4 ms·
Only tangentially on topic (but more interesting that the actual content of the video I think), but I suspect no warhead reentry shield would actually be shaped
by jlgreco 14y ago
Only tangentially on topic (but more interesting that the actual content of the video I think), but I suspect no warhead reentry shield would actually be shaped as pointy as that.
Although you would think a more aerodynamic shape would reduce the drag and therefore heat of reentry, the reality is not quite so simple. In fact, the opposite is actually true. As you make the reentry shield blunter (increasing the drag coefficient as you do so) the heat load the shield needs to take actually drops. The reason for this apparently is that blunt reentry bodies form a sort of cushion of air around themselves that separates the shockwave caused by reentry from the reentry vehicle itself, insulating it.
I suppose sharp pointy warheads are more theatrical though.
- biscarch 14y agoIt has to be pointy! http://www.youtube.com/watch?v=RtahqXjFcxU http://www.youtube.com/watch?v=RtahqXjFcxU
- solarbunny 14y agoGood one! Is it worth watching the whole movie?
- biscarch 14y agoIMO, yes. It helps if you're familiar with Sacha Baron Cohen's sense of comedy and aren't easily offended.
- KMag 14y agoIt's important to note that the purpose of a heat shield on a warhead is significantly different from that of a manned vehicle or scientific probe. For the latter, the goal is to safely and efficiently transfer as much kinetic energy as possible (subject to acceleration limits) to the atmosphere so that parachutes will survive being deployed. For a warhead, (disregarding burrowing nukes), they don't care how much kinetic energy is expended since they don't want the warhead touching down. In fact, they would prefer to minimize the amount of time that reentry takes, and so want to minimize the amount of kinetic energy lost to heating the atmosphere. For burrowing nukes, they want the nukes traveling as fast as possible, as long as the impact won't break the nuke, which is somewhere in between the airburst and manned vehicle design cases.