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from the nothing-is-lighter-than-*nothing* dept.
A vacuum airship made of a homogenous material cannot withstand the atmospheric pressure on Earth for any material humans have yet discovered, which can be proven using the critical buckling load of a sphere. However, from an initial analysis of the vacuum airship structure and relationship to atmospheric conditions, Mars appears to have an atmosphere in which the operation of a vacuum airship would not only be possible, but beneficial over a conventional balloon or dirigible. In addition, a multi-layer approach, in conjunction with a lattice, would circumvent the buckling problems of a single homogenous shell. The lattice used to support the two layers of the vacuum airship shell can be made, using modulation of the lengths of the members, to fit the curvature of the vacuum airship precisely by following an atlas approach to the modulation.
The Martian atmosphere has a pressure to density ratio that is very beneficial to the operation of a vacuum airship; this is a result of the high average molecular weight of the atmosphere (relative to other planets in the solar system) and the temperature of the atmosphere, the trend for which can be observed from the ideal gas law. Through a more in-depth analysis of the vacuum airship model, it can be shown that the vacuum airship may theoretically carry more than twice as much payload as a modeled dirigible of the same size, a 40-meter radius, in the Martian atmosphere.
NASA Innovative Advanced Concepts (NIAC) Program. NBF.
(Score: 2) by Fluffeh on Wednesday April 19 2017, @06:03AM
Yeah, the EMDrive would work - if it does work :P
Part of the problem with using an Ion Drive though is due to the extreme velocities that it expels the propellant (why they are so efficient in the first place) would create all sorts of wake issues behind the craft - possibly in a dangerous manner to the craft itself even in a very thin atmosphere. I'm not sure though. I'm not saying it is impossible - just that thrust will be very hard. A propeller won't work much at all - there's 100 times less air to grab (and push) but also what is pushed will move easier due to the air it is pushed into not having the same outward pressure.
Maybe harvesting the ice, then using water as a propellant to create the thrust would work - but again, that means carrying loads of heavy fuel as thrust.