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Tesla Roadster is going to be able to hover over the ground, says Elon Musk

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Re: Tesla Roadster is going to be able to hover over the ground, says Elon Musk

#2
Anything that would replace the back seat of the car that generates thrust downward I would expect would cut into area that would be allocated for battery. So less area for battery but a major demand for the battery being added? Sounds like wishful thinking to me unless it’s just a few USB fans with spaceX written on the side of them facing down.

Re: Tesla Roadster is going to be able to hover over the ground, says Elon Musk

#4
post #2

Anything that would replace the back seat of the car that generates thrust downward I would expect would cut into area that would be allocated for battery. So less area for battery but a major demand for the battery being added? Sounds like wishful thinking to me unless it’s just a few USB fans with spaceX written on the side of them facing down.

Maybe they reduce the >600miles range to 60?

Re: Tesla Roadster is going to be able to hover over the ground, says Elon Musk

#5
With compressed air? No. I don't care how "not joking" he is, the power density is just not enough to lift a car for more than a few seconds even if the entire car were filled with tanks. It's just common sense. Have you ever seen compressed air VTOL on anything?

He also claims it will allow the car to accelerate "at the limit of human endurance" which would imply thrust vectoring also.

Perhaps he's testing the limits of human credibility...

Re: Tesla Roadster is going to be able to hover over the ground, says Elon Musk

#6
post #5

With compressed air? No. I don't care how "not joking" he is, the power density is just not enough to lift a car for more than a few seconds even if the entire car were filled with tanks. It's just common sense. Have you ever seen compressed air VTOL on anything ? He also claims it will allow the car to accelerate "at the limit of human endurance" which would imply thrust vectoring also. Perhaps he's testing the limi…

Even if it would work... what would hovering even do that is beneficial? Without tires touching the pavement, you won't turn or stop well at all. You will bottom out over every speed bump and driveway and parking lot entrance, unless you're hovering like a foot off the ground. The efficiency gains from the decreased rolling resistance will certainly not overcome the juice that these things will suck down...

Re: Tesla Roadster is going to be able to hover over the ground, says Elon Musk

#7
post #6
post #5

With compressed air? No. I don't care how "not joking" he is, the power density is just not enough to lift a car for more than a few seconds even if the entire car were filled with tanks. It's just common sense. Have you ever seen compressed air VTOL on anything ? He also claims it will allow the car to accelerate "at the limit of human endurance" which would imply thrust vectoring also. Perhaps he's testing the limi…

Even if it would work... what would hovering even do that is beneficial? Without tires touching the pavement, you won't turn or stop well at all. You will bottom out over every speed bump and driveway and parking lot entrance, unless you're hovering like a foot off the ground. The efficiency gains from the decreased rolling resistance will certainly not overcome the juice that these things will suck down...

Parallel parking?

(There are no "efficiency gains from decreased rolling resistance" if the tires aren't even touching the ground. Your wheels will spin without moving the car, an efficiency of 0%)

Re: Tesla Roadster is going to be able to hover over the ground, says Elon Musk

#8
Some time ago, Eaton invented a hydraulic hybrid system that stored hydraulic fluid under compressed air tanks from braking. It was incredibly efficient because of minimal conversion losses in a simple system. It didn't take off, sounds like what's mentioned

Re: Tesla Roadster is going to be able to hover over the ground, says Elon Musk

#9
Here’s the tweet that the article makes reference to:

> SpaceX option package for new Tesla Roadster will include ~10 small rocket thrusters arranged seamlessly around car. These rocket engines dramatically improve acceleration, top speed, braking & cornering. Maybe they will even allow a Tesla to fly...

[Emphasis mine.]

https://twitter.com/elonmusk/status/1005577738332172289?s=12

Re: Tesla Roadster is going to be able to hover over the ground, says Elon Musk

#10
post #5

With compressed air? No. I don't care how "not joking" he is, the power density is just not enough to lift a car for more than a few seconds even if the entire car were filled with tanks. It's just common sense. Have you ever seen compressed air VTOL on anything ? He also claims it will allow the car to accelerate "at the limit of human endurance" which would imply thrust vectoring also. Perhaps he's testing the limi…

> With compressed air?

Nope, with cold gas thrusters: https://twitter.com/elonmusk/status/1083128521801822213

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