Could I build an airship (rigid dirigible) that used a vacuum rather than lifting gas? There are other questions (c.f. What gas is used in airships to give them buoyancy?) that discuss the use of lifting gasses such as Helium and Hydrogen in airships. Helium is rare and Hydrogen is flammable.

If one could build a light-enough and strong-enough rigid outer frame, then couldn't one use a vacuum rather than lifting gasses?  At ground level, the frame would only have to withstand 15psi (100,000 pascals), which isn't a tremendous amount of force. Theoretically, a vacuum should provide even greater lifting force than any gas. 

Have there been any attempts at vacuum based rigid-dirigibles -- and if not, what are the technical or mechanical limitations to doing so?
what are the technical or mechanical limitations to doing so?


There is no known material that has a sufficient combination of lightness and strength to support a vacuum that would support the weight of the container on Earth at sea-level. 

There was a similar question with a good answer on Physics.se 


Beryllium Vacuum Sphere Boat/Aircraft



  Is it possible to make a solid rigid evacuated "balloon" out of Beryllium or other elements or alloys?


The currently first answer runs through the maths 


  calculated it over a database of almost 3700 materials including all common aerospace composites, metals and alloys.  


and concludes


  So in short, the best materials fall short of achieving our aim by a factor of just over 2. It is conceivable we might push up the stiffness / density ratio by perhaps developing some kind of Beryllium foam. For example, a closed cell foam of this Beryllium with a relative density of 0,041 would give a value of about 920 at the expense of lowering the Young's modulus to about 600MPa - however, I have no idea if such a foam is even possible. Alternatively it might be possible to come up with some clever engineering of the envelope geometry to overcome the buckling constraint. However, I suspect the effort is unlikely to pay off with a better boyancy ratio than is already achievable by conventional balloons.


Other related questions 


Is it possible to create a vacuum ballon using concentric partially pressured spheres?