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>... >[...] > B. Rashis, "Preliminary Indications of the Cooling Achieved > by Ejecting Water Upstream from the Stagnation Point of > Hemispherical, 80 degree conical, and Flat-Faced Nose Shapes > at a Stagnation Temperature of 4000 degrees F", NACA RM L57I03, > October 23, 1957. This one is available online at: http://naca.larc.nasa.gov/reports/1957/naca-rm-l57i03/naca-rm-l57i03.pdf It does seem like water works really well. Testing was done in the heat from a rocket engine exhaust. This is something that would not be too hard to do today. Instead of needing a multi-million dollar high speed wind tunnel, you just need someone who is testing a rocket engine. I like the idea of an aluminum boiler that ejects the steam into the stagnation point. It naturally has feedback where it increases the mass of steam if there is a lot of heat getting in and reduces it if there is not. No matter how thick the boundary layer, or how laminar/turbulent the flow, the aluminum should not melt as long as it did not run out of water. It would use exactly the amount of water needed to keep the boiler at the boiling temperature for water at whatever pressure you picked for the pressure release. The test setup would just have more than enough water and after the test you would know how much was really needed. The first flight of a reusable rocket could also have more than enough water. Seems like this could make a good nose cone design for a reusable single stage to tether rocket. If the nose is cool and the flow is laminar, the rest of the rocket should not get too hot. It is interesting that at least 4 out of 5 of the papers Jeff listed are from 1957 to 1962. In my own searching on the net it seems like most of the papers are from back then too. It really seems like something worth more experimentation in the last 40 years. So, Jeff, if I built something along these lines, could I put it in the exhaust of an Xcor rocket that you are testing? - Vince ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Vincent Cate Space Tether Enthusiast vince@offshore.ai http://spacetethers.com/ Anguilla, East Caribbean http://offshore.ai/vince ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ You have to take life as it happens, but you should try to make it happen the way you want to take it. - German Proverb