Reply To: General thought on old coal mines.

[zapkitty]

vansig wrote:

… Even with the most optimistic shielding estimates you still have to have over 4.2 metric tons of water with each power module in addition to the FF cores, caps, onion etc…

not quite. the power modules don’t need to be shielded from each other; so really there is just enough shielding to protect the payload and crew.

… and the people under your craft, above your craft, beside your craft, behind your craft…

Shadow shielding requires adding the operational costs of building dedicated special facilities unrelated and unattached to current cargo and passenger handling infrastructure and the need for exclusive routing in air and space will make it much more expensive than integrating a fully-shielded craft into the traffic control system.

vansig wrote: … but regardless, it seems the biggest problem to manage is heat, after all.

I think the problem is requiring ~1400 5MWe cores to do something that a Skylon or a Falcon 9 can do… and do much cheaper.

I’m still rebuilding my basic flight proposals so I’m figuratively down in the soup at the moment but I think you might be spending too much time in the upper atmosphere… how many G’s do you pull at the max?