Re:Seven earth-sized planets discovered circling a star 39 l...
by dragonwriter on Wednesday February 22, 2017 @07:32PM
(#13710609)
> Isn't that just a building with an engine in the basement?
No, it turns out that the requirements of generating thrust (which require generating energy and using it to toss something out the back of your ship) end up running into hard limits in the delta-V you can carry based on the available thrust-generating technology. Surviving 1g of constant acceleration in easy (well, I mean, it requires a certain degree of structural strength, which as mass gets large--which it will even with something delivering a minute payload--becomes challenging because of square/cube issues), but building something that can actually generate 1g of constant acceleration for 7 years is a non-trivial engineering challenge.
> Seems like one of the harder parts would be making sure it can survive freefall at launch, turnaround and arrival.
No, surviving free fall is a non-issue. Literally, that means surviving not having external forces acting on it. There's nothing to it.
No, it turns out that the requirements of generating thrust (which require generating energy and using it to toss something out the back of your ship) end up running into hard limits in the delta-V you can carry based on the available thrust-generating technology. Surviving 1g of constant acceleration in easy (well, I mean, it requires a certain degree of structural strength, which as mass gets large--which it will even with something delivering a minute payload--becomes challenging because of square/cube issues), but building something that can actually generate 1g of constant acceleration for 7 years is a non-trivial engineering challenge.
> Seems like one of the harder parts would be making sure it can survive freefall at launch, turnaround and arrival.
No, surviving free fall is a non-issue. Literally, that means surviving not having external forces acting on it. There's nothing to it.