Why can the space shuttle reenter “slowly”?
I am 50 years old and high school educated. I was recently engaged in a conversation with my step-father concerning why the shuttle needs to be traveling at such a high rate of speed upon reentry. He suggests that if the shuttle were stopped or significantly slowed, and then gently “nudged” that reentry could be accomplished without the excessive heat build up associated with reentry. I realize that during the Apollo missions, this wasn’t an option but we wonder why gravity couldn’t just “pull” the craft in now. Reply Your step-father suggests that the shuttle can be “stopped or significantly slowed,” but actually that is not possible, for two reasons: first, the shuttle’s speed is what keeps it in its orbit, and if it loses even a fraction of that, it starts losing altitude and moving down into denser air. And two, it has a lot of energy: at 24 times the speed of sound, weight for weight it has about 100 times as much energy as a rifle bullet. How are you going to bleed off that energ
