How does gravity affect space travel?

Think of it like this, in space there is no gravity. This makes it very hard to move. This is why spacesuits have mini propellers. And the reason why rockets well... have rockets.

the diagram which shows forces as either balanced = same speed or unbalanced = accelerarting

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.