What is the likelihood of a chunk of concrete flying off and hitting the dome fast enough to break the glass?
Quote from: lamontagne on 10/31/2016 03:05 pmWhat is the likelihood of a chunk of concrete flying off and hitting the dome fast enough to break the glass? Look up what happened to Surveyor 3 when Apollo 12 landed 600 feet away. It was blasted by particles traveling at a minimum 70m/s. I think landing on the other side of the hill from the domes is a sensible idea.
How about a tunnel from the main dome to the landing/launch pads? You could keep the domes several kilometers away.
Quote from: Robotbeat on 10/31/2016 12:40 pmHow about a tunnel from the main dome to the landing/launch pads? You could keep the domes several kilometers away.As a transportation infrastructure, I expect a surface road and rovers is less expensive than a tunnel. The pad won't be used all that much after all, so low traffic. The pads might be further away, but then they wouldn't fit into the illustration any more. A little artistic licence there, perhaps. At least I'm not landing Petawatt class spaceships in the middle of cities with km tall towers ;-)
One thing to bear in mind is that Mars will either be an energy-rich and tunneling-intensive place, or else it won't be very much of an inhabited place at all.
..here..
Hi guckyfan, I might have just deleted the msg you were replying to. Moved it to the correct thread:Quote from: KelvinZero on 11/01/2016 08:29 am..here..
About a decade ago I worked with some ~40" glasses-free 3D 1080p plasma displays that shifted perspective 9 times as you walked around them. They required(and displayed) 18 video inputs. They worked pretty well, for any number of people from differing viewing geometries, simultaneously.Every time I read about the importance of windows in the ITS and transparent elements of habs being psychologically important on this site, I think back to those.
So is the need to live on Mars. If displays or VR were sufficient, they could just stay home and save a whole lot of money, risk, and comfort.
I put a bit of structure inside the dome.
Quote from: lamontagne on 11/01/2016 03:12 pmI put a bit of structure inside the dome.Hi lamontagne,I don't think flattened spheres are robust pressure containers. For example in the extreme, upper and lower sides approach flat and would be worse than cubes. I think you can elongate, but not flatten. Cigars and conical points are ok.. I think?Why not just go the full sphere? I posted a picture of a hydrogen tank in the other thread but just noticed there is a picture of it in a NSF article right now:https://www.nasaspaceflight.com/2016/10/ksc-groundwork-sls-block-1b-upgrades/These were the links I posted in the other thread:these gas tanks or this big liquid hydrogen tankEDIT:Ok I did a search on pressure tanks and did find lots of examples that look flattened at the ends. Can anyone explain that to me? (none of them where wider than they were tall though, and when I searched for high pressure tanks, more had spherical ends.)
I put a bit of structure inside the dome.Mostly platforms wit a lot of greenery. Could be sports areas instead. Possibly a floor of high intensity agriculture, but that might better be done in closed rooms with controlled atmosphere and lighting. Plants are happy in conditions that people sometimes find not all that pleasant...Again, most of the living area is actually underground, these are just entry points to the city.The exterior wall is a form of curtain wall, in a way. It's self supporting, mostly, and pressure driven, except for the gravity loads that are transmitted by columns to the ground.
You can look at the Wikipedia page "Pressure vessels". There is a nice, short overwrap pressure vessel. Or you can look at the propane pressure tank on your barbecue, if you have one. It's pretty stuby.The vessel will keep its shape because there are no compression forces, all forces push equally towards the exterior and the walls are under pure tension. But yes, an ellipsoid is less mass efficient that sphere. The strain in about double that of a sphere, or almost equal to that of a cylinder. So this allows manufacturers to use the same thickness throughout.