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Proposal for a Vacuum Airship for Mars

posted by martyb on Tuesday April 18 2017, @09:56PM   Printer-friendly
from the nothing-is-lighter-than-*nothing* dept.

takyon writes:

https://www.nasa.gov/directorates/spacetech/niac/2017_Phase_I_Phase_II/Evacuated_Airship_for_Mars_Missions

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.

Original Submission

 
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  • (Score: 1) by khallow on Wednesday April 19 2017, @01:02PM

    by khallow (3766) Subscriber Badge on Wednesday April 19 2017, @01:02PM (#496269) Journal
    In addition, the hydrogen will expand as the balloon rises (the limit being the buoyancy of the Martian atmosphere which would be a much lower altitude than on Earth). Lift from vacuum is pretty much fixed, unless you have some complex, mass-adding mechanism for increasing the volume of the vacuum as the craft rises. But a light gas like hydrogen automatically expands, if allowed to (current high altitude balloon designs generally allow this), and that means near constant lift until one reaches the limits either of the balloon's capacity to expand or the Martian atmosphere to provide buoyancy.