Lifters typically have a tether don’t they? So I think it depends on whether you consider the tether a moving part. It has to move for the craft to move…
A self contained unit like the MIT one is an improvement on the lifter, because the ion drive is itself an improvement on the lifter. Or at least, a production version of one. What they’ve done is get the mass to thrust ratio below a threshold that allows for flight in atmosphere. That’s definitely worth some points, but not all the points.
The tether is there to supply power and hold it down. Lifters require a power to weight ratio greater than one, which probably isn't possible with an on-board power supply. This MIT plane integrates the power supply and uses wing lift to reduce the required power, just as all planes do, and as the ionic propulsion planes did before (as others have linked to).
This is just the MIT press department embarrassing themselves again, or perhaps proving that sensationalism is a required part of science/funding these days.
Ground effect planes and to a lesser extent gliders are cheating and we can’t forget that.
But taking an ion propulsion system that previously only worked in vacuum and making it work at sea level is not nothing. I haven’t seen anything here to convince me it’s pure parlor trick. It’s part parlor trick for sure, but the sort that opens wallets.
How were they cheating? Lifters don't use ground effect at all. With a proper power supply, they have a power/weight ratio much greater than one. Does a helicopter or F22 Raptor cheat to fly?
> taking an ion propulsion system that previously only worked in vacuum
You misunderstand what this is. This ionizes air and accelerates it towards a surface with opposite charge. This design will not work in a vacuum, since it requires atmosphere [1] as a propellant. I built one of these thrusters when I was a kid using an old TV power supply. It takes some wire, aluminum foil, tens of thousands of volts, and a stomach for inefficiency (for example, the mentioned plane has a thrust of 6.25N/kW, the motor/prop on a drone is nearly 10x that). The only difference between a lifter and this is the direction of thrust, and the use of wings to supply lift, which all aircraft with a power to weight ratio less than 1.0 necessarily do. The accomplishment, and it is impressive, is the engineering to make it all light/efficient, given the terrible efficiency of these types of motors, while using the advancements in the energy density of batteries to allow it to be integrated.
> I haven’t seen anything here to convince me it’s pure parlor trick
I don't understand this. I don't think anyone is saying it's a parlor trick. It's impressive engineering. I just don't think it's accurate to say it's the first [2]. 20 years ago, there were sites with people attaching these to gliders (although, I can't find them anymore).
> This is just the MIT press department embarrassing themselves again.
Is the MIT press department capable of being embarrassed? Maybe they embarrass MIT, or at least people associated with MIT, but I don't think they embarrass themselves or they'd have changed their behavior.
