From: vince@offshore.ai (Vincent Cate) Newsgroups: sci.space.tech Subject: Re: Reentry without ablation or ceramics? References: <9186edb5.0305121517.3f7bfc4f@posting.google.com> <9186edb5.0305152010.d27c97@posting.google.com> <9186edb5.0305192235.3607d942@posting.google.com> <9edf6d40.0305270908.1cf7471f@posting.google.com> NNTP-Posting-Host: 207.42.133.230 jgreason@xcor.com (Jeff Greason) wrote in message news:<9edf6d40.0305270908.1cf7471f@posting.google.com>... There seem to be a number of terms for things very similar to "transpiration". Some of the terms and some of the places used are: transpiration: injecting through lots of little holes film-cooling: injecting through a slit or small number of holes blowing: people doing simulations sometimes use this term and talk of "blown boundry layer" mass injection: term mostly used when cooling jet engines effusion cooling: in rocket engines Not only does transpiraton give you a layer of cooler gas near your vehicle, it also keeps the oxygen away for your vehicle. So it seems like a really good thing for making a vehicle last long enough to be called a reusable vehicle. -- Vince