=wObBrd9wB6M). Way more controllable and practical, and equally mind blowing.

View on HN

I just wish he was wearing a wing suit and had transitioned to horizontal flight.

Jetpacks are officially dead. The advantages of not lifting your own o2, of burning fuel using air, means that systems based on rockets are now done.

Then perhaps your first sentence should have read, "Rocket packs are officially dead".

I think that the terms have historically been used interchangeably, but the distinction should be made. It's awfully nice not to need to carry oxidiser for your propellant.

A rocket is something with only an exhaust. A jet also has an intake. And it goes a little further than just not lifting the 02. Any unburnt gas (air) becomes a 'working fluid' that can be pushed. A rocket moves by throwing gas away at speed. Jets also grab gas from the air and accelerate it along with exhaust products. That's why a jet or turbofan can have a high specific impulse with such a low exhaust velocity, higher (>8k) than even an ion thruster in vacuum.

Flyboard Air is so cool.

In terms of innovation, what do you think of their execution strategy?

The founder has extensive experience with Jet Skis, created an innovative hovering contraption using water jets and a business around it, then used some of that money to fund this next innovation - Flyboard Air.

Also, I've read that the engines are repurposed Jet Ski engines. Is this true?

Reply on news.ycombinator.com