The generation ship in my fictional story was built by aliens that know how to use these 3 things: Artificial gravity to make it feel like earth throughout the ship. Controlled nuclear fusion with 6 tanks. Only 1 needs to be fueled and you have fuel that will last for at least thousands if not millions of years. Going at .5c(half the speed of light), this is no problem Artificial magnetic field to protect from high energy gamma ray bursts while still letting visible light through After they randomly select 5000 passengers that fit a certain set of criteria for being on board and in a 1:1 sex ratio with lots of genetic diversity, they use booster rockets that immediately detach once they are in space. They then use nuclear fusion. At half the speed of light, it takes them nearly 2 years to traverse the solar system. They arrive at Mars within minutes but all the planets from there take at least an hour to arrive at. But there is 1 main danger when going from Mars to Jupiter. That is the asteroid belt. A similar danger arises when they reach Pluto and the Oort cloud, but in this case it is comets, not asteroids. But there is 1 thing that puzzles me about the asteroid belt. Meteroids, some as small as a speck of dust, I have heard are more dangerous than asteroid collisions regardless of your speed. I get 1 factor into why meteroids are more dangerous, they are much more common than asteroid collisions with a spacecraft would be. But if the aliens were able to travel to earth, they probably ran into both of these things. Thus they would have developed technology for their ship to withstand both of these things a lot before they went to earth. So if the generation ship can withstand meteroids and asteroid collisions, meteroids would probably be as dangerous to them as a black hole is to us on earth, in other words, less than a 1% chance of them being dangerous, much less. Asteroid collisions in comparison are much more dangerous. Even though the ship is what takes most of the force of the collision, there would still be a lot of sudden force inflicted on both the aliens and the humans. Luckily, the aliens have a 2 thumbed hand with each thumb on the opposite side of their hand so their grip strength is much stronger than ours. If it breaks anything, it would likely be the eggs of which there can be 5-15 per clutch and there is 1 clutch every few years(yes, my reptilian aliens lactate). Anyway, for the humans, this sudden force from an asteroid collision is dangerous. Even with a very strong grip, the human hand just can't take that much force without letting go of whatever it is holding on to. Thus there would literally be a pile of humans with fractures in all sorts of places and probably some bad burns(the generation ship has a metal surface that is heated to a comfortable temperature. Since metal conducts heat, all the force from humans falling and sliding due to an asteroid collision could cause blistering burns). Obviously, my generation ship has a medical bay for this problem and more. But is my reasoning right? Is an asteroid collision with a very fast spacecraft as dangerous as I think it is? Would it really cause fractures and burns from all that force? Would humans even survive the force of an asteroid collision?