Personally, I would prefer to see a fixed wing unmanned aircraft used on Mars.Imagine one equipped with a pair of HD digital cameras and transmitting the images to an HMO orbiter relay overhead. Imagine such a craft flying through the martian grand canyon and recording and transmitting HD streaming video of such an awesome scenic flight.
The atmospheric pressure on Mars is so low that getting anything to fly won't be easy. I could *just* about imagine a super-capacitor powered lurch into the air followed by a barely controlled descent, all of which seems a bit of a reach, especially when you add any payload.
Now, put a helicopter on Titan, or Venus - then we'd be talking!
Quote from: Bob Shaw on 01/25/2015 09:45 pmThe atmospheric pressure on Mars is so low that getting anything to fly won't be easy. I could *just* about imagine a super-capacitor powered lurch into the air followed by a barely controlled descent, all of which seems a bit of a reach, especially when you add any payload.Did you actually watch the video? Especially the part where they were testing the helicopter in the JPL vacuum chamber at Mars surface pressure conditions? The number of ~500 meters per day was based on actual analysis of the current capabilities of the design without invoking supercaps or any other exotic technologies.In fact, given that they were able to get so much range out of a tiny (look like 10 cm2) solar cell, it really begs the question of if you could scale up the system and build a helicopter with an instrument package similar to Spirit/Opportunity. Given the issues with Curiosity's mobility system severely limiting its range, a "heli-rover" capable of traveling a km per sol (and then resting for a few sols to recharge take data) would be extremely competitive.QuoteNow, put a helicopter on Titan, or Venus - then we'd be talking!I don't know why you would want a helicopter on Venus. Anything at low altitudes would more like a high-temperature submersible, while at higher altitudes and Earth-like pressures, you don't want to sit still but rather move around and sample. I know for a fact that Northrop Grumman is working on a hybrid fixed-wing dirigible (think a plane with inflatable wings) to do just that.On Titan, a helicopter would work great, but the solar flux at the surface of Titan is so low that you just could not do it solar powered. It would have to be RTG-powered, which makes the vehicle much larger...
QuoteNow, put a helicopter on Titan, or Venus - then we'd be talking!I don't know why you would want a helicopter on Venus. Anything at low altitudes would more like a high-temperature submersible, while at higher altitudes and Earth-like pressures, you don't want to sit still but rather move around and sample. I know for a fact that Northrop Grumman is working on a hybrid fixed-wing dirigible (think a plane with inflatable wings) to do just that.
Yeah, the low blade length is surprising to me. Total thrust is a function of power and blade-sweep area; you can boost your thrust without increasing power usage simply by increasing the area swept out by your blades.But then again I'm sure they had a good reason, given the tests they've done. Maybe there was a concern about materials integrity with longer blades potentially reaching transonic speeds at the tip. The altered density and pressure of Martian atmosphere means a much lower local speed of sound.I suppose another reason to minimize blade length would be the physical size of the craft....