3 ms·
I thought delta-v from LEO to Mars was over 6km/s? There are near-Earth asteroids at much lower delta-v. https://www.planetaryresources.com/2015/08/how-we-choos
by abecedarius 10y ago
I thought delta-v from LEO to Mars was over 6km/s? There are near-Earth asteroids at much lower delta-v. https://www.planetaryresources.com/2015/08/how-we-choose-our-asteroid-targets/ https://www.planetaryresources.com/2015/08/how-we-choose-our... gets into some of this.
At the 1km radius you give, a 2m human would have head at 0.2% lesser acceleration than feet. Am I miscalculating? Note that 1g is just one place in the design space, though an attractive one for a big enough station.
- tonmoy 10y agoI am probably wrong with the 4.3 number (compiled the first result from google without double checking). And it won't be 0.2%, the head's speed would be 0.2% of the feet, but since g=v^2/r, the gravity difference would be about 3%
- abecedarius 10y agoNo, g also equals omega^2 r. The angular velocity omega is the same for head and feet, leaving only the change to r. https://en.wikipedia.org/wiki/Circular_motion#Formulas https://en.wikipedia.org/wiki/Circular_motion#Formulas (So what's wrong with g = v^2/r? Nothing -- both v and r change in that change to g. To first order, they cancel out in the change to v/r, leaving only a linear factor.)
- tonmoy 10y agoYou are right, I was had made a very ugly mistake I guess
- abecedarius 10y agoNo worries! It's a natural mistake.