EmDrive study officially published

Re:EmDrive study officially published by sonium on Saturday November 19, 2016 @03:48PM (#12995563)

To put into proportions: The radio isotope thermoelectric generator (RTG) of the Voyager spacecraft wheighs 37kg. So let's say we can build a spacecraft using this and the EM drive weighing a total of 50kg. The RTG produces 157W of power. This translates to a change in speed 30cm per day.

Bonus question: The power of the RTG halfes avery 87.7 years. What is the asymptotic speed the spacecraft will reach?

[ Parent | on HN ]

Re:EmDrive study officially published by photogrammetry on Sunday November 20, 2016 @03:45AM (#12997942)

Asking this is like asking how long it should take for a sperm cell to swim across the Atlantic Ocean.

The EMD is simply not applicable to scales where RTGs are used, much as a 5MW maritime diesel turbine is not applicable to swimming motions of a biological cell. The power density of Voyager is a hundred times lower than what an EMD ship would need.

[ Parent | on HN ]

Re:EmDrive study officially published by keenerd on Sunday November 20, 2016 @01:42PM (#13000334)

This is simpler to calculate than you might assume - you need only find the velocity after one half life and double it. Doing that gives you 15.4 km/s.

Of course this is considering only the decay of the plutonium and none of the active decay products. I've also disregarded the decrease in mass over time.

[ Parent | on HN ]

Re:EmDrive study officially published by chegra on Sunday November 20, 2016 @04:19AM (#12998041)

I am just going to go ahead and say c.

[ Parent | on HN ]