Be sure to read the rule before you leave

You're replying to a comment about a lot more than just space travel. Those things are absolutely necessary to our civilization. They weren't necessary for all of history because we didn't have them but now we do. We know that there is no abstract civilization in general, each one exists in its historical context. Our civilization today needs all those things. If we just stopped doing them, huge numbers of people would suffer or die due to food and medicine shortages and all sorts of other related issues.