i_have_no_enemies@lemmy.world to Technology@lemmy.worldEnglish · edit-23 days agoA Stunning Fusion Rocket Could Cut Interplanetary Travel in Half—and We'll Try It in Just 2 Yearswww.popularmechanics.comexternal-linkmessage-square15fedilinkarrow-up174arrow-down16file-text
arrow-up168arrow-down1external-linkA Stunning Fusion Rocket Could Cut Interplanetary Travel in Half—and We'll Try It in Just 2 Yearswww.popularmechanics.comi_have_no_enemies@lemmy.world to Technology@lemmy.worldEnglish · edit-23 days agomessage-square15fedilinkfile-text
https://web.archive.org/web/20250331084035/https://www.popularmechanics.com/space/rockets/a64256267/fusion-rocket-sunbird/
minus-squareJonC@programming.devlinkfedilinkEnglisharrow-up4arrow-down1·edit-24 days agoShip gets lighter as more fuel is destroyed. Ship gets heavier as it gets closer to light speed. At 90% of light speed, the ship’s mass would be around 2.3x its rest mass. I haven’t looked at your calculations in detail, but you seem to be missing that important point!
minus-squaregandalf_der_12te@discuss.tchncs.delinkfedilinkEnglisharrow-up4·3 days agothe mass increase due to relativistic effects is really really small, significantly smaller than the weight loss due to fuel consumption, which btw is described by the Rocket Equation.
Ship gets lighter as more fuel is destroyed. Ship gets heavier as it gets closer to light speed.
At 90% of light speed, the ship’s mass would be around 2.3x its rest mass.
I haven’t looked at your calculations in detail, but you seem to be missing that important point!
the mass increase due to relativistic effects is really really small, significantly smaller than the weight loss due to fuel consumption, which btw is described by the Rocket Equation.