[HN Gopher] Interstellar nuclear-powered transport (FJ Dyson) (1...
       ___________________________________________________________________
        
       Interstellar nuclear-powered transport (FJ Dyson) (1968) [pdf]
        
       Author : antondd
       Score  : 33 points
       Date   : 2021-08-10 18:57 UTC (4 hours ago)
        
 (HTM) web link (people.eecs.berkeley.edu)
 (TXT) w3m dump (people.eecs.berkeley.edu)
        
       | lovecg wrote:
       | The postmortem was a great read too:
       | https://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.69...
        
       | alex_young wrote:
       | More details and sketches of potential designs:
       | https://newatlas.com/orion-project-atom-bomb-spaceship/49454...
       | 
       | One thing I'm sure I don't understand: from a material science
       | perspective, how would you produce shock absorbers capable of
       | repeated and sustained shockwaves at 100 second intervals from
       | h-bombs? It seems like any material you select, as exotic as it
       | may be, will degrade pretty quickly. Doesn't seem like 200 years
       | will solve this problem.
        
       | andyxor wrote:
       | also see
       | https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...
        
         | hermitcrab wrote:
         | I spoke to Freeman Dyson at a book signing he did after a talk
         | about Project Orion (at the wonderfully named 'festival of
         | inappropriate technology'). I asked him about the environmental
         | impact. He said (from memory) that most big engineering
         | projects (dams, bridges etc) kill people, but nuclear pulse
         | probably shouldn't be used in the atmosphere. And wasn't worth
         | using if you weren't going to use it in the atmosphere.
        
       | ionwake wrote:
       | Weirdly I asked hn about this yesterday not sure what happened to
       | the thread but I'm super glad someone else picked up from there
       | it's been a great read thanks !
        
       | pkdpic_y9k wrote:
       | Seems like there might be but wondering if theres any overlap
       | here with the frozen brain solar sail nuclear bomb space
       | detonation acceleration idea from Liu Cixins Dark Forest romance
       | novel?
        
       | mariojv wrote:
       | One interesting tidbit toward the end is that the author thinks
       | building this ship is feasible within 200 years of the writing,
       | with a cost estimate of $10^11 in 1968 dollars, assuming a 4% GNP
       | growth rate. I haven't calculated what $10^11 would become in
       | 2021 dollars, but growth hasn't been that high since the 90s, and
       | it wasn't sustained growth, even then.
        
         | MichaelZuo wrote:
         | For a government project I would at least double the numbers.
        
         | TrainedMonkey wrote:
         | He gives a comparison estimate that each Saturn V cost about
         | 10^8 each. Per quick Google search actual cost in 1970s dollars
         | was $185m which is $1.15b today:
         | https://en.wikipedia.org/wiki/Saturn_V#Cost (important, but
         | unrelated to rest of computation fact is that this cost was
         | amortized over 35 flights)
         | 
         | 10^11 is 1000 * 10^8, applying same inflation to 10^11 we get
         | $1.15t. To put this number in a context, Iraq war is estimated
         | to have long term cost of $1.1tn to $1.92tn:
         | https://en.wikipedia.org/wiki/Financial_cost_of_the_Iraq_War
        
       ___________________________________________________________________
       (page generated 2021-08-10 23:01 UTC)